My Science School

Plants of the Rain Forest Community

The rain forest is woodland of tall trees growing where the weather is warm and wet the year around. Trees in the rain forest stay green all year, and they often grow very tall.

There are three layers to the rain forest. The top layer - branches that extend the highest in the forest - makes up the emergent layer. The main “umbrella” of huge leaves is called the canopy. Sometimes there is a lower canopy made up of the leaves of smaller trees.

Many other plants grow on the upper branches of the trees. Vines and plants twine around the trees, climbing up towards the sunlight. Plants such as orchids perch high up on tree branches and trunks. Many flowering plants are brightly coloured to attract insects, birds, and other animals that help spread their pollen or seeds.

Picture Credit : Google

Rain Forests

Many kinds of trees grow best where it is always wet. So much rain falls in these places that they are known as rain forests. Throughout the year, life is always much the same in a rain forest. Rain storms soak these forests almost every day. The trees are always green.

In tropical rain forests, the air is hot night and day. Millions of animals live in tropical rain forests. The animals are very noisy as they call out in the deep shade. Most of them live in the trees. Monkeys, apes, flying squirrels, anteaters, snakes, insects, and parrots all make their homes in the branches. Animals eat in the trees and make their nests there.

Few animals live on the rain forest floor, where there is less food to be found and more danger from predators. The large trees and their huge leaves block out most of the sunlight and so keep smaller plants from growing.

Not all places called rain forests are hot. The temperate rain forest of the northwest coast of the U.S.A. is cool, wet, and green all year round.

Picture Credit : Google

Plants of the Northern Forest Community

The huge northern forests are mostly spruces, firs, pines, and other conifers. These trees can live where the weather is really cold. Their needle-like leaves are tough enough to hold water through the long, dry winter. The wind blows through the needles without making the trees sway too much. The sloping shape of the trees allows heavy snow to slide off without breaking branches.

Not many small plants grow in the northern forests. The soil is too poor, and there is limited sunlight. But ferns, horsetails, mosses, a few kinds of wild flowers, and such shrubs as bunchberry and cranberry can survive there.

In the northern parts of the world, winters are long and cold and summers are cool. Northern lands are home to spruce, firs, and other conifers. These trees grow well in cold places.

Conifers grow close together in the northern forests. There are many ponds and lakes. Beavers, muskrats, moose, deer, and water birds live on the many plants that grow around the water. The lynx and the mountain lion are two big cats that live among the conifers.

In winter, it snows heavily in the northern forests. Many birds fly south. Squirrels and bears go to sleep. Other animals, such as elk, stay awake and active all winter. In spring, the snow melts and soaks into the ground. This gives the trees most of the water they need.

Conifers are able to live in many parts of the world. But they do best in cold, northern forest communities.

Picture Credit : Google

Plants of Watery Communities

Water plants may grow partly in and partly out of the water. Freshwater plants such as cattails, bulrushes, bur reeds, and papyrus have tough roots that give them a firm grip in the mud. Saltwater plants that do this include cordgrass, sedges, and mangroves.

Water lilies and lotuses root themselves in the mud at the bottom of a pond and spread their plate-like leaves over the surface of the water. The leaves of the huge Amazonian water lily grow up to 1.8 metres across.

Other water plants, such as duckweed and frogbit, float on top of the water. Their roots hang down into the water. They do not have stems at all.

Still other water plants live completely underwater. Even plants that live underwater need air. Freshwater plants have special features that enable them to survive. These plants have air spaces in their stems. The air spaces carry air down through the stem to the roots. They also help keep the plant standing up straight in the water.

Picture Credit : Google

There are two main types of water communities - freshwater and saltwater. Freshwater communities include ponds, lakes, rivers, and marshes. In summer, some ponds are so covered with plants that you can hardly see the water underneath. Saltwater communities are found along sea coasts. There, the tides rise and fall, so the plants are sometimes above water and sometimes underwater.

Plants that grow in and around watery places give food and shelter to many animals. Grebes and other water birds use these plants to make nests. Muskrats eat plants such as cattails and also use them for building houses. Frogs often fasten their eggs to water plants. When the eggs hatch, the tadpoles use the plants as food. Bass and other big fish hide among water plants. From these hiding places, they dart out to snap up careless frogs and small fish.

The grass on grassland may be short or tall, depending on how much moisture there is. Hardly any trees or bushes grow on grassland, but there are many small plants with white or coloured flowers.

In North America, grasslands with tall grasses are called prairies. In South America, they’re called pampas. Parts of North America once had prairies where the grasses grew 1.8 metres tall or even taller.

In Africa and Australia, the grassland is quite dry and the grasses are short. In Africa, there are savannas that have scattered trees and clumps of grasses. Australian grassland is covered with tough Mitchell grass and kangaroo grass. Acacia bushes grow among these grasses. In Argentina, central Asia, and Russia, grasslands called steppes also have short grasses.

Many grassland plants have special features that help them survive dry conditions. Soft hairs on their leaves and stems help them hold water. Their roots spread out far and wide so they can collect water when rain falls.

Grasses don’t need as much water as trees and bushes do. So grasses grow well in wide, open places that are too dry for most trees but not dry enough to be deserts. These places are like giant lawns. They are called grasslands.

Grasslands are special in another way. They sometimes burn up naturally - and this helps them stay healthy! The fire burns the plants to the ground. The ashes feed the new plants that replace them.

