BIOLOGY 103
FALL, 2002
LAB 12

Organism Diversity and Assemblies


Name:  kathryn bailey, sarah frayne
Username:  kbailey@bmc, sfrayne@bmc
Subject:  
Date:  2002-12-03 14:23:18
Message Id:  3938
Comments:
http://www.cotf.edu/ete/modules/msese/earthsysflr/biomes.html

http://www.radford.edu/~swoodwar/CLASSES/GEOG235/biomes/intro.html

http://earthobservatory.nasa.gov/Laboratory/Biome/

http://curriculum.calstatela.edu/courses/builders/lessons/less/biomes/introbiomes.html

Biomes vary with location because of a multitude of environmental differences, such as temperature and precipitation. These factors are directly related to longitude and latitudes, as well as topography.

Different communities are describes most generally in seven different biomes.
1. coniferous forest: temperature = -40-20 C / precipitation= 300-900 mm/year
2. temperatue decidous forest: temp= -30 - 30 C / precip = 750-1500 mm/year
3. Desert: temp= -3.9 -38 c / precip= 250 mm/year
4. grassland: -20 -30C / precip 500-900 mm/year
5. rain forest: 20 -25 C / precip= 2,000-10,000 mm/year
6. shrubland: 20- 10 C / precip= 200-1,000 mm/year
7. tundra: -40-18C / precip= 150-250 mm/ year

Biomes are subject to change due to deforestation, global warming, and climate change. A typical progression is from forest to grassland to desert.


Name:  
Username:  Anonymous
Subject:  Aquatic Biomes
Date:  2002-12-03 14:37:04
Message Id:  3939
Comments:
Brenda Zera and Elizabeth Damore

We chose to compare the different aquatic biomes on Earth. There are two main categories: marine and freshwater.

Marine: Covers 75% of the Earth. Is comprised of oceans, coral reefs and estuaries. Within the ocean there are different zones (each zone supports a different series of flora and fauna).
The tidal zone has a lower diversity because the wave action disrupts the area from becoming a stable habitat. Shorebirds will come to feed on what is washed up. The shorebirds will vary on what part of the world you are in: in Alaska, you might find bird like puffins which are adapted to the cold water, while in Florida a heron or egret will be easier to find.
The pelagic zone (farther out into the ocean) is home to whales, dolphins and other large marine species (as well as lots of plankton!)
The benthic zone hosts primarily bacteria and fungi.
The deep sea, or abyssal zone, is very cold yet supports a great biodiversity near mid-oceanic ridges (thermal rifts which heat the nearby water, as well as provide nutrients).
Closer to the surface, coral reefs surround islands in the tropics. They are home to many different plants and animals. A single reef can support a diverse population.
The final marine category is estuaries, which is where rivers meet the ocean. The mixture of fresh and salt water creates an enviornment for unique species of trees, birds and other wildlife.

Freshwater: Must have less than 1% salt content, and is divided into ponds and lake, streams and rivers, and wetlands (this last category is controversial).
Ponds and lakes have a lower biodiversity because they are isolated environments. Within a single pond or lake there will be many species of fish, birds and amphibians. Species will vary from one lake/pond to another. Fish species vary because they cannot transplant themselves between isolated bodies of water (they [or their eggs] must be carried by birds). The birds will vary from lake to lake because of their mating habits and climatic differences. You're not gonna find a flamingo in Minnesota.
The next sub-division is streams and rivers. These offer more diversity, but it depends on the type of stream (meandering, braided, etc.) and how turbid the water is. If the water is full of sediment, it will block sunlight (therefore block plant growth), but will offer habitats for fish like catfish. The diversity of a stream/river will increase towards the center of the channel. Along the edge, other wildlife will venture into the water to drink or eat.
The third category is wetlands. Wetlands are home to acquatic plants known as hydrophytes. Wetlands are placed in neither the freshwater nor the marine category, since both saltwater and freshwater wetlands exist. This difference alone will vary the biodiversity between each wetland.

a few links:
http://www.ucmp.berkeley.edu/glossary/gloss5/biome/aquatic.html

http://www.worldbiomes.com/biomes_aquatic.htm


Name:  Amanda Maclay and Diana Fernan
Username:  Anonymous
Subject:  Communities
Date:  2002-12-03 14:48:52
Message Id:  3940
Comments:
Amanda and I were interested in studying the desert community system. The harsh conditions of the desert produce a surprising amount of diversity as species have adapted over time. deserts come in different variations, as we found on http://www.ucmp.berkeley.edu/glossary/gloss5/biome/deserts.html, an excellent source on biomes. These variations are hot and dry, semiarid, coastal, and cold. Mande and i chose to compare hot and dry deserts to cold deserts to note the different types of biological systems that occur and contribute to desert landscapes. Interestingly enough we found that there were many similarities among the two types of desert although they have different climates.

