Review. Impact of grazing on plant communities in forestry areas

Abstract

The depopulation of mountainous areas and the accompanying reduction in livestock that has traditionally grazed on the spontaneous vegetation of these areas, has led to the uncontrolled growth of shrubs and a significant increase in the risk of fire due to the increased availability of combustible fuel. The reintroduction of extensive grazing may be a viable way of ensuring a sustainable ecosystem compatible with the economic and social life of these areas. Modifications to native plant communities as a result of grazing, however, may lead to directional changes in their structure and composition. Thus, knowledge of animal-plant relationships is essential if foresters are to make appropriate management decisions. Current knowledge of these animal-plant interactions is here reviewed, with special attention paid to tolerance mechanisms, the effects of grazing and plant community dynamics.