Download Review For Test 2 PART 1 - Biomes

Review For Test 2
PART 1 - Biomes
Chap 6
Biomes
Terrestrial
Desert
Grassland (prairies)
Tropical rainforest
Temperate deciduous forest
Tiaga (coniferous forest)
Tundra
Savannah
Chaparral/ Scrublands
Tropical Dry Forest
Mountain
Polar Ice caps
Factors which determine the type of biome:
Climate major factor
a. Temperature
b. Rainfall
Biome – terrestrial (land) community that covers a
major geographical area
Deserts = yellow
Desert
Types of Terrestrial Biomes
Desert - <10 inches of precipitation/year,
harsh environment, rain =short intense storms, evaporation is
high, short growing season, windy; large temperature
swings
• animals - reptiles, snakes, camels, Numerous species = few in
number and very specialized to conserve water
• plants - cactus, Joshua trees
• SW US, N Africa, Australia
Desert
• Human impact on deserts:
– Modern technology allows for the transport of
water to the desert.
– This has resulted in the development of cities in
some desert areas and some limited agriculture as
a result of irrigation.
Saudi Arabia
Store Water
Water can be stored by animals in fatty
deposits in their tails and other tissues
(e.g., in the gila monster's tail). Water
can be stored in the roots, stems,
and/or leaves of plants (plants that do
this are called succulents).
Dissipate Heat
Get rid of body heat by
evaporation through long
appendages (legs, ears, etc.), or
small "bodies" that radiate heat.
Most desert animals are active at night and gain
moisture through the food they eat
Plants have small leaves or prickly spines like cactus
and can store water in roots or spongy parts of the
plant
Temperate Grasslands
Fig. 6.7
Grasslands
Grasslands, prairies or steppes - temperate
environment; minimal water, windy, hot summer,
mild to cold winter; fire is important in preventing
trees
• soil = ultra-rich farmland, US and Asia
• animals - migratory animals, buffalo, wildebeests,
Lots of insects
• plants - 60-90% grass, Very few trees
Grassland
• Human impact on grassland:
– Most of the wet grasslands of the world have
been converted to agriculture.
– Most of the drier grasslands have been converted
to the raising of grazers like sheep, cattle, and
goats.
–Little undisturbed grassland is left
This
to
This
SAVANNAS
Savanna
Types of Terrestrial Biomes
Savanna -50-150 cm of precipitation/year, uneven
distribution, heavy rain then drought
• animals – migrate across the savannas following
the rain/ water
• plants = grasses with drought resistant trees
• Africa, South America and Australia
Large herds of grazing animals
Large Carnivores such as Lions, Leopards
Large herbivores such as elephants, Zebra
Many insects, reptiles, rodents, birds
Savannas
Have more trees than grasslands
Climate change may allow more
trees to invade these areas
Human Impact
Many African animals hunted to extinction, or close to
it
Areas have been converted to farmland
Areas overgrazed by livestock
Some areas have been designated as a wildlife refuge
Mediterranean Scrubland (Chaparrals)
Mediterranean
Shrublands
(Chaparral)
shrubby woody plants.
Mediterranean Shrublands (Chaparral)
• near oceans = shrubby woody plants.
• Their climate = wet, cool winters and hot, dry
summers.
• 16-40 inches annual precipitation.
• the Mediterranean coast, coastal southern
California, parts of Africa, Chile, and Australia.
• Fire is a common feature.
Many birds, reptiles, insects, mammals, rodents
Mediterranean Shrublands (Chaparral)
• Human impact:
– Very little undisturbed Mediterranean shrubland
still exists.
– Agriculture (often with the aid of irrigation)
– Major cities are located in this biome.
Tropical Dry Forest
Tropical Dry Forest
• Annual precipitation ranges 20-80 inches.
• monsoon climate (several months of rain
followed by a long dry season)
• Plants have developed special adaptations to
survive drought. (some drop leaves during dry
season to conserve water)
Tropical Dry Forest
Animals similar to other tropical forests- just less in
number
Tropical Dry Forest
• Human impact:
– Some forests occur in areas of very high human
population.
– Harvesting of wood for fuel and building materials
– Many of the forests have been converted to
farming or the grazing of animals.
Tropical Rainforest
Tropical Rain Forest
Types of Terrestrial Biomes
Tropical rainforest -80+inches( up to
200) of precipitation/year, rains
every day
• warm, constant temperatures, no
frost, at equator
• numerous diverse animals
• plants,= multi-layered canopy.
Multi layered
Canopy
Tropical Rainforest
• Human impact
– logging and agriculture.
– Clear cutting areas = loss of animal habitat
Brazil
Area cleared for
Agriculture (on Left)
Rain forest (on Right)
scientists have not been able to
research and explore most of the
rainforest plants to find all of the
possible medicines and species of
plants and animals.
Deciduous Forest
Deciduous Forest
Temperate Deciduous Forest four
seasons-Trees lose leaves
• moderate climate with evenly
distributed precipitation
• animals - birds, reptiles, deer
• plants - trees that lose their leaves,
maples, oak
• Europe, eastern US, Canada
Deciduous Forest
• Human impact:
– cleared for farming.
– logging.
– Large cities were built in these forest areas =
original forests are gone
Fig. 6.16c
Coniferous Forest= Tiaga
Types of Terrestrial Biomes
Coniferous Forest, (Taiga or Boreal) snow,= soil freezes in the winter
• Short summers, hard winters,
snow
• animals - migratory birds, deer,
moose, wolves
• plants - evergreen pines, soil is
poor and acidic, used for wood
• northern Canada, Russia
Coniferous Forest (Taigas)
The trees are adapted to winter conditions:
Needle-shaped leaves prevent water loss.
Flexible branches
Human impact:
Human impact = Climate Change
Logging is common.
