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臺灣生態系
Ecosystems in Taiwan
Cara Lin Bridgman
Center for General Education
China Medical University
Taichung, Taiwan
Published by the China Medical University, Taichung City, Taiwan.
Copyright 2012 text: China Medical University.
Copyright 2012 images: Yu-Cheng Chang 1-4, 3-4 (part), 11-22; Shyhmin
Chao 3-11, 10-3 (part); Ai-Teh Lin 8-6.
Copyright 2012 images without citations: Cara Lin Bridgman.
Copyright 2012 cover images: Cara Lin Bridgman.
The author gratefully thanks Yu-Cheng Chang, Shyhmin Chao, and AiTeh Lin for permission to use their photographs. The author is also
grateful to these governmental organizations for producing the noncopyrighted images used in this book: National Aeronautics and Space
Administration (NASA) at the Johnson Space Center, the Goddard Space
Flight Center, and the Earth Observatory 2-1 (part), 3-13, 5-3, 5-4, 5-5, 81 (part), 8-2, 10-1, 10-6, 11-1 and the National Oceanic and Atmospheric
Administration (NOAA) 8-4.
Table of Contents
Chapter 1: Introduction
1
Chapter 2: What is Ecology?
8
Chapter 3: Cycles and Flow
13
Chapter 4: Evolution—the Origin of Species
39
Chapter 5: Extinction—the Death of Species
49
Chapter 6: Populations Rise and Fall
62
Chapter 7: Life Histories
68
Chapter 8: What Shapes Taiwan’s Climate?
84
Chapter 9: Taiwan’s Aquatic Ecosystems
101
Chapter 10: Taiwan’s Terrestrial Ecosystems
116
Glossary
148
References
171
Chapter 1:
Introduction
Taiwan is an amazing island! The island is about 36 km2 and is
shaped like a sweet potato. It is 34 times the area of Yushan National Park,
Taiwan’s largest national park. Most of Taiwan is densely packed with
mountains as high as the Rocky Mountains in the United States of
America (USA). These tightly packed mountains run from north to south,
forming the island's backbone. The alluvial plane on the western side of
the mountains has most of Taiwan’s people. This is where they grow
much of their rice, sugar cane, and fruit. In the middle of the mountains, it
is possible to be 2-3 day's hike away from any other people. Taiwan is a
land of extremes, including extremely dense cities and extremely isolated
mountain areas.
Taiwan's terrain goes from sea level to almost 4000 meters. This
allows for incredible habitat diversity: from coral reefs and mangrove
swamps to sub-alpine forests and alpine grasslands. Since Taiwan is
bisected by the Tropic of Cancer, its habitats also range from sub-topical
to boreal.
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Ecosystems in Taiwan
The mountains are incredible. They are also still growing. They are
high enough that they dominate Taiwan’s weather through orthographic
uplift. These mountains reach heights as high as most of the American
Rockies and all of the Canadian Rockies. The difference is that the
Rockies are nicely spaced mountains with wide park-like valleys in
between the mountains. The mountains in Taiwan are crammed in,
making the valleys very steep. There are many places where the valleys
plummet over 1000 m to the river below and the sides are so close that
Figure 1-1.
Looking down almost 600 m to the Central Cross-Island Highway and the
Liwu River from the Jhuilu Ancient Trail in Taroko National Park.
Chapter 1: Introduction
2
Figure 1-2.
Jinmentong Cliffs in Yushan National Park. The Chenyoulan River is
cutting through the Batongguan Grassland to capture the headwaters of
the Laonong River.
it almost feels as though it is possible to touch the other side (Figure 11). Since Taiwan is so small and so steep, it is possible to go from
freezing in the snow on top of one of the tallest mountains in the morning
to sunning on a hot beach in the evening.
Taiwan has a very active geology. In many places around the world,
geology is often presented as something that happened 10,000 years ago
(for example: Pleistocene glaciation) or even further back. In Taiwan, the
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Ecosystems in Taiwan
geology is happening now! In Taiwan, it is possible to see stream capture
in action (Figure 1-2). Stream capture is when one river digs away soil so
quickly that it captures the headwaters of another stream. In Taiwan right
now, geological events are happening that will be completed in our
lifetime.
Figure 1-3.
Jack in the Pulpit (Arisaema
sp.) at Dasyueshan National
Forest Recreational Area.
Taiwan's mountains are among the youngest in the world. The
Appalachian Mountains in the USA are among the oldest. Even though
the ages of these mountains are so different and even though they are on
Chapter 1: Introduction
4
opposite sides of the planet, many of Taiwan’s plants are in the same
genus as many of the Appalachian plants. This is because the habitats and
climates are very similar. The biggest difference is that Taiwan may be
more diverse and has many bamboo species. Taiwan has three genera of
oaks (Fagus, Cycobalanopsis, Quercus), but eastern USA has two (Fagus
and Quercus). Taiwan has nine species of Jack in the Pulpit (Wang
1996)(Figure 1-3), but the eastern USA has two (eFloras 2008).
Taiwan has all sorts of extremes. The rain is extreme. In the
mountains, there can be 7-8 meters (as much as 8000 mm) of rain in a
year. In the mountains, there are trees that are 2000-3000 years old, with
some >4000 years old!
Table 1-1.
Number of species in the world and Taiwan
World
Taiwan
Total
Endemic
Butterflies*
>17,500
>400
56
Birds*
>10,000
>470
15
Mammals*
>5,700
>80
20
* numbers from wikipedia.org (accessed July 2012).
Taiwan is a very exciting place to do ecology. In the USA, scientists
are busy trying to do a complete inventory of the species of plants and
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Ecosystems in Taiwan
animals in the Smokey Mountain National Park. Since almost all the
species are already identified, the goal is to find out which ones are
actually inside the park. In Taiwan, scientists are still trying to identify
the species (Table 1-1).
Figure 1-4.
Asiatic Water Shrew (Chimarrogale himalayica) immediately after
swimming for shrimp. Picture printed with kind permission of Yu-Cheng
Chang.
Taiwan’s scientists are still discovering and identifying mammals.
Since 1996, scientists have discovered a new species of weasel, many new
species of bats, and some really fantastic rodents. One of these rodents is
the Asiatic Water Shrew (Chimarrogale himalayica). This water shrew
Chapter 1: Introduction
6
dives into cold mountain streams to catch shrimp, thus spending most of
its life on the edge of hypothermia (Figure 1-4).
Discussion Questions
1) Taiwan is a subtropical island, so how is it possible for an organism to
get hypothermia?
2) What are some explanations for why places would have similar plants
and animals even though the places are on opposite sides of Earth?
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Ecosystems in Taiwan
Chapter 2:
What is Ecology?
Ecology comes from the Greek word Oikos. Oikos means house or
household. Ecology and Economics share the same root in Oikos.
Economics is about managing the household. Ecology is about studying
the household. Many ecological theories have hopped over into
economics to explain economic theories.
A
B
Figure 2-1.
Ecosystems can be as large as the entire planet (A) or smaller than a bamboo
stump (B). This bamboo stump ecosystem contains a male Kurixalus eiffingeri
guarding eggs. Image of Earth courtesy of NASA Johnson Space Center and
accessed via <http://visibleearth.nasa.gov/view.php?id=55418>.
Chapter 2: What is Ecology?
8
For ecology, the household is as big as Earth or as small as the water
trapped in a bamboo stump (Figure 2-1). This household is often defined
as the ecosystem. This is because the household is a system where the
environment affects organisms and organisms affect the environment.
Therefore, an ecosystem includes the physical characteristics of a place;
the flow of energy; the cycle of elements, nutrients, and water; and the
cycle and evolution of the life forms living there.
Basically, ecology is the study of the organism in context. It is the
study of life in the world, not in the lab. Ecological studies can vary from
examining single species to studying populations, communities, and entire
ecosystems.
Ecologists, people who study ecology, have the task of trying to
identify unifying principles that explain the function and interactions of
ecosystems. One of the biggest problems is explaining the way the
diversity of organisms varies within and among habitats. Why are there so
many species? Why do these species live here, but not there? What does
a species need to survive? How does one species affect others? How do
species affect the environment? How does the environment affect species?
Ecologists often start trying to answer these questions by making
descriptions. They will record the presence of species and population
sizes: the numbers of individuals within that species. This includes
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Ecosystems in Taiwan
questions, such as is the population of Taiwan Black Bear (Ursus
thibetanus formosanus) decreasing and why?
Ecologists are interested in the interactions with in a group and the
relationship of the individuals within that group. They will record
behavior and examine the things that influence behavior, such as whether
merely watching an animal will cause it to change its behavior.
Ecologists study phenology: when things happen and for how long.
This can include things like the effect of temperature on bat activity. They
want to know the species that pollinate a flower and the species that eat
that flower.
Ecologists study the interactions and transfer of energy and nutrients.
They study cycles: energy cycles, nutrient cycles, water cycles, and life
cycles. They can examine the ways animals conserve energy, based on
where they sleep and when they are active. They will measure
environmental variables, such as temperature, rainfall, and wind speed.
Once ecologists have described the ecosystem, the next step is to
describe the maintenance and regulation of the ecosystem. They are
interested in things like what affects the location of a bird’s nest; how
insects affect plant growth; how frogs affect insect populations; how
spraying for pesticides affects frogs; the way deforestation affects animal
communities; and the effects of non-native plants on native plants.
Chapter 2: What is Ecology?
10
Ecologists are also interested in the causes and effects of changes to
an ecosystem. This includes studying what happens after all the plants
have been removed from an area, and the effects overpopulation has on
the habitat. Often this has to be done by experiment.
Figure 2-2.
Backhoe removing trees from the roadside in Tanzih, Taichung.
Ecological experiments are usually difficult to design. When using
the Scientific Method, the methods of an experiment should be designed
such that anyone repeating those methods should get the same results. In
ecological studies, one typhoon or one landslide or one backhoe (Figure
2-2) can completely destroy the study site. From one year to the next,
rainfall and temperature change. Populations increase and decrease.
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Ecosystems in Taiwan
There are changes in species composition. This makes it difficult to repeat
an experiment to get the same results. On the other hand, repeating the
same experiment over time produces important results on changes in
organisms, habitats, and environments. Experiments such as these are
important for documenting and understanding the effects of things like
global climate change.
With increasing understanding of an ecosystem, the next step is to
test aspects of the ecosystem’s function with models. Models can study
things as relatively simple as population growth to things as complicated
as hypotheses for species diversity and community interactions. Models
also explore things that are difficult to study in the wild, such as the
variables driving a species to extinction and the existence and effects of
climate change.
Discussion Questions
1) What are some ecological questions you are interested in? How do you
know these are ecological questions?
2) How might ecology be relevant to you and your life?
Chapter 2: What is Ecology?
12
Chapter 3:
Cycles and Flow
Essentially all energy is from the sun. Without the sun, there would
be no life and no energy. There is a slight exception: geothermal energy.
This is created by the Earth itself. That Taiwan has this is demonstrated
by Taiwan’s many hot springs. Other than geothermal energy, therefore,
all energy is from the sun. Energy can be summarized by the first and
second laws of Thermodynamics.
The First Law of Thermodynamics is that the form of energy can
change, but energy is not created or destroyed. It can, however, be
changed from usable to unusable.
The Second Law of Thermodynamics is that whenever energy is
changed, some of the energy becomes unusable. Therefore, usable energy
is always lost.
The First and Second laws of Thermodynamics are important
because they explain why energy cannot be recycled. Instead, energy
flows through ecosystems (Figure 3-1). With increasing energy
efficiency, an ecosystem can be increasingly complex. Eventually,
however, energy is lost as heat.
13
Ecosystems in Taiwan
Trophic Levels
Energy flows through ecosystems (Figure 3-1). For the energy to
enter the ecosystem, plants are necessary.
Figure 3-1.
The flow of energy and cycle of nutrients through an ecosystem. Energy flow is
indicated by solid arrows. Nutrient flow is indicated by dotted arrows. The
ecosystem is indicated by dashed lines because this ecosystem is an open
system and may exchange organisms, nutrients, and energy with other
ecosystems. If this figure represents Earth, then the ecosystem is closed. Earth
exchanges almost no nutrients with systems outside Earth’s atmosphere.
Chapter 3: Cycles and Flow
14
Photosynthetic plants use photosynthesis to catch energy from the
sun. Every green plant is a photosynthetic plant. Every green plant is a
naturally evolved solar cell. Unlike human solar cells, plant solar cells
store energy in the form of carbohydrates. The plant grows by
accumulating and processing these carbohydrates. Human solar cells
collect energy for storage in batteries. For both plant and human solar
cells, not all the energy from the sun is collected. Since the process of
capturing energy from the sun is not very efficient, ecosystems are limited
by the amount of energy captured by photosynthetic plants.
Because plants can capture energy from the sun, they are
sometimes treated as though they produce energy. Green plants are often
called producers. Although they really cannot make energy, they can store
energy in carbohydrates, a form that is useful for all other life. Plants,
therefore, are the basis for life on Earth. Producers support all the other
trophic levels in an ecosystem (Figure 3-2).
Primary consumers are the animals that eat plants. If these animals
only eat plants, they are also called herbivores. Animals that eat animals
are called carnivores. Carnivores that eat primary consumers (herbivores)
are also called secondary consumers. Carnivores that eat secondary
consumers are called tertiary consumers. In most ecosystems, there are
15
Ecosystems in Taiwan
only four or five trophic levels. The ecosystem summarized in Figure 3-2
has four trophic levels.
Figure 3-2.
Trophic levels for Taiwan’s high elevation forest: plants (producers), insects
(primary consumers), pheasants (secondary consumers), and weasels (tertiary
consumers. Numbers and population sizes decrease with each step away from
producers. Animals featured here are beetles, Mikado Pheasant chicks
(Syrmaticus mikado), and a Siberian Weasel (Mustela siberica).
Chapter 3: Cycles and Flow
16
As the herbivores eat plants and secondary consumers eat herbivores
and tertiary consumers eat secondary consumers, the energy flows through
the ecosystem from plants to herbivores to secondary consumers to tertiary
consumers. Each time an animal eats a plant, it takes the energy within
that plant for its own use. It converts the energy within that plant. With
each conversion of energy from one trophic level to another, energy is lost
as heat.
Energy is also lost because not everything can be consumed (Figure
3-3). Herbivores do not process all their plant food into energy, some is
eliminated as waste. A Mikado Pheasant (Syrmaticus mikado) does not
process every part of the insects consumed. In pheasant poop, it is
possible to find beetle wing cases. Siberian weasels (Mustela siberica) do
not consume every part of a pheasant. Weasels will not eat the bones or
feathers.
Finally, energy is lost because all the food processed by a Mikado
Pheasant from all the beetles it ate in its lifetime will not be consumed by
the Siberian Weasel (Figure 3-3). Over the lifetime of the pheasant,
energy will be used to grow and replace feathers, to grow and regenerate
bones, and to operate other physiological systems. Energy will also be
used as the pheasant runs around looking for food, reproducing, and
escaping predators. If the weasel kills a pheasant that is seven or eight
17
Ecosystems in Taiwan
years old, the weasel will not be eating the equivalent of seven or eight
years of pheasant breakfasts, lunches, and suppers.
Figure 3-3.
How energy as lost as it moves from one trophic level to the next.
Arrow size represents amount of energy transferred and lost. Animals featured
here are beetles, Mikado Pheasant (Syrmaticus mikado), Siberian Weasel
(Mustela siberica).
Chapter 3: Cycles and Flow
18
Figure 3-4.
An extremely simplified food web for Taiwan’s high elevation forest community.
This food web includes only plants and eight animal species: worms, beetles,
Mikado Pheasant (Syrmaticus mikado), Ferret Badger (Melogale moschata),
White-bellied Rat (Niviventer culturatus), Crested Serpent Eagle (Spilornis
cheela), Siberian Weasel (Mustela siberica), and Alishan Turtle-designed
Snake (Trimeresurus monticola). Arrows indicate direction of energy flow from
plants through each animal species. Photo of the White-bellied Rat printed with
kind permission of Yu-Cheng Chang.
19
Ecosystems in Taiwan
Food Webs
Trophic levels are extremely simplified ways of looking at an
ecosystem. Even the examples shown in Figures 3-2 and 3-3 are
inaccurate. This is because Mikado Pheasants also eat plants. They are
documented to eat more than 30 types of plants (Bridgman 1994). They
also eat many types of insects.
In fact, trophic levels are too simple. Therefore, ecologists often try
to describe natural systems through food webs. Food webs can get very
complicated very quickly (Figure 3-4).
The worm in Figure 3-4 is actually a detritivore. Detritivores are
animals that get their nutrients by eating decaying organic matter. They
work with decomposers, such as fungi, to move dead organic matter back
into the food web. This dead organic matter is called detritus (Figure 3-5).
Nutrients
Food webs represent more than energy flowing through an
ecosystem. Food webs also represent the cycling and recycling of
nutrients through an ecosystem (Figure 3-1). Nutrients are essential for
Chapter 3: Cycles and Flow
20
Figure 3-5.
Detritus at Dasyueshan in
November: the tree trunk,
twigs, and leaves are all dead
and decaying. The tree trunk
is covered with moss (a
decomposer).
life to function. All life forms on Earth contain Oxygen (O), Carbon (C),
Nitrogen (N), Phosphorus (P), and many other chemical elements.
Oxygen
Throughout the life of Earth, carbon has been extremely common.
Before there could be animals, plants had to evolve to put oxygen into the
air. This oxygen is critical for the survival of almost all animals. This
makes plants doubly important: 1) they capture energy and make it
available for other organisms and 2) they convert carbon dioxide into
oxygen. As the plants take carbon dioxide into their bodies and move
oxygen out of their bodies, they also lose water. This process is called
21
Ecosystems in Taiwan
Figure 3-6.
