Aforest is a piece ofland with manytrees. Forests are important and grow in many places around the world. They are anecosystem which includes many plants and animals. Manyanimals live in forests and need them to survive.
Temperature andrainfall are the two most important things for forests. Many places are too cold or too dry for them. Forests exist from theequator to near thepolar regions, but differentclimates have different kinds of forests. In cold climatesconifers dominate, but intemperate zone andtropical climates forests are mainly made up offlowering plants. Differentrainfall also makes different kinds of forest.
There are no forests indeserts, just a few trees in places where their roots can get some underground water.Aquifers beneath theSahara desert have plentiful water, and also beneath Australian desert areas. The general term for this is "groundwater".
Coniferous forests stretch acrossCanada,Alaska, Northern Asia, andNorthern Europe. Their main trees areevergreen conifers which produce seeds in cones.
The weather during the winter is cold, but when snow melts in the spring, some parts of the forest becomeswamps. There are not many different types of trees in coniferous forests because of the cold weather, and the poor soil. Fallen branches, needles, and dead animals do not decay as fast as in warmer regions. This is why the soil in coniferous forests is not very fertile. Also, only those trees that have adapted to cold weather and poor soil can survive. These trees have flexible branches that support heavy snowfalls. Less water evaporates from their leaves because of the shape of their needles.[3][4]
Many coniferous trees shade large parts of the soil below them, which keeps many plants from growing on the forest ground. Some animals that live in the coniferous forests arepine martens,deer,bears,caribou,moose, severalowls,crossbills, andred squirrels.
Deciduous forests mostly grow in thetemperate zone ofNorth America,Europe andAsia. They have a moderate climate during the spring, summer, autumn (fall) and winter, with rainfall of at least 500mm a year. Summers are warm and winters are cold, but not as cold as the northern coniferous forests. In the winter, snow covers the ground and the deciduous trees and plants lose theirleaves. The decaying leaves help make the soil rich innutrients. Many insects,spiders,snails, andworms make their homes in this rich soil. Wild flowers andferns grow almost everywhere in the spring. New leaves capture the energy of the sun and sprout before the tall trees shadow them.[5][6]
During the winter, many birdsmigrate to warmer climates. Many small animalshibernate oraestivate, in other words, they slow down theirmetabolism and sleep or stay in their burrows. Some of the other animals just slow down their metabolism and eat food they stored during the summer and fall months. The trees in winter are bare, but with the coming of spring, leaves sprout, birds return, animals are born, and all the forest animals get busy with their lives. Animals that we may see or hear in this biome includebears,deer,raccoons,otters,beavers,foxes,frogs,squirrels,snakes,salamanders, and birds such aswoodpeckers,robins (European or American),owls,blue jays and the small birds usually calledtits (familyParidae).[7]
Some deciduous forests grow intropical places that do not have a winter but do have a wet season and a dry season.
Tropical rainforests grow inSouth America, theCongo,Indonesia and some nearby countries,Hawaii, and north easternAustralia. Tropical rainforests are well named, as it rains here on about half the days. The only season in a tropical rain forest is summer, so plants grow for all 12 months of the year. Trees are tall and thick in the rain forest and they grow so close together that they form a big umbrella of greenery called a canopy. This blocks out most of the sunlight. The air is muggy as it filters through the dense canopy cover of the trees. The light that filters through this tree cover is dim and green. Only along river banks and in places that have been cleared does enough sunlight allow plants to grow on the forest ground.[8]
Millions of species of plants and animals live in the world's tropical forests. Life in the rain forest exists at different levels or layers in the trees. Each layer has a name, such as 'emergent', 'canopy', 'understory', and 'forest floor'. Animal life is found on all levels.
An etching shows the way forests might have looked in the Carboniferous period
The first forests on Earth were about 380million years ago), in the laterDevonian period.Archaeopteris grew to about 10 meters tall (33 feet). The plant was ratherfern-like, with deciduousfronds which dropped onto the forest floor. Streams running through the forest picked up fronds, which perhaps stimulated freshwater fishes.Wattieza was an even earlier plant which has been claimed as the "first tree". They were also fern-like, reproduced withspores and grew in groups together.
↑ Vogt, Kristina A, ed. 2007. Global societies and forest legacies creating today's forest landscapes. In:Forests and Society: sustainability and life cycles of forests in human landscapes. CABI. pp. 30–59.ISBN 978-1-84593-098-1