Hot and Dry:
"Canopy in most deserts is very rare. Plants are mainly ground-hugging shrubs and short woody trees. Leaves are "replete" (fully supported with nutrients) with water-conserving characteristics. They tend to be small, thick and covered with a thick cuticle (outer layer). In the cacti, the leaves are much-reduced (to spines) and photosynthetic activity is restricted to the stems. Some plants open their stomata (microscopic openings in the epidermis of leaves that allow for gas exchange) only at night when evaporation rates are lowest. These plants include: yuccas, ocotillo, turpentine bush, prickly pears, false mesquite, sotol, ephedras, agaves and brittlebush.

The animals include small nocturnal (active at night) carnivores. The dominant animals are burrowers and kangaroo rats. There are also insects, arachnids, reptiles and birds. The animals stay inactive in protected hideaways during the hot day and come out to forage at dusk, dawn or at night, when the desert is cooler."

Cold Desert:The winters receive quite a bit of snow. The mean annual precipitation ranges from 15-26 cm. Annual precipitation has reached a maximum of 46 cm and a minimum of 9 cm. The heaviest rainfall of the spring is usually in April or May. In some areas, rainfall can be heavy in autumn. The soil is heavy, silty, and salty. It contains alluvial fans where soil is relatively porous and drainage is good so that most of the salt has been leached out.

The plants are widely scattered. In areas of shad-scale, about 10 percent of the ground is covered, but in some areas of sagebush it approaches 85 percent. Plant heights vary between 15 cm and 122 cm. The main plants are deciduous, most having spiny leaves. Widely distributed animals are jack rabbits, kangaroo rats, kangaroo mice, pocket mice, grasshopper mice, and antelope ground squirrels. In areas like Utah, population density of these animals can range from 14-41 individuals per hectare. All except the jack rabbits are burrowers. The burrowing habit also applies to carnivores like the badger, kit fox, and coyote. Several lizards do some burrowing and moving of soil. Deer are found only in the winter.

Comparision:
We found that there were many similar animals in both hot and cold deserts which led us to conclude that the harsh conditions and ground brush found in both deserts may make the similarties; such as the kangaroo rats and burrowing predaters. Differances amongst the two desert creatures may be attributed to the homogenous climate of the hot and dry desert to the variations in hot and dry to the cold and moist. This is demonstrated by teh deer that exist in the cold desert during the winter times. We found that these deer most likely leap down the surrounding mountains - as cold deserts are nestled betwixt mountain ranges- when the climates of the mountain become too cold on the tipey tops. Thus, the location of the desert affects whether or not the desert is cold or hot, and also affects teh surounding locations such as teh mountains aroudn the cold desert.


Name:  KKS
Username:  Anonymous
Subject:  The "bo...real" forest
Date:  2002-12-03 14:52:19
Message Id:  3941
Comments:
Kate Amlin
Katie Campbell
Stephanie Lane

Web Sources

http://www.ucmp.berkeley.edu/glossary/gloss5/ biome/forests.html#boreal

http://www.borealnet.org/overview/whatistheboreal.html

http://www.borealnet.org/overview/whataretheproblems.html

http://www.borealnet.org/overview/whycare.html

In the boreal forest temperatures are generally very low and little precipitation in the form of snow. The plant population is composed of "cold-tolerant evergreen conifers with needle-like leaves like pines, firs, and spruces. The lack of floor vegetation, apart from fungi, is because the canpoy of these trees allows low light penetration so it's difficult for floor or "understory" plants to grow.
The boreal spatial arangement is effected by humans logging the trees for paper and drilling for oil.
Before people tree arangement looks like:
aghe;wagn;asn
a;genaoighwaoi
nage;owingaeio
angeo;inae
After people:
B B B B
B B B B
B B B B
In this "emerald halo" there are five thousand species of fungi. This is possible because they are able to grow without so much sunlight. The presence of fungi relates to the fauna population that in addition to woodpeckers, hawks, moose, bear, weasel, lynx, fox, wolf, deer, hairs, munks, and bats, includes squirrels that eat the fungi and spread the spores.
Obviously there is reason behind the spatial array of the boreal forest.


Name:  marybeth yarimee virginia
Username:  vculler@brynmawr.edu
Subject:  BIOMES
Date:  2002-12-03 14:57:43
Message Id:  3943
Comments:
Yarimee Gutierrez
Virginia Culler
MaryBeth Curtiss

in our search, we found that "biomes" are basically the different types of ecosystems found on the earth. the most inclusive list we found is as follows:

rainforest, tundra, taiga, desert, temperate, grasslands, rivers & streams, ponds & lakes, wetlands, shorelines, temperate oceans, and tropical oceans.

examples for each and explanations:

rainforest - there are actually 2 types of rainforest, temperate and tropical. we will focus on tropical as it is the more well known of the two. some characteristics is that they are warm and moist and very green with a large array of diverse plant and animal life. in fact, half of the earth's plant and animal species are found in the tropical rainforests of the world.

