Shade-tolerant and -intolerant species

From Wikipedia, the free encyclopedia

Shade-tolerant species: are species of trees that are able to thrive in the shade, and in the presence of natural competition by other plants.

Shade-intolerant species require full sunlight and little or no competition. Intolerant species grow quickly in a clearing so that they will not be shaded by taller trees. They tend to grow in low stand densities, have shorter, cylindrical crowns and die earlier than tolerant species. Tolerant species grow slowly, but steadily and eventually overtake the tree stand. They tend to grow in high stand densities, have longer, tapered crowns and are long-lived. The wood of tolerant species is often harder as well. A clearing, like one produced by a forest fire, is necessary for intolerant species to regain control and forests without disruptions, naturally or unnaturally, may be composed almost entirely of tolerant species. Foresters can favor the development of intolerant species by leaving open spaces when logging. This can be done in pockets so that clearcutting is unnecessary.

Aspen, pine and poplar are very intolerant to shade and competition. Tolerant to very tolerant genera include beech, fir, hemlock and maple. Elm, oak, and spruce are intermediate in tolerance.

[edit] Source

• Tolerance of Tree Species

This article or section relies largely or entirely upon a single source. Please help improve this article by introducing appropriate citations of additional sources.