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| "The deciduous forest" |
By: Sana Shahidi
What is an Ecosystem?
Most of us are confused when it comes to the words ecosystem and biome. What's the difference? There is a slight difference between the two words. An ecosystem is much smaller than a biome. Conversely, a biome can be thought of many similar ecosystems throughout the world grouped together. An ecosystem can be as large as the Sahara Desert, or as small as a puddle or vernal pool.
Ecosystems are dynamic interactions between plants, animals, and microorganisms and their environment working together as a functional unit. Ecosystems will fail if they do not remain in balance. No community can carry more organisms than its food, water, and shelter can accomodate. Food and territory are often balanced by natural phenomena such as fire, disease, and the number of predators. Each organism has its own niche, or role, to play.
Most of us are confused when it comes to the words ecosystem and biome. What's the difference? There is a slight difference between the two words. An ecosystem is much smaller than a biome. Conversely, a biome can be thought of many similar ecosystems throughout the world grouped together. An ecosystem can be as large as the Sahara Desert, or as small as a puddle or vernal pool.
Ecosystems are dynamic interactions between plants, animals, and microorganisms and their environment working together as a functional unit. Ecosystems will fail if they do not remain in balance. No community can carry more organisms than its food, water, and shelter can accomodate. Food and territory are often balanced by natural phenomena such as fire, disease, and the number of predators. Each organism has its own niche, or role, to play.
What is a Biome?
A biome is a large area with similar flora, fauna, and microorganisms. Most of us are familiar with the tropical rainforests, tundra in the arctic regions, and the evergreen trees in the coniferous forests. Each of these large communities contain species that are adapted to its varying conditions of water, heat, and soil. For instance, polar bears thrive in the arctic while cactus plants have a thick skin to help preserve water in the hot desert. To learn more about each of the major biomes, click on the appropriate heading to the right.
How have humans affected the ecosystems?
We have affected ecosystems in almost every way imaginable! Every time we walk out in the wilderness or bulldoze land for a new parking lot we are drastically altering an ecosystem. We have disrupted the food chain, the carbon cycle, the nitrogen cycle, and the water cycle. Mining minerals also takes its toll on an ecosystem. We need to do our best to not interfere in these ecosystems and let nature take its toll.
We have affected ecosystems in almost every way imaginable! Every time we walk out in the wilderness or bulldoze land for a new parking lot we are drastically altering an ecosystem. We have disrupted the food chain, the carbon cycle, the nitrogen cycle, and the water cycle. Mining minerals also takes its toll on an ecosystem. We need to do our best to not interfere in these ecosystems and let nature take its toll.
The Major Biomes:
Click on the appropriate heading to learn more...
Click on the appropriate heading to learn more...
- Mountains (High Elevation)
- Tundra
- Temperate Forest
- Marine/Island
- Desert
- Tropical Dry Forest
- Cold Climate Forest
- Grassland
- Savannah
- Tropical Rainforest
Mountains: The High Elevation Biome
Mountains are a common sight on this planet. They make up one-fifth of the world's landscape, and provide homes to at least one-tenth of the world's people. Furthermore, 2 billion people depend on mountain ecosystems for most of their food, hydroelectricity, timber, and minerals. About 80 per cent of our planet's fresh water originates in the mountains. Since about half of the world's people are reliant upon mountains for fresh water, and in this time of increasing water scarcity, it is becoming increasingly important to protect the mountain biome.
All mountain ecosystems have one major characteristic in common--rapid changes in altitude, climate, soil, and vegetation over very short distances. Mountain ecosystems sport a high range of biodiversity, and are also a home to many of our planet's ethnic minorities. These cultures are sometimes 'protected' due to the challenging environment to produce a living, but others are not. More and more these indigenous people are being kicked out of their homes due to population and commercial growth, logging, and mining. An example of the mountain's wide variety of organisms can be seen in California's Sierra Nevada range (the home of Yosemite, which is pictured above, far left). It has been estimated that this range alone houses 10,000 to 15,000 DIFFERENT species of plants and animals! This is all mainly due to elevation changes, which produces belts, or zones, of differing climates, soils, and plant life.