Evapotranspiration in a tree in Taichung. Leafy plants must open their stomates
(openings to the inside of a leaf) to take in carbon dioxide and process energy
from the sun. Opening stomates allows oxygen and water to escape (1). As the
water escapes from the leaves, capillary action pulls water up the tree stem as
though it were a gigantic straw (2). As water gets pulled from the stem, the roots
pull water from the ground (3) to replace water into the stem. During times of
drought, leafy plants prevent water loss by dropping their leaves.
Chapter 3: Cycles and Flow
22
evapotranspiration (Figure 3-6). Animals complete this cycle by
breathing in oxygen and exhaling carbon dioxide. This process is called
respiration.
But the valley and the morning were green.
And the air!
All about, like a moving current, a mountain
river, came the new air, the oxygen blowing from the
green trees. You could see it shimmer high in the
crystal billows. Oxygen, fresh, pure, green, cold
oxygen turning the valley into a river delta.
Ray Bradbury (1950) The Martian Chronicles.
Water
Earth is called the blue planet because it has water and clouds.
Without water, most life on Earth would die. Water can be a gas in the air,
making the air humid and forming clouds. Water can be a liquid, falling
from the sky as rain, and forming rivers and lakes and oceans. Water can
be a solid, forming ice and snow.
23
Ecosystems in Taiwan
The way water forms ice allows fish to survive long, frozen winters.
This is because ice is lighter than water. As the water freezes, the ice rises
to the surface. This means lakes and ponds freeze from the surface down.
If the lake or pond is deep enough, fish and other aquatic animals can
survive in the cold water below the ice.
Figure 3-7.
The water cycle in Taiwan’s mountain area.
The water cycle (Figure 3-7) can be said to begin with the surface of
ground, plant leaves, lakes, and rivers. As the water evaporates from these
Chapter 3: Cycles and Flow
24
surfaces, it moves into the air. If it moves high enough, the moist air cools
to form clouds (see Orthographic Uplift in Chapter 8). This cooled water
is heavy. When enough accumulates, there is precipitation: rain, snow,
hail, and sleet. If this precipitation hits hard surfaces, it runs off into lakes
and rivers. Water in rivers eventually reaches the ocean. If the
precipitation hits absorbent surfaces, it soaks into the soil. This process is
Figure 3-8.
A close-up view of the water cycle on Tadushan, Taichung. On this mountain,
the soil is dense clay. Most of the rain runs along the surface rather than
percolating into the water table more than 200 m below the surface.
25
Ecosystems in Taiwan
A
B
Figure 3-9.
Flooding on top of Tadushan, Taichung, is caused by heavy rains, clay soils,
inadequate drainage systems, and poor land management. Storm drains are
too small. The pressure of uphill water is forcing water out of the drains to
flood the road (A). Floodwater is orange because poor land management has
allowed the rain to erode the soil (B).
called infiltration. The water in the soil can eventually percolate into the
water table (Figure 3-8). The water table contains stored ground water.
Humans affect the water cycle in many ways. Global climate change
affects rainfall patterns, making some places drier, and other places wetter.
By constructing roads and buildings, humans create hard surfaces,
increasing runoff that causes flooding and soil erosion (Figure 3-9). By
cutting down trees to grow farms, humans affect the water cycle by
making the land drier. Trees hold moisture. By absorbing water during
Chapter 3: Cycles and Flow
26
rains, they reduce runoff. When humans leave the ground bare, they leave
the soil vulnerable to erosion. In Taiwan, this soil erosion is most
frequently noticed as landslides. Erosion from rain and floods can happen
on smaller scales.
Carbon
About half of each plant and animal is made of carbon. Carbon is
one of the three main components of carbohydrates. All carbohydrates are
chains of carbon, oxygen, and hydrogen.
The carbon cycle can be said to start in the air (Figure 3-10). Plants
take carbon dioxide from the air. This carbon is now available to flow
through the ecosystem. Carbon is released into the atmosphere by burning
plants. Carbon gets stored in shellfish and corals. Volcano eruptions
spew out the carbon dioxide stored in the limestone made of long decayed
shellfish and corals. Respiration of shellfish, corals, algae, and other sea
life also restores carbon to the atmosphere.
It is possible to say that the function of Earth during all of its 4.5
billion year history has been to remove carbon from the atmosphere and
store it as limestone, coal, oil, and natural gas. It takes millions of years to
compress oceanic sediments into coal, oil, and natural gas. These are
27
Ecosystems in Taiwan
Figure 3-10.
The carbon cycle. Dashed arrows show the influence of humans and their
civilization.
called fossil fuels because they are made by compressing dead plants and
animals for millions of years. When these extinct organisms are found
imbedded into rocks, they are called fossils. It also takes Earth millions of
years to compress sediments of shellfish into limestone and it takes
millions more years before this limestone is recycled back into the
atmosphere during a volcano eruption.
Humans affect the carbon cycle in two key ways. The primary way
is by burning carbon materials. Throughout human history, humans
Chapter 3: Cycles and Flow
28
burned wood. Then they discovered coal, then oil, then natural gas.
When humans started burning coal and oil and natural gas, they started
putting back into the air all the carbon that had been accumulated and
stored for millions of years. Humans have been burning coal for about
400 years. They have been burning natural gas and oil for a little longer
than 100 years. During the past 100 years, humans have burned about half
of the world’s oil: millions of years of carbon were returned to the
atmosphere in about 100 years. Therefore, atmospheric carbon has
increased over this past 100 years and continues to increase. This increase
is thickening the Earth’s atmosphere and causing changes to the world’s
climate in many ways.
By putting carbon back into the atmosphere, humans are doing more
than causing global climate change. Humans are also making the ocean
acidic. The ocean has helped slow the rate of climate change by absorbing
carbon. The problem is that storing carbon in the ocean triggers a
chemical reaction. When carbon dioxide (CO2) combines with water
(H2O), carbonic acid is produced (H2CO3). This acid can dissolve the
calcium in coral reefs and in the shells of shellfish. As the shells dissolve,
the shellfish die.
Around the world and in Taiwan, the coral reefs are in trouble for
two reasons: global climate change and carbonic acid. The changes in
29
Ecosystems in Taiwan
climate are making the ocean’s waters warmer. Sometimes, the water can
get too hot. This kills causes coral bleaching (Figure 3-11) because all the
coral animals leave the coral. Coral bleaching kills the coral. Making the
ocean’s water acidic dissolves the coral. Coral reefs are important because
many of the world’s fish start their lives hiding in the safety of coral reefs.
A
B
Figure 3-11.
A healthy coral reef (A) and a brain coral dead (Faviidae) from coral bleaching
(B). Pictures printed with kind permission of Shyhmin Chao.
Nitrogen
Nitrogen is necessary for producing amino acids and proteins. It is
not common in rocks and minerals. Nitrogen is in the air, living
organisms, and decaying organic matter.
Chapter 3: Cycles and Flow
30
The nitrogen cycle also begins in the air (Figure 3-12). The process
of putting nitrogen in a form that can be used by plants is called fixing.
Lightening from thunderstorms can fix nitrogen. Certain kinds of plants
can fix nitrogen. Most nitrogen-fixing plants are beans (Leguminosae,
also called Fabaceae). The roots of nitrogen-fixing plants are hosts for
bacteria that actually do the work of fixing the nitrogen.
Figure 3-12.
The nitrogen cycle. Dashed arrows show the influence of humans and their
civilization.
This fixed nitrogen is now in the soil and available for the bean plant.
Once these plants take up the nitrogen, it can move through the ecosystem.
31
Ecosystems in Taiwan
When plants and animals die, they release nitrogen back into the soil.
Because usable nitrogen, is rare, most of this released nitrogen is
immediately absorbed by plants. Some, however, gets emitted into the air.
The process of nitrogen returning to the air is called denitrification.
Nitrogen is also released by animals as metabolic waste: in urine. The
sour smell of urine is from the ammonia (NH3) in urine.
Historically, humans fertilized their fields with manure and urine.
From their food, humans get nutrients from the soil. With their manure
and urine, humans can return these nutrients to the soil. Composting
manure, urine, kitchen waste, and other organic materials can produce a
natural fertilizer that returns nitrogen and other nutrients to the soil in a
way that plants can use very efficiently. Composting gives detritivores
and decomposers time to process the organic matter into healthy organic
soil.
Humans also use green manure to fertilizer their fields. They do this
by growing legumes (Leguminosae). These plants are then plowed into
the soil. As they decay, they release nitrogen and carbon for future crops.
Humans can fix nitrogen in factories. This factory-fixed nitrogen is used
as fertilizer to grow crops. Often these crops are fed to animals to grow
meat. As the crops and animals die, nitrogen is added to the soil.
Chapter 3: Cycles and Flow
32
The problem is: humans often put too much factory-fixed nitrogen
on the soil. Instead of making the soil more fertile, too much nitrogen can
make the soil less fertile. Too much nitrogen can kill plants. This means
the nitrogen remains in the soil and is not taken up by plants. Some of this
nitrogen returns to the air through denitrification. Excess nitrogen in the
air is one of the causes of acid rain. When rains come, they may be acid
rain. When the rains come, nitrogen in the soil is washed into rivers and
lakes. Excess nitrogen in the water creates algal blooms.
Algae in the water respond to having so much nitrogen available by
growing. An algal bloom is a population explosion of algae. The algae
population increases so quickly, it can change the color of a lake or river.
The algae, however, can grow so fast that it can use up all the oxygen in
the water. This causes a die-off of algae and all other aquatic organisms
that need oxygen to breathe. Humans are releasing so much nitrogen into
the water that they have created dead zones (Figure 3-13). One of the
largest dead zones is where the Mississippi River enters the Atlantic
Ocean. Here, the ocean floor never has enough oxygen to support life.
Taiwan also has dead zones.
33
Ecosystems in Taiwan
Figure 3-13.
Map of East Asia showing location of coastal dead zones. Size of red circles
represents size of dead zones. The largest circle represents a dead zone
2
10,000 km . Black circles represent dead zones of unknown size. Image
prepared on 1 January 2008 by Robert Simmon & Jesse Allen for the NASA
Earth Observatory using data from Robert Diaz, Virginia Institute of Marine
Science. <http://earthobservatory.nasa.gov/IOTD/view.php?id=44677>.
Chapter 3: Cycles and Flow
34
Phosphorus
Phosphorus is a rather rare element. It is rare enough that lack of
phosphorus probably limits plant growth, especially in aquatic ecosystems.
In animals, it is an important element for nucleic acids and for growing
teeth and bones.
Unlike carbon and nitrogen, the phosphorus cycle starts in the soil
(Figure 3-14). Like carbon and nitrogen, plants are necessary to get
Figure 6-14.
The phosphorus cycle. Dashed arrows show the influence of humans and
their civilization.
35
Ecosystems in Taiwan
phosphorus moving through the ecosystem. As plant roots grow in the
soil and poke through cracks in rocks, the plants absorb phosphorus. They
can also absorb it from water. Animals get phosphorus from the plants
they eat. Animals can eliminate excess phosphorus through urine.
Phosphorus only rarely enters the atmosphere. The entire cycle is from
ground through organisms and back into the ground.
Humans get phosphorus by mining sediment rock created over
millions of years. The rock is ground into a powder. The powder is
applied to agricultural fields as a fertilizer. When too much is applied,
rain can wash it into rivers and lakes. Phosphorous can also contaminate
water by leaching through the soil with water percolating through the soil.
Phosphorus becomes a problem when humans allow too much of it to get
into aquatic systems. Like nitrogen, it uses the same method to contribute
to the creation and maintenance of coastal dead zones by causing algal
blooms.
Eutrophication
Because phosphorus is so limited in the environment, it is highly
conserved once it enters the food web. As soon as one organism releases
phosphorus, another will pick it up. Lakes and pond undergo a succession
Chapter 3: Cycles and Flow
36
A
B
Figure 3-15
Eutrophication of a garden pond: A) oligotrophic in June 2005 and B) eutrophic
in July 2012.
based on the phosphorus accumulated in the system. Succession is the
process of a community changing over time, usually in response to the
actions by members of the community.
When a lake or pond is first created, it is empty of nutrients and
organisms. The water is clear. Animal and plant productivity is low.
These lakes and ponds are called oligotrophic (Figure 3-15A). Over time,
the animal and plant community grows and diversifies. As animals and
plants die, their remains accumulate on the bottom of the lake or pond.
Phosphorus begins to accumulate and circulate through the food web. As
the nutrients build up in the system, the lakes and ponds become eutrophic
37
Ecosystems in Taiwan
(Figure 3-15B). Eventually, the lake or pond fills in with organic material
and the area becomes habitat for land plants. This process is called
eutrophication and occurs naturally. Humans can speed up the process
and cause algal blooms if nutrients are added too quickly.
Discussion Questions
1) How many trophic levels are represented in Figure 3-3? What animals
are included in this food web? What animals are missing from this
food web?
2) Describe the trophic levels, food web, nutrient cycles, and energy flow
for your room.
3) How does burning fields after harvest affect the environment and the
soil?
4) What is the problem with this philosophy: if some is good, more is
better? What are the ways that this philosophy has created
environmental problems?
Chapter 3: Cycles and Flow
38
Chapter 4:
Evolution—the Origin of Species
As organisms adjust to and affect their environments, the
environment changes them. Organisms also affect each other, thus
changing each other. These changes are called evolution. Over time,
changes can accumulate such that new species may occur. Over time,
changes happen that organisms cannot adjust to, so these species go
extinct. In the history of Earth, millions of species have been born and
millions have gone extinct.
Species
What is a species? There are many different definitions of species.
A biological species is when a female of one species mates with a
male of another species but cannot produce young. The barriers to mating
can include location; behavior before mating; behavior during mating;
physical structure of body parts used for mating; chemical incompatibility
after mating; and chromosome incompatibility. Sometimes, young can
39
Ecosystems in Taiwan
result, but the young are infertile and cannot produce young, themselves.
Most often, a biological species is what is meant when scientists talk about
species.
Morphological species are the easiest to determine. In fact, this is
the main way species have been determined throughout the history of
classifying species. The idea with morphological species is that if they
look different, then they are different. This can get inexperienced
scientists in trouble because within a species, males and females can often
look very different. This is especially common with birds (Figure 4-1).
Figure 4-1.
Male (right) and female (left) Mikado Pheasants (Syrmaticus mikado) look
very different. This female was a research subject and is tagged with a radiotransmitter and white and pink leg bands.
In many bird species, males and females look alike. This includes
Large-billed Crows (Corvus macrorhynchos) and Yellow Tits (Parus
Chapter 4: Evolution—the Origin of Species
40
holsti). The Yellow Tit is endemic to Taiwan. Bird species, however, are
known for the differences in coloration between males and females. The
Vivid Nitalva (Nitalva vivida) male has a brilliant blue back and a brilliant
blue breast. The female Vivid Nitalva, however, has a dark brown back
and a dusky gray breast.
Another problem with identifying species by morphology is when
individuals look the same, but they are really different species. This is
especially common in plants, but also frequent in animals. Sometimes, it
is a matter of not examining the organism closely enough. Sometimes, it
is a matter of different chromosome numbers.
Species can also be identified by counting their chromosomes. This
is called karyotyping. More and more, species are identified by looking at
the patterns of nucleotide bases within the DNA. Genetic species are
species identified by their DNA.
No one really knows how many species there are living on Earth
right now. Almost 2,000,000 species have been given names (IUCN
1996). Estimates range from 2,000,000 species to 100,000,000 species.
41
Ecosystems in Taiwan
Classification
Species are living things. Species are organisms. Theoretically,
species are classified based on relatedness. That is the idea, anyway.
Often, species are first classified based on morphology. More recently,
scientists use genetics to test for relatedness. Taxonomic categories for
classifying species are shown in Table 4-1.
Table 4-1.
The main taxonomic categories for classifying species
Classification
Weasels
N*
Pheasants
N*
Kingdom
Animalia
10 million?
Animalia
10 million?
Phylum
Chordata
>60,000
Chordata
>60,000
Class
Mammalia
>5700
Aves
>10,000
Order
Carnivora
>280
Galliformes
>290
Family
Mustelidae
27
Phasianidae
>150
Genus
Mustela
17
Syrmaticus
5
Species
siberica
1
mikado
1
Common Name
Siberian Weasel
Mikado Pheasant
* data via wikipedia.org, accessed 24 July 2012.
In Taiwan, there are currently three species of pheasant: Ringnecked Pheasant (Phasianus colchicus), Swinhoe’s Pheasant (Lophura
Chapter 4: Evolution—the Origin of Species
42
swinhoii), and Mikado Pheasant (Syrmaticus Mikado). Taiwan’s Ringnecked Pheasant is different enough from Ring-necked Pheasants in the
rest of Asia that it is considered a subspecies: Phasianus colchicus
formosanus. Swinhoe’s and Mikado Pheasants are endemic to Taiwan.
Endemic means they do not naturally occur anywhere else.
In Taiwan, there are currently three species of weasel (Figure 4-2):
Least Weasel (Mustela nivalis), Siberian Weasel (Mustela siberica), and
Yellow-throated Marten (Martes flavigula). None are endemic to Taiwan.
Until the late 1980’s, there was a fourth weasel: the River Otter (Lutra
lutra). The River Otter is probably extinct on Taiwan Island, but there are
still some on Kinmen Island. All kinds of weasels are in the same family:
Mustelidae. They are called mustelids because they carry glands that are
really stinky or musty. Skunks, famous for defensive spraying, are also
mustelids.
The Least Weasel in Taiwan is not enough different from Least
Weasels elsewhere to be considered a separate species. It is classified as
an endemic subspecies: Mustela nivalis formosana (Lin et al. 2010). Both
the Least Weasel and the Siberian Weasel are in the same genus: Mustela.