tundra - characterized by being fairly stark and barren, year-round. short cool summers, long cold winters. plants grow low to the ground. animals breed fast and are well adapted for the extremely cold conditions, and many animals even hibernate during hte winter months

taiga -this biome stretches across a large portion of the world. in fact, it is the largest biome in the world. winters are cold. summers are warm. lots of conifers grow here. snow, cold, and a scarcity of food make life very difficult, especially in the winter. some taiga animals migrate south, others go into hibernation, while others just cope. the taiga is characterized by having larger numbers of hte same plant and animal species - i.e. much less diveristy than a tropical rainforest

desert - There are 2 main types of desert, hot and cold. both get very small amounts of precipitation. Only difference is that cold deserts main form of precipitation is snow, and for warm deserts it's rain. deserts have more plants and animals than people think. in fact, deserts are second only to tropical rainforests in the variety of plant and animal species that live ther

temperate - temperate climates are those in which there are defined seasons with significant rainfall, just slightly less than that of a rainforest. These areas are also characterized by the presence of deciduous forests and significant coverage by wooded areas. Bryn Mawr, and much of the United States are located in temperate biomes.

grasslands - Grasslands are typified by low, ground-covering plant life, such as grasses and shrubs. Grasslands are generally located in plains, valleys, and other flat landscapes. The Midwestern United States praries are a kind of this grassland environment.

rivers & streams - Rivers and streams are one of the primary habitats for aquatic life on earth. Rivers and streams are the homes and breeding grounds for many species of fish, plantlife, amphibians, and others. These waterways are also vital to the suvival of many land species for drinking and bathing.

ponds & lakes - Ponds and lakes are also the homes of countless fish and animals, but are also hugely important for aquatic plantlife. The stillness of the pond and lake setting is ideal for kinds of algae and others to form on the surface of the water. Again, these bodies of water are important for the survival of surrounding land species, as well.

wetlands - Wetlands are marshy landscapes that can range from swamps to bogs. Wetlands are key in the sustenance and reproduction of many bird species, as well as some tall grasses and plants. Wetlands also play a key role in the maintenance of the ecosystem in that they often act as a kind of filtration system for the waters before they move on to rivers, streams, ponds, lakes, and oceans.

shorelines - Shorelines are another aquatic habitat for many shellfish, insects, and grasses, among others. The Shoreline is an environment that is always changing, and quickly. Therefore, all species who live in this habitat are mobile, or firmly attached to the earth or rocks, such as deeply rooted grasses, and barnacles.

temperate oceans - Temperate oceans share seasons like those familiar to us. These marine habitats are home to both the largest and smallest species known to man.

tropical oceans - Tropical oceans are most frequently characterized as the homes of coral reefs. These bodies are located in the south Pacific and Indian Ocean.
http://mbgnet.mobot.org/

Each of these ecosystems has a very distinct array of lifeforms because the climates have affected the evolution of these species. They've adapted to contend with the different challenges posed by each of these habitats.


Name:  Maggie and Kyla
Username:  kellis@brynmawr.edu
Subject:  
Date:  2002-12-03 15:02:18
Message Id:  3944
Comments:
Margaret Hoyt, Kyla Ellis.


We were interested in comparing the different types of forest biomes. 3 different forests exist, Tropical, Temperate (Decidious), and Boreal (Tiaga). We concentrated on Temperate and Boreal forests with the hope of understanding more about biomes and biological communities.

According to http://www.ucmp.berkeley.edu/glossary/gloss5/biome/,
"the world's major communities, classified according to the predominant vegetation and characterized by adaptations of organisms to that particular environment"

In other words, different animals (and plants and insects) live in different environments. The type of climate and vegetation highly influence the type of organisms inhabiting a biome.

http://www.cotf.edu/ete/modules/msese/earthsysflr/biomes.html suggests that different animals live in different areas because of the weather conditions. Animals must adapt to live in their environment - after living in one particular climate for so many years, their systems become accustomed to the fluctuations of one particular biome.

In fact, all of the changes that differentiate one type of biome from another are directly responsible for the varying organisms living within. For example, Boreal forests do not let a lot of sunlight reach the understory layers of the forest; therefore, only plants thta do not require large amounts of sunlight can live there. It is a codependent environement: the plants live in a particular biome because of the climate, and the animals live in a biome because of the plants. Therefore, the climate is responsible for all living organisms within a biome.

Below are the key differences between a Temperate forest and a Boreal or Tiaga forest.