Herding of reindeer occurs in northern
Scandinavia.
Tundra
Types of Terrestrial Biomes
•
•
•
•
•
Tundra - permanently frozen soil, very harsh environment
poor soils
animals - migratory birds, musk ox, caribou,
plants - no trees, short plants, moss, grass
northern Canada, alpine tundra - tundra found above
timber line
Animals have
adapted to
survive in cold
weather
Tundra
• Human impact:
– Biggest threat= Climate Change
– Local native people often rely on hunting for food.
– Because of the very short growing season,
damage to this kind of ecosystem is slow to heal,
so the land must be handled with great care.
Polar Ice Caps = covered by snow and ice year around
The biggest threat is from global warming and
oil and gas exploration
Global warming is
decreasing year- round
ice and snow
Many animals need the ice to reproduce and hunt for
food
Polar bears hunt their main food source, seals, primarily while on sea ice.
Changes in the ice are driving the bears to spend more time on land, where
they have to go longer without eating and rely on fat reserves .
As the ice melts, walrus’ crowd together on the shoreline,
making the spread of infection easier, and increasing the dangers
of trampling for the young.
Credit: Joel Garlich-Miller/U.S. Fish and Wildlife
Caribou may be affected by changes in their food
sources, as a result of the warming climate, and
increased human activity along shipping routes may
affect their migration
Alpine/ Mountain Biomes
A mountain biome is very cold and windy. The higher the
mountain, the colder and windier the environment. There
is also less oxygen at high elevations.
Alpine/ Mountain Biomes
Many of the animal species are similar to those that would be found in taiga
Alpine animals have to deal with two types of problems: the cold and too
much high UV wavelengths. This is because there is less atmosphere to
filter UV rays from the sun. And they must adapt to the rocky areas
Alpine animals adapt to the cold by
hibernating, migrating to warmer
areas, or insulating their bodies with
layers of fat and fur. Their bodies
tend to have shorter legs, tails, and
ears, in order to reduce heat loss.
Alpine animals also have larger lungs.
Mountain goats have special
pads on their hooves which are
both cushioned (to absorb the
shock of jumping from rock to
rock) and slip resistant
Mountaintop plants must survive very dry
conditions (water runs off mountaintops
quickly, the soil may have little ability to hold
water, and the air may be dry with a constant
wind).
Many high mountains plants are succulents,
with water stored in thick leaves.
Flagging; where tree limbs only grow in the
direction the wind blows (right).
POPULATIONS
A population is a group of individuals
of the same species inhabiting the
same area.
Population Principles
• Current World Population
is 7.5 Billion
• By the year 2025 (or
before) the population will
be 8 Billion
Population Principles
• Birthrate - number
added to a population
through reproduction
(natality)
• Death rate - number
of deaths (mortality)
Birthrate and Death rate depend on:
3. Population Density - number of plants or animals in an
area
changes occur in density because of overcrowding (lions),
war, famine, drought, and politics,
Carrying Capacity: number of individuals of a
species that can be supported in an area over an
extended time
Scientist predict the earth may reach this
somewhere near 2050
Carrying Capacity:
limiting factors - combination of all environmental
influences that tend to keep a population stable:
A. availability of raw materials, water, food
B. availability of energy, sunlight
Carrying Capacity
Limiting Factors
C. accumulation of waste
products and their
disposal, bacteria
D. interaction among
organisms, man or
predator
Human Population Growth:
•
•
•
•
•
1000’s of years to reach 1 Bil
130 years to reach 2 Bil
45 years to reach 4 Bil
51 years to reach 8 Bil
We are increasing in population by 93 Mil/yr,
Annual increase of 1.2, double population in 58 yr.
• World population is growing
• A key to controlling worldwide environmental
problems is to SLOW population growth!
Human Population Issues
• Most increases will be in Africa, Asia, and Latin America they have 82% of the world’s pop. (by 2050 they will have
86% of the world’s population)
Human Population Issues
• The impact of a society on the environment depends on:
a. population size
b. population density - number of people per unit of land
area, available resources for population
c. technological development - higher development uses
more resources, called the ecological footprint
Consequences of Population Growth
• War, Famine, Disease
• Pollution increases – from agriculture and waste
• Destruction of habitats to make way for farms,
mismanaged agriculture and ranching destroys land, called
desertification
• Decreased resources – more competition for resources
Human Population Growth
• A major reason for the increasing
human population growth rate is an
increase in medical care, and a
decrease in death rates.
• people live longer
• mother’s care is better before birth
The ecological footprint is a measure of the
land area required to provide the resources and
absorb the wastes of a population.
The most important factor influencing the
rate of human populations grow is related to
how many women in the population are
having children and the number of children
each woman will have.
When level of education increases, birth rates fall.
Financial independence leads to marriage later in
life. Better-educated women are more likely to
have access to and use birth control.
Early marriages = high birth rate
What Does the Future Hold?
1. Available raw materials
•
•
•
not limited to the amount of food available.
dependence on technology.
Our lifestyles are tied to use of other resources such
as irrigation water, genetic research, and antibiotics.
2. Available energy
•
•
Need of raw materials.
Increases in energy efficiency and the development of
renewable fuels can reduce dependence on fossil
fuels.
What Does the Future Hold?
3. Waste disposal
•
•
Pollution is the waste product of human activity.
Lack of adequate sewage treatment and safe drinking
water causes large numbers of deaths.
4. Interactions with other organisms
•
•
•
We are not the only species of importance.
Converting land to meet our needs displaces other
species from their habitats.
What today seems like an unimportant organism may
one day be seen as an important link to our own
survival.
What Does the Future Hold?
• If the world continues to grow at its current rate,
population will surpass 12 billion by 2060.
– The human population will ultimately reach a
carrying capacity and stabilize.