They are more closely related to each other than they are to the Yellowthroated Marten or the River Otter. There used to be three genera of
43
Ecosystems in Taiwan
A
B
C
Figure 4-2.
Three extant members of the Mustelid family in Taiwan: A) Mustela siberica,
B) Martes flavigula, and c) Mustela nivalis. The smallest is Mu. nivalis, but it
lives at the highest elevations (>3000 m). The largest is Ma. flavigula, it lives
at medium elevations. Mustela siberica is expanding its range from low
elevations to higher and higher elevations
Chapter 4: Evolution—the Origin of Species
44
mustelids in Taiwan. Now that the River Otter is gone, there are only two
genera.
Adaptation and Fitness
Species adapt to their environments, just as they can affect their
environments. Earthworms (Animalia, Annelida, Clitellata, Megadrilacea)
affect their environment by burrowing through the ground (Figure 4-3).
Figure 4-3.
An earthworm is nosing
its way back into the
safety of the soil in a
garden in Taichung.
They also mix nutrients in the soil by dragging plant material from the soil
surface into the ground. By eating plant material, they fertilize the soil
with their castings. Worm castings are a prized natural fertilizer. Worms
are particularly well adapted for this work. Their bodies are long and soft
45
Ecosystems in Taiwan
and flexible. This allows them to poke through almost any crack in the
soil.
Organisms that are well adapted to their environment survive to
reproduce. Their young will survive, too. A species is fit or has high
fitness when it produces many offspring. The more offspring produced,
the higher the fitness. If there are no offspring or if the organism dies
before producing offspring, then that animal had low fitness and its DNA
dies out.
Evolution
Evolution is about adaptation and fitness. The DNA of organisms
with high fitness survives. The DNA of organisms with low fitness dies
out. Organisms that are well adapted to an environment survive and have
high fitness. Those that cannot adapt will die and have low fitness.
Evolution happens as organisms die and survive. If all the organisms in a
species die, that species goes extinct. Sometimes, populations within a
species get isolated. These isolated populations evolve for that specific
habitat and can eventually result in new species.
Taiwan’s Mikado Pheasant was isolated on Taiwan from other
Syrmaticus pheasants in China and Japan. By adapting to Taiwan’s high
Chapter 4: Evolution—the Origin of Species
46
mountains, Taiwan’s Syrmaticus pheasant evolved to become Syrmaticus
mikado.
Taiwan’s Least Weasel is a subspecies of Mustela nivalis. Although
there is no way for Taiwan’s Least Weasel to meet and mate with Least
Weasels in other countries or even on other mountain tops in Taiwan,
Taiwan’s Least Weasel has not become different enough to be considered
a separate species. With more time, it is likely to adapt more specifically
to Taiwan’s environment. Someday, it may have evolved to be different
enough to be classified as Mustela formosana.
A very clear example of evolution comes from a study of Darwin’s
Finches in the Galapagos Islands by Peter and Rosemary Grant (Grant &
Grant 2002). This study has now lasted 40 years. Each year, beginning in
1972, the Grants traveled to Daphne Island in the Galapagos to catch and
measure two species of Darwin’s Finches: the Medium Ground Finch
(Geospiza fortis) and the Cactus Finch (Geospiza scandens). They took
blood samples to measure DNA. For each bird, they measured body size,
beak shape, and beak length. Like most finches, these birds have strong
beaks, because they must crack open seeds to eat the nuts inside.
Over time, the Grants found that in years when there was drought
and food was rare, the only seeds available were large. During this time,
larger birds with heavier beaks survived because they were able to get and
47
Ecosystems in Taiwan
eat these large seeds. Smaller birds with weaker beaks starved to death.
In years when there was plenty of rain, there were enough seeds, both
large and small. During this time, all birds survived. The Grants found
that finch body and beak size were correlated with food and food was
correlated with rainfall and rainfall was correlated with the global climate
patterns of El Niño and La Niña.
El Niño years tend to be wet and warm. La Niña years tend to be dry
and cool. Historically, the shift from El Niño to normal years to La Niña
to normal years and back to El Niño takes 4-7 years. Global climate
change, however, means this pattern is changing. It is possible that global
climate change is making El Niño years more frequent.
Discussion Questions
1) Why is DNA relevant for identifying species?
2) Are there any places where worms are a problem? Why?
3) If global climate change is making El Niño years more frequent, what
do you predict will happen to Darwin’s Finches?
Chapter 4: Evolution—the Origin of Species
48
Chapter 5:
Extinction—the Death of Species
In Taiwan, both the Swinhoe’s and Mikado Pheasants are considered
protected species because of the possibility that they might go extinct.
Internationally, they are considered near-threatened (IUCN 2012). This
means that if we do not take care of their habitat and if their populations
decline, they could be threatened with extinction.
Extinct means every individual of that species dies. Extinction
means the DNA and behavior and function of that species is gone forever.
Extinction is natural. Every 1000 years, a genus probably goes extinct
(Caughley & Gunn 1996). Every year, 1-100 species probably go extinct.
The lifetime of a species can be several million years.
Since the beginning of life on Earth, species have been born and
species have died. In fact, >99% of all species have gone extinct. Most
species have gone extinct during five mass extinctions. This includes the
Cretaceous extinction that killed the dinosaurs 65,000,000 years ago.
Removal of the dinosaurs allowed mammals and birds to diversify and
become the dominant animals. During the Cretaceous extinction, many
49
Ecosystems in Taiwan
land organisms went extinct. An estimated 85% of species and 20% of
families disappeared forever.
Possibly the largest mass extinction was the Permian extinction
245,000,000 years ago. At that time, an estimated 96% of all marine
species, 83% of all marine genera, and 54% of all marine families went
extinct. The Permian extinction allowed dinosaurs to become the
dominant animals.
The question now, is whether humans are causing a sixth mass
extinction. Current extinction rates are 1,000-10,000 species per year!
The highest estimate is 40,000 species per year (Myers 1979). These
extinction rates are 100-1000 times the background extinction rate (Pimm
et al. 1996) of 1-100 species per year.
Species Threatened with Extinction
Species are classified according to the risk that they will go extinct.
Species decline from safe to least concern to low risk to threatened to
extinct. Within threatened, there are three levels of increasing risk of
extinction: vulnerable, endangered, and critically endangered. Of 10
species classified as vulnerable, there is a chance that two of them will go
extinct within 10 years or three generations (whichever is longer). If the
Chapter 5: Extinction—the Death of Species
50
10 species are classified as endangered, half are expected to go extinct
within 10 years or three generations (whichever is longer). If the 10
species are classified as critically endangered, all but two are likely to go
extinct within 10 years or three generations (whichever is longer). With
help, populations of some critically endangered species have increased.
The general trend, however, is towards decline. It is very rare that a
species threatened with extinction increases its populations to the point
that it is considered safe.
Table 5-1.
Number of endangered plants and animals
in Taiwan (IUCN 2004)
Classification
Animals
Plants
Extinct
1
1
Critically Endangered
3
10
Endangered
19
27
Vulnerable
42
23
139
39
Low Risk
The list of threatened animals and plants in Taiwan (Table 5-1) is
only for species endemic to Taiwan. This list is tentative because so little
is known about so many of Taiwan’s species.
51
Ecosystems in Taiwan
Some species have gone extinct in Taiwan, but they may not be
considered threatened because they have healthy populations outside
Taiwan. The Clouded Leopard (Neofelis nebulosa) is extinct in Taiwan
(Sanderson et al. 2008). Globally, it is classified as vulnerable, mainly
because of habitat loss. All throughout its range, humans are busy cutting
down the forests needed by the Clouded Leopard and its prey. The
Clouded Leopard is also illegally hunted for its fur and bones.
Causes of Extinction
The main causes of extinction today are habitat loss, over hunting,
introduced species, and pollution (Figure 5-1). These are mostly caused
by humans. The main causes of extinction for Swinhoe’s and Mikado
Pheasants are over hunting and habitat loss.
In Taiwan, habitat loss can occur naturally from typhoons and
earthquakes that trigger landslides. The problem is: humans also disturb
the habitat, making these landslides bigger in size and bigger problems.
One species of animal can hunt another species of animal to
extinction, but humans do this more effectively than almost any other
species. Before humans went to North America, there were as many and
as diverse large animals as there are in Africa. Since the African animals
Chapter 5: Extinction—the Death of Species
52
Figure 5-1.
Causes of Extinction: primary causes (habitat loss, over hunting, introduced
species, and pollution) decrease populations until emergent causes
(unstable populations and inbreeding) accelerate the population decline into
a vicious circle that results in extinction.
evolved as humans evolved, the African animals learned to be afraid of
humans. The North American large animals, however, evolved without
humans. When humans entered North America, the large animals were
easy to hunt and many were hunted to extinction.
Species can be introduced naturally. Species can move from one
place to another. Sometimes, species manage to travel to places where
53
Ecosystems in Taiwan
they never lived before. In Indonesia, the volcano forming the island
Krakatoa exploded in 1883. The explosion was so big that it destroyed
half the island and destroyed all life on the island. Spiders were the first
animals to colonize the destroyed island (Winchester 2004).
Although long a resident in Taiwan, the Eastern Cattle Egret
(Bubulcus coromandus) has expanded its range throughout southern Asia
by flying from island to island. The Eastern Cattle Egret expanded its
range on its own, but it did have help. Humans created farmland habitats
which are suitable for this egret (Figure 5-2). Therefore, when it arrives
at a new place, a suitable habitat is already available for it to use.
Figure 5-2.
Eastern Cattle Egrets
(Bubulcus coromandus) in a rice paddy in
Taichung.
Chapter 5: Extinction—the Death of Species
54
Pollution also naturally occurs. When the volcano at Krakatoa
exploded, it spewed ash into the air. In 2010, a volcano erupted in Iceland
(Figure 5-3). The ash from that volcano was so thick that airplanes were
grounded throughout north-western Europe. Visibility in the air was so
bad, that flying was unsafe. The ash landed all over northern Europe.
Figure 5-3.
Grey ash plume from Eyjafjallajökull Volcano, Iceland. Ash plume (arrow)
surrounded by white clouds. Photographed by NASA on 7 May 2010
<http://earthobservatory.nasa.gov/NaturalHazards/event.php?id=43253>.
55
Ecosystems in Taiwan
On 26-27 April 2012, a huge dust storm blew out of the Gobi Desert,
covering northwest China (Figure 5-4). Dust storms from the Gobi Desert
are getting worse. The desert is expanding because of bad land
management of adjacent areas. These dust storms can affect air quality
and visibility throughout East Asia, especially South Korea, Japan, and
Taiwan. These dust storms can even travel across the Pacific Ocean to
affect air quality and visibility in North America’s Rocky Mountains.
Figure 5-4.
Brown dust from the Gobi Desert blowing over Beijing, China. White clouds
are floating above the swirls of dust. Photographed by NASA on 27 April 2012
<http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=77782>.
Chapter 5: Extinction—the Death of Species
56
Although habitat loss, over hunting, introduced species, and
pollution can occur naturally, humans are doing all these things so
effectively and so quickly that humans are causing many species to go
extinct. It can be difficult to make a species go extinct immediately. The
process of extinction has several stages.
Over hunting reduces the numbers of individuals in populations.
The habitat needed for these species can be destroyed or reduced by
human actions, such as logging trees, making farms, and building roads
and cities. Animals die when there is no place for them to live and no
food for them to eat. When humans bring a new species to an area (i.e.
introduce new species), the new species will compete with and eat local
species, also reducing population sizes.
Humans are very effective at polluting air, soil, and water. This
pollution can weaken and kill plants. Weakened plants are more
vulnerable to being killed by animals. Depending on the type of pollution,
animals can become sick and die from eating polluted plants. The
pollution can kill animals directly by making them sick. Weakened
animals are more vulnerable to predators. Pollution also makes humans
sick. Smog created by cities (Figure 5-5) is a main cause of respiratory
and asthma problems in humans. Often, the smog in Taichung is so thick
that the Central Mountain Range cannot be seen (Figure 5-6). All these
57
Ecosystems in Taiwan
A
B
Figure 5-5.
Air quality in Beijing, China, showing: A) smog on 10 December 2011 and B)
no smog on 11 December 2011. Visibility was clear on 11 December because
a storm shifted the smog shifted south. Photographed by NASA on December
2011 <http://earthobservatory.nasa.gov/IOTD/view.php?id=76935>.
Chapter 5: Extinction—the Death of Species
58
A
B
Figure 5-6.
Air quality in Taichung showing A) smog on 21 November 2006 and B) no
smog on 22 November 2006. Rain during the night cleared away the smog,
greatly improving visibility of Taichung. Usually, Taichung’s smog is so thick
that Central Mountain Range cannot be seen.
59
Ecosystems in Taiwan
activities by humans affect individual organisms. Some will lose places to
live and food to eat. Some will die. This makes the population sizes
decrease. It also divides large populations into small populations. When
populations become small and divided, new problems emerge. These new
problems are called emergent effects because they are the result of the new
conditions. These new problems are inbreeding and unstable populations.
Populations become unstable because they so small. One disaster
can kill the entire population, further reducing the number of individuals
in the species. Near Alishan, there is the Taiwan Pleione Nature Reserve
to protect the one orchid: Pleione formosana. Populations of this orchid
are small and widely separated. One typhoon or one backhoe or one
greedy orchid seller can easily wipe out one population.
As populations become small, the number of possible mates also
becomes small. This can cause inbreeding. Inbreeding creates its own
problems by producing offspring with many genetic problems. These
inherited problems mean the offspring have low survival and low fitness.
Although they are not endangered, inbreeding explains many of the
physical problems in popular breeds of dogs. Inbred dogs often have
problems with hip displacement and bladder control. In the wild, these
dogs would have difficulty surviving. They might, however, live long
Chapter 5: Extinction—the Death of Species
60
enough to mate and have puppies. Their puppies would inherit this
problem too, making the population weaker and vulnerable to stress.
Inbreeding and unstable populations produce a negative feedback
effect that accelerates population decline. As the population gets smaller,
inbreeding becomes a bigger problem and populations become even more
unstable. Once a species has declined to this point, recovery is very
difficult. Even if the species is helped with suitable habitat and protected
from hunting, introduced species, and pollution, the species can still go
extinct.
Discussion Questions
1) What are some specific ways that humans drive other species to
extinction?
2) Does is matter if a species goes extinct? Why or why not?
3) What are the reasons for inbreeding of popular dog species? If you
wanted a dog from a popular species, what would you do to ensure
your dog does not have the physical problems common in inbred dogs?
61
Ecosystems in Taiwan
Chapter 6:
Populations Rise and Fall
A species describes the individuals. The individuals are usually
grouped into populations. It is possible to talk about all the individuals of
a species as the species or as the population of that species. Populations
are also groups of individuals in a specific area.
This means it is possible to talk about Tainan’s population of Blackfaced Spoonbills (Platalea minor), Taiwan’s population of Black-faced
Spoonbills, and the world’s population of Black-faced Spoonbills. The
world’s population contains all the individuals existing on Earth today.
Tainan’s and Taiwan’s populations contain only those individuals
spending the winter in Taiwan.
Populations grow or shrink based on the numbers of individuals
being born or dying. Sexual and asexual reproduction produces new
individuals. Accidents, parasites, predation, and disease kill individuals.
Chapter 6: Populations Rise and Fall
62
The Allee Effect
Populations are affected by the Allee Effect. The Allee Effect
explains why large populations keep growing larger and why small
populations keep growing smaller. The Allee Effect is like having money
in the bank.
When you are rich, your money makes money because of compound
interest. With compound interest, the money you have now (Nt) is based
on the money you had at the beginning (No), the interest rate (r), the
number of years you left your money in the bank (t), and the base of the
natural log (e). This e is about 2.7183. The formula is: Nt = Noert. The
more money you have, the more money you are going to get.
When you are poor, you start losing money. If your balance goes
below a certain level, the bank may stop giving you interest. If your
balance goes even lower, the bank may start charging fees. Therefore, the
less money you have, the less money you are going to have because you
start losing money.
The same formula for compound interest works to describe
population growth rates. In this case, No is the starting population size, r
is the population growth rate, t is the number of years, and Nt is the
population size now. When a population is large, it is going to increase
63
Ecosystems in Taiwan
because of the growth rate. When the population is small, it is going to
decrease because penalties begin: inbreeding and disasters that destroy
fragments of the population.
Carrying Capacity
Money seems to be able to grow forever. There seems to be no limit
to the amount of money. Banks make money every day by giving out
loans. Money is made when people pay interest on the loans. Money may
be unlimited, but human economic systems are limited by the Earth’s
ecosystem. This is because human economies are based on natural
resources, such as wood, agricultural crops, water, oil, rare earth metals,
and aluminum.
The amount of these natural resources on Earth is not increasing.
The amount available for use is increasing because humans work so hard
to get it. Sooner or later, however, there will no longer be any more trees
to cut down. Sooner or later, there will be no more space to grow crops or
put houses. Sooner or later, all the water will be polluted. Sooner or later,
all the oil and rare earth metals and aluminum will have been taken from
the ground.
Chapter 6: Populations Rise and Fall
64
Like human economies, populations cannot grow forever. Sooner or
later, they will get so big that the individuals have eaten up all the food.
Sooner or later, they get so big that there is no place to raise young.
Therefore, populations are also limited by their ecosystems. When they
use all the space in their ecosystem, there is no other place for them to go.
If all the resources are used up, then all the individuals begin to die of
starvation. These populations are crashing because they passed carrying
capacity.
Carrying capacity is the population size that an ecosystem can
support (Figure 6-1). If the population goes over this amount, the
ecosystem becomes degraded and the population risks crashing. When the
population is at carrying capacity, there are exactly enough food and
resources to keep every individual alive.