Temperate:
*well defined seasons with distinct winter
*soil is very fertile
*canopy is moderately dense and allows some light to penetrate through to the forest floor
*flora: about 3-4 species for every square kilometer.
According to http://www.enchantedlearning.com/biomes/:
*Fall Colors: In the Fall, the number of hours of daylight decreases. This causes some plants and trees (called deciduous) to stop producing chlorophyll (a green pigment that converts sunlight into chemical energy) and eventually lose their leaves. During this time, these leaves turn brilliant colors, ranging from red to orange to yellow to brown.
*Soil: The soil in the deciduous forests is quite fertile, since it is often enriched with falling leaves, twigs, logs, and dead organisms.
Layers of the Temperate Deciduous Forest: There are five layers (also called zones or strata) in the temperate deciduous forest. These include the:
* Tree stratum, the tallest layer, 60 -100 feet high, with large oak, maple, beech, chestnut, hickory, elm, basswood, linden, walnut, or sweet gum trees.
* Small tree or sapling layer - short tree species and young trees.
* Shrub layer - shrubs like rhododendrons, azaleas, mountain laurels, and huckleberries.
* Herb layer - short plants.
* Ground layer - lichens, clubmosses, and true mosses.


Boreal or Tiaga
*short, moist, warm summers, and long, cold, dry winters.
*soil is thin and acidic, is rocky and has deep gorges often frozen over with water.
*canopy is thick and allows almost no light to reach understory
*flora is comprised of only cold-tolerant evergreens
*taiga, also called a boreal forest or northern coniferous forest, is a cold woodland or forest. This biome span the northern parts of North America, Europe, and Asia. Taigas are generally located south of tundras and north of temperate deciduous forests and temperate grasslands. The taiga is the largest land biome on Earth, covering about 50 million acres of land (20 million hectares); this is about 17% of the Earth's land area. Taiga is a Russian word for marshy pine forest.
*The taiga is characterized by a cold, harsh climate, a low rate of precipitation (snow and rain), and short growing season. There are two types of taigas: open woodlands with widely spaced trees, and dense forests whose floor is generally in shade.
*Taigas are relatively low in animal diversity because of the harsh winters. Some taiga animals are able to cope with the cold winter environment, but many migrate south to warmer climates during the winter and others go into hibernation.

Because of the temperate climate, fertile soil, moderate canopy, and sunlight, a plethora of animals and other organisms inhabit a Temperate forest. Whereas the Boreal forest has little sunlight and extremely cold temperatures, the organisms and animals living there are less in number.

Studying forests is very important for the advancement of mankind. Potential medicines and undiscovered plant speicies could exist. The trees seem to exist as a buggering agent for the ozone layer and the effect of global warming. And because all of the organisms within the forests have evolved together, the resulting biome is interdependent.


Name:  
Username:  Anonymous
Subject:  
Date:  2002-12-03 15:07:48
Message Id:  3945
Comments:
Websites:
1.www.bio.bris.ac.uk/research/community/

2.www.ucmp.berkeley.edu/glossary/gloss5/biome/

3.www.emc.maricopa.edu/faculty/farabee/BIOBK/Biobookcommecosys.html

4.www.pbs.org/wgbh/evolution/library/04/1/1_041_01.html

5.www.scu.k12.ca.us/pomeroy/1st/Animals.html

Groups of organisms live together because they are adapted to live with each other. An example of this is the food web, where organisms are interedependent and are adapted to eat what is available to them. It is also important that the food web is not disrupted by one organism not being too overly preyed upon. Groups of organisms occur in different locations because of the limitations of their geography and because of their specific adaptations. Certain organisms depend on others with which they live to create the environment in which they need to survive.

Christine Traversi
M.R.
Sarah Tan


Name:  Joanna Robertson
Username:  jjrobert@brynmawr.edu
Subject:  dessert biomes
Date:  2002-12-03 15:17:47
Message Id:  3947
Comments:
Joanna Robertson
jen Rusk

Desert Biomes
Desert Biomes are the final stage of a biome. Due to global warming and climate change. The Biome cycle starts with aquatic to forest, grassland, and finally deserts. Desert biomes differ according to location. There are four different types of deserts that vary in temperature and location.

Hot and Dry
temps on average range from 20-24c. They are located inthe lower latitudes of North America.

Semiarid
Temps on average range from 20-24c. They are located in the basins of America, for example in Utah. The Semiarid deserts are similiar to hot and dry deserts.

Coastal
Temps on average range from 13-20c They are located on the coast of chile.

Cold
Temps range from -2-4c. They are located in colder climates, such as Greenland. Cold deserts has precipatation due to snowfalls. As a result there are plant life and animal life as such as deers and rabbits. Opposed to the other 3 which contains lizards.

