The influence of rainfall and grazing on the population and compositional response of some Savanna grasslands.

[摘要] The study aimed to differentiate the effect of rainfall and grazing onthe compositional change of savanna grasslands, and to explain responsesin terms of the life history patterns of the main species, An extinctionprone perennial grass under heiry grazing was identified as a palatable,obligate seed reproducer with low seed production and poor dispersal (e.g.Themeda triandra and Reteropogon contortus), wnich could become extinctif the established population and the seed bank were eliminated. Aristridaspecies were expected to show the converse pattern. Grazing wasmanipulatedfor three or five years, and rainfall for one year, on asandveld site, and two clay soil sites which supported the same speciesin different amounts, respectively. (Abbreviation abstract)

[发布机构] University of the Witwatersrand