Carrying capacity is not a comfortable place to be. Animals living at
carrying capacity are healthy, but thin. There are no extra resources to
make any individual fat. Most of the offspring die. Only enough live to
replace those individuals that die of old age. Populations at carrying
capacity can be stable, but it is not a fun place to be.
The fun place to be is when the ecosystem is empty and resources
seem unlimited. In this situation, every individual can be fat and every
baby can grow up. Because of this, populations can grow extremely
65
Ecosystems in Taiwan
quickly. If their growth rate is too fast, however, they can overshoot
carrying capacity. Then, the population will crash because everyone will
die of starvation.
Figure 6-1.
Population growth curves. The J-curve is the blue, dashed line. The
S-curve is the pink, solid line. Carrying capacity is the black, dotted
line.
Sometimes, the crash can be so hard that every single individual dies
and the species goes extinct. If just a few individuals survive, then after
the environment recovers, their population can start growing again. If the
population grows as the same rate as before, it will also crash again. This
Chapter 6: Populations Rise and Fall
66
population is following a J-curve. If the growth rate is slower, the
population may stabilize at carrying capacity.
Discussion Questions
1) What is the carrying capacity for feral dogs and cats? What might
humans do to change this carrying capacity?
2) What is the carrying capacity for humans? How do you define this
carrying capacity? Can this carrying capacity change?
67
Ecosystems in Taiwan
Chapter 7:
Life Histories
Reproduction
Populations can only grow if there is some way to reproduce.
Organisms reproduce using asexual and sexual reproduction.
Asexual reproduction results in perfect fitness (also see Adaptation
and Fitness in Chapter 4). This is because the DNA of the offspring is
exactly the same as the DNA of the parent. Sometimes the parent
reproduces by dividing itself.
Species using asexual reproduction have perfect fitness, but only as
long as the environment is stable. They can be perfectly adapted for the
current environment. If the environment changes, they are no longer
perfectly adapted. Therefore, their fitness may decrease. If the
environment changes fast enough, they can even go extinct. The only way
asexual organisms evolve is through random changes in their DNA.
Sexual reproduction is mating with another individual of the same
species. This mating provides an opportunity to mix up the DNA from
Chapter 7: Life Histories
68
two individuals to produce offspring with different combinations of their
parent’s DNA. If one of the parents was perfectly adapted to her
environment, then mixing her DNA with another individual would
produce offspring less perfectly adapted to the environment. This would
decrease the parent’s fitness.
Environments, however, change all the time. By mixing DNA with
another individual, the offspring are all just a little bit different. Some
offspring will survive very well and some will not. The ones that survive
well also produce many offspring, thus improving fitness for themselves
and for their parents. The ones that do not survive or have few offspring
will have low fitness.
The advantage of sexual reproduction is that it mixes up the DNA
and produces offspring that are all a little bit different. This is how the
species evolves. This is a way to ensure that some of the parent’s DNA
will survive in future generations.
Reproduction in Plants
Many plants can reproduce asexually, but many can produce both
sexually and asexually. Duckweed (Lemnoideae) is common in water
gardens. It is a simple plant that reproduces asexually by budding. Each
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Ecosystems in Taiwan
new leaf can become a new plant. This plant buds so quickly, that the
population size can double in 2.3 days. Asexual reproduction is effective
for fast population growth. If one duckweed plant produces a large
population, then that plant has very high fitness.
Many plants reproduce asexually and sexually. The Water Lettuce
(Pistia stratiotes) is a common water garden plant in Taiwan. This plant is
not native to Taiwan. It was first discovered in Africa. Since it can adapt
to almost any water environment, it probably should be classified as an
invasive plant. Duckweed and Water Hyacinth (Eichhornia sp.) have also
invaded Taiwan’s waterways. All can reproduce asexually. Since Water
Lettuce and Water Hyacinth have flowers, they can also reproduce
Figure 7-1.
Mother and daughter
Water Lettuce (Pistia
stratiotes) connected
by a stolon (arrow).
Chapter 7: Life Histories
70
sexually. The flowers on Water Lettuce, however are so small, they are
rarely noticed. What is noticed is that the plant reproduces asexually. The
mother plant sends out a stolon from which the daughter plant grows
(Figure 7-1). On land, strawberry plants reproduce the same way, but
send out racemes from which the daughter plant grows.
Plants with flowers reproduce sexually. If the plant is divided into
male and female plants, it is called dioecious. If the plant has male
flowers and female flowers, then that plant is monoecious. If there are
both male and female parts within one flower, then that plant is
hermaphroditic (Figure 7-2). All of these plants may also reproduce
asexually. Some plants have flowers, but no longer reproduce through the
flowers. When this happens, the animal that pollinated the flower has
probably gone extinct. The plant continues to survive, because it
Figure 7-2.
Passion Fruit (Passiflora
edulis) is originally from
South America, but is
commonly grown in
Taiwan. This plant is
hermaphroditic and was
photographed in Taichung.
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Ecosystems in Taiwan
reproduces asexually. Throughout the world, there is much concern
because the populations of bee species are declining rapidly. Bees are
extremely important pollinators. If Earth loses its bees, then many plants
important to humans may also go extinct.
Some plants are sequentially hermaphroditic. An example is the
Jack in the Pulpit (Figure 1-3). In good years, when the plant is strong
and healthy, it will produce female flowers. If it has been a bad year or if
the plant is recovering from a good year or if the plant is young, it will
produce no flowers or male flowers. Within a population of Jack in the
Pulpits, usually some are males and some are females, but the ratio will
change from year to year as each plant becomes male or female based on
its own physical condition.
Reproduction in Animals
Figure 7-3.
Brahminy Blind Snake
(Ramphotyphlops braminus)
from a garden in Taichung
where it eats ant and termite
larvae.
Chapter 7: Life Histories
72
Most animals reproduce sexually. This means, the species is divided
into males and females. Animals, however, can also be asexual or
hermaphroditic.
When an animal reproduces asexually, it is called parthenogenesis.
The Brahminy Blind Snake (Ramphotyphlops braminus) is probably
parthenogenic (Figure 7-3). Only females have ever been found.
Females give birth to young snakes. If this species is truly parthenogenic,
then each young snake will have the same DNA as the mother. These
snakes are now common around the world. They travel in flowerpots with
garden flowers.
The most commonly known hermaphroditic animals are snails
(Figure 7-4) and worms. Each individual is male and female. Each
Figure 7-4.
Mating Apple Snails
(Pomacea canaliculata).
These snails are
exchanging sperm. The
two white love darts hold
the snails together and
may improving mating
success.
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Ecosystems in Taiwan
individual has male sex organs and female sex organs. When one
encounters another, they mate. Each will be both male and female.
Some animals are sequentially hermaphroditic. Clownfish
(Amphiprioniae) are born male, but become female when they get larger.
Clownfish live in coral reefs. Other marine fish, the Wrasses (Labridae),
start out as female, but change to male as they grow. The mating system
and male behavior changes as the males get bigger.
Figure 7-5.
Barn Swallow (Hirundo rustica) parent feeding nest of four chicks.
Most animals are sexual. The sexual systems can vary from
monogamous to promiscuous. Monogamous is when animals pair up into
Chapter 7: Life Histories
74
one male and one female. Many song birds are generally monogamous.
Each pair will work together to build a nest and raise young (Figure 7-5).
Also common are polygynous systems. These are systems with one
male and many females. Pheasants usually have this system. This
includes Taiwan’s Swinhoe’s Pheasants (Lophura swinhoii) and Ringnecked Pheasants (Phasianus colchicus). In polygynous systems, the
males tend to be larger and more colorful than the females. The males
have to attract females. The females are picky about choosing a male,
because females do all the work of building nests and raising chicks.
During the mating season, males protect the females by fighting other
males and by keeping a look out for predators. After the mating system,
the male does not help build nests or raise chicks.
Polyandrous systems are rare. These are systems with one female
and many males. In Taiwan, the Pheasant-tailed Jacana (Hydrophasianus
chirurgus) is polyandrous. The female is larger and more brightly colored
than the male. She has to attract males. In Taiwan, the male makes a nest
in fields of Water Chestnut (Trapa sp.). After the female puts eggs into
the nest, the male will incubate the eggs and take care of the chicks.
Promiscuous systems are when mating between the sexes appears
random. This can include extra-pair copulations, in which one member of
a pair mates with an animal outside the pair. Dogs and cats are
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Ecosystems in Taiwan
promiscuous. Males will mate with many females. A female dog or cat
may mate with several males when she is in ovulating (in heat). When her
young arrive, they could have different fathers.
Mortality
Organisms are born and organisms die. Organisms can die because
of accidents, parasites, predation, competition, disease, and old age.
Figure 7-6.
Round worms (Toxascaris sp.) from a house cat. This cat was
hosting a very large population of intestinal parasites. There were
enough round worms to keep the cat from growing normally.
Chapter 7: Life Histories
76
Accidents can happen any time. Accidents can kill strong and
healthy organisms and weak and sick organisms.
Parasites can be internal or external. Internal parasites include
intestinal parasites such as worms (Figure 7-6). External parasites include
fleas and ticks. Parasites live off an organism, but usually do not kill it.
Sometimes, however, there can be enough parasites to weaken an animal
and affect development.
Figure 7-7.
Rodent bones in an owl
pellet in Yushan National
Park. After eating their
prey, owls and other
raptors (birds of prey) will
spit out a pellet containing
the indigestible parts:
bones and hair.
Predation is when one animal (predator) kills another animal (prey).
Figure 7-7 shows the remains of a small rodent killed by an owl.
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Ecosystems in Taiwan
Organisms fight for space, food, and access to mates. These fights
can result in injuries or death.
Diseases and illness are also causes of mortality. When organisms
are living in high densities, it is easy for diseases to spread. In the natural
world, few organisms actually die of old age.
Life History Strategies
The life history strategy is one way to classify organisms. It is based
on the age of reproduction; the number of offspring produced; and body
size and life span (longevity) of the organism.
Organisms are called r-selected if they are small, reproduce early,
and have many offspring. These organisms also tend to have short life
spans. Most plants that are considered weeds are r-selected. Most insects
are r-selected.
Organisms are called K-selected if they are large, reproduce late, live
long lives, and have few offspring. Humans and elephants are clearly Kselected.
The usefulness of r-selection and K-selection, however, can quickly
break down. A Mikado Pheasant female, who produces only 1-5 eggs a
Chapter 7: Life Histories
78
year could be considered K-selected, especially compared to a Ringnecked Pheasant female who produces 1-28 eggs a year.
Survivorship of r-selected and K-selected organisms can vary. If all
the young tend to survive until they grow up and then die of old age, then
that organism has the Type I survivorship curve (Figure 7-8). Human
tend to have this survivorship curve. Many organisms, whether r-selected
Figure 7-8.
Survivorships curves. Species with individuals that tend to die of old age
have the Type I curve (A). Species with individuals that rarely survive to
old age have the Type II curve (B).
or K-selected, have a Type II survivorship curve. Many young may be
born, but they die off quickly from predation, disease, parasites, and
starvation. Only a few will live long enough to die of old age.
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Ecosystems in Taiwan
Life History of the Mikado Pheasant
Taiwan’s Mikado Pheasants have a Type II survivorship curve.
Each year, a female produces one nest of 1-5 eggs in April or May. The
number of eggs in the nest depends on the health of the mother. The
survival of the eggs in the nest depends on the experience of the mother.
Experienced mothers are likely to put their nests in places safe from
predators. Egg predators include Large-billed Crows (Corvus
macrohynchos), large snakes, and mammals. A possible snake predator is
the Taiwan Beauty Snake (Orthriophis taeniura friesi)). Possible
mammalian predators are Siberian Weasels, Wild Boar (Sus scrofa) and
Formosan Macaques (Macaca cyclopis). If a female loses her eggs, she
may try again with a new nest in a new location. Mortality can happen
before the egg hatches, if something is not right genetically or
developmentally. Most eggs will hatch in May or June.
Song bird chicks (Figure 7-5) are altricial. These chicks are born
blind and without feathers. They must have a parent to keep them warm
and to feed them. Mikado chicks (Figure 7-9) are precocial. They can
walk around and peck at food almost as soon as they hatch.
Chapter 7: Life Histories
80
Figure 7-9.
Mikado Pheasant
chick that is about
one month old. This
chick is inside
Yushan National
Park.
For Mikado Pheasants, there are mortality risks after the eggs hatch.
For the first few weeks, however, the chicks need their mother to keep
them warm. Even though they have downy feathers, their metabolisms
need some time to develop. If they get too cold or wet during this time,
they can die of hypothermia. Their mother leads them around their
environment, showing them food to eat, showing them safe places to sleep,
keeping them warm at night, and protecting them from predators, such as
Siberian Weasels, Crested Serpent Eagles (Spilornis cheela), and Brown
Wood Owls (Strix leptogrammica).
After a few months, Mikado Pheasant chicks will start to wander
from their mother. By October, they may be spending a night or two away
from their mother. By December, the family group has split up. Now, the
chicks may die because they are living on their own, but they lack
experience.
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Ecosystems in Taiwan
Figure 7-10.
Female Mikado Pheasant crossing a landslide in Yushan National Park.
In the winter, plants tend to die back. Therefore, finding food could
take more effort. More importantly, loss of these plants means loss of
protective cover. This is when pheasants are easily killed by avian
predators, such as Crested Serpent Eagles and Brown Wood Owls. It is
also possible for pheasants to be killed through accidents, such as getting
tangled up in vines or hit by rocks falling down a landslide (Figure 7-10).
When breeding season begins, many of the Mikado Pheasant chicks
born the previous year have probably already died. Breeding season
brings new problems. The males fight. If one male gets trapped, the other
Chapter 7: Life Histories
82
male could kill him. With reproductive activity also comes carelessness.
Males may be so intent on fighting other males or impressing females that
they become vulnerable to predators. Females may be so intent on eating,
that they become vulnerable to predators. Finally, females may have
trouble laying eggs. Female birds can become egg-bound. This is when
an egg gets stuck in their bodies.
If a Mikado pheasant survives its first year, it may live a long time.
Mikado Pheasants can live and breed until they are at least seven years old
(Bridgman 2002).
Discussion Questions
1) What are the arguments that coconut trees, dogs, and cats are r-selected?
What are the arguments that they are K-selected?
2) Feral animals are domesticated animals that have become wild.
Taichung City has many feral cats and dogs. What is the survivorship
curve for feral cats and dogs?
3) What species of birds are precocial and what species are atricial?
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Ecosystems in Taiwan
Chapter 8:
What Shapes Taiwan’s climate?
The Earth’s climate can be considered very simple: cold at the poles
and hot at the equator. The further away you are from the equator, the
colder the temperatures. This works longitudinally (moving north or south
from the equator) and attitudinally (moving away from Earth into space).
Taiwan Island, is subtropical. It is fairly close to the equator. This
makes Taiwan’s climate warm, averaging 23°C. The island, however, has
many very tall mountains reaching altitudes (also known as elevation) of
almost 4000 m. Because these mountains are so far away from sea level,
their climate is colder. This means it is possible to experience the tropical
climate of Borneo, Indonesia, or along the Amazon River, Brazil, the
temperate climate of northern China or Kentucky, USA, and the boreal
climate of northern Canada or Hokkaido, Japan, without ever leaving
Taiwan!
Chapter 8: What Shapes Taiwan’s Climate?
84
Global Climate Patterns
Global Air Circulation
The heat of Earth at the equator (where it is closest to the sun) and
Earth’s cold at the poles (where it is furthest from the sun) affects wind
currents and rainfall patterns. Air rises when warm and descends when
cool. This makes for cells of rising air and falling air (Figure 8-1). At the
equator (0° latitude), air rises. This rising air moves away from the
equator. By the time the air reaches 30° latitude in the North or South, it
has cooled and starts to fall. This falling air creates a vacuum that sucks
air down to the ground. This vacuum drives the creation of the next cell of
cool air moving along the ground from 30° latitude to 60° latitude where
the air rises. This rising air then moves through the atmosphere to 30°
latitude or 90° latitude where it falls. In this way, the heat created at the
equator by the sun drives three cells of circulating air from the equator to
the poles.
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Ecosystems in Taiwan
Figure 8-1.
Effect of Earth’s rotation on air circulation patterns. Earth image by Reto
Stöckli for NASA Goddard Space Flight Center
<http://visibleearth.nasa.gov/view.php?id=57723>.
The Coriolis Effect
The Earth spins. The Earth image in Figure 8-1, the Earth’s spin is
counter-clockwise: from west to east. This does more than create the
Chapter 8: What Shapes Taiwan’s Climate?
86
gravity that glues everything to Earth and keeps muscles toned and bones
strong. This spin creates the Coriolis Effect. The entire earth is spinning,
but the speed at the equator is faster than the speed at the poles.
Think of a playing compact disc (CD). Each time the disc rotates,
the innermost part of the disc is moving slower than the outside edge. If
you were small enough to stand on a spinning CD, you could stand up
straight if you were at the center. The further you moved from the center,
the faster things would seem to move and the harder it would be to stand
up straight.
Now, if you were at center of the merry-go-round and threw a ball a
friend on the outside edge, where would the ball go? As the ball moved in
a straight line, the merry-go-round would be spinning to move your friend
away from the line of the ball. From yours and your friend’s perspective,
it would be as though the ball moved away from you!
Global Wind Patterns
The wind moving from the North Pole to 60° latitude has a curve.
This curve shows where the wind would end up after it leaves the North
Pole. As the wind moves south, the Earth moves underneath it, making it
look as though the wind had curved away from the earth’s spin. As the
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Ecosystems in Taiwan
wind moves south, it is as though the wind moves slower. This is because
the rotation speed of the earth increases towards the equator. If the wind
moves north from the equator, the Earth moves underneath it, but the
Earth’s rotation speed decreases as the wind moves north. This results in
the wind looking as though it moved faster and curved with the direction
of the Earth’s spin.