In general the mortality rate in desert Biomes are higher than Rain forest. In hot and dry deserts plants absorb and store water becuase there is a lack of rainfall.
http://www.ucmp.berkeley.edu/glossary/gloss5/biome/deserts.html

http://www.cotf.edu/ete/modules/msese/earthsysflr/biomes.htmlhttp://www.cotf.edu/ete/modules/msese/earthsysflr/biomes.html


Name:  
Username:  Anonymous
Subject:  tropical rainforests
Date:  2002-12-04 14:16:40
Message Id:  3955
Comments:
Roma Hassan and Melissa Brown

We decided to investigate the climate and environment of rainforests.
Tropical rainforests are complex ecosystems, which are made up of four distinct environments. These "sub-ecosystems" are referred to as levels. In each level, animals and plants have adapted to the existing environmental conditions. The different levels are: the emergent level, the canopy, the understory, and forest floor.
Tropical rainforests are spread over the Americas, Africa , Asia and the Caribbean with the largest portion found in Puerto Rico and Trinidad.
Lush vegetation, rainfall througout the year and a high temperature make the rainforest one of the world's most diverse ecosystems.
Rainforests are a product of planetary processes and are - in turn - contributors to the water and carbon cycles on which all life depends. Rainforests control climate by influencing wind, rainfall, humidity and temperature. They recycle water, oxygen and carbon which reduces soil erosion, flooding and air pollution.
More than 65 million years old, rainforests are the oldest major vegetation types on Earth. Fossil records show that the forests of Southeast Asia have existed in more or less their present form for 70 to 100 million years.
Certain environmental conditions must be present in order for the delicate balance of rainforest to be held intact. There must be substantial rainfall (at least 80 inches) of rain each year, but many rainforests receive in excess of 200-300 inches annually.
Because rainforests are in tropical areas, they have a very hot, wet climate. Temperatures can be above 24 degrees centigrade all year round and rainfall levels can be up to 2,400mm a year.
The soil in the rainforest is 4 inches deep with a layer of clay beneath, hence trees have shallow roots.
A variety of living organisms at all different sub-ecosystems exist in the rainforests. Tropical rainforests contain more than half of the Earth's plant and animal species, yet cover only about 7% of the earth's land surface. A typical forest in the United States contains from 5 to 12 different kinds of trees, while a typical rainforest may have over 300 different kinds. If the rainforests are destroyed, most of these plant and animal species will be lost forever. The different species of plants and animals along with microscopic living organisms co-exist in their own way in the rainforests. In just four square miles of some Rainforests you might find over 750 species of trees, 1500 types of flowering plants, 125 different kinds of mammals, 400 different birds, 100 reptiles, 65 amphibians, and a staggering number of insects. One quarter of today's pharmaceuticals come from Tropical Rainforest plants.
The Amazon Rainforest is the richest biological incubator on the planet. It supports millions of plant, animal and insect species - a virtual library of chemical invention. In these archives, drugs like quinine, muscle relaxants, steroids and cancer drugs are found. More importantly, are the new drugs still awaiting discovery - drugs for AIDS, cancer, diabetes, arthritis and Alzheimer's. Thus it is very clear that the rainforests are a major part of life on earth and all living organisms are dependent on this biome in some way or another.
Loss of these incredibly diverse forests would be a serious loss for people everywhere. The loss of thousands of acres of tropical rainforests is already causing serious local problems, including increased soil erosion and water pollution. As more deforestation occurs, the problems will increase.
People don't have the right to destroy the world's rainforests and other habitats for their own purposes.
IDEA: Further investigation can be carried out on the differences between tropical and temperate rainforests.

WEB REFERENCES:
http://www.animalsoftherainforest.org/map.htm
http://www.orecity.k12.or.us/ogden/BBBeck/TropicalRainforest.html
http://www.stemnet.nf.ca/CITE/rainforest_what.htm


Name:  Rosie, Anastasia
Username:  Anonymous
Subject:  
Date:  2002-12-04 14:19:20
Message Id:  3956
Comments:
We observed organisms that live in both the desert and the arctic. Organisms are grouped together because of adaptations that they have made to specific climates. The climactic characteristics for the desert are harsh environments, very dry, and very little rainfall. There is limited plant and animal life as well. Animals in the desert have adapted to cope with lack of water, extreme temperatures and lack of food. They emerge at night to collect food in order to avoid high heat.

The climactic charactetic he arctic are cold, windy temperatures, and often snowy biomes. Dry air, wind, and snow are part of the climate. 90% of the land area is covered with hardy, cold-and-dry vegetation. Animals that live in the Arctic are adapted to extreme conditions. Those with coats, have coats that thicken and change color to white in order to be camoflouged with the snow. Many animals also hibernate.

ArcticAnimals


Name:  Brie Michelle Will Diana
Username:  Anonymous
Subject:  desert life
Date:  2002-12-04 14:31:37
Message Id:  3957
Comments:
DESERT LIFE

There are four different types of deserts. They vary in
temperature and location.

Hot and Dry
20-24c. Lower latitudes of North America.

Semiarid
20-24c. Basins of America (Utah). Similiar to hot and dry deserts.

Coastal
13-20c. Coast of chile.

Cold
-2-4c. Colder climates (Greenland). Cold deserts have precipitation due to snowfalls. Plant life and animal life exists.

Plants and Animals have adapted to these extreme desert climates. The lack of water creates a survival problem for all desert organisms, so they have evolved behavioral and physiological mechanisms to avoid excess heat, dissipate heat, retain water, and acquire water.

