Tree Line

The tree line is the edge of the habitat at which trees are capable of growing. Beyond the tree line, they are unable to grow because of inappropriate environmental conditions (usually cold temperatures or lack of moisture). Some distinguish additionally a deeper timberline or forest line, where trees form a forest with a closed canopy.

At the tree line, tree growth is often very stunted, with the last trees forming low, densely matted bushes. If it is caused by wind, it is known as krummholz formation, from the German for 'twisted wood'.

The tree line, like many other natural lines (lake boundaries, for example), appears well-defined from a distance, but upon sufficiently close inspection, it is a gradual transition in most places. Trees grow shorter towards the inhospitable climate until they simply stop growing.

Famous quotes containing the words tree and/or line:

    It is remarkable how closely the history of the apple tree is connected with that of man.
    Henry David Thoreau (1817–1862)

    The line it is drawn
    The curse it is cast
    The slow one now
    Will later be fast
    As the present now
    Will later be past
    The order is
    Rapidly fadin’.
    And the first one now
    Will later be last
    For the times they are a-changin’.
    Bob Dylan [Robert Allen Zimmerman] (b. 1941)