The Earth’s spin combines with the cells of circulating air to drive
prevailing winds. These winds circulate all around the globe.
At the equator, the air is rising. There is not much wind. This area
is called the Doldrums. There is also a lot of rain here because the air
loses moisture as it moves up in altitude and cools. Here is where there
are tropical rain forests.
From 0° latitude to 30° latitude, the winds are generally moving
towards the west. This helps explain why typhoons go to Taiwan and not
to California! From 30° latitude to 0° latitude, winds in the Northern
Hemisphere are moving south and west. These winds are called the Trade
Winds. They are steady and good for sailing. They were good for
international trade before motors were invented.
Around 30° latitude, the air is descending. This is called the Horse
Latitude. Here, the weather is sunny. There is almost always a high
Chapter 8: What Shapes Taiwan’s Climate?
88
pressure system. There tends to be little rainfall. Here is where deserts
often form.
From 30° latitude to 60° latitude, the winds in the Northern
Hemisphere are moving north and east. These winds are called Westerlies
because they come from the west.
At 60° latitude, the air is rising and cooling again. This creates
much rainfall or snow.
From 60° latitude to 90° latitude, the winds return. In the Northern
Hemisphere, the winds are again moving south and west.
At 90° latitude, the air is descending again. The cold air descending
onto the cold poles, making the polar regions even colder.
Between the equator and Antarctica the Southern Hemisphere, there
is less and less land to block the wind. The closer these winds are to
Antarctica and the South Pole, the faster they flow. Winds below 40°
latitude are called the Roaring Forties. Winds below 50° latitude are
called the Raging Fifties. Winds below 60° latitude are called the
Screaming Sixties. Therefore, the fastest and wildest sail around the
world would be in the Southern Hemisphere below 60° latitude.
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Ecosystems in Taiwan
Figure 8-2.
Circulation of ocean currents in the Ocean Conveyor Belt. Red is warm, surface
current. Blue is cold, deep current. Image by Robert Simmon for NASA and
accessed via <https://en.wikipedia.org/wiki/Thermohaline_circulation>.
Ocean Currents
The Earth’s spin also combines with the heat of the equator and the
cold of the poles to cause water to move, forming the ocean currents
(Figure 8-2). Unlike wind patterns, ocean currents can be said to begin in
the North Atlantic Ocean. This is the furthest north the currents go. Here,
the water is cold and very salty. Being cold and salty makes the water
dense and heavy, so the water sinks to the bottom of the ocean. Once at
Chapter 8: What Shapes Taiwan’s Climate?
90
the bottom of the ocean, it flows south. As it flows south, it gradually
warms up, coming to the surface in the Indian Ocean and in the western
Pacific Ocean. It may take 1000 years for one molecule of water to make
the entire circuit. This entire circuit is called the Ocean Conveyor Belt.
Figure 8-3.
Sea lions sunning themselves on a rock near San Francisco,
California, USA. Beds of kelp are in the water behind the rock.
This flow of ocean current explains why the temperature of ocean
around Taiwan is so much warmer than the temperature of ocean around
Southern California. In southern Taiwan near Kenting, there are coral
reefs. In northern Taiwan, there are the mangrove forests at Guandu
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Ecosystems in Taiwan
Nature Park. In Southern California, it is too cold for mangroves and
coral reefs. Instead, there are kelp beds, otters, and sea lions (Figure 8-3).
The ocean current also affects land temperatures. The warm ocean
current along the western coast of Europe means the European climate is
much warmer than the climate along the northeastern coast of Canada and
Newfoundland where the ocean current is cold.
Gyres
The circulation of the ocean current and the circulation of wind
currents around the earth combine to create five gyres (Figure 8-4).
Gyres are whirlpools. These five gyres, however, are gargantuan
whirlpools, where the water slowly circulates with wind and current.
The North Atlantic Gyre explains the location of the Sargasso Sea. Sea
turtles and eels breed in the masses of seaweed growing here. The Pacific
Gyre explains the location of the Great Pacific Garbage Patch. All the
garbage dumped into the ocean from western North America and East
Asia (including Taiwan) eventually accumulates here. This is an
especially big problem for plastic garbage, because plastics do not
biodegrade. The pieces of plastic will get smaller and smaller, but the
molecular structure is always the same. Once the pieces are small enough,
Chapter 8: What Shapes Taiwan’s Climate?
92
plankton and fish and birds and turtles eat them. Sometimes this plastic
kills the animals because of starvation. Sometimes the larger plastic (such
as plastic bags) kills the animals by entrapment. Sometimes, the animals
do fine, storing the plastic in their bodies until they are eaten by larger
animals.
Figure 8-4.
Effect of earth’s rotation on water circulation: oceanic gyres. Image from
National Oceanic and Atmospheric Association via
<http://en.wikipedia.org/wiki/File:Oceanic_gyres.png>.
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Ecosystems in Taiwan
Rainfall
The timing of precipitation in Taiwan is affected by global patterns.
Taiwan has two monsoons: winter and summer. The winter monsoon
moves in from the north-west to affect northern Taiwan. This monsoon
darkens northern Taiwan with clouds. Rainfall is mainly a slow drizzle.
The summer monsoon moves in from the south-west to affect southern
Figure 8-5.
Damage caused by Typhoon Morakot in August 2009 near Shuili,
Nantou County.
Chapter 8: What Shapes Taiwan’s Climate?
94
and central Taiwan. This monsoon mainly brings afternoon thunderstorms
and heavy rain. Typhoons approach from the south and east. They mainly
affect southern and eastern Taiwan, but typhoons can and do affect the
entire country. Typhoons and summer thunderstorms are no joke. They
can and do destroy natural habitat, create landslides (Figure 8-5), bury
towns, and kill people.
Local Climate Patterns
The mountains play a very important role in creating the weather
around Taiwan. Each day as the sun shines, hot air moves up the
mountainsides. As the air moves into higher elevations, it cools to form
clouds (Figure 8-6), eventually making rain. This is the main reason why
it is sensible to expect rain every afternoon in the mountain areas. This is
why the weather can so quickly change from hot and sunny to cold and
rainy. Most of the year, clouds start to build in the early afternoon.
Clouds will thicken into fog. Rain begins in the late afternoon. The
clouds will dissipate after the sun sets, leaving a clear sky for star gazing.
Globally, orthographic uplift combines with wind patterns to explain the
location of deserts. Warm air moves from the ocean over land. As the air
reaches mountains, it starts to rise, cool, and make rain. By the time the
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Ecosystems in Taiwan
Figure 8-6.
Orthographic uplift forming clouds on mountain tops and along ridges
inside Yushan National Park. Picture printed with kind permission of AiTeh Lin.
air has moved over the mountains to the other side, there is no more water
to fall. This creates a rain shadow. In western North America, there is
forest in Oregon west of the Cascade Range (Figure 8-7A). In the rain
shadow east of the Cascade Range, the forest has becomes grassland
(Figure 8-7B). The Sierra Madre Mountains in eastern California make
the rain shadow that creates the Great Basin desert in Nevada, Utah, and
Arizona.
Chapter 8: What Shapes Taiwan’s Climate?
96
A
B
Figure 8-7.
Rain shadow effect of the Cascade Range of northeastern North America.
A) Looking towards Mt. Rainier from the west showing forests in the
foreground. This picture was taken in late afternoon, so the mountain is
hiding behind clouds created by orthographic uplift. B) Looking towards
Mt. Rainier from the east, showing dry grassland in the foreground. This
picture was taken at midday, before the clouds started building up behind
the mountain because of orthographic uplift.
In Taiwan, the east coast gets more rain than the west coast because
the west coast is in a rain shadow caused by the Central Mountain Range.
Different sides of a mountain can get different amounts of rainfall
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Ecosystems in Taiwan
depending on wind direction. Because of orthographic uplift, Taiwan’s
mountain areas get more rain than Taiwan’s lowland areas. Annual
precipitation (rainfall and snowfall) in Taiwan ranges from <1000 mm to
almost as much as 8000 mm. The mountain areas in the northeast part of
Taiwan (southern Ilan County and northern Hualien County) have the
highest precipitation. Western Taichung has the lowest precipitation.
Microclimate Patterns
Because of the effects of wind, elevation, and disturbance by
landslides and fire, habitat can vary greatly from one meter to the next.
An area that recently experienced a landslide will have very different
habitat compared to an area that has remained undisturbed for a long time.
An area in the shade of a tree will have habitat with different animal and
plant communities than an area a few meters away in the sun. North
facing slopes will be cooler than south facing slopes because south facing
slopes get more sunlight. East facing slopes may be warmer than west
facing slopes because east facing slopes receive more sunshine before
clouds build up from orthographic uplift. In the morning, the mountain
ridge may block the sun from west facing slopes (Figure 8-8). In the
afternoon, clouds may block the sun on both east and west-facing slopes.
Chapter 8: What Shapes Taiwan’s Climate?
98
Figure 8-8.
Clouds blocked by a ridge near Nanhudashan, Taroko National Park. The
clouds were created by orthographic uplift.
In the evening and at night, areas on mountainsides that are concave, such
as depressions where streams are likely to flow, may be colder than areas
that are convex. This is because cold air is like water and always flows
downhill. Peaks and ridges will cool faster, causing the cooled air to flow
downhill. Peaks and ridges are also likely to be cold because they will
have more wind, more rock, less soil, and fewer trees. Valley floors may
be cooler at night because of cold-air drainage, but may be hotter during
the day because they are at lower elevation, because there may be less
wind, and because of the way rocks can absorb and hold heat.
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Ecosystems in Taiwan
Discussion Questions
1) How do global wind patters and ocean currents affect the movement of
typhoons?
2) Are there any deserts in Taiwan? Why or why not?
3) If you were going to sail a boat (no motor) from Hualien to San
Francisco, USA, what route would you take and why?
4) Why does Chiayi City often have the coldest temperatures in Taiwan’s
lowland?
Chapter 8: What Shapes Taiwan’s Climate? 100
Chapter 9:
Taiwan’s Aquatic Ecosystems
Taiwan has many aquatic ecosystems ranging from marine to
intertidal zones to rivers to small lakes and ponds. Humans affect all of
these ecosystems.
Marine Ecosystems
Being an island in the Pacific Ocean, Taiwan is surrounded by
marine ecosystems. These ecosystems are affected by light, pressure,
temperature, salt, currents, waves, and tides.
Just as the climate on land changes with elevation, the climate in the
ocean changes with depth. In the water near the ocean’s surface, light,
pressure, and temperature may be similar to that in the air. As an animal
dives down to the bottom of the ocean, light decreases until it is
completely dark. Temperature also decreases. One thousand meters
below the surface, temperatures are close to 3°C.
101 Ecosystems in Taiwan
Pressure, however, increases. When organisms dive deep into the
ocean, they have to deal with the pressure. Pressure limits how far down
humans can go without the protection of a submarine. When humans
swim back to the surface, the change in pressure causes another problem:
the bends. The bends happen gasses can become liquids when under
pressure and body tissues can absorb these gasses. Gasses can leave the
lungs and enter tissues. When the pressure is reduced by swimming back
to the surface, these gasses expand to form air bubbles. These bubbles can
damage body tissue. The bends can be avoided by returning to the surface
very slowly. This gives the gasses a chance to disperse before they form
bubbles. When organisms are brought up from the deep ocean, they are
usually dead by the time they arrive the ocean’s surface because of tissue
damage by gasses.
The salt means that any organism living in these systems has the
challenge of maintaining osmotic balance. This means each organism has
to adapt to the salty water by finding ways to control the amount of salts
within their bodies. They also have to find ways to retain water. If the
ocean water is more salty than the inside of an organism, water will move
from the organism into the ocean. Most ocean animals have to constantly
fight dehydration.
Chapter 9: Taiwan’s Aquatic Ecosystems 102
Ocean currents are like wind currents. These currents can move
organisms and nutrients around the planet. Many marine organisms use
these currents for their migrations in the same way that many birds and
butterflies use wind currents for their migrations.
Waves are created by wind on the surface of the water. Waves are
important for moving deep, nutrient rich water to the surface. Places
where this occurs are called upwellings. The pounding of waves also
shapes the shoreline.
Tides are caused by the moon’s gravity. This gravity pulls the water
into a bulge. This is most obvious on the shore, where it is easy to see the
water level move up and down twice each day. The sun’s gravity also
affects the tides. When there is a full moon or a new moon, the gravity of
the sun and the moon combine to make spring tides. These tides cause the
water to have the greatest rise and fall. When the moon is halfway
between new and full, the moon’s gravity and the sun’s gravity cancel
each other out to make neap tides. These tides cause the water to have the
smallest rise and fall. Sometimes, a neap tide may not even be noticeable.
The ocean is not a big soup in which life is evenly distributed. The
bottom of deep ocean and the centers of the oceans can be ocean deserts.
Most marine species live near the ocean’s surface and near coastlines.
103 Ecosystems in Taiwan
On Taiwan’s west coast lives the Chinese White Dolphin (Sousa
chinensis chinensis). It is also called the Taiwan Pink Dolphin. Globally,
this dolphin is classified as near-threatened (IUCN 2012). This is because
there are probably >10,000 Sousa chinensis individuals in the world. Each
population of Sousa chinensis chinensis, however, may have 50-1200
dolphins. The total population of Sousa chinensis chinensis may be
<10,000. If this subspecies is classified as a species, then it will probably
be categorized as vulnerable to extinction because of it has small and
fragmented populations and because habitat degradation and loss. This
dolphin is always close to shore. It prefers to live near river mouths.
Shore habitats and river mouths are increasingly affected by humans.
Humans tend to build harbors and cities along river mouths. These
harbors and cities replace the dolphin’s natural habitat with human
structures and probably affect food availability. These harbors and cities
also add pollution to river water already polluted by upstream activities.
This pollution includes sewage and heavy metals, both of which can make
a dolphin sick. Heavy metals, however, can also affect a dolphin’s ability
to reproduce.
Chapter 9: Taiwan’s Aquatic Ecosystems 104
Figure 9-1.
Arabuka Atoll, Kiribati, from space. White are clouds. Waves can be seen on
the dark blue ocean. Shallow water inside the atoll is light blue. Land is dark
with vegetation or light with sand. Kiribati may be the first country to
disappear because of sea level rise caused by global climate change. Image
ISS023-E-26498 was taken on 21 April 2010 and is courtesy of the Image
Science and Analysis Laboratory, NASA Johnson Space Center.
<http://eol.jsc.nasa.gov/scripts/sseop/photo.pl?mission=ISS023&roll=E&fram
e=26498>.
105 Ecosystems in Taiwan
Intertidal Ecosystems
Intertidal ecosystems are primarily affected by the tides. There are
parts of each day when the ecosystem is exposed to air during the low tide.
This causes stress to the organisms living there. The stress can be caused
by desiccation, heat, and chemical. Desiccation is drying out. Marine
organisms exposed to air may dry out and die. If low tide is during the
day, the shallow water may reach high temperatures. Evaporation of
water during this time also concentrates the salts, causing chemical stress.
During low tide, there is also a very real risk of predation from land
animals.
Coral Reefs
Coral reefs are produced by small marine animals (Cnidaria,
Anthozoa). These animals live in colonies and secrete calcium carbonate
to build skeletons to protect themselves. These skeletons combine to form
coral and build the reef. Corals are important for building land. Many
islands in the Pacific Ocean (Figure 9-1) have coral reefs holding them up.
Coral reefs are important habitat for many marine organisms. The coral’s
structure provides protection to many fish species. Young fish swim into
Chapter 9: Taiwan’s Aquatic Ecosystems 106
the coral to hide from predators. Swimming in a coral reef can be a mindboggling experience because of all the brilliant colors of coral, plants, and
fish.
Figure 9-2.
Coral reef in Kenting exposed by low tide. The tide retreats to leave
shallow pools.
Coral reefs in the intertidal zone are exposed to air at low tide
(Figure 9-2). This causes stress to the organisms living within the coral
reefs. Chao (1993) documented that sea cucumbers (Holothuria atra)
living in deep and large tide pools are not affected by low tides. This is
because the temperature and chemical conditions within the pool do not
107 Ecosystems in Taiwan
A
B
Figure 9-3.
Sea cucumbers (Holothuria atra) in Kenting. The large sea cucmber (A)
is from a deep tide pool. The white strands coming from the sea
cucmber’s head are for protection. These strands are very sticky and can
be hard to remove. They could entangle a predator. If these strands are
not enough to discourage predators, the sea cucumber can also squirt out
water, intestines, and gonads. The small sea cucumber (B) has almost
finished dividing into two sea cucumbers because of the stressful
conditions in a shallow tide pool at low tide during the middle of the day.
This sea cucumber is still connected by a very thin black strand. Picture
B is printed with kind permission of Shyhmin Chao.
Chapter 9: Taiwan’s Aquatic Ecosystems 108
change much. Sea cucumbers within these pools can grow to be larger
than grapefruits (Figure 9-3A). In shallow tide pools such as those shown
in Figure 9-2, conditions during low tide can be very stressful, especially
if low tide is during the middle of the day. During this time, temperatures
within the pools increase. As water evaporates from these pools, salt
content also increases. These stressful conditions can induce sea
cucumbers to divide into smaller sea cucumbers. Sea cucumbers in these
shallow tide pools are always small and long. Sea cucumbers are capable
of reproducing sexually. When conditions are stressful, the population in
shallow tide pools is reproducing asexually by fission (Figure 9-3B). Sea
cucumbers in large tide pools are too round to reproduce asexually. They
have to reproduce by casting sperm into the water.