To avoid heat , many animals (especially mammals and reptiles) are active only at dusk and again at dawn. Likewise, many animals are completely nocturnal, restricting all their activities to the cooler temperatures of the night. Bats, many snakes, most rodents and some larger mammals like foxes and skunks, are nocturnal, sleeping in a cool den, cave or burrow by day.

To dissipate heat , many desert animals are paler than their relatives elsewhere in more moderate environments. Pale colors may be seen in feathers, fur, scales or skin. Pale colors not only ensure that the animal takes in less heat from the environment, but help to make it less conspicuous to predators in the bright, pallid surroundings.

Some animals retain water by burrowing into moist soil during the dry daylight hours (all desert toads). Some predatory and scavenging animals can obtain their entire moisture needs from the food they eat (e.g., Turkey Vulture) but still may drink when water is available.

Acquiring water in the desert is a challenge. Kangaroo Rats, for example, live in underground dens which they seal off to block out midday heat and to recycle the moisture from their own breathing. They also have specialized kidneys with extra microscopic tubules to extract most of the water from their urine and return it to the blood stream. Much of the moisture that would be exhaled in breathing is recaptured in the nasal cavities by specialized organs.

Thousands of animal species exist in the desert. Obviously, the extreme conditions have created a need to evolve and adapt their needs to the environment. Desert animals are characteristic to this environment because if these animals were relocated, they would have no need for these specializations. Their adaptations would be detrimental in a different environment. If a desert animal was relocated to a tropical environment, retaining water might result in drowning. Pale coloring that helps to dissipate heat in the desert would make the animal a target in a darker, greener biome.

Plant Life in Deserts
Most desert plants are succulents, meaning they store water to survive the dry, hot, desert climates. One of the most well known species of desert plants is the cactus. The Saguaro Cactus has grows in a dry hot desert climate. It's waxy skin helps it keep water in. When it rains, the Saguaro Cactus soaks up water and holds it in its ribs. The ribs on the plant expand to absorb a lot of water. The plant itself does not need a lot of water to survive. It depends on heavy winter precipatation. During dry periods, the Saguaro Cactus uses water it has stored. The Saguaro has a very special root system. It has two sets of radial roots, a thick set about one foot long, and a thinner set which is often as the same length as the height of the cactus itself. The Saguaro, like many other species of Cactus, has 3-4 inch spines to protect it from predators. In addition to protection from predators, these spines help cool the outer skin of the plant, as well as redirect the wind and insulate the outer skin of the cactus. The Saguaro typically flowers at night when it is cool. Animal and insect species that live in the same environment are: long-nosed bats, bees, wasps, ants, butterflies, and some small rodents, like pocket mice.

For More information:

Mojave Desert
Desert Plants
Desert Animal Survival
Desert Biomes

Organisms live in characteristic environments. Desert Life is related by certain adaptations to their environment. Therefore, if life from other climates and conditions were relocated to the desert, they would not survive.


Name:  
Username:  lsilvius@brynmawr.edu
Subject:  Tundras
Date:  2002-12-04 14:40:19
Message Id:  3959
Comments:
Laura Silvius
Tegan Georges
Chelsea W. Rosenthal

In investigating websites on the ecosystem known as the tundra, we found observations which show organisms which are interdependent and existing in specific, cooperative communities. This system of organisms, like other systems which we have studied, exhibits a quality of being substantially influenced by the physical conditions in which it exists. The thick protective fur pocessed by the musk ox of the tundra is one instance of the relationship between organisms and the physical conditions under which they live and have evolved. It's fur is composed of two layers: an outer protective layer and an under layer which is nearly waterproof (The Tundra Biome). Examples of the interdependence of organisms includes the presence of lichen in the tundra, which then provides sustinence for caribou and musk ox (Tundra Plants).
The teperature in the tundra tends to range from -40 to 18 degrees celcius (Earth Observatory Tundra). The ground is permanently frozen -- permafrost (The Tundra Biome), and thus soil in a form useable by plants only exists in small clumps, like in cracks between rocks. The bacteria that can survive in such conditions in turn enables specific low-growing shrub-like plants to grow.
It can be infered that, as tundra organisms have developed under similar conditions (i.e.: those of extreme cold and little moisture) they have also developed to be dependent upon those things which are available under those conditions, leading them to evolve into interdependent communities.


