school energy&environment

Plants of the temperate forest

Unlike tropical forests, temperate forests have just two layers of vegetation. The tallest trees have their foliage generally about 15-30 m above ground and a layer of shrubs and smaller trees underneath, at approximately 5-10 m. This is why the soil receives more light than in tropical forests and the undergrowth is luxuriant: ferns, mosses and lichens, especially in very rainy areas.
During the spring growth, i.e. when the tree foliage has not completely formed yet, there is plenty of light reaching the ground and this makes plants grow on the ground. This is why many of the species that live on the ground grow, flower and bear fruits before late summer. Later on, sciophilus plants, i.e. plants that like shade, start to grow. These plants have extremely efficient mechanisms to capture and use low-intensity light and are able therefore to survive even when the foliage completely covers the soil underneath.
The main trees living in this biome are: beeches, sycamores, oaks, aspens, walnut trees, lime trees, chestnut trees, birches, elms and in America tulip trees.
The beech
Beeches (Fagus selvatica) can reach up to 40 mt tall and have a large, dome-shaped foliage. Their fruits, called beech nuts, look like chestnut husks, but their thorns do not prick since they are softer and more rounded. They prefer clayey and airy soils, in wet areas, away from harsh winter frost. They are common in Central and Western Europe, where they are largely used to make timber. They are not only extremely useful (furniture, parks, railway sleepers, cellulose), but also commonly used as ornamental trees.
Sycamore
Sycamores (Acer pseudoplatanus) live essentially in hilly and mountainous northern woods only, up to 1800 m above sea level. They grow quickly, they like fresh and wet soils and can reach up to 25-30 mt tall.
Oak
Oaks (Quercus spp.) are trees or shrubs that can reach up to 40 mt tall. Oaks can live to 500 – 1000 years of age. Their fruits are elongated acorns, protected at the base by a cup-shaped shell. They are widespread in tropical mountain areas (Mexico, Himalaya, Indonesia), in Mediterranean climates (California, Mediterranean areas) and in temperate climates (North America, Asia, Europe). Oaks are used to make timber, stairs, parks, furniture, casks and railway sleepers.
Aspen
Aspens (Populus tremula) are medium-size trees than can reach up to 25 mt tall. They grow quickly. They like warm and sunny areas. They are scattered about Central Europe and rarer in Western Europe. They can be grown on uncultivated land to graft them quickly and for long. They are very resistant to industrial waste, and actually grow well in town.
Walnut tree
Walnut trees (Juglas regia) are large trees that can reach up to 20 mt tall. Their fruits are stone fruits (they are fleshy fruits, i.e. the ovary wall that envelops the seeds becomes juicy when mature) with a green fleshy part (husk), which, when dry, releases its woody stone (walnut) which contains an edible seed rich in fats. Walnut trees are widespread everywhere as fruit trees and for their precious timber which is used to make furniture; they are productively grown in temperate areas: the most important walnut producing country are the United States.
Lime tree
Lime trees (Tilia cordata) are beautiful, straight-trunk trees that can reach up to 30 metres tall. There are a variety of lime trees, one of the most common ones being the Tilia platyphyilos. Wild lime trees can be found in coppices, bushes, sunny slopes and rocks, along riverbanks in the mountain and submontane areas of Central Europe; it is rarer in Western Europe. Lime trees are often used to shade town streets, to decorate parks and gardens. For its look and scent, the ancient Greeks have always associated this plant to womanliness; they actually considered it as Aphrodite’s favourite tree.
Chestnut tree
Chestnut trees (Castanea sativa) are big, 20-30 m tall trees. Their flowers are encased in a thorny “husk”, which is first green, then turns brown-yellowish. Once fecundated, it produces the fruits, i.e. the chestnuts. More specifically, these fruits can be called chestnuts if each husk contains two or three fruits. If a husk produces only one fruit, then such fruit, which is very big and spheroid, is called ‘marron’. Chestnuts ripen in autumn. Depending on the variety, some of which ripen earlier, some later, they can be eaten fresh from early September to early November.
Birch
Birches (Betula pendula) come from Europe and the south-east of Asia. They grow well in sandy and peaty soils. The genus takes its name from the Celtic betu. Silver birches are widespread in Europe, where they reach a latitude of 65° north and Sicily south. They love the sun, they grow alone or in small groups in hilly and mountainous sparse woods, along with broad-leaved and coniferous trees. In the wild state, they can grow even on dry and bare, preferably acid, soils, with enough water, and can tolerate the cold quite well. They are used as ornamental trees for their elegant deportment and the decorative colour of their bark and leaves., associandosi a latifoglie e conifere.
Elm
Elms (Ulmus carpinifolia) come from North-Africa, Europe and south-western Asia. They are Ulmaceae plants and can reach up to 30 m tall. Their foliage is hemispherical, their branches are thin and pale brown, their flowers are small and red. Their bark is grey-brown with deep furrows, their leaves are oval with a pointed end and a slanting base.
Tulip tree
Tulip trees (Liriodendron tulipifera) take their name from the fact their flowers are shaped like tulips. This species comes from the eastern part of North America and has been brought to our continent in the mid-17th century, when it was used as an ornamental tree for the beauty of its flowers and leaves and in Central Europe also to make timber. A heliophilus (that loves light), rural and long-living plant, it tolerates harsh cold quite well, but is very demanding when it comes to soil, that must be deep and fertile. The wood of the tulip-tree is pale yellow and is called “yellow poplar” because it looks like it; it is fairly good quality, woodworm-proof and can be used in a wide range of applications, especially in