Growth and shape of trees - page 1/4 |
A tree is going to grow from the young plant to the grown-up tree, in 20 - 50 years for the most common Species. If I plant a tree (in general it is in its fourth year of culture), I want to see it growing under my eyes, therefore that it attains some metre high before its tenth year. According to its shape, its staggering will be reduced (shape fastigiate) or important (weeping or spreading shape). Optimum size and acceptable shape depend on the environment: a city garden (less than 1000 m ² and very often less than 300 m ²) will hardly support large trees as oaks or chestnut trees. They will prefer Species with slow growth which I describe below.
the shape of a tree is also interesting to notice to identify the tree in winter. The following shapes are differentiated:
the fastigiate shape, the typical type of which is the Lombardy Black Poplar, that edges channels and man-made lakes. Many cultivars were created with a shape fastigiate. | |
the columnar shape, or "fastigiate", but narrower and more cylindrical. Example: the Cypress. | |
the conical or pyramidal shape (conical) of some conifers (Norway Spruce, Larch), and Alder, which also resembles them because it produces fruits in cones. | |
the spreading shape, for example of Ginkgo, which carries almost horizontal branches (they are said "plagiotropics"). Its foliage is scattered. As to most conifers, the growth of stems occurs at the same time by the lengthening of the long stems and by the appearance of lateral, short stems. | |
the broad shape of the English Oak: its branches are tortuous and massive. Its light foliage lets penetrate light in the undergrowth. | |
the shape graduated by the Cedar: branches are massive, in arch. With age, the crown widens in table (like the Fir). Cedars resist the big storms better than most conifers. | |
the weeping shape the most known representative of which is the weeping willow. Many cultivars are weeping. | |
the shape with pendulous branches (not weeping) of the Common birch or of the Fir of China. | |
the shape multi-trunk (several trunks) of the Hazel and of Japanese Maples. | |
the tortuous shape (branches and tortuous stems) of the Hazel and the "tortuous" Beech (uncommon trees). |
Of course the growth of trees depends on environment (climate, habitat, wind, soil), but usually, we notice, under european climates, the growth on next page.
Trees are less tall in Europe for introduced species than in their homelands for the simple reason that they have been introduced there less than 3 centuries ago and they have not shown all their ability: large conifers from North America and the cedars are half tall in Europe than in their native habitat. The world's tallest, the Sequoia Redwood (not the giant Sequoia) reaches 113 m in America, half in Europe (it was introduced into 1840). Worse, the oxydendum arboreum is a tree reaching 18 m in North America, and a shrub 3-4 m in France. Similarly, Katsura (Cercidiphyllum japonicum) is a handsome ornamental shrub in Europe, and a tree 30 meters in China. Note that by convention, a tree exceeds the size of six to seven meters at maturity. A shrub does not reach it. Another difference between a tree and shrub: the first supports its branches around a central core, while the shrubs produce several stems. Thus, the hazel is a shrub that grows by annual releases, even if it is cut vigorously. The hazel of Byzantium (the like) is a tree. As for life of trees, this is more important for the forest officials than individuals. Know that the oldest tree is a pine tree which grows in Tasmania Huron (off Australia). It would have 10,500 years.
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