(also called timber line) the point on mountain or high elevations beyond which no trees grow. The line varies depending on latitude, climate and soil conditions. Also northern boundary of boreal forest.
Upper limit of normal tree growth. This varies across Scotland depending on the climate and soil type, and ranges from about 150m on the extreme north west coast to above 700m in the north east.
Either the latitudinal or elevational limit of normal tree growth. Beyond this limit, closer to the poles or at higher or lower elevations, climatic conditions are too severe for such growth.
line marking the upper limit of tree growth in mountains or northern latitudes
The upper limits of tree growth in mountains or at high latitudes.
The height on a mountain above which the climate is too cold for trees to grow
The point at which climate conditions are no longer hospitable for trees. In the Arctic, it is the point at which it becomes too cold to sustain tree life. (There are other tree lines in the Antarctic, on mountains, in deserts and in other regions.)
The farthest limit, either in altitude on a mountain, or the farthest north in the northern hemisphere, in which trees are able to grow. Beyond this line, the environment is too harsh for trees to survive.
The poleward limit of tree growth; the botanical boundary between tundra and boreal forest. The arctic tree line has been studied extensively, but in the Southern Hemisphere, a "tree line" can be inferred only by comparison of vegetation on islands in the southern oceans. See also timber line.