Unit 6: The diversity of the ecosystems                                      1   2   3

2.2. Biomes of temperate zones

a) The deciduous forest

This type of forest is found in middle latitudes with a mild, rainy climate (oceanic climate). There is no dry season. The summers are long and wet and the winters are not very harsh and have lots of precipitation, sometimes in the form of snow.

The typical flora is formed by trees like oaks, beech, chestnut trees, maples, and shrubs like heather, broom, blueberries and genistas. The trees in these forests are mainly deciduous, so the soil contains a large amount of organic matter, which is transformed into mineral matter by decomposers. As a result, the soil of the biome is very well developed. In Spain, this type of forest is found in the north.

The typical fauna is composed by mountain cats, birds of prey, martens, wild boards, dormice, deer, mice, moles, voles, as well as different species of birds and insects.

The animals and plants which inhabit these forests adapt to the changing conditions which determine the seasons. So, in winter the trees lose their leaves, many birds migrate, and amphibians, reptiles and some mammals usually hibernate.

The fertile soil in these regions and its capacity to retain water mean the land is perfect for cultivation purposes. So, large areas of these forests have been cut down in many regions of the planet and the land is used for farming.

b) The Mediterranean forest

Mediterranean forests are found around the Mediterranean region at altitudes between 800 and 1000 m. They are also found on the coasts of California (USA) and Chile, in the south of Australia, and in South Africa.

It is typical in the Mediterranean climate, which has hot, dry summers and warm winters. Rainfall is scarce and irregular, with most precipitation in the spring and the autumn. There is often an intense period of drought in the summer.

Mediterranean forests are also called sclerophyllous forests, because the trees have hard leaves. The typical vegetation of these forests is made up of plants which have adapted to arid climates. The leaves of the trees and shrubs are covered with a hard cuticle which prevents water evaporation. This is also why the trunks of the trees are covered with thick bark and tree roots grow deep down into the ground in order to find water.

It is very difficult to decompose this type of vegetation, so the soil of these forests is poor in humus and in mineral matter. It is not very fertile.

The most typical trees in this forest are cork trees and holm oaks. Nowadays stone pines are also found because they were planted to replace the holm oaks which had been cut down or destroyed by fire. There are also many shrubs in these forests, for example kermes oaks, strawberry trees, mastic trees, laurustinus and rockroses.

The fauna is mainly composed of mammals, such as wild boards, deer, bucks, rabbits, hares, foxes, mountain cats, lynxes, weasels, badgers, and small rodents. There are also reptiles, vipers and lizards for instance, and insects and birds. Many birds are migratory.

c) The steppe and the prairie

The steppe and the prairie are the grasslands of temperate zones.

- Steppe

Steppes are found in continental climates. This is the most common ecosystem found in dry Spain.

The vegetation is mainly composed of grasses and some low shrubs, such as the agave.

The fauna is abundant and varied: it includes a large variety of insects, small rodents, partridges, grouse, great bustards and birds of prey such as the kestrel.

- Prairie

Prairies are also found in continental climates; however, they receive more rain than steppes, and have longer summers.

The most common herbaceous plants are grasses. The fauna mainly consists of large herbivores, such as the bison, and carnivores, such as the coyote.

2.5. Animals that hibernate, such as bears, or migrate, such as gooses,

        belong to ecosystems  of temperate zones. Why is this type of animals

        not found in other kind of ecosystems?

2.6. What type of adaptations present the typical vegetation of sclerophyllous

        forests?  Put some examples.

2.7. Indicate what is the main difference between the prairie and the steppe?