Tundra The tundra is located around the North Pole in the Arctic Circle. For most of the year it is covered in snow. In the short summers, the snow and ice melt to leave pools of meltwater. The layer of earth beneath the tundra is frozen all year long. This is called the permafrost. Industrial activity in the tundra may add to the world's environmental problems. Dust and grime make the ice darker, so less heat is reflected from the ice and global warming is increased. The tundra is the coldest region in the world. Fierce winds blow while snow and ice cover the ground. Even the sea freezes as the temperature gets colder. The tundra receives less than 10 inches of precipitation yearly. Sometimes the strong winds create "white outs" when the snow blows so much that it is hard to see! White outs last for days. The tundra has a short summer that lasts from May to July. During the summer, the temperature only rises to about 50 degrees Fahrenheit. The average yearly temperature is only 10 to 20 degrees Fahrenheit. Some plants are able to survive in the tundra. These plants are small. They stay near the ground to avoid the strong wind and cold temperatures. Hairy stems help to keep some plants warm. Plants in the tundra do not come alive until summer when the conditions are just right for growth. They spend most of their time in the snow. The dark red leaves on the plant pictured above allow it to absorb more heat from the sun. A large variety of animals live in the tundra for the whole year. They have special adaptations that allow them to survive in the winter weather. Some of these include: short legs; long hair; and a coat of thick fur. They have short tails and large, furry feet. Many animals have white fur which camouflages them against the snow. Every ten or thirteen years, the small mammals in the tundra breed in large numbers. The larger animals also grow in number because of the increase in their food supply. Soon the small mammals run out of plants to eat and many die. The larger animals begin to die and then the plants can grow back. Some animals that live in the tundra are polar bears, caribou, and snowy owls. In the summer months, the sun shines all the time, even at midnight. The poles were not always so cold. The movement of the plates that make up the earth's surface, plus the warming and cooling of the planet, have caused the cold conditions that are present today. As the sea freezes, the salt rises to the surface as crystals called ice flowers. The only tree that grows in the tundra is the dwarf willow tree. It grows to a maximum of four inches tall. Caribou are animals that are often called reindeer. They have thick fur to protect them from the cold weather of the tundra
Desert Deserts are places on earth that are characterized by little vegetation and rain. They are made up of sand or rocks and gravel. Deserts cover about one-fifth of all the land in the world. Most deserts lie along the Tropic of Cancer and Tropic of Capricorn, imaginary lines that lie north and south of the equator. Oases are parts of the desert where plants grow and water is almost always available. An oasis is formed by a pool of water trapped between layers of rock beneath the desert floor. The regular water in an oasis allows people to settle in the desert and even grow crops. The desert is the hottest biome on earth, but not all deserts are hot. The desert is also a land of extremes. It can be over 100 degrees Fahrenheit during the day but below 32 degrees at night. This change is because deserts are bare. There is little protection to keep them from heating up in the sun and cooling off when the sun disappears at night. The amount of rainfall also varies. Though there is little rain in a desert, and when it does rain, it pours. Violent rainstorms can cause flash floods in the desert. After a storm, the desert may not see any rain for weeks or months. There are some plants that are able to survive in the desert. They may have to go without fresh water for over a year! They also have to adjust to very hot days and very cold nights. Some plants have very long roots which grow in to the ground to reach underground water sources. Some suck up as much water as they can during the rain and save it in their stems and leaves. Some store the food and water underground in thick roots. Rain brings life to the desert. Shortly after a big storm, billions of seeds come to life in the form of flowering plants. These plants are called ephemerals. Eight weeks after a rain, the flowers are gone. Cacti are the most well known desert plants. This cactus has a layer of hair that helps it to store water. There are hundreds of different animals that live in deserts. However, most of them can only be found at dawn or dusk because that is when they move around. For the rest of the day, animals bury themselves in the sand or hide beneath rocks to keep cool. Animals that come out at night are called nocturnal. Animals in the desert eat plants and each other to survive. Many feed on the roots, stems, leaves, and seeds of plants. These animals are then eaten by bigger animals. Some animals get enough water from their food, but others must travel to water holes. The desert jack rabbit eats plants, such as the cactus. It is very careful to avoid the prickly spines! Its ears pick up any sound of danger. They also help keep the rabbit cool because heat can escape through the tiny blood vessels that are found there. Camels are the most well known desert animals. They are sometimes called "the ship of the desert" because they can cross the desert better than any other animal. Camels have bushy eyebrows and two rows of eyelashes to keep the sand out of their eyes. Their nostrils can also be closed. The humps on camels' backs do not hold water as commonly believed. Instead they store fat reserves that can be broken down into food when crossing the desert. The hump will shrink if a camel is starving.