Most big animals that live on grasslands, such as zebras, eat grass. Most small animals, such as rabbits, eat plant leaves and seeds. There are also meat-eating animals, such as foxes, snakes, and in some places, lions and leopards. Many meat-eating birds, such as hawks, hunt on grasslands.

It’s hard for a hunted animal to hide in grassland. The ground is low and flat, and there are few trees or bushes. Many animals crouch near the ground. Some, such as rabbits and zebras, can save themselves by running fast or skilfully. Others dig tunnels in which to hide.

Picture Credit : Google

 

Plants of the Temperate Forest Community

Temperate forests have many kinds of trees, shrubs, and other plants. They provide animals with shelter, food, and places to bring up their young. Broadleaf trees, such as oaks, maples, elms, lindens, beeches, and hornbeams, are the most important plants in these woodlands. Many smaller plants and shrubs grow on the forest floor. Wild flowers often cover the woodland floor in spring.

Do the trees where you live “change their clothes” during the year - from light green buds in the springtime, to dark green leaves in the summer, to reds, golds or purples in the autumn? If so, then they make up a temperate forest community.

Temperate means “mild”. Temperate forests grow where summers aren’t too hot and winters aren’t too cold, and where the ground gets just about the same amount of moisture all year. In spring, wild flowers bloom in a temperate forest. Then trees and bushes bud. Birds build nests. In summer, fruits and nuts grow and ripen. The woodland is filled with birds, squirrels, raccoons, and many other small animals.

In autumn, the leaves change colour. Most birds fly south for winter. Snakes, turtles, frogs, and many insects hibernate. So do some furry animals. But if the winter is mild, the animals stay active.

Sea otters inhabit the Pacific coast. These sleek, furry marine mammals have no insulating layer of fat like other animals that live in colder climates, but are kept warm by their fur and high metabolism.

Sea otters were hunted for their fur to the point of near extinction. In fact, sea otters have the densest fur of any mammal; the coat of a sea otter has over half a million hairs per 6.5 square centimeters! These animals are very clean as well; they wash themselves after eating and frequently clean their fur with paws.

The way sea otters eat is interesting; they use their stomach as a table. A sea otter eats in the water, lying on its back, with its food on its chest. Sea otters are the only otters to give birth in the water. Mother sea otters have the ability to nurture their young while floating on their backs.

Sea otters play an instrumental role in controlling sea urchin populations which would otherwise inflict extensive damage to kelp forest ecosystems (underwater forests).

The humpback whale is an enormous creature; it is as big as a school bus! It is known both for the howling sounds it makes and the amazing acrobatic abilities.

Humpbacks feed primarily in summer and live off their fat reserves during winter. They use many innovative methods for feeding. One such method is called bubble net feeding.

A group of whales will swim in a shrinking circle blowing bubbles below a school of prey. The shrinking ring of bubbles will encircle the school and confine it in an ever-smaller cylinder. This way, they can swallow thousands of fish in a single gulp.

Mother humpbacks swim close to their young ones, often touching one another with their flippers. Humpbacks roam all over the world and the place where they could be located depends on the time of the year.

The walrus has a unique look with a long tusk and a moustache. It is usually found in the Arctic Circle, basking along with its companions. Though it is extremely sociable and playful, a walrus can be really aggressive during the mating season.

The diet of a walrus usually consists of clams and mussels. It occasionally includes fish and even small seals. It roots along the ocean floor with its tusk and identifies its prey with its whiskers.

The walrus has an iconic tusk which it uses for a variety of reasons. It is used to haul its enormous body out of frigid waters, and to break breathing holes into ice from below. But it is not used to dig up food.

Walruses usually live in large groups numbering up to a hundred and above. They occupy the coasts and margins of ice shelves, where they periodically haul themselves onto beaches and ice floes to rest and bask.

Sea lions are relatives of seals and walruses. They can be distinguished by their external ear flaps, long fore-flippers, short, thick hair, and a big chest and belly. Their strong flippers and streamlined body make them well-adapted to the aquatic way of life.

California sea lions are known for their intelligence, playfulness, and noisy barking. Keeping their playfulness aside, they are skilled hunters - they can hunt continuously for up to 30 hours!

California sea lions are also known to cooperate with other predators like dolphins while hunting large schools of fish. They prey on a wide variety of seafood, mainly squid and fish, and sometimes clam. The fish and squid species they commonly eat include salmon, hake, Pacific whiting, anchovy, herring, rockfish, lamprey, dogfish, and market squid. Depending on how much food is available, they either eat alone or in groups.

California sea lions aren’t normally dangerous to humans, and attacks are uncommon, but they are large and unpredictable wild animals with sharp teeth; so it’s better to maintain a healthy distance!

The leopard seal is named after its black and grey spotted coat. It is also known as sea leopard. Its resemblance with leopards, however does not stop with the appearance. Like leopards, sea leopards too are fierce hunters.

Leopard seals are the most formidable hunters of all the seals. They are the only seals that feed on warm-blooded prey. They have powerful jaws and sharp teeth with which they devour their prey including small fish, squid and other seals. Leopard seals occupy Antarctic and sub-Antarctic waters, which give them an opportunity to prey on penguins as well.

The way a leopard seal hunts penguins is interesting. At first, it surveys the entire edges of the ice while remaining submerged. It then waits for the birds to enter the ocean and catches them while they are swimming. It grabs the penguin by its feet and shakes it vigorously until the bird is dead, a cruel death for the penguin indeed.