Are defoliators beneficial for their host plants in terrestrial ecosystems—a review?

摘要: The impact of herbivory on food plants has engaged mankind for millennia. detrimental browsing by cattle the performance seedlings and young trees species other than crop was noticed long ago, e.g. Scotch pine Surrey heaths (Darwin 1859). For more a century physiologists have studied responses defoliated (Vochting 1884, Reinke Kny 1894). Since seventies ecologists developed number hypotheses to describe defoliation under field conditions. It been hypothesized that certain conditions may result in better growth and/or higher fitness (Harris 1973, Owen & Wiegert 1976, 1980, McNaughton 1983a). In this paper these hypotheses, especially those possible beneficial defoliation, are discussed, survey is given, finally which effects occur summarized.