Rainfall varies greatly across the world's montane (mountain) biomes, ranging from very wet to very dry. However in all the biomes comes swift weather changes. For example, in just a few minutes a thunder storm can roll in when the sky was perfectly clear, and in just a few hours the temperatures can drop from extremely hot temperatures to temperatures that are below freezing.
The world's mountains provide a home to several thousand different ethnic groups. The mountain people, which mainly consist of indigenous people, ethnic minorities, and refugees, have been able to cope with this harsh environment of the mountain ecosystem. They live as nomads, hunters, foragers, traders, small farmers, loggers, and miners, etc. Most mountain people all share one attribute -- material poverty. However, what they lack in material wealth they make up in community life. They have been able to live off the land without widespread destruction and deforestation. Plant and animal species have been preserved by these people. For instance, in India's Garhwal Himalaya, local women were recently successful in identifying over 145 species of plants that had been destroyed by commercial logging and limestone mining; the national foresters could only list 25! Unfortunately, these cultures have been subjected to discrimination and other violations of human rights. They have been called degrading words such as 'hillbillies' (United States), 'oberwalder' (Austria), 'kohestani' (Afghanistan), and 'bhotias' (India). We need to learn not only how to preserve the biological diversity in the mountains, but the cultural diversity also.
The Himalayan Yew, a slow-growing conifer, is currently on the World Wildlife Fund's list of the ten most endangered animals. This plant can be found throughout Bhutan, Afghanistan, India, Nepal, Burma, and maybe China. Taxol, which is promising to be a drug which can help cure cancer, is present in both the Pacific and Himalayan varieties. Found in the world's highest mountain range, the Himalayan Yew is extremely rare because of heavy deforestation and harvesting for Taxol extraction, without replanting. About 10 kilograms of yew leaves, bark, and needles will only produce one gram of the drug! New controls need to be imposed on this plant to make sure it is replanted and our supply remains sustainable, otherwise a valuable resource, and possible cure for cancer, may be lost!
Commercial industries, especially large mines and hydropower projects, cause exceptional damage in mountains. This is because many companies are ignorant of the fragility of the ecosystems and rights of local communities. The U.N. Food and Agriculture Organization (FAO) discovered that during the past decade, tropical mountain forests have had both the fastest rates of both annual population growth and deforestation. Somehow, we need to come up with a way to find a compromise between preserving the cultural and biological diversity in mountains, and using them as a valuable resource. After all, if the mountains are exploited until they run dry, there will be no more resources for future generations. Currently, only 8 per cent of all mountains are protected in some form. If our world's highest mountains are able to inspire the greatest of mountain climbers to accomplish great feats, we should provide no lesser commitment to preserving the fragile ecosystems and endangered cultures which lie within them.
In Glacier National Park, near Logan's Pass (pictured above, middle), there are many Rocky Mountain goats who don't make their home in their natural ecosystem, but lounge around the parking lot. They enjoy licking the anti-freeze from cars, because they like the salt
Tundra
This biome circles the world in the highest northern latitude and in the southern hemisphere is found only in the Antarctic Peninsula and Islands close by. Here temperatures often reach about -50°F in the winter. Tundra covers about one-fifth of the Earth's land surface. Because of the cold climate it is impossible for trees to grow, thus leaving room for low-growing plant life and wildflowers. For this reason the Tundra biome looks like a frozen-over prairie land.
In the Ice Age, massive glaciers dwelled here. As the Earth warmed these glaciers retreated leaving bare rock and scoured soils. The freezing temperatures leave deeper layers of soil frozen throughout most of the year- this condition is called permafrost. Only the top layer on the surface is able to thaw out in summer conditions. However, this occurs just briefly because summers are extremely short here. The combination of a harsh climate, the lack of nutrients in the soil, and soil being so sparse make it very hard for any type of plant life to grow.