Seagrass Beds
Seagrass beds are another intertidal habitat in Taiwan. Here, the
ocean floor is sand or mud, not coral rock. The long Seagrass grows
through the sand and mud. Seagrass looks like grass (order Poales), but
are very different plants (order Alismatales). Like coral reefs, seagrass
beds supply important habitat for fish. The seagrass is also important for
protecting young fish from predators. Coral reefs are often very
109 Ecosystems in Taiwan
complicated and diverse, having very many different kinds of corals.
Seagrass beds, however, often contain just one species of seagrass.
Mangroves
Figure 9-4.
Mangroves at Guandu Nature Park in northern Taiwan. Location of leaves
shows the extent of high tide.
Mangrove trees (Rhizophoraceae) are land builders (Figure 9-4).
By growing in the intertidal zone, their roots can trap soil and nutrients.
Their roots provide important protection for young fish and other
organisms.
Chapter 9: Taiwan’s Aquatic Ecosystems 110
A
B
Figure 9-5.
Young mangroves floating in the water (A) after falling from the parent plant (B).
These young mangroves will eventually stick into the soil and take root.
Mangrove forests are also land protectors. When the 2010 Tsunami
that traveled from Indonesia to Sri Lanka, mangroves protected the land.
Areas with mangroves were flooded by the tsunami, but mangroves
blocked the force of the wave. This protected people and houses on land.
In areas without mangroves, the force of the wave destroyed buildings and
carried away people. Every year, however, mangrove forests are cut down
every year to make room for beaches and shrimp farms.
111
Ecosystems in Taiwan
Mangroves are viviparous. The seeds shown in Figure 9-5 are not
seeds but young plants. When the plants drift close enough to shore to
stick into the ground, they will grow into trees. Mangroves are so well
adapted to the salty intertidal environment that they cannot grow in fresh
water. They can eliminate excess salt through their leaves.
River Ecosystems
Most rivers are constantly changing environments. There are
changes from the river’s edge to the middle and from one part of the river
to the next. The flow of water along a river varies from slow to fast.
Where the water moves slowly, there are pools. Water can be deep in
these pools. Where the water moves quickly, there is whitewater or rapids.
The water can be shallow in the rapids. As the water tumbles through
rapids and is exposed to air, it is cleaned. It also absorbs oxygen. Many
organisms are specially adapted to the conditions of different parts of a
river. Study of invertebrates can indicate the oxygen content and
cleanliness of the water.
Chapter 9: Taiwan’s Aquatic Ecosystems 112
Figure 9-6.
Mouth of the Yellow River, China. Area inside the circle is new land created
from silt deposited by the river. Photographed by NASA on 20 June 2009.
<http://earthobservatory.nasa.gov/Features/WorldOfChange/yellow_river.php
?all=y>.
On Taiwan’s lowlands, rivers are wide. The water tends to flow
more slowly. Oxygen levels can be lower. Pollution levels are higher.
These rivers are carrying fine particles of dirt (silt). As the water speed
slows, the rocks and sand and silt are dropped. By the time a river, such
113 Ecosystems in Taiwan
as the Tadu River, reaches the ocean, it only has silt to drop. Therefore,
the soil in the river bed is soft mud. This silt, however, can be enough to
create land. If land management practices upstream are poor, that land can
be carried downstream and dumped into the ocean (Figure 9-6).
Figure 9-7.
Flooding of Salishien River during Typhoon Morakot on August 2009
created this landslide by cutting away at the base of the mountain. This
landslide broke two roads.
Throughout most of Taiwan’s mountain areas, however, the rivers
are narrow. The water moves quickly. During typhoons and heavy
rainfall, the rivers carry enough water and rocks and silt to cut through soil
Chapter 9: Taiwan’s Aquatic Ecosystems 114
and rock. Undercutting of riverbanks during typhoons causes landslides
(Figures 8-5 and 9-7). Much of Taiwan’s landscape is shaped by the
cutting action of rivers. Taroko Gorge in Taroko National Park was
formed in this way.
Discussion Questions
1) Salt is a big challenge for the survival of marine organisms. Does the
lack of salt in freshwater cause similar challenges to freshwater
organisms?
2) If sea cucumbers from shallow and deep tide pools traded places, what
would happen?
3) What would happen at the mouth of the Yellow River if upstream land
management practices improved?
4) What is the role of rivers and erosion on the shape and height of
Taiwan’s mountains?
115 Ecosystems in Taiwan
Chapter 10:
Taiwan’s Terrestrial Ecosystems
Figure 10-1.
Satellite image of Taiwan showing location of mountain ranges. This image also shows
how the mountains block clouds, making Taiwan’s eastern coast wetter than the western
coast. Image prepared by Jeff Schmaltz of the MODIS Rapid Response Team, NASA,
at the Goddard Space Flight Center, from a satellite photograph taken 15 December
2002. <http://visibleearth.nasa.gov/view.php?id=63673>.
Chapter 10: Taiwan’s Terrestrial Ecosystems 116
Taiwan is located on Earth is at 23°N latitude. Taiwan is an island
in the Pacific Ocean (Figure 10-1). Taiwan has mountains that almost
reach 4000 m in elevation. Because of these three facts, Taiwan has
incredible ecosystem diversity for its size.
Earth’s Ecozones
Global climate affects the diversity and location of habitats. In 1947,
Holdridge (1971) realized that the world’s habitats and their locations
could be summarized by three variables: evapotranspiration, annual
precipitation, and humidity (Figure 10-2).
Evapotranspiration is a word that joins evaporation with
transpiration. Evaporation is when water changes from a liquid to a gas.
This is most often observed when water evaporates from a puddle on the
ground into the air. When water leaves a plant, this is called transpiration
(Figure 3-6). Precipitation is moisture falling from the sky. This includes
rain and snow. Humidity is the moisture that is retained in the air. When
the air is dry, puddles will evaporate quickly. When the air is humid, there
is already much water in the air, so puddles will evaporate slowly. Taiwan
is very humid.
117 Ecosystems in Taiwan
(Feng & Kao 2001) are
Ecozones in Taiwan
and temperature.
precipitation, humidity,
of evapotranspiration,
based on the effects
(Holdridge et al. 1971)
Earth’s ecozones
Figure 10-2.
Figure 10-2.
evapotranspiration, precipitation, humidity, and temperature.
Ecozones in Taiwan (Feng & Kao 2001) are marked in blue.
marked in blue.
Earth’s ecozones (Holdridge et al. 1971) based on the effects of
Chapter 10: Taiwan’s Terrestrial Ecosystems 118
Areas with low humidity and high evapotranspiration are very dry.
These areas are warm desert. Areas with low evapotranspiration and low
annual precipitation are also very dry. These areas are cold deserts and
tend to be covered in ice. Areas with high humidity and high annual
precipitation are very wet. These places are tropical rain forests.
With global climate change, temperature and rainfall patterns are
changing. This will probably affect Taiwan’s diversity of ecozones. It is
possible that Taiwan will lose its subalpine rainforest and lower montane
dry forest (Feng & Kao 2001). If these habitats are lost, then all the
organisms adapted to these habitats are likely to go extinct.
Elevation and Taiwan’s Forests
Temperatures decrease with distance from the equator. Figure 10-2
shows that there are parallels between elevation (moving from earth into
the atmosphere) and latitude (moving from the equator to the poles). In
Taiwan, the mountains are so tall that there are enormous changes in
climate as elevation increases.
These changes in climate affect plant communities. Therefore, there
are enormous changes in forest ecosystems as elevation increases. Forests
119 Ecosystems in Taiwan
change (Figure 10-3) from low elevation broadleaved forests to conifer
forests at high elevations to subalpine meadow at the highest elevations.
The effect of elevation means that Taiwan has incredible habitat
diversity. It is possible to see many of the world’s ecosystems without
ever leaving Taiwan. The Ficus-Machilus ecosystem at low elevations is
very similar to the tropical rain forests of Indonesia. Ficus sp. trees grow
taller near the equator. On Borneo, these trees supply habitat for
Orangutans. In Taiwan, these trees supply habitat for Formosan Macaques
Figure 10-3.
Taiwan’s forests change with elevation. Drawing based on data from Su (1984).
Chapter 10: Taiwan’s Terrestrial Ecosystems 120
(Macaca cyclopis). The Quercus ecosystem has a very similar climate to
that of Tennessee and Kentucky in the USA. In this region, there can be
snow for a few weeks each winter. In Taiwan, the Quercus forests also
experience snow. The Tsuga-Picea ecosystem is very similar to high
elevation forests in the Smoky Mountains, USA, and southern Canada.
The dense mossy undergrowth of the Abies ecosystem is very similar to
the dense moss of the Abies forests in central Canada. This diversity of
ecosystems also means that the plant and animal species are also diverse.
As planetary systems are affected by global climate change, the
habitats and organisms living in Taiwan’s habitats are likely to change.
Because mountains are shaped like pyramids, the area at the tops of
mountains is smaller than the area at the base. This means that subalpine
habitats provide a smaller space for organisms to use. As the climate
changes and the subalpine meadow habitat is replaced by Abies forest, the
land area occupied by the Abies forest is likely to decrease. This
decreased area will also apply pressure to the organisms living in the
habitat. They will be more crowded. Competition among individuals and
species will become more intense.
121 Ecosystems in Taiwan
Ficus-Machilus Forest Ecosystem
Figure 10-4.
A Ficus sp tree strangling another tree at Nanrenshan. The white roots of the
Ficus sp. tree are wrapped around the brown trunk of the host tree. Eventually,
the host tree will die. The Ficus sp. tree, however, will probably be selfsupporting by then.
Chapter 10: Taiwan’s Terrestrial Ecosystems 122
The Ficus-Machilus ecosystem used to be common in Taiwan’s
lowlands at elevations below 500 m. Now, it is found in small patches in
southern Taiwan, such as Nanrenshan in Kenting. This habitat is
dominated by Ficus sp. and Machilus sp. trees. Because of the rainfall,
these forests have a very complex structure. The structure has layers of
herbs, shrubs, small trees, and canopy trees. Vines and ferns and small
plants can grow on trees. Figure 10-4 shows that these trees can grow on
other trees.
Although the plants of this forest are unique to Taiwan, the large
animals are not. This forest has hosts a wide diversity of animals that are
also found in other habitats and elevations. The Red Giant Flying Squirrel
(Petaurista petaurista) lives here (Figure 10-5), as do Formosan Macaque
and Wild Boar (Sus scrofa).
Figure 10-5.
A Red Giant Flying
Squirrel (Petaurista
petaurista). These
squirrels can be found in
forests from lowlands to
2000 m in elevation.
123 Ecosystems in Taiwan
Much of this habitat has been replaced by farms and towns and
cities and industrial zones. Areas in the lowlands that are currently
forested are managed. Most of the trees were planted by humans for
future use after they are cut down. Some areas are regions of secondary
growth. In these regions, seeds from adjacent areas have been carried by
animals or wind to colonize the newly exposed ground. This, however,
only happens on plots of land that are no longer being managed by
humans.
Sanyi Township is famous for its Tung Oil Trees (Vernicia fordii).
Each spring, people flock to Sanyi to see the flowers. These trees were
originally planted for their oil. Although these trees have replaced the
original forests, many of Taiwan’s animals use the new habitat. One
animal is the Spiny Country Rat (Niviventer coninga). It is unique
because it has some spines in its fur. This rat is restricted to forested
habitats. Males will fight for territory and access to females.
As Sanyi Township has developed, even the Tung Oil Forest has
decreased in size. The forest has been fragmented by roads, railroad, six
lanes of restricted access highway, and farms and houses. Each nonforested habitat provides a barrier to dispersal by the Spiny Country Rat
(Wang et al. 2008). Some barriers, like gravel roads are narrow enough
Chapter 10: Taiwan’s Terrestrial Ecosystems 124
that they might not function as barriers at all. Other barriers, like the sixlane restricted access highway (Taiwan’s Highway 1), are barriers so
complete that there is no way for a rat to survive crossing the highway,
even if it tried. These barriers have fragmented a once continuous
population of rats into many small and isolated populations. Already,
there is evidence that these barriers are affecting the movements and gene
flow of the Spiny Country Rat. Eventually, this could affect the long-term
genetic diversity of this population. Other species living in Sanyi’s Tung
Oil forests, such as the Leopard Cat (Felis bengalensis), are also probably
affected by this fragmentation.
Lauraceae-Fagaceae Forest Ecosystem
The Lauraceae-Fagaceae forest occurs in Taiwan from about 500 m
in elevation to about 1500 m in elevation. Here, too, the high rainfall has
created a complicated forest structure (Figure 10-6) that includes trees
covered with epiphytes (Figure 10-7). Epiphytes are plants that live on
other plants. Most of the trees in this forest are oak trees (Fagaceae) and
laurels (Lauraceae). The laurels in this forest are of the same family as the
Machilis sp. trees in the Ficus-Machilus forest at lower elevations.
125 Ecosystems in Taiwan
Figure 10-6.
A Lauraceae-Fagaceae forest at Chitou, central Taiwan.
Taiwan has incredible laurel diversity. Laurel species exist from low
elevations to high elevations.
Chapter 10: Taiwan’s Terrestrial Ecosystems 126
Figure 10-7.
Tree covered with
epiphytes at Fushan,
northern Taiwan.
Most of these
epiphytes are ferns.
The frog Kurixalus eiffingeri also exists from low elevations to as
high as 2500 m. This frog lives in trees and breeds in water captured by
holes in the trees (Lin & Kam 2008). When humans converted FagaceaeLaraceae forest to bamboo forests (Figure 10-8), populations of this frog
increased because the bamboo stumps increased the number of breeding
places.
127 Ecosystems in Taiwan
Figure 10-8.
Bamboo grove in Chitou, central Taiwan. Water in bamboo
stumps is used for breeding by Kurixalus eiffingeri.
Figure 10-9.
Female Kurixalus
eiffingeri depositing
eggs to feed her
tadpoles.
Chapter 10: Taiwan’s Terrestrial Ecosystems 128
The life history of this frog is interesting because the male cares for
the eggs (Lin & Kam 2006). He keeps the eggs moist and drives away
predators (Figure 2-1B), such as snails and slugs. After the eggs hatch
into tadpoles, the female returns to the stump to feed the tadpoles. This is
because there really is no food inside each small pool. The female lays
unfertilized eggs for her tadpoles to eat (Figure 10-9).
Figure 10-10.
Taiwan Slug Snake (Pareas formosensis) and its snail prey. The
snake is not interested in eating because it is shedding its skin.
Taiwan has high snake diversity. Many of these snakes eat
amphibians, such as Kurixalus eiffingeri. Many of these snakes are also
129 Ecosystems in Taiwan
poisonous. Most snake species live in the lowlands. Several have very
unique behaviors. The Taiwan Slug Snake (Pareas formosensis) survives
by eating snails (Figure 10-10). It does not swallow the snails shell and
all. Instead, it pulls the snail out of the shell. This snake is endemic to
Taiwan. The Greater Green Snake (Cyclophiops major) hunts frogs and
worms. The Bamboo Viper (Trimeresurus stejnegeri) has the same color
green as the Greater Green Snake, but it is very poisonous. Unlike the
Greater Green Snake, the Bamboo Viper has a triangular-shaped head, red
eyes, and a red tail. The Bamboo Viper will lurk at ponds to catch frogs.
Quercus Forest Ecosystem
The Quercus forests (Figure 10-11) occur in Taiwan from about
1500 m in elevation to about 2500 m in elevation. These forests are
dominated by oak trees (Quercus sp. and Cyclobalanopsis sp.). These
oaks are in the Fagaceae. In this forest, the structure is also complex, with
many epiphytes and hanging vines. The forest layers go from herbal
layers near the ground through shrub layers and subcanopy trees to canopy
trees.
Chapter 10: Taiwan’s Terrestrial Ecosystems 130
Figure 10-11.
A Quercus forest in Yushan National Park.
These forests also have trees that are taller than the canopy:
Formosan Cypress (Chamaecyparis formosensis). Formosan Cypress is
found from 1000 m to 2700 m in elevation. It is endemic to Taiwan.
These trees are classified as endangered because they are threatened with
extinction (IUCN 2012) because of logging. Their wood is valued
because it resists insects and rot (Figure 10-12). Formosan Cypress trees
can live several thousand years. Full grown, they are several meters in
diameter and 50-60 m tall.
131 Ecosystems in Taiwan
Although young Formosan Cypress trees have been planted over the
past 40 years, they are still very small and very young. Many of these
young trees will not survive to grow up. A recent threat to these small
trees is Sambar Deer (Cervus unicolor swinhoei). Each year, male deer
grow new antlers for the breeding season. Newly grown antlers are coated
a thin layer of fur that must be removed. Deer remove this layer by
rubbing their antlers against trees. For some reason, male Sambar Deer
seem to prefer polishing their antlers on young Formosan Cypress. This
polishing action
Figure 10-12.
Remains of a Formosan
Cypress (Chamaecyparis
formosensis) forest at
Shokuping (>3500 m in
elevation) in Yushan
National Park.
Chapter 10: Taiwan’s Terrestrial Ecosystems 132
removes bark from the tree. If bark is completely removed from the tree’s
circumference, then the tree is girdled (Figure 10-13). Girdling will kill a
tree.
Many animal species live in these Quercus forests. They include
Swinhoe’s Pheasant (Lophura swinhoii), Mikado Pheasant, Taiwan Black
Bear (Figure 10-14), Perny’s Long-nosed Squirrel (Dremomys pernyi),
and White-faced Flying Squirrel (Petaurista alborufus). Although these
animals can live at other elevations, the acorns from Quercus sp. and
Cyclobalanopsis sp. trees are an important source of food.
Figure 10-13.
Girdled Formosan Cypress (Chamaecyparis formosensis) in Yushan
National Park.
133 Ecosystems in Taiwan
Figure 10-14.
A Taiwan Black Bear (Ursus
thibetanus formosanus)
enjoying acorns from a
branch pulled off a Quercus
sp. tree. This bear is in the
Taipei Zoo.