Name:  Laura B. and Adrienne
Username:  lbang@brynmawr.edu
Subject:  biomes: tundra vs. grassland
Date:  2002-12-04 14:42:39
Message Id:  3960
Comments:

Biomes: Arctic Tundra vs. Grasslands
Brought to you by: Laura Bang and Adrienne Wardy

  Arctic Tundra Grasslands
Average Temperatures -34 degrees Celsius in winter; 3-12 degrees Celsius in summer as low as -40 degrees Celsius in winter; higher than 38 degrees Celsius in summer
Yearly Precipitation 15-25 cm 50.8-88.9 cm
Characteristics
  • Extremely cold climate
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  • Low biotic diversity
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  • Simple vegetation structure
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  • Limitation of drainage
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  • Short season of growth and reproduction
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  • Energy and nutrients are in the form of dead organic material
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  • Large population oscillations
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  • Permanently frozen soil (permafrost)
  •  
  • Plants are short and group together; adapted to harsh conditions
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  • Dominated by grasses rather than large shrubs and trees
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  • Seasonal drought and occasional fires are important to biodiversity
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  • Drought, fires, and grazing by large animals prevent shrubs and trees from becoming established
  •  
    Location The Arctic regions of the Northern Hemisphere Veldts of South Africa; puszta of Hungary; pampas of Argentina and Uruguay; steppes of former Soviet Union; plains and prairies of central North America
    Plant Life About 1700 kinds of plants: low shrubs, sedges, lichen, reindeer mosses, liverworts, grasses; about 400 varieties of flowers Lots of different kinds of grass; very few tall shrubs and/or trees, although there are some trees in river valleys
    Animals lemmings, wolves, caribou, arctic hares, foxes, polar bears, ravens, falcons, terns,... gazelles, zebras, rhinos, wild horses, lions, wolves, prairie dogs, jack rabbits, coyotes, foxes, skunks, badgers, blackbirds, grouses, meadowlarks,...

    For more exciting information about these biomes, go to Biomes.


    Name:  Heidi Mer Diana Chelsea
    Username:  dlafemin@brynmawr.edu
    Subject:  Not ALL deserts are created equal!
    Date:  2002-12-04 14:48:20
    Message Id:  3961
    Comments:
    Are all deserts created equal? I think not!

    One of the best known deserts in the world: The Sahara Desert, Africa

    Geographical features: Shallow basins, highest point is 11,204 feet, lowest .....point is 436 feet, 25% sand sheets and dunes, underground waterways.

    Weather: short to medium length dry and humid conditions.

    Two major climates:
    .....dry tropical climate: mild and dry winters, hot and dry season, 1 annual temperature cycle, 5 in annual rainfall.

    .....dry subtropical climate: annual high temp ranges, cold winters, hot summers, two rainy seasons, 3 in annual rainfall at most.

    Vegetation: varied, sparse, include grasses, shrubs, and trees that are .....adapted to unreliable precipitation and excessive heat

    Animal life: varied and numerous, gerbil, jerboa, Cape hare, the desert hedgehog, dorcas gazelle, dama deer, Nubian wild, anubis baboon, spotted hyena, common jackal, sand fox, Libyan striped weasel, and the slender mongoose. Variety of birds also exists.

    The largest block of ice you'll ever see: Antarctica

    Geographical features: 95% ice, 70% of the earth's fresh water is locked .....within this ice

    Weather: coldest temp -129F, high winds

    Climate: less than 2 in annual precipitations, this makes it a desert.

    Vegetation: current tundra cannot have vegetation, fossilized plants have been found from 2 million years ago.

    Animals: exist in water and on coastline, includes macaroni penguins as well as other species, albatross, elephant seals and leopard seals as well as other seals, killer whales and right whales as well as other whales, seabirds.


    Conclusion: Both the Sahara and Antarctica are technically deserts because they each get very little annual precipitation. However, as noted above, the organisims that live within each desert are obviously different. In the Sahara desert, reptiles are the most obvious difference because being cold blooded, they need to remain in an area that remains warm. The other birds and mammals are found in and around oasises for the most part. The Sahara also consists of two subclimates because of the span of latitude in relation to the equator. Antarctica never has a significant difference in distance from the equator to change the climates.

    Antarctica, being almost a complete sheet of ice, is obviously much colder and as a result all of the plants and animals that might live in that climate have a thick layer of fat or other natural protection from the cold. Therefore, the zebra that lives in the Sahara could not live in the arctic and the penguin would probably overheat and die in the Sahara.


    Name:  
    Username:  Anonymous
    Subject:  Marine Ecology
    Date:  2002-12-04 14:50:21
    Message Id:  3962
    Comments:
    Marine Ecology

    Basically, I looked at "underwater communities" to see why life is "organized", inside them. Obviously, organisms living in water are categorized separately from other organisms for a reason. What I found out from mainly one site is that many different factors create an active aquatic environment. These factors control the distribution of plants and animals in a "liquid column of water". The balance of co-existence and dependency sets the levels of each ecosystem. These elements are viable for life to reach an equilibrium.
    Aquatic ecology is a composed piece of nature developing to a point of harmony within its own set parameters. The sun and gas/liquid forms set the medium for existence and occupation. Boundaries and temperatures distribute plant and organism lives. Consumption and redistribution of energy and nutrients keep the numbers in certain boundaries.
    Name:  
    Username:  dlafemin@brynmawr.edu
    Subject:  
    Date:  2002-12-04 14:53:10
    Message Id:  3963
    Comments:
    Websites we forgot to mention:

    Animal Live
    The Living Africa
    Nature: Antarctica-Life In The Icebox


    Name:  Maggie Scott-Weathers
    Username:  mscottwe
    Subject:  Forest Biomes
    Date:  2002-12-04 14:59:03
    Message Id:  3964
    Comments:
    The Earth has many different environments, varying in temperature, moisture, light, flora, fauna, and other factors. Each of these habitats has distinct life forms that form complex communities of interdependent organisms. A complex community of plants and animals in a region and a climate is called a biome. I decided to research the differences between forest biomes. There are three types of forest biomes: tropical, temperate and boreal. Tropical forests are what we sometimes call rainforests, and boreal forests are also called tiagas.

