Download Terrestrial Biomes Review Sheet - Chautauqua Lake Central School

Terrestrial Biomes Review Sheet
Courtesy of: Pamela J. Shlachtman, Miami Palmetto High School
Succession
Over long periods of time, it is possible to see trends in the way the structure of a community
changes. The regular predictable changes in that structure over time is SUCCESSION. Succession
occurs because organisms make changes in their environment that make the area unsuitable for
them and more suitable for other species. A short term succession is pointed out by vinegar eels.
When apples are crushed, the bacteria and yeasts that live on an apple are mixed with the juice of
the apple. Yeasts multiply using the sugar and producing CO2 and alcohol. So much alcohol is
produced, the yeasts die and new bacteria convert it to vinegar. The vinegar concentration gets too
high and the bacteria die and the vinegar eels feed upon the bacteria.
Primary Succession
Primary succession begins on bare rock, usually where lava comes out of the ground. The usual
beginning is lichens. Lichens are part algae and part fungi. The can grow on the surface of the rock
for 100 years or more. Lichens produced an acid that causes the rock surface to break down and is
mixed with the organic matter from dead lichens to produce a very thin soil layer. This allows
mosses and sedges to grow on the rock which out compete the lichens. The loss of the lichen and
the start of the mosses is called a SERE or a successional stage. Grasses will eventually take over,
then more complex plants until a stable, reproducing community occurs called a CLIMAX community.
Aquatic Primary Succession
The same situation occurs in lakes , especially gravel pits and newly formed lakes. Only floating
plants and algae can form in new lakes. Eventually, the dead plants sink to the bottom and make the
lake shallow enough for other plants to start. The network of roots and stems below the surface
results in the accumulation of a lot of decayed matter and the lake gets very shallow. Grasses and
emergent plants become established and the lake eventually becomes a meadow. Grasses are
followed by shrubs and then trees.
Secondary Succession
This occurs when an existing community is destroyed in some way. A forest fire, food or
destruction to make farmland occurs. Secondary succession is much faster than primary. Firebush
or fireweed is usually the first replacement dying and providing nutrients to the other plants.
Immediately after a fire, firebush returns. Palmetto bushes do the same in Florida. Herbs and
weeds are replaced by grasses, thin shrubs, coniferous trees then hardwoods. The climax
community is named for the climax plant involved such as Oak-Hickory Climax Community or Maple
Poplar CC.
Biomes
The climax community is called a BIOME. They can reproduce themselves on a continual basis.
Biomes depend upon rainfall and temperature. The rainfall has more to it than just the amount of
rain. When does it fall? Is there a drought-rainy season cycle? In what form does it fall? Rain,
Snow? Many limiting factors are in various biomes. Fire is an important terrestrial limiting factor.
Fire is needed to get the decayed plants out of the holes in the rocks in the Everglades so water
will be available to animals in the spring drought period. Fire is needed in forests to make nutrients
available again to the trees.
Cold Desert - Temperature and water are the limiting factors. Polar Bears, seals, walruses, arctic
fox, arctic hare, lichens and sedges are the predominant organisms. Species number is very limited.
Hot Desert - A large segment of the world is a hot desert. Deserts are divided into 2 types,,,
tropical and temperate. Tropical deserts are very dry and usually vast. The Sahara and Nahim of
Africa are examples. Temperate deserts are not as dry. The Mohave of California and the Gobi of
China are good examples. It is very hot in the day and cold at night. Water is the major limiting
factor receiving less than 10 inches per year. SW USA, Gobi, Australian Outback, Sahara, Namib,
Atacama in Chile, Arabian are the major deserts. Soils erode very fast, rainfall accumulates on the
hard soil and runs off in flash floods. Water cut canyons ( Arroyos) are common in deserts. Salt
lakes are common. Some deserts have only Oasis type growth and some have a lot of plants. Deserts
are likely to be very windy. Most deserts are created by a rain shadow effect. When the water
laden air goes over a plateau or mountain, it rains. As the air goes further and down the mountain, it
is dry and doesn't have a capability of raining. Some deserts are created by the tropical rainforest
shadow as follows Many organisms have special adaptations to desert living. Thorns instead of
leaves, recessed stomate openings, seeds that generate only with water and of course, being
nocturnal. Plants such as the Mesquite have a long tap root. Others have huge root systems that
spread out along large surface areas. Most mammals are very small which reduces heat gain and
loss. Many rodents live on seeds and blue-green algae crusts. Sage, cacti, creosote bushes, Acacia,
Saguaro, palo verde, sagebrush, tamarisk and yucca are the major producers. Snakes, lizards, birds,
foxes, coyotes do quite well in a desert environment. Take care that you do not think a desert is a
vast amount of sand as it isn't. Most deserts have plants and animals and are much more populated
than you might think.
