Trends in woody vegetation cover in the Kruger National Park, South Africa, between 1940 and 1998

摘要: Changes in the cover and density of shrubs trees were assessed from aerial photographs (1940, 1974 1998) as well fixed-point taken 1984 1996 Kruger National Park, South Africa. Woody (trees combined) increased by 12% on granite substrates but decreased 64% basalt over past 58 years. Both these figures are expressed terms initial values, respectively. The large tree component woody vegetation both substrates. declined fire return periods became shorter, relationship was weak. increases plant thought to be result competition grasses, which turn is a overgrazing wild herbivores whose numbers have been kept high through provision surface water. These effects not seen relatively nutrient-rich basalts, where grasses can recover rapidly even after heavy grazing. decline overall basalts interpreted regular, short-interval prescribed burning 40 years, while universal seems an interaction between frequent fires utilization elephants. implications for management discussed.