Grassland/ Savannas Grasslands are large areas with rolling hills of grasses and wildflowers. Grasslands are found on every continent but Antarctica. Sometimes grasslands are called prairies, savannahs, or steppes. The roots of the grasses and small plants make the soil rich and great for farming. Some of the grasslands are used for animal grazing, too. Grasslands are extremely hot during the summer months and very cold during the winter months. The grasslands receive anywhere from 10-30 inches of rain per year. Sometimes the summers are so hot that the grass catches on fire very easily. Fires are very often seen during these hot summer months. These fires are dangerous because they spread through the dry grass very quickly. During the winter, on some grasslands, the snow might be so high that it comes up over your head. WOW! That is a lot of snow! There are so many animals that live in the grasslands. Some of them are very small such as mice, prairie dogs, and the little insect called the aphid. These animals can hide easily in the tall grass of the grasslands. Other animals roam the grasslands of Africa such as the African elephant, lions, zebras, giraffe, black rhinoceros, and many more! These animals are too large to hide in the grasses, so they must protect themselves in other ways. Lions, cheetahs, and coyotes are able to protect themselves by running very fast. Other large animals travel in groups. Elephants, zebras and rhinoceros roam the grasslands in huge herds. These herds are able to protect the smaller, weaker animals from lions and other predators. Here in the United States, buffalo used to roam the grasslands, but no so much anymore. Buffalo are huge animals with thick, brown fur. A long time ago, many people hunted the buffalo. Today, a person can not shoot a buffalo, so the mammal is slowly making a comeback. In other grassland areas, such as Africa, there is a big problem with people shooting animals. Elephants and rhinoceros are shot for their tusks, and lions are killed for their fur. We need to protect these animals before it is too late! Prairies, as grasslands are sometimes called, have many beautiful wildflowers. Just look at the pictures below! There are not many tall trees or bushes in the grasslands, because there is just not enough water for them to live. Also, there is too much wind on the prairie for tall trees to survive. Grasslands are considered the transitional biome. This means that grasslands are usually found between the desert and the forest. It would become a forest if grasslands received more rain. If it received any less rain, it would be a desert. True prairies and grasslands are becoming harder and harder to find. People are taming the wild lands, and the grasslands are becoming as extinct as the animals that are missing from them today In Africa, national parks are being set up to preserve the grasslands. This will help the animals such as lions and elephants as well. The United States is starting to preserve the wild grasslands, too. It is even replanting grass where it has been cleared for farming.
Rainforest The tropical rainforest is the richest source of life on earth. It is a treasure chest of plant and animal life. The seasons do not change in the tropical rain forest. It has been hot and wet for millions of years. The average temperature year-round is about 80 degrees. The tropical rain forest is the wettest place on earth. It rains every day. In one year it may rain about 100 to 400 inches. This means that 9 to 30 feet of rain may fall each year. The heat and moisture in the rainforest cause plants and animals to rot quickly once they have died. This is called decay. When things decay, all the rich nutrients are recycled back into the soil to feed the roots of other plants. Rain forests even recycle their rain! As water evaporates from the forest back into the air, it forms clouds above the canopy. Later, the clouds will rain once again over the forest. Scientists think destroying rainforests makes our earth warmer. This is called the Greenhouse Effect and is not good. Without rainforests, we will have less rain. This will harm the trees and plants that help to keep the air we breathe clean. Our earth could become very dry and barren, like a desert. The tropical rain forest is the richest source of plant life on earth. There are so many different kinds of plants there, scientists don't even know them all yet. It is a perfect place for growing plants. The average temperature is 70 to 90 degrees and there is plenty of water. Here are some facts about a few kinds of plants you will find in the rain forest. Trees - Some canopy trees grow to 120 feet. The leaves are so big they can be used for an umbrella! The leaves are thick and waxy, and have "drip tips" so that water can drain off. Fruit trees provide food for many rainforest animals and people. Air Plants - Thousands of flowering plants grow on the trees. Their roots are not planted in soil, but take their food from air and water all around. Insects and even small animals live in and on these air plants. They have beautiful flowers and fruit, to provide food for forest dwellers. Butterflies, hummingbirds and bees drink the nectar from the flowers. Bromeliads - The bromeliad is a kind of tropical plant with leaves like a pineapple. It collects water in its' center. This water forms a small pool for frogs, lizards, and insects to live in. There are many kinds of vines and ferns which connect the layers of the rain forest. Mushrooms and herbs grow on the forest floor. People can learn to gather fruits and nuts for food, as well as plants for medicine, without harming the rain forest. Rain forest people have done this for thousands of years. Billions of animals, birds, and insects live in the tropical rainforest. Why do living things love to live in this environment? It is because they can find all the food they need to live. They can also find the kind of habitat they need to make a safe home and raise their young. Animals and insects live in all the layers of the rainforest. Some prefer the emergent layer, some the canopy. Others thrive in the understory, or the forest floor. There are many different types of rain forests. They can grow on mountains, seacoasts, plains, or in river valleys. How are they different from each other? One difference is how much rain falls in a year. Another is the average temperature. The plants and animals which live in each type of rain forest can be different too. You will learn about the tropical rainforest on this page. In the tropical rainforest, there are more kinds of plants, animals, birds, and insects than anywhere else on earth. In fact, there are millions of different kinds! Why are they called tropical rain forests? Tropical means close to the equator. The equator is an imaginary belt which circles the earth and divides it into two halves. Near the equator, the sun shines directly on the earth. The areas directly above and below the equator are called the tropics and are always warm and humid, much like summertime. Most tropical rain forests are located on the continents of Central and South America, Africa, Asia and Australia. The largest tropical rain forest in the world is the Amazon Rain Forest in South America. The world's largest river, the Amazon, flows through it. Much of this rain forest is in the country of Brazil.