Tundra - Most people have never seen a tundra. Temperature is its major limiting factor. Tundras
are VERY cold. Northern Canada, Siberia, Alaska and the tops of tall mountains are tundras. There
are some remote tundras in Greenland and Iceland but nobody lives there. The ground is
permanently frozen except for 60 days. The condition of the soil is called PERMAFROST. The
ground is soaked with water and forms bogs. Water will not sink through the permafrost and water
stands all over the tundra. These water areas are called muskegs. Spruce trees occur in the
southern tundra but never attain their 80 ft height because of the frozen ground. They are usually
3-8 feet high even though they might be 50 years old. Sedge, sorrell, grasses and krumholtz (
gnarled dwarf trees), lichens, cranberries, blueberry and cotton grass are the major producers.
Many classify the tundra as a arctic grassland. Consumers include the caribou, wolves, bear, musk
ox, arctic hare, arctic ground squirrel, lemmings and many birds. Ravens, sparrows, pipits, owls and
jaegers are the most common birds. Mid July is the insect HORDE of blackfies, mosquitoes and
deerflies which coincides with the large bird population at that time. Tundras get about 20 inches
of rain per year
TAIGA ( Also called Boreal Forest and Coniferous Forest )
- The coniferous forest gets over 20
inches but not over 30 inches of rain per year. They are usually associated with COLD. N. Europe,
Canada, Russia, Japan are Taigas. Pine, hemlock, spruce and fir are the most important producers.
They all have cones which is important because many birds feed on the seeds in those cone. High
numbers of insects and birds are in taigas. Warblers , finches and thrushes are the most common.
Hares, rabbits, deer and squirrel are common. Black Bears, foxes and the lynx are common
consumers. The floor of the forest is usually damp or even wet but the temperature is so cold that
not much decomposition occurs so nutrients cycle slowly. Temperature is the major limiting factor.
The biggest problem with the Taiga is its value to man. Taigas are logged to oblivion. Logging is not
the only problem. Logging produces chips which start fires and roads are cut into the forest that
produce a lot more erosion than you would think possible. The small amount of topsoil is eroded off
though the clear cuts and roads. Clear cutting is a practice that goes through an area and
everything is cut. The area is cleared or burned and new trees are planted. The problem is that the
area animals must go into other areas of the forest. Because of the territoriality of most forest
animals, most of them die. Soil erosion is very high. It is highly ugly. The trees regrow but the
forest doesn't,. The shrubs are not replaced nor any of the other trees. The understory will not
regrow. To try to alleviate this, loggers are not spot clear cutting or strip clear cutting to allow the
forest to over grow. It still eliminates many niches of the forest and is ecologically a nightmare.
Other methods are not as efficient. Selective cutting is another way to cut forests where a Light
rain per year but can be as much as 40. There are 4 stratas to the forest. The upper canopy is
made of the larger trees, usually oak , hickory, maple and poplar. The lower canopy is made of
smaller trees. The Shrub Layer is made of shrubs. The ground layer is full of leaves and herbaceous
plants. Leaves are shed each year from the deciduous plants and the trees lie dormant and bare.
This is the major limiting factor - cover. During the winter months, there is no cover for the
animals except the leaves on the bottom and blending in as a tree stick or branch. Birds, such as
warblers and thrushes are common, mice, shrews, squirrels, foxes, lynx , skunks and raccoons are
common consumers. Most of Europe, much of Russia, Eastern USA ,eastern Australia and China are
Temperate Forests.
Grasslands - 20 inches of rain per year. Soils and rainfall do not support trees. Trees are only
found in depressions and near rivers and streams. Fire is the major limiting factor. Most grasslands
have been converted to farms of corn, soybeans and wheat. The Steppes of Russia, Great Plains of
USA and Canada, South American Pampas, South African Veldt and Hungary's Pusztas are the
major grasslands. Tall prairie grasses are near the forests to 12 feet tall. Short prairie grasses ar
2-4 feet tall and are near the desert. Blue grama and buffalo grasses are common producers. Bunch
grasses are found in USA. Ants, beetles, spiders, butterflies, rodents, rabbits, prairie dogs, bears,
sparrows and coyotes are common. Bison and antelope have been replaced by cattle and sheep.