    Characteristics

    Tropical
    -greatest diversity of species
    -occur near the equator, within the area bounded by latitudes 23.5 degrees N and 23.5 degrees S.
    -two seasons are present are rainy and dry
    -daylight is 12 hours with little variation.
    -temperature is on average 20-25 C and varies little
    -precipitation is evenly distributed throughout the year, with annual rainfall exceeding 2000 mm.
    -soil is nutrient-poor and acidic
    -canopy in tropical forests is multilayered and continuous, allowing little light penetration.
    -flora (plantlife) is highly diverse, one square kilometer may contain as many as 100 different tree species. Examples include trees (mostly evergreen, with large dark green leaves), plants such as orchids, bromeliads, vines, ferns, mosses, and palms.
    -fauna (animal life) includes numerous birds, bats, small mammals, and insects

    Tropical forests can be further subdivided based on seasonal distribution of rainfall:
    evergreen rainforest has no dry season.
    seasonal rainforest has a short dry period in a very wet tropical region
    semievergreen forest has a longer dry season
    moist/dry deciduous forest has a dry season that increases as rainfall decreases

    Temperate
    -occur in eastern North America, northeastern Asia, and western and central Europe
    -have well-defined seasons with a distinct winter
    -moderate climate and a growing season of 140-200 days during 4-6 frost-free months
    -temperature varies from -30 C to 30 C.
    -precipitation (75-150 cm) is distributed evenly throughout the year.
    -soil is fertile, enriched with decaying litter.
    -canopy is moderately dense and allows light to penetrate, resulting in well-developed and richly diversified understory vegetation and stratification of animals
    -flora is characterized by 3-4 tree species per square kilometer. Trees are distinguished by broad leaves that are lost annually and include such species as oak, hickory, beech, hemlock, maple, basswood, cottonwood, elm, willow, and spring-flowering herbs
    -fauna is represented by squirrels, rabbits, skunks, birds, deer, mountain lion, bobcat, timber wolf, fox, and black bear

    Temperate forests can be further subdivided based on seasonal distribution of rainfall:
    moist conifer and evergreen broad-leaved forests have wet winters and dry summers
    dry conifer forests dominate higher elevation zones, have low precipitation
    mediterranean forests have precipitation that is concentrated in winter, with less than 1000 mm per year
    temperate coniferous have mild winters, high annual precipitation (greater than 2000 mm)
    temperate broad-leaved rainforests have mild, frost-free winters, high precipitation (more than 1500 mm) evenly distributed throughout the year

    Boreal
    -represent the largest terrestial biome
    -occur between 50 and 60 degrees north latitudes
    -found in the broad belt of Eurasia and North America, two-thirds in Siberia with the rest in Scandinavia, Alaska, and Canada
    -seasons are divided into short, moist, and moderately warm summers and long, cold, and dry winters
    -growing season in boreal forests is 130 days
    -temperatures are very low
    -precipitation is primarily in the form of snow, 40-100 cm annually
    -soil is thin, nutrient-poor, and acidic
    -canopy permits low light penetration, and as a result, understory is limited
    -flora consist mostly of cold-tolerant evergreen conifers with needle-like leaves, such as pine, fir, and spruce
    -fauna include woodpeckers, hawks, moose, bear, weasel, lynx, fox, wolf, deer, hares, chipmunks, shrews, and bats

    Conclusion
    Groups of organisms live in the same areas and are associated with each other because they adapted to live in similar environments. Organisms, depending on their specific adaptations, depend on each other and their environment in different ways. The food chain in an example of how animals depend on each other, and plants, in order to live. By looking at the specific information about the three different types of forests, it is apparent that different types of animals and vegetation are found in different environments.


    Sources
    http://www.enchantedlearning.com/biomes/
    http://www.ucmp.berkeley.edu/glossary/gloss5/biome/forests.html


    Name:  the crew
    Username:  lfriedma@brynmawr.edu
    Subject:  A Tundra Site we made
    Date:  2002-12-04 15:00:27
    Message Id:  3965
    Comments:
    Tundra Website! by Lauren, Carrie, Jodie, and Lawral
    Name:  Catherine
    Username:  Anonymous
    Subject:  Anonymity
    Date:  2002-12-04 15:27:53
    Message Id:  3968
    Comments:
    The anonymous was me.

    Underwater Life



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