Despite these harsh living conditions animals still manage to survive here. During the Tundra's brief summer, insects hatch out of eggs which were frozen in the top soil. Creating a vast feeding ground for birds, thousands migrate here during this time to feed on these insects. Millions of migrating waterfowl and shore birds come to the shore and lake areas in the arctic tundra of Alaska during the summer months. Also, ravens, hawks, ptarmigans, and the open country owl are common. Besides birds and insects mammals dwell in this icy zone. The Caribou, arctic hare, mink, weasel, lemming, wolf, wolverine, brown bear, vole and reindeer, roam this land. And the Polar bear, walrus and arctic fox are commonly seen on the ice pack and coastal areas.
Temperate forest
The temperate forest biome is found in the middle latitudes around the globe and this biome is very seasonal.
Temperate forests dominate the mid-latitudes in eastern North America, western Europe, and eastern Asia. In the southern hemisphere, smaller areas of temperate forest can be found in South America, southern Africa, Australia, and New Zealand. Because temperate forests are highly seasonal they have warm summers and cold winters. The trees being deciduous (meaning they drop their leaves in the fall) change colors as the seasons cycle: the green leaves of summer give way to the grey bare branches of winter. Temperate forests blend into the pines and firs of the taiga (cold climate forests).
Human Activities
The Temperate forest biome is one of the most altered biomes on the planet. By looking at a map you will see that our population density very closely corresponds to the distribution of Temperate Forests. We use the wood of these trees for construction, firewood and art. They have been cleared for farming and to build communities. These human activities have led to the decline and loss of these forests in many parts of the world.
Marine Islands
. IslandsIslands vary tremendously when it comes to shapes, sizes and climates. Some are tropical and lush, while others are jagged and arid. They also support thousands of unique and unparalleled types of animals, such as the giant tortoises of Galapagos, Madagascar's lemurs, and the humongous Komodo dragons, the largest lizards in the world. Oceanic and continental are two broad categories of islands, regardless of the islands' shape, size or the type of animals that dwell on their surfaces.
Oceanic islands were created from the lava of giant underwater volcanoes. An example of this would be the Hawaiian Islands. Normally these islands are located far from major land masses. Continental islands once were part of a larger land mass and in recent geologic history, have become separated from the mainland because of rising sea levels after massive glaciers melted thousands of years ago or by earthquakes which separated them from the original land mass. An example of a continental island would be California's Channel Islands. These types of islands have an older and more complicated geological history than the oceanic islands.
Desert
Of all the biomes of the world, the desert biome has the driest climate.
The great expanses of the world's desert lie between 20 degrees to 30 degrees north and south latitude. It is here that equatorial air falls down toward the Earth's surface and rainfall is rare because rain usually occurs when air begins to rise, not fall. The equatorial air that is falling prevents most air from rising. North Africa, southwestern North America, the Middle East, and Australia support the largest deserts, but there are smaller deserts in other regions such as on the Pacific coast of South America (the Atacama) and the Atlantic coast of southern Africa (the Namib), where moisture from cold water currents is evaporated immediately by the hot land masses adjacent to the currents.
Rainfall in the desert often totals a few inches yearly or, in some regions, there is absolutley none. Desert soils are often salty because whatever little rain that does fall quickly evaporates from the ground, leaving salt and other minerals behind.
Important Fact |
The Sahara Desert is expanding southwards, engulfing degraded grasslands, at a rate of 30 miles every year. |
Since rainfall is so scarce, plants in the desert are almost always drought-tolerant, meaning they can survive without water for a long time. With unique features such as, thick or waxy leaves, large root systems, and water storage systems-like in the cactus, these adaptive plants are built to store water, find water quickly or live with the littlest amount of water possible. The vegetation in deserts varies tremendously. The mojave desert in California is known for it's unique Joshua trees, in the Sonoran Desert there is the thorn-covered Ocotillo and the giant Saguaro Cactus. Sagebrush covers the Great Basin in the western United States and the Chihuahua Desert (in between Mexico and Texas), is well known for its mesquite trees.
The animals which live in this arid biome are usually light-colored and use camouflage to blend into their surroundings, and possibly for protection against predators. Being more active at night and around dawn and dusk, allows them to escape the scorching heat. During the day they often lay in burrows or under rocks. Different species of life in the desert include jackrabbits (North America), kangaroo rats, owls, snakes, lizards and tortoises.
