Growth - a young generation of trees that has grown under a forest canopy or in a place free from forests (cutting, burning, etc.) that can become the main tier of the stand (what is different from the underbrush [1] ). The origin of the undergrowth can be both seed and vegetative . Usually they distinguish directly undergrowth and “seedlings” of seed origin ranging in age from one to three to five years (in the north to ten years). "Shoots" depending on the seeds are distinguished by:
- self - sowing - for heavy seed breeds (conifers and some hardwoods)
- raid - for breeds with light seeds (some deciduous species, for example, birch, aspen) [2]
Undergrowth group of age - young . Even in the same age undergrowth, differences in various characteristics are noticeable: in height, thickness, foliage, and the like. Lighting, temperature, soil, the closeness of the existing canopy are the main factors that determine the intensity of the canopy development. Individual trees, both older and those in this undergrowth, have an impact. The most viable and economically valuable are the undergrowth groups formed by the same breed , that is, creating a pure forest plantation . The undergrowth is good for the environment, thanks to it the trunks of older generations are less overgrown with branches. For the emergence and preservation of undergrowth produce activities that promote the natural renewal of the forest, for example, thinning , gradual cutting, selective cutting, the creation of forest belts and much more. Places with disturbed closure of the forest canopy are usually the best for the natural development of undergrowth [3] .
The undergrowth can be either natural or artificial or combined . The origin of the undergrowth can be continuous, preliminary, concomitant and subsequent renewal, and, moreover, mixed. The main characteristics of undergrowth are: the number of plants per unit area (in absolute units), density, occurrence, quality. Different systems for evaluating a particular undergrowth have from two (viable - non-viable) to six levels [4] .
Notes
- ↑ Underwood // Forest Encyclopedia / Ch. editor GI Vorobyov. - M .: Owls. Encyclopedia , 1986. - T. 2. - 631 p. - 100 000 copies
- ↑ Podrost / / The Great Soviet Encyclopedia : [in 30 t.] / Ch. ed. A. M. Prokhorov . - 3rd ed. - M .: Soviet Encyclopedia, 1969-1978.
- ↑ Undergrowth // Forest Encyclopedia / Ch. editor GI Vorobyov. - M .: Owls. Encyclopedia , 1986. - T. 2. - 631 p. - 100 000 copies
- ↑ Encyclopedia of forestry. - M .: VNIILM, 2006. - T. 2. - 416 p. - ISBN 5-94737-023-9 .