Temperate Forest/ Deciduous Forest Temperate forests are often called deciduous forests. In a temperate forest, most of the trees lose their leaves in the winter. During the fall, when the weather gets cooler, the trees begin to shut down. Their leaves turn beautiful shades of colors. Come winter time, the leaves fall off of the trees. Why do you think this is so? The deciduous trees must lose their leaves, because water is not available for the leaves to survive. Also, the trees are not strong enough to keep their leaves and hold up all the snow that comes in the winter. In a temperate forest, there are four definate seasons. In some biomes, like the tundra, it is usually cold, but not in the temperate forest. Spring time brings new life to the trees and plants, warm temperatures, and rain which helps everything grow. Summer is hot, and everything is green for all the trees now have leaves. Fall is cool. The trees are beginning to change colors such as red, yellow, and bright orange. Winter months are extremely cold. All the trees loose their leaves. The average temperature for a year in the temperate forest is about 50 degrees F. The temperate forests are always changing due to the weather, animals, and people. A forest has many layers of plant life. There are the small plants such as shrubs, moss, ferns, and lichens which grow quietly beneath the shadows of the tall trees. The trees found in a temperate forest are called hardwoods. This means the trees loose their leaves in the winter. Their trunks are also made of a bark that is very hard. Most of the trees are maple, birch, beech, oak, hickory, and sweet gum. There are many other types of trees found in the forest too. A temperate forest also contains a few pine trees and other coniferous trees. The Taiga is usually found north of the temperate forests, but sometimes they overlap. Animals in a forest come in all different shapes and sizes. Below are a few examples of the kinds of animals you might find in a forest. Have you ever seen any of these animals before? Cardinal - A cardinal is a bird that is often found in the United States. You can tell it is a cardinal by its bright red feathers. Squirrel - Here is an animal that you might have seen before. A squirrel is a furry animal with a big, bushy tail. It eats nuts and seeds and lives in the trees. Bear - There are many types of bears around the world. There are grizzly bears, black bears, and polar bears just to name a few. The largest tree in the world is found right here in the United States. You can find it in California. This giant sequoia tree is 275 feet tall and 95 feet around. Boy, that's HUGE! The largest forest in the world covers parts of Scandinavia and northern Russia. It has over 3.5 million square miles of land covered in trees! Most hardwood trees are used for firewood, construction, or art. Lots of forests are being cut down for farm land.
Taiga/ Coniferous Forest The taiga is the largest biome in the world. It covers large parts of Canada, Europe, and Asia. This forest is covered with coniferous trees. In fact, sometimes the taiga is called a coniferous forest. Conifer trees are often called evergreens. These trees have long, waxy needles instead of wide, flat leaves like hardwood trees. Evergreens do not loose their needles come wintertime. The needles stay on all year long. In the taiga, summers are warm and rainy, and the winters are very cold. There is lots of snow in the forests, too. During the summer, it is usually around 70 degrees Fahrenheit. In the winter, the high temperature averages around 30 degrees Fahrenheit, whereas the low temperature is 65 degrees BELOW zero! Now that is very cold! The taiga gets about 12-33 inches of rain in one year. During the summer months, the taiga is prone to wildfires because of the hot temperatures and the small amount of rain. There is not much diversity in the taiga, because many plants cannot survive such harsh conditions. Lichens and mosses are important, but most of the plants are evergreen trees. There are many types of coniferous trees such as pine, spruce, hemlock, and fur. The trees are narrow and grow very close together. This is so they can help protect each other from the weather. That snow and wind can be really cold! Did you know that coniferous trees are usually shaped like a cone? This is for their protection. Being shaped like a cone helps the tree limbs not break under the weight of all that snow. The snow falls right off those waxy needles! Animals who live in the taiga must be ready for some cold weather in the winter and some really warm weather in the summertime. During the summer, the taiga fills up with hundreds of insects. Birds come from all over the world hungry and ready to eat all the insects. couple of them. There are other animals that live in the forest as well. Let's learn a thing or two about a Moose- A moose is a large animal with huge antlers. It lives in areas near lakes and streams. Bald Eagle- The bald eagle has a head covered in white feathers which makes it look bald. It is an endangered species, so we must take good care of it. This huge bird likes to eat fish. It has powerful wings and great eye sight to help it find it's food. The world's oldest trees are the bristlecone pines found in California. One of them is 4,600 year old. Coniferous trees grow thick bark to protect them from wildfires. Needles actually help keep coniferous trees warm during the winter. The trunks of the conifer trees are used to make paper. Like the stuff you use to write on in school or at home. Weasel- A weasel is a small animal that runs along the forest floor. It is small enough to get into the tunnels that mice and voles have created and then catches them to eat. Fox- The red fox which is shown in this picture has a red coat and a bushy tail. It is a very good hunter. It eats anything from rodents, rabbits to fruits and sometimes garbage.