Because of our carelessness, deserts are spreading over regions where there was once green, fertile land. This is mainly due to misuse of the planet. However, the desert expansion can be stopped through anti-desertification projects, and better land and agricultural management. This will turn the deserts back, by making the soil stronger with the roots of plants embedded into them, and replenishing the soil with nutrients and minerals.
Tropical Dry ForestsWith a well defined dry season, tropical dry forests have high temperatures throughout the entire year.
A home to such animals like the Tasmanian devil and the American alligator, this biome occurs in areas of slightly lower rainfall next to tropical rain forests. Found primarily in Central America, southern Asia (forests here are known as Monsoon Forests), and some portions of Australia, their well defined dry season limits plant growth and the activity of animals.
There is really no actual distinction between this zone and the tropical rain forest because the length of the dry season varies tremendously throughout the tropics, one biome usually gradually changes into the other over hundreds of miles. Wetter or drier soils sometimes produce pockets of tropical dry forest within a tropical rain forest.
Cold Climate Forests: The Taiga
This cold climate that supports coniferous trees (which means that they carry cones) is found at very high latitudes extending across Eurasia and North America. Rainfall in this climate is moderately high but is spread throughout the course of the year, with snow covering the ground in winter. Very little water is evaporated by the sun, thus ponds, lakes and bogs also known as "muskegs" are found everywhere, especially in glacially carved areas.
Vegetation found in the Taiga
Trees in the taiga (Taiga is a Russian word) use a lot of energy to grow their leaves, thus they have found a way to keep their needles all year round. This way, when the sun comes out again in the spring these trees are already gathering much needed sunlight instead of wasting more energy to grow new leaves. In addition they have adapted their needles to be filled with a chemical that repels grazing animals, and their thick bark resists the loss of moisture in the cold winters. Trees of this biome are also known as boreal or the Northern coniferous forests, usually have shrubs underneath them with blueberries (which is a favorite food of many animals) which act as heath plants.
The days in the Taiga are very short in the winter, as short as six hours. In the summer the days lengthen and plants grow rapidly in the 70°F weather.
Along the river banks throughout the taiga, willows and many other well known trees can be found. Leaves cover the ground for the relatively low temperature and the acidic soil slows down the process of decay.
Taiga Animals
Many animals migrate to the taiga in the summer months. However, those who do not have learned to adapt to the cold. Moose, wolves, woodland caribou, wood bison, black bear, marten, lynx, and the arctic ground squirrel are common, although they are not as abundant as the mammals living in the grasslands and the savanna biomes. Most of the animal activity in the taiga is seasonal, with large quantities of birds, such as the redpoll, raven, gray jay, red-throated loon, northern shrike, sharp-tailed grouse, and fox sparrow, present only in summer. Also the bald eagle, peregrine falcon, and osprey which are fish eaters, live in this biome.
For the animals that stay in the taiga during the winter months, conserving heat is one of the most important steps of survival. Most animals go into long-term hibernation and other animals such as the Canadian Lynx grow an insulating layer of fur or in other cases feathers. In order to conserve heat some animals have a rounded body structure, with shortened limbs to create less heat loss from long limbs and skin surfaces. Also other animals grow fur or plumage that camouflage with the snowy white background.
Activities of Humans
This biome has a population of approximately 21,400 people, and 60% are aboriginal. Major communities are Inuvik Hay River, Fort Nelson, Fort Simpson, and Fort Smith. Fishing, hunting and trapping are common activities that take place in these communities. Also, tourism, mining, oil and gas extractions and forestry are main activities which occur in this biome. Many of these human activities affect the natural systems in this ecosystem.
The GrasslandsThroughout the world, grasslands are known by many different names. In North America they are known as "prairie", in Asia "steppe", in South America the "pampas" and in South Africa a "veldt".
This biome is a highly seasonal environment of temperate regions. Grasslands stretch basically thousands of miles primarily in the continents of North America and Asia. A limited area of grasslands lies across southern South America. Its hot summers cause the flora to be baked into a nice crisp golden brown, and in the winter the land freezes over and is carved by powerful winds that are able to gather terrific speed because of the vast open area grasslands provide.