Erosion is high, especially in the winter when crops are gone. Very little grassland is left as most of
it has been converted to farms. Tropical grasslands are called Savannahs and they have very erratic
rainfall.
Chaparral - The Chaparral is a very strange biome. Almost nobody really wants to live there but a
lot of people do. 20 - 40 inches of rain per year. Life is spotty, some areas are lush and full of life
and others are totally barren. There are two types of Chaparral , High and Low. High Chaparrals are
usually rocky plateaus. Baja, Arizona, New Mexico and Spain are high chaparrals. Low Chaparrals are
parts of Australia, Greece, Egypt, Israel and Italy. Eucalyptus, oak, sage, sagebrush, citrus and
blackberry are common producers. Hot dry summers are common. Mice, birds small mammals, deer ,
rabbits ,quail, koala, kangaroo, fox, coyote and dingo are consumers. It is an odd area that supports
life fairly well when water is available but water is not available to each part at the same time in
the same amounts.
Savanna - 40 inches per year but there is a definite rainy season and a definite drought. Grasses
and tree hammocks which are higher places in the landscape. Moats form around the hammocks
from runoff during the rainy season and the hammocks are basically fireproof. They have an ability
to last a long time. Central Africa is the most famous savanna, the Svelte and the Serengeti Plains
of Africa, the Evehe soil which provide water in the drought season. Without fire, savannahs will
not survive.
Tropical Rainforest - There are mature tropical rainforests, deciduous tropical rainforests and
tropical shrub rainforests. Mature forests have the giants, deciduous have smaller trees as the
rainfall is not as heavy and shrubs have a problem because of rock cover , pH problems and other
such items. An example is the dwarf cypress trees of the Everglades. Their growth is stunted. A
normal 50 year old cypress is over 50 feet tall and 3 ft thick. Everglades cypress trees in some
areas that are 50 years old are 10 ft tall and 3 - 5 inches thick. Used to cover 20 % of the earth
but now covers less than 7%. We cut an area similar to both North and South Carolina each year.
There are 5 layers of plants in the forest. The Giant, Canopy, 2nd Canopy, Shrub Layer and Ground.
Epiphytes are common, vines, mahogany , ficus are also. Plants must be able to tolerate a lot of
water. Insects, monkeys, bees, beetles, termites amphibians, snakes, jaguars, gorilla and leopards
are the consumers. There are different major niches in the rainforest, thus a high number of
species. Birds bats and insects take the high canopy while monkeys, sloths, snakes and reptiles feed
up and down the vine structure. Insects, large predators and apes feed on the floor. It is a mistake
to think that the rainforest is a dense jungle. Many times it is but more often than not,the floor is
relatively empty . Nutrients are quickly grabbed by the larger plants. We are losing too many
rainforests. People are hungry and the rainforest provides money and food for people as farms and
pasture. Tropical rainforests soils are very poor as most of the nutrients are picked up immediately
by the plants. They are very thin and will produce foods and crops for about 2 years and then
require a lot of expensive fertilizer. When the crops do not do well, they just cut a new area.
Recovery time is about 20 years. The soils of the Tropical Rainforest are called Lateritic soils. Our
global weather patterns are dependent upon Tropical Rainforests rain and low pressure areas. South
and Central American countries are doing something about the loss of the forests and preserving
more and more as they can afford it but Africa and SE Asia are not. They are just too poor and
there are too many hungry people. Greed, hunger and the need for fuel are destroying the forests
of the world.
Ecotone
An ecotone is an area between two biomes that have the characteristics of both systems. The area
between the forest and a grassland has a few trees and grasses. It is a great place for an animal to
feed in one area and hide in the other. Deer, for example, are perfect ecotone animals. They feed in
the meadows and hide in the forests. Some organisms live ONLY in the ecotone.. Many Estuarine
organisms are ecotone animals, not surviving in salt water and not in fresh water either. Many birds
are found only the ecotones.
Ecotype
Ecotypes are organisms that share the same niche but in a different biome. An antelope in the
savanna is an ecotype of a musk ox of a tundra. A wolf of the taiga is an ecotype of the coyote in a
desert.