.
Tsuga and Picea Forest Ecosystem
The Tsuga and Picea forest (Figure 10-15) is from about 2500 m in
elevation to about 3100 m in elevation. Both Tsuga sp. (Hemlocks) and
Picea sp. (Spruce) are conifers. In these forests, the structure is fairly
simple. The herb layer is mainly Yushania bamboo (Yushania
niitakayamensis). Shrub layers and subcanopy layers are rare. Although
rainfall is high, there are fewer epiphytes growing on the trees. The
weather is cooler here and the growing season is shorter.
Chapter 10: Taiwan’s Terrestrial Ecosystems 134
Figure 10-15.
Tsuca-Picea forest at Nanhudashan, Taroko National Park.
Many of the animals that occur in other forest types can be found in
these forests. Coal Tits (Periparus ater ptilosus) can often be heard
135 Ecosystems in Taiwan
calling from the tops of the taller conifers. White-faced Flying Squirrels
nest in holes in the trees (Figure 10-16).
Figure 10-16.
White-faced Flying Squirrel (Petaurista alborufus)
nesting in a Tsuga sp. in Yushan National Park.
Abies Forest Ecosystem
The Abies kawakamii forests (Figure 10-17) grow from about 3100
m in elevation to about 3600 m in elevation. These forests tend to be cold
and dark. Except for the fact they are on steep hillsides, they look very
much like the boreal forests of Canada. The trees grow closely together.
Chapter 10: Taiwan’s Terrestrial Ecosystems 136
Figure 10-17.
Abies forest. This is the Black Forest near Shueshan in Sheipa National
Park.
Their leaves in the canopy block light to the ground. They have a thick
mossy herb layer. There are patches of Yushania bamboo . Shrub and
subcanopy layers are essentially absent. These forests regularly
experience snow in the wintertime.
These forests also tend to be quiet. Birds do feed in the canopy, but
they call and sing quietly. Possibly one of the loudest birds is the Whitebacked Woodpecker (Dendrocopus leucotos). It can be heard tapping the
wood and occasionally calling ‘Kip!’ Animals on the ground, such as
137 Ecosystems in Taiwan
Mikado Pheasant, are hard to see. The open understory provides little
shelter from predators, making prey animals wary.
Subalpine Meadow Ecosystem
Figure 10-18.
Subalpine meadow at Nanhudashan, Taroko National Park.
Chapter 10: Taiwan’s Terrestrial Ecosystems 138
The subalpine meadows (Figure 10-18) occur in Taiwan anywhere
over 3600 m in elevation. The main plant in these meadows is Yushania
bamboo. In these meadows, the height of the bamboo depends on wind
and when the last fire occurred. When this bamboo grows in forests, such
as the Quercus, Tsuga-Picea, and Abies forests, it can get as tall as 2 m.
On the meadow, however, wind breaks off the growing ends and fire burns
it to the ground. Sambar Deer graze on this bamboo, keeping it short.
Figure 10-19.
Human trampling effects. Here, there are three trails instead of one
because hikers do not like to get their boots wet and because the
impacted soil encourages rainwater run-off. Trails at these
elevations often turn into gullies.
139 Ecosystems in Taiwan
These habitats are fragile. Because it is so cold, these meadows can
be covered by snow for as long as a few months each year. This cold also
makes for a short growing season. Since these meadows are on the tops of
Taiwan’s mountains, the soil layer is very thin. It can take many years for
these meadows to recover from damage such as trampling by hikers
(Figure 10-19). Since most hikers do not like to get their boots wet, they
will often walk beside the original trail. This trampling results in several
trails running in parallel. Gradually, these trails often turn into gullies.
The hardened soil encourages runoff that ends up speeding the creation of
the gully. Many gullies can be avoided by careful trail planning and by
hikers staying on established trails.
Other Subalpine Habitats
Taiwan’s highest elevations also have other habitat types. Juniper
forests grow near the tops of Taiwan’s highest peaks (Figure 10-20). At
these highest elevations, the wind is very strong. It is strong enough to
affect the growth of trees. Juniper trees may be very old, but they are
rarely taller than 2 m. The wind continuously blows them over.
Krumholtz is when trees are shaped by the wind. This phenomenon was
first described in the Alps of Europe.
Chapter 10: Taiwan’s Terrestrial Ecosystems 140
Figure 10-20.
Krumholtz effect on a
Juniperus sp. tree in
Yushan National Park.
The winds have bent this
tree so that it cannot grow
tall. Instead, it has grown
down the hill.
Taiwan’s subalpine regions show evidence of glaciation. Ten
thousand years ago during the Pleistocene, Taiwan’s mountains had
glaciers. The evidence of these glaciers is glacial cirques (Figure 10-21).
These are rounded areas on mountain tops made smooth by the weight of
glacial ice. There are at least three glacial cirques in Taiwan: two at
Nanhudashan in Taroko National Park and one on Shueshan in Sheipa
National Park.
141 Ecosystems in Taiwan
Figure 10-21.
Glacial cirques at Nanhudashan, Taroko National Park. The upper cirque is in
the center of the picture. The house in the bottom right corner (arrow) is in the
lower cirque.
Pleistocene Relicts
Because of Taiwan’s location as a subtropical island and because of
Taiwan’s mountains, Taiwan has climates and forest communities similar
to those in northern Japan and in the Himalayas. Ten thousand years ago
during the Pleistocene glaciation, many animals and plants had
Chapter 10: Taiwan’s Terrestrial Ecosystems 142
distributions that included Taiwan. As the glaciers melted and sea levels
rose, these cold climate animals and plants got trapped in Taiwan’s
mountains.
The Bird-lime Tree or Wheel Tree (Trochodendron araliodes) is one
of these Pleistocene relicts. It is sequentially monecious. This means it
can produce male flowers or female flowers, but not at the same time.
This strategy of changing sex has helped ensure its survival since the
dinosaurs roamed Earth 65 million years ago. Because the Bird-lime Tree
is a gymnosperm with flowers, it is also considered an evolutionary relict.
Most conifers are gymnosperms. They produce cones, not flowers. Most
deciduous trees and green plants are angiosperms because they produce
flowers. During the Pleistocene, the Bird-lime Tree was widely
distributed across East Asia. After the glaciers melted, it became trapped
on Taiwan and in Korea and Japan. In Taiwan, it occurs from 500-2500 m
in elevation.
Another Pleistocene relict is the Least Weasel (Figure 4-2C). It
lives in the Subalpine Meadows. It is stranded at Taiwan’s highest
elevations. This weasel is small because it lives in burrows created by the
Kikuchi’s Field Vole (Microtus kikuchii). The Least Weasel preys on
Kikuchi’s Field Vole. This vole (Figure 10-22) is another Pleistocene
relict, but it is endemic to Taiwan. Because of the harsh environment of
143 Ecosystems in Taiwan
Taiwan’s Subalpine Meadows, male and female voles work together to
raise their young.
Figure 10-22.
Kikuchi’s Field Vole (Microtus kikuchii) in captivity. This vole
was captured at Hohuanshan, Taroko National Park. Picture
printed with kind permission of Yu-Cheng Chang.
Migrations
Taiwan has such incredible animal diversity because of the
incredible diversity of habitats. Few of the animals, however, are truly
specific to a particular habitat. Swinhoe’s Pheasants are more common in
Chapter 10: Taiwan’s Terrestrial Ecosystems 144
medium elevation forests such as the Fagacea-Lauracea forests. They are,
however, encountered in the Quercus forests. In these forests, they cooccur with the Mikado Pheasant.
Some animals show seasonal altitudinal migration. They move too
higher elevations during the summer. When things get too cold in winter,
they move back down to lower elevations. Many of Taiwan’s bird and
butterfly species have seasonal altitude migration.
In the summer, Himalayan Black Bulbuls (Hypsipetes
leudocephalus) can be found as high as 1500 m in elevation. In the fall,
they will gather together in large flocks of 50 or so individuals. These
flocks will fly to lower elevations and spend the winter together.
Some valleys in southern Taiwan are the winter homes for butterflies.
Butterflies fly from all over Taiwan to winter in these butterfly valleys.
In late October, when sitting on a sunny morning at Tatachia Gap in
Yushan National Park, it is possible to watch flock after flock of Greychinned Minivets (Pericrocotus solaris) migrate over the gap from
western Taiwan to eastern Taiwan. These Grey-chinned Minivets are
colorful birds. The males have red bodies. The undersides of their wings
are red, too. Females have yellow bodies and yellow undersides of wings.
Migrating flocks of about 10-20 birds are always a colorful sight. Some
145 Ecosystems in Taiwan
flocks are of females. Some flocks are of males. Some flocks contain
both sexes.
Taiwan also has incredible diversity because of its location on the
Pacific Ocean. Taiwan is perfectly placed for latitudinal migrations
(Figure 10-23). Some birds and butterflies fly to Japan for the summer.
Other birds and butterflies fly to the Philippines for the winter.
Figure 10-23.
Flock of Intermediate Egrets (Mesophoys intermedia) flying up the Salishien
River, Nantou, to gain altitude.
Some Black-faced Spoonbills spend the winter on the salt marshes
near Tainan. In the spring, they will fly north to Korea and Japan to breed.
The Pacific Swallow (Hirundo tahitica) spends the summer breeding in
Taiwan. When winter approaches, it flies to south to South-east Asia and
Chapter 10: Taiwan’s Terrestrial Ecosystems 146
the Philippines. Some birds, such as the Grey-faced Buzzard (Bastatur
indicus), fly through Taiwan during their migrations. Autumn migrations
of Grey-faced Buzzards and other raptors now attract crowds of tourists to
Kenting National Park.
These migrations mean Taiwan’s bird diversity is almost as great as
the bird diversity for the entire eastern North America. These migrations
also make Taiwan one of the world’s butterfly hot spots.
Discussion Questions
1) With global climate change, what species might disappear from Taiwan?
Why?
2) Taiwan does not have any desert habitats. For Taiwan to get desert
habitats, what would have to change?
3) With global climate change, how might latitudinal and altitudinal
migrations change?
4) What are some reasons for why mammals and birds might be adapted to
live across a broad range of elevations and forest types?
5) What might global climate change mean for some of Taiwan’s
Pleistocene relicts?
147 Ecosystems in Taiwan
Glossary
Accident. Bad luck.
Acid Rain. Rain that is acidic, usually because it contains nitrogen and
sulfur compounds. This rain can erode rocks and corrode glass and
metals.
Acorn. The seeds of oak trees (Quercus sp. and Cyclobalanopsis sp.).
Adapt. Able to live well in an environment. Able to adjust to an
environment.
Algae. One-celled plants that live in water.
Algal Bloom. Huge bursts of population growth by algae.
Allee Effect. The process of small populations getting smaller and large
populations getting larger.
Alluvial Plane. A flat habitat constructed by the sediment from rivers.
Altitude. Distance from sea level.
Amino Acid. Molecules containing nitrogen necessary for producing
protein.
Angiosperm. Plants with flowers.
Antler. Horn-like projections from the heads of male deer. Each year,
males will grow new antlers.
Glossary 148
Aquatic. Having to do with water.
Asexual Reproduction. Reproducing without sex. Producing the next
generation by cloning.
Atmosphere. Air. Earth’s atmosphere contains everything from the
ground until space.
Atoll. A donut-shaped island created by coral reefs.
Atricial. Being born helpless: no feathers, no eyesight, and no ability to
walk or find food.
Backhoe. A machine commonly used in Taiwan for construction and road
repair.
Balance. The amount of money you have in the bank.
Barrier. Something that prevents movement.
Bends. The condition of air in body tissues returning to a gas form as a
swimmer moves from deep ocean to the ocean’s surface.
Biological Species. A group of organisms that can reproduce among
themselves, but not with other organisms.
Budding. Asexual reproduction in which part of the mother’s body
becomes the offspring.
Boreal. Cold climate around 60° latitude.
Broadleaved. Deciduous trees. These trees have large leaves. In
temperate zones in the fall, these trees will lose their leaves.
149 Ecosystems in Taiwan
Burning. The process of reducing organic matter into carbon and other
elements.
Burrowing. Digging into the soil.
Butterfly Valley. Warm, south-facing valleys in southern Taiwan where
butterflies spend the winter.
Canopy Layer. Layer of the tallest trees in a forest. This layer makes the
forest seem to have the same height above the ground.
Capillary Action. The process of liquid flowing up a very narrow tube.
Carbohydrates. Energy packed molecules made up of oxygen, hydrogen,
and carbon. Many carbohydrates are sugars.
Carnivore. Animals that eat animals.
Carrying Capacity. The limit of the environment to support a population
indefinitely.
Casting. Worm waste.
Chemical Stress. The problems caused by exposure to chemicals such as
salts (NaCl), mercury (Hg), and cadmium (Cd).
Chromosome. A strand of DNA. Humans have 23 pairs of chromosomes.
Climate. Weather conditions.
Clouds. White masses of water gas cooling and changing into water
liquid.
Community. Groups of organisms of different species.
Glossary 150
Competition. Fighting between individuals for access to resources: space,
food, and mating partners.
Compost. Combining organic materials together to decay. Process is
often helped by fungi and animals.
Compound Interest. Interest being applied to interest being applied to
money kept in a bank account.
Concave. The inside of a curve.
Conifer. Trees that keep their leaves all year round. Leaves are usually
small and needle-shaped.
Conserve. To use carefully.
Consume. To eat. To use up.
Convex. The outside of a curve.
Coral. Calcium carbonate shelter produced by coral animals.
Coral Reef. The accumulation of corals into large masses.
Coriolis Effect. The way the Earth’s spinning affects the speed and
direction of things in the air.
Correlate. To describe the pattern of relationship between two things.
Crash. When a population exceeds its limit and all or almost all the
individuals die.
Critically Endangered. The classification that out of 10 species, eight
may go extinct in 10 years or three generations.
151 Ecosystems in Taiwan
Cretaceous. A geological age that occurred about 65 million years ago.
Current. The flow of water or wind.
Dead. No longer being alive.
Dead Zone. Regions in water where organisms cannot survive because
there is no oxygen.
Decay. The process of an organism slowly coming apart into minerals
and nutrients.
Decomposers. Organisms that break apart dead organic matter, such as
fungi.
Deforestation. The process of removing trees from an area.
Degrade. The process of making something less good or less healthy.
Dehydration. The process of losing water. If enough water is lost, the
organism will die.
Denitrification. The process of fixed nitrogen returning to the
atmosphere.
Desert. Parts of Earth too dry to support life.
Dessication. Drying out. A result of dehydration.
Detritovore. An organism that eats dead things, decaying matter.
Detritus. Dead things. Decaying matter.
Development. The growth of an organism from birth to adulthood.
Glossary 152
Use of land by humans to construct farms, roads, towns, cities, and
industrial zones.
Disease. Sickness.
Dioecious. Plant species where individuals are divided into male plants
and female plants.
Dissipate. To come apart.
Disturbed. To move or rearrange.
Doldrums. Area near the equator where there is little wind.
Domesticated. Tamed and managed and bred by humans.
Dominant. To be the most powerful and the most common species.
Downy Feathers. Soft fluffy feathers that keep a bird warm.
Drizzle. Really slow and light rainfall.
Drought. A dry period. A time when there is not enough rainfall.
DNA. Deoxyribonucleic Acid. The molecules that combine to form
chromosomes
Ecologists. Scientists who study ecology.
Ecology. The study of organisms and their interactions with each other
and their environment.
Economics. The study of money and money systems.
Ecosystem. An environment and organisms living in that environment.
Ecozone. Regions of Earth with different climates and habitats.
153 Ecosystems in Taiwan
Egg Bound. When a female bird has an egg stuck inside her body.
Egg Predator. An animal that eats eggs.
Elements. Basic chemical atoms, such as oxygen (O) and Carbon (C).
Elevation. Distance from sea level.
Eliminate. To excrete from the body as waste.
El Niño. A global climate pattern that tends to bring warm and wet
weather.
Emergent Effects. New problems that come into existence after a
population has become small and fragmented.
Endangered. The classification that out of 10 species, five may go
extinct in 10 years or three generations.
Endemic. Species that are only found in a particular place. It is possible
to be endemic to Taiwan’s high elevations, endemic to Taiwan,
endemic to East Asia, and endemic to Earth. Species endemic to
Taiwan are not found any other place.
Energy. The ability to do work.
Epiphyte. Plants that live on other plants.
Equator. The widest part of Earth: 0° latitude.
Erosion. The process of wearing away soil. Can be done by wind or
water.
Glossary 154
Eutrophic. Old lakes and ponds with murky water and accumulated
nutrients.
Eutrophication. The process of young lakes becoming old lakes and then
land.
Evaporation. The process of water turning into a gas.
Evapotranspiration. The process of a plant ‘breathing’ during which it
releases oxygen and water and takes up carbon dioxide.
Evolution. The process of changing over time.
Evolutionary Relict. Species that remain unchanged after millions and
millions of years.
Extinct. The death of a species. All the individuals in the species have
died.
Extinction. The process of going extinct.
Genetic Species. Species that have different DNA.
Family. A classification that contains related genera.
Feces. Unprocessed food eliminated by an animal through its intestines.
Fertile. Having the ability to produce: to grow plants or to reproduce.
Fertilizer. A compound of nitrogen, carbon, and hydrogen spread on
fields to provide nutrients needed for plants to grow.
Fission. Dividing into two. A type of asexual reproduction.
155 Ecosystems in Taiwan
Fitness. Having your DNA survive by producing offspring and having
them produce offspring.
Fixing. The process of storing nitrogen in a form that can be used in a
food web.
Flower. The sexually reproductive part of a plant.
Fossil. An imprint of an organism in rock.
Fossil Fuels. Fuel from coal, oil, and natural gas.