The seasonal changes always have helped maintain this biome. However not just the seasonal changes can keep this biome in check. Wildfires help maintain this biome.
Rainfall in the grasslands is somewhere between the amount of precipitation temperate forests and deserts receive. However, the amount of rain is not sufficient enough to support clusters of trees. Regions where more rain falls than another area results in taller grasses that can reach impressive heights. These grasses dominate the vegetation in this biome. Besides the grasses that grow here, wildflowers every spring provide a beautiful display of color. Arriving when this biome's rainy season comes, wildflowers help transform the land from a dreary solid brown into a green rainbow-filled landscape.
Wildfires play a very important role. They allow the grasslands to be open and free of trees and shrubs. Any seedling of a tree that appears is killed off by the intense heat. If the fire does not clear out the seedlings, the grasslands would become a shrubland changing forever. Remarkably, the plants in the grasslands have adapted to the wildfires that come through, and actually need them to keep healthy and grow new vegetation in the spring. Not only do wildfires reduce the growth in this area but so do grazers such as, bison, deer, and horses.
Savannah: Tropical Grasslands
Dominating the continent of Africa, savannahs are also found in India and the northern part of South America.
Savannahs are in fact tropical grasslands for they are located at tropical latitudes, however much drier than many tropical forests. Rainfall in this biome is between 20 to 60 inches a year, and can be very seasonal (usually falling within a time period of a couple weeks). Growth after the rainfall occurs, however long periods of drought follow.
Throughout the savannahs, the dominant plant life are grasses and small plants. Trees are sparse throughout this semi arid landscape, only growing where there are cracks in the surface or deep soil. In many savannahs around the world palm trees play an important role in the landscape. The most dominate wooded form in the savanna are the thorn woodlands. Often following the thorn woodlands come tropical dry forests. There is a large amount of wild fruit-trees, which provide food for many birds and animals.
Savannah Animals
Types of birds found in the Savannah biome are shrikes, hornbills, grey louries, flycatchers, knysna, purple-crested louries, green pigeons, rollers and raptors. Larger mammals of this biome are lions, leopards, cheetahs, elephants, buffalos, rhinoceroses, giraffes, hippopotami, gazelles, zebras, kudus, waterbucks, oryxes and many others.
Tropical Rainforests: Equatorial Forests of Rain
Of all the world's forests, it is those in the tropics that face the greatest threat from mankind. Tropical rainforests are one of nature's treasures, and many of them are now at risk. We have already destroyed half of the world's original tropical rainforests! Just in a few decades, we can possibly witness the complete elevation of the world's rainforests. The biodiversity of this biome is legendary -- this biome contains the largest biomass. Did you know that enough rainforests are being destroyed every minute to fill 50 football fields? We need to preserve these valuable resources because they are the lungs of our planet, and can possibly hold cures for many of our most deadly diseases. The tropical rainforests are a critical link in the ecological chains of our our earth's biosphere. To learn more interesting facts about the tropical rainforests, please visit our Did you know? section.
Important Facts |
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Technically, this type of forest can be defined as a forest in the tropics receiving 4-8 meters of rain each year. Tropical rainforests are found in Central and South America, Southeast Asia and islands near it, and West Africa. There are smaller rainforests in northern Australia and other small islands. All tropical rainforests are found along the equator where the temperatures and the humidity is always high, with the days being equal to the nights.
Eco-Joke |
What do you call a parrot wearing a raincoat? |
Answer: Polly Unsaturated |
Generally, there is a flow of air that comes from the poles of the Earth, towards the equator. These winds are filled with moisture and the intense heat that is located at the equator causes the moisture to rise, cool and then condense to create rain. This continuous cycle causes it to rain almost 24 hours a day around most of the tropical areas. In some regions there can be more than 15 feet of rain a year. There are one or more "dry" months in this tropical biome, however if one would visit they would see it still is astonishingly wet.
Important Facts |
Despite covering only 2% of our planet's surface, over half of the earth's animal, insect species and flora live there. Within a four mile square area of a tropical rainforest, you would find:
**Only 1% of these species has ever been studied** |
By: Sana Shahidi
very informative. Great
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Neptune