Anthropogenic Vegetation

the aggregate of phy-tocoenoses created by man or altered by his activity. Human influence on vegetation may be direct (for example, in mowing hay, grazing cattle, or cutting forests) or indirect (for example, in fertilizing meadows, draining swamps, or polluting the water and air). Other indirect influences are seen in flooding created when building reservoirs; the erosion that follows plowing; the destruction of soil and vegetation at quarries, field boundaries, screes, dumps, ruins, and banks; and the replacement of destroyed vegetation with cultivated vegetation, such as plantings, sown meadows, gardens, parks, and forests. Anthropogenic vegetation, like natural plant communities, has its own forms of self-organization and self-regulation which are expressed to varying degrees (usually to lesser degrees than in communities of natural vegetation). Communities of cultivated plants, which are becoming increasingly important in the vegetative covering of the earth, are an exception. In such communities man himself regulates the relationships between the plants as well as between the plants and the environment. When man ceases to act on the communities that he has altered, they frequently revert almost to their original state (for example, the restoration of forests in cleared, plowed, and burned areas; of the steppe on idle lands; and of swamps in drained areas when the reclamation works are removed).