Food Web. Diagrams of the energy flow among organisms in a
community.
Fragment. To break into small pieces.
Fresh Water. Most water in lakes and rivers. It is not salty like the ocean.
Gargantuan. Really, really, big.
Gene Flow. The movement of DNA from one part of a population to
another.
Genera. More than one genus.
Generation. Each level of offspring: children, grandchildren, and great
grandchildren.
Genetic Diversity. Many kinds of genes in the DNA of a population or
species.
Genus. A classification that contains related species.
Geothermal Energy. Energy generated from within Earth.
Glossary 156
Girdling. The removing of bark from the circumference of a tree. This
can kill the tree.
Glacial Cirque. The place in mountain areas smoothed out by a glacier.
Glaciation. A time when there were glaciers, such as the Pleistocene
Glaciation.
Glacier. Snow and ice that remain in a place all year.
Global Climate Change. The currently ongoing condition of humans
changing the climate, mainly by emitting carbon dioxide.
Gorge. A really steep and really deep valley, such as Taroko Gorge.
Gravity. Spinning of Earth holds things to the Earth’s surface.
Ground Water. Water stored in cavities below the Earth’s surface.
Grounded. Not allowed to fly.
Growing Season. The time of the year with it is warm enough and wet
enough and has enough sunlight for plants to grow.
Gully. A deep cut in the soil along which water flows during rains. Once
a gully is formed, it usually continues to deepen.
Gymnosperm. Plants with that have cones, not flowers.
Gyre. Whirlpool. Places where water moves in a circle.
Inbreeding. Mating with relatives.
Individual. One organism.
Infiltration. The process of water slowly soaking into the ground.
157 Ecosystems in Taiwan
Instability. Not stable. The situation where a population is at risk of
random events, such as natural disasters.
Interaction. The process of communicating with or affecting other
organisms.
Interest rate. The speed at which money earns money when in a bank
account.
Intertidal. The area between ocean and land that is affected by tides.
Invasive. The moving of organisms into new regions that results in
competition with native organisms.
Inventory. The process of counting what you have.
Isolated. Separated from other organisms.
Habitat. Home. The place where an organism lives.
Habitat Loss. Destruction of habitat needed for the survival of a species.
Hatch. When baby animals break out of their eggs.
Headwaters. The source or beginnings of a stream or river.
Heavy Metals. Large chemicals such as mercury (Hg) and cadmium (Cd).
These are often poisonous.
Herb Layers. Layer of small plants growing close to the ground.
Herbivores. Animals that eat plants.
Hermaphrodite. A plant or animal that can be both male and female.
Horse Latitude. Around 30° latitude where there is little wind.
Glossary 158
Humid. Air that have a lot of water in it.
Humidity. The amount of water in the air.
Hypothermia. Dying from being too cold.
Hypothesis. Questions asked that might e can be answered by scientific
study.
Infertile. Cannot reproduce.
In Heat. When a female has ovulated and is ready for sex.
Introduced Species. Species that humans have carried from one habitat
to another. Sometimes these species become invasive.
Invasive Species. Introduced species that out compete native species,
causing populations of native species to decline.
Invertebrates. Animals without backbones, such as worms, snails, and
insects.
J-Curve. A population growth rate that vastly exceeds carrying capacity
and crashes.
K-selected. Organisms with the life history of large body size, long life
span, slow reproductive rates, and good offspring survival.
Karyotyping. Counting chromosomes.
Krumholtz. The process of wind bending trees over so trees grow
horizontally, not vertically.
159 Ecosystems in Taiwan
La Niña. A global climate pattern that tends to bring cool and dry
weather.
Larvae. Baby insects.
Latitudinal Migration. Movements of animals north or south based on
the seasons.
Latitude. Imaginary bands around Earth to mark distances from the
equator.
Leach. To leak through something.
Legume. Bean plants.
Life History Strategy. The lifestyle of an organism based on body size,
longevity, reproduction method, and number of offspring produced.
Lightening. Big electrical discharges from the atmosphere. Usually
followed by thunder.
Limestone. Stone made from millions of years of accumulated shellfish.
Limit. A constraint. A point beyond which it is not possible or advised to
go.
Longitude. Imaginary bands around Earth to mark distances along the
equator.
Local. Belonging to a place.
Logging. Cutting down trees.
Lurk. Hide and wait.
La Niña. A global climate pattern that tends to bring cool and dry
weather.
Larvae. Baby insects.
Latitudinal Migration. Movements of animals north or south based on
the seasons.
Latitude. Imaginary bands around Earth to mark distances from the
equator.
Leach. To leak through something.
Legume. Bean plants.
Life History Strategy. The lifestyle of an organism based on body size,
longevity, reproduction method, and number of offspring produced.
Lightening. Big electrical discharges from the atmosphere. Usually
followed by thunder.
Limestone. Stone made from millions of years of accumulated shellfish.
Limit. A constraint. A point beyond which it is not possible or advised to
go.
Longitude. Imaginary bands around Earth to mark distances along the
equator.
Local. Belonging to a place.
Logging. Cutting down trees.
Lurk. Hide and wait.
Glossary 160
Management. Taking care of something.
Manure. Feces.
Marine. Having to do with the ocean.
Mass Extinction. A time when huge numbers of species go extinct very
rapidly.
Mate. 1) A sexual partner. 2) The act of sexual reproduction.
Meadow. A small grassland.
Metabolic Waste. See Waste.
Migration. The process of moving from one place to another.
Microclimate. The climate of a very small area, such as underneath a
rock.
Model. A simplified version of a system that can be used to study that
system.
Monoecious. Plant species that have male flowers and female flowers.
Monogamy. Sexual reproductive system of one male and one female.
Monsoon. A seasonal weather pattern that brings rain.
Morphological Species. A group of organisms that look similar to each
other but look different from other organisms.
Morphology. Shape. How an organism looks.
Mortality. Death.
Mouth. See river mouth.
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Mustelid. Having to do with the Mustelidae (the weasel family).
Native. Belonging to a place.
Natural Resources. The products of ecosystems.
Neap Tide. The tide each month that has the smallest difference between
low tide and high tide.
Near-threatened. A classification of organisms that are approaching the
risk of going extinct.
Northern Hemisphere. The northern half of Earth.
Nucleic Acid. Molecules necessary for life: DNA and RNA.
Nutrients. The chemical elements needed to support physiological
activities.
Oligotrophic. New lakes and ponds with clear water and few nutrients.
Order. A classification that contains related families.
Organism. Life forms. These could be animals or plants or fungi.
Orthographic Uplift. The process of air being forced to rise because it is
blown against mountains.
Osmotic Balance. When there is the right mix of salts and water inside a
cell or body.
Over Hunting. Humans hunting and killing too many individuals in a
species. Includes over fishing.
Glossary 162
Overpopulation. The problem of having too many individuals for the
habitat to support.
Overshoot. Exceeding carrying capacity.
Ovulating. When a female’s egg leaves her ovary.
Parasite. Organisms that get their nutrients from other organisms.
Parthenogenesis. Asexual reproduction in animals. It works the same
way as sexual reproduction, but no males contribute DNA.
Pellet. A mass of undigested material spat out by raptors, such as owls
and eagles.
Percolation. The process of water slowly filtering through the ground
into the water table.
Permian. A geological age that occurred about 245 million years ago.
Phenology. The study of when things happen.
Photosynthesis. The process green plants use to convert sun energy into
carbohydrates.
Planitary. Having to do with a planet, such as Earth.
Poisonous. Toxic. Can kill or make ill.
Pollinate. The process of fertilizing a flower so it can make seeds.
Pollinator. Animals that fertilize flowers, such as bees.
Pollution. Waste emitted into the air and water and land.
163 Ecosystems in Taiwan
Pleistocene Glaciation. The glacial period that ended about 12,000 years
ago.
Pleistocene Relict. Organisms remaining in a place after the Pleistocene
Glaciation.
Polyandrous. Sexual reproduction reproductive system of one female and
many males.
Polygynous. Sexual reproductive system of one male and many females.
Population Crash. When all or most individuals in a population die.
Population Explosion. Extremely rapid population growth.
Population Growth Rate. The speed at which a population grows.
Populations. Groups of organisms of the same species.
Porus. Being absorbent. Having holes.
Prey. Animals that are hunted by predators.
Precipitation. Water falling out of the sky as rain or snow or hail or sleet.
Precocial. Being born with feathers and able to walk and find food.
Predation. The process of hunting and killing animals.
Predator. An animal that eats other animals.
Prevailing Winds. The main direction wind blows.
Primary Consumers. Animals that eat producers.
Producers. Plants that can do photosynthesis.
Glossary 164
Promiscuous. Sexual reproductive system of many females and many
males.
Protective Cover. A safe place to hide.
Protein. Complex molecules made up of amino acids. These molecules
drive physiological processes.
Physiological. Having to do with the internal function of an organism.
r-selected. Organisms with the life history of small body size, short life
span, rapid reproductive rates, and poor offspring survival.
Raceme. A baby land plant growing from the land mother plant.
Rain Forest. Very warm and humid parts of Earth that support
gargantuan amounts of life.
Rain Shadow. Dry or desert area on the opposite side of a mountain from
the prevailing winds. It rains on the windward side of the mountain,
leaving no moisture for rain on the leeward side of the mountain.
Range. 1) The area within which a species can occur. 2) A row of
connected mountains.
Rapids. See whitewater.
Recycle. The process of reprocessing something so it can be used again.
Regenerate. To grow back.
Related. Being of the same family group. Having similar DNA.
Relevant. Meaningful.
165 Ecosystems in Taiwan
Relict. Left behind or still remaining. See Pleistocene and evolutionary
relicts.
Reproduce. Making babies. The process of producing the next
generation.
Respiration. Breathing. The process of animals releasing carbon dioxide
and taking up oxygen.
Resources. The food and water and space needed to survive.
River Bank. The land edge of a river.
River Mouth. Where a river enters a lake or ocean.
Rot. See decay.
Rotation. The Earth’s spinning around.
Runoff. The process of water flowing over the ground.
S-Curve. A population growth rate that levels off once carrying capacity
is reached.
Safe. Not any risk of going extinct.
Seasonal Altitude Migration. The movement of animals up and down a
mountainside based on the seasons.
Secondary Consumers. Animals that eat primary consumers.
Secondary Growth. The plant community that grows back after a
disturbance.
Glossary 166
Sediment. The layer of dead organic matter that drifted to the bottom of
an ocean or lake or river.
Sequentially Hermaphrodite. A plant or animal that can be both male
and female, but not at the same time.
Sexual Reproduction. Combining the DNA of two individuals to
produce offspring.
Shellfish. Aquatic organisms with shells, such as shrimp, lobsters, and
oysters.
Shrub Layer. Layer of bushy plants that are too tall to be herbs and too
short to be trees.
Silt. Really fine pieces of sand or soil.
Skeleton. The support structure of an animal, such as bones.
Smog. Polluted air produced by cities and industrial zones and burning of
fields.
Southern Hemisphere. The area of Earth south of the equator.
Species. A group of organisms different (reproductively, genetically, and
morphologically) from other organisms.
Sperm. Structures containing a male’s DNA that can fertilize eggs.
Spring Tide. The tide each month that has the greatest difference
between low tide and high tide.
167 Ecosystems in Taiwan
Starve. The process of being going without food and being hungry. If
this goes on long enough, the organism will die.
Stolon. A baby water plant growing from the mother water plant.
Stomates. Holes on the underside of plant leaves that permit
evapotranspiration to occur. These holes can be opened or closed.
Strategy. See Life History Strategy.
Stream Capture. The process of one stream capturing the headwaters of
another stream.
Subcanopy Layer. Layer of small trees that grow beneath taller trees.
Subspecies. Organisms not quite different enough to be classified as
species.
Subtropical. Being near the 23° latitude.
Succession. The process of a community changing over time.
Survive. To live.
Survivorship Curve. The pattern of individuals in a population living to
old age.
System. The organization and function.
Tadpole. Frog larvae.
Taxonomy. The process of identifying and classifying species.
Temperate. The comfortable climate around 40° latitude.
Tentative. Uncertain.
Glossary 168
Tertiary Consumers. Animals that eat secondary consumers.
Thermohaline Circulation. The movement of water around the ocean.
Thermodynamics, First Law. The law of physics that energy can be
changed, but not made or destroyed.
Thermodynamics, Second Law. The law of physics that each time
energy is changed, some of it becomes unusable.
Threatened. Having the risk of going extinct.
Tide. The rise and fall of the ocean’s surface in response to the moon’s
gravity.
Tide Pool. A pool of water left by low tide.
Toast. Bread that has been sliced and lightly burned on both sides.
Trade Winds. Winds from 0° latitude to 30° latitude.
Trampling. Stamping on or walking on ground and plants. Trampling
along the same route can eventually make trails.
Transpiration. Plants breathing. Plants emitting oxygen and taking up
carbon dioxide.
Trophic Level. A simple representation of the flow of energy through the
organisms in an ecosystem.
Tropical. The hot climate near the equator between 0° and 20° latitude.
169 Ecosystems in Taiwan
Tsunami. Tidal wave. A really big wave usually caused by an
earthquake. As this wave approaches land, it builds up to flood
inland areas.
Type I Survivorship Curve. Most individuals live to die of old age.
Type II Survivorship Curve. Most individuals die soon after birth.
Typhoon. Gargantuan spinning storms of wind and water.
Understory. The plants living below the canopy layer.
Undisturbed. Opposite of disturbed.
Unfertilized. Eggs that have not been in contact with male DNA.
Urine. Liquid waste eliminated from the body via kidneys. Contains
much nitrogen.
Viviparous. Live birth. Humans and mangroves are viviparous.
Vulnerable. 1) At risk of being hurt. 2) The classification that out of 10
species, two may go extinct in 10 years or three generations.
Wave. The rise and fall of the ocean’s surface in response to wind.
Waste. 1) To carelessly use something up. 2) Urine or feces or pellets
eliminated from the body because they cannot be used.
Waterway. Rivers, ponds, and lakes.
Westerlies. Prevailing winds from 30° latitude to 60° latitude.
Whitewater. Rapids. Fast shallow moving water in rivers.
Glossary 170
References
Bradbury, R. 1950. December 2001: The Green Morning. Pp. 73-77 in
The Martian Chronicles. Bantam Books, New York, NY, USA.
Bridgman, C.L. 1994. Mikado pheasant use of disturbed habitats in
Yushan National park, Taiwan, with notes on its natural history.
Thesis. Eastern Kentucky University, Richmond, KY, USA.
Bridgman, C.L. 2002. Habitat use, distribution and conservation status of
the mikado pheasant (Syrmaticus mikado) in Taiwan. Dissertation.
University of Tennessee, Knoxville, TN, USA.
Caughley, G. & A. Gunn. 1996. Conservation Biology in Theory and
Practice. Blackwell Science. Cambridge, MA, USA.
Chao, S.M. 1993. Reproductive biology of sea cucumbers in southern
Taiwan (Echinodermata: Holothuroidea). Dissertation. Tunghai
University.
Grant P.R. & B.R. Grant. 2002. Unpredictable evolution in a 30-year
study of Darwin’s Finches. Science 296:707-711.
171 Ecosystems in Taiwan
eFloras. 2008. Floras of North America. Missouri Botanical Guarden, St.
Louis, MO, and Harvard University-Herbaria, Cambridge, MA
<http://www.efloras.org>. Accessed 16 July 2012.
Feng, F.L. & J.T. Kao. 2001. Application and simulation in eco-region of
Taiwan by Holdridge method. Quarterly Journal of Forest Research
of Taiwan 23(1):83-100 (in Chinese).
Holdridge, L.R., W.C. Grenke, W.H. Hatheway, T. Liang, & J.A. Tosi.
1971. Forest Environments in Tropical Life Zones. Pergamon Press.
New York. NY, USA.
IUCN. 2012. IUCN Red List of Threatened Species. Version 2012.1.
<www.iucnredlist.org>. Accessed 25 July 2012.
Lin, L.-K., M. Motokawa, & M. Harada. 2010. A new subspecies of the
Least Weasel Mustela nivalis (Mammalia, Carnivora) from Taiwan.
Mammal Study 35(3):191-200.
Lin, Y.-S. & Y.-C. Kam. 2008. Nest choice and breeding phenology of an
arboreal-breeding frog, Kurixalus eiffingeri (Rhacophoridae), in a
bamboo forest. Zoological Studies 47:129-137.
Myers, N. 1979. The Sinking Ark: a New Look at the Problem of
Disappearing Species. Pergamon Press, Oxford, UK.
References 172
Pimm, S.L, G.J. Russel, J.L. Gittleman, & T.M. Brooks. 1995. The future
of biodiversity. Science 269:347-350.
Sanderson, J., Khan, J.A., Grassman, L. & Mallon, D.P. 2008. Neofelis
nebulosa. In: IUCN 2012. IUCN Red List of Threatened Species.
Version 2012.1. <www.iucnredlist.org>. Accessed 25 July 2012.
Su, H.J. 1984. Studies on the climate and vegetation types of the natural
forests in Taiwan (II): altitudinal vegetation zones in relation to
temperature gradient. Quarterly Journal of Chinese Forestry 17:5773.
Wang, J.-C. 1996. The systematic study of Taiwanese Arisaema (Araceae).
Botany Bulletin of Academia Sinica 37:61-87.
<http://ejournal.sinica.edu.tw/bbas/content/1996/1/bot371-09.html>.
Accessed 25 July 2012.
Wang, Y.-H., K.-C. Yang, C. L. Bridgman, & L.-K. Lin. 2008. Habitat
suitability modelling to correlate gene flow with landscape
connectivity. Landscape Ecology 23:989-1000.
Winchester, S. 2004. Krakatoa. Perennial Press, New York, NY, USA.
173 Ecosystems in Taiwan