Soils and habitat

The big categories of soils are limestones (alkaline, pH> 7) and clay soils (acid, PH <7), which come from the decomposing rock: the Provençal mountains are calcareous, while the Hercynian massifs (Massif central, Armorican Massif) are sour. The peaty soil is typically sour (and it is suitable for plants " acidophiles ", rhododendron, azaleas).

Most trees prefer clay soils, therefore sour, which keep the water, while limestones, more permeable, dry out fast and warm up. The trees which do not support limestones are "calcifuge" (The word is derived from a latin word meaning 'to flee from chalk'). Trees preferring limestones are rarer: they are said "calcicole". See the list

To feed, trees also scoop out some nitrate of the soil: they are nitrophile. But some pioneer species accept poor soils, because they adapted a technology to extract the nitrogen from air. For this, they join mushrooms fixed on their roots (alder) or bacteria (Rhizobium of the family of leguminous plants).

Humidity and drought are also habitat distinctives: the trees which grow preferably in humid zones are said hygrophilic. Those which fit to drought are xerophilous. See the list

Other necessary factor (in photosynthesis): sunny position. Some species need light: they are heliophilous. Those which support the shade are shade plants.

The appearance of forests is the logical culmination of a natural process: a moor or an uncultivated abandoned agricultural ground (ground a priori richer than the moor unless it was exhausted by cultures) is colonized by so called pionee species, few demanding as soil but demanding in light: Scotch Pine, Birch. The fall of leaves and of pine needles maintains a humus (rather acid in the case of the pine), which can receive shade species (beech, fir). These are going to rise so as to pick up the light, making shadow to the young shoots of the previous species, which turn white and cease renewing.

Finally, some species fit in seaside, what does not prevent them from losing its shape in the wind, and from developing less on the side exposed to the wind. Others support altitude.

  1. Trees of full light

  2. The growth of a tree in undergrowth is considerably decelerated. If shade is dense, the more difficult is growing, often without blossoming nor fructification. Here is the list of trees requiring a full light : click here.

  3. Trees tolerating shade
  4. Few trees search shade, because by definition, light is their source of growth. However some conifers demand covered setting at the beginning of their installation:
    False cypress, Chamaecyparis
    some Pines, Picea
    Fir, Abies
    Eastern Arborvitae, Arborvitae occidentalis

    Here is the list of trees which accept shade : click here.

  5. Trees tolerating the sea air (halophilous)

  6. Salt air is dangerous, it burns leaves, and at times far inside lands when the wind blows from the sea. One saw the foliage of trees burnt at 3 km far from the shore.
    •  Deciduous trees

    • The most salt-tolerant species are :
      Tree of Heaven, Ailanthus altissima
      Arbutus, Arbutus
      Cork oak, Quercus suber
      Evergreen oak, Quercus ilex
      Blackberry with leaves of plane tree, Morus platanifolia
      Russian Silverberry, Elaeagnus angustifolia
      Olive tree, Olea europea
      Wych Elm, Scots Elm, Ulmus montana
      Pterocarya in leaves of ash, Pterocarya fraxinifolia
      Wisconsin Weeping Willow, Salix alba
      Goat Willow, Salix caprea

      Resistant to the saline spray :

      Hawthorn monogynous, Crataegus monogyna
      Wood of St Lucia, Prunus mahaleb
      Birch, Betula
      Wintersweet or odorous Wintersweet, Chimonanthus praecox, Chimonanthus fragrans
      Maple of Montpellier, Acer monspessulanum
      Norway Maple, Acer platanoides
      Sycamore, Acer pseudoplatanus
      Ash, Fraxinus excelsior
      Holly, Ilex aquifolium
      Southern magnolia, Magnolia grandiflora
      Chestnut tree, Aesculus hippocastanum
      Gean, Prunus avium
      White mulberry, Morus alba
      White Poplar, black, trembles, Populus alba, nigra, tremula
      Pittosporum, Pittosporum tobira
      Pissardi Cherry Plum, Prunus cerasifera
      Tamarisk, Tamarix
      Crimean Linden, Tilia euchlora

    • Conifers
    • Very resistant to the saline spray :

      Araucaria of Chile, Araucaria araucana
      Cryptomeria of Japan, Cryptomeria japonica
      Cypress of Monterrey, Cupressus macrocarpa
      White Fir, Picea pungens " glauca ", sitchensis
      Pine of Alep, Pinus halepensis
      Laricio pine, Pinus laricio "forms"
      Maritime pine, Pinus pinaster
      Umbrella Pine, Pinus pinea
      Scotch Pine, sylvan Pinus

      Resistant to the saline spray: 

      False Cypress, Chamaecyparis
      Umbrella Pine of Japan, Sciadoptys verticillata
      Fir pectinate, Abies pectinata
      Douglasfir, Pseudohemlock douglasii
      Grand Fir, exaggerated Abies
      Western red cedar, Arborvitae plicata
      Eastern Arborvitae, Arborvitae occidentalis

  7. Trees tolerating altitude
    •  Deciduous trees

      Whitebeam, Sorbus aria
      Whitish alder, Alnus incana
      Birches, Betula
      Spanish chestnut, Castanea sativa
      English Oak, Quercus pedonculata
      Norway Maple, Acer platanoides
      Sycamore, Acer pseudoplatanus
      Beech, Fagus sylvatica
      Common Holly, Ilex aquifolium
      Smoothleaf Elm, Ulmus campestris
      Elm of mountain, Ulmus montana
      Poplars, Populus
      Locust tree, Robinia pseudoacacia
      Willows, Salix
      Rowans, Sorbus aucuparia
    • Conifers : most support altitude.

      Araucaria of Chile, Araucaria araucana
      Cypress of the Arizona, Cupressus arizonica
      Norway Spruces
      Common Juniper, Juniperus communis (dwarf in altitude)
      most Pines (except the Maritime pine)
      most Firs, of which the Fir pectinate, Abies alba
      Douglasfir, Pseudohemlock douglasii
      Giant, Sequoiadendron giganteum Sequoia
      Western red cedar, Arborvitae plicata
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