Short-term response of burnt grassland to defoliation in a semi-arid climate of South Africa

摘要: The impact of defoliation on the productivity and soil temperature burnt grassland (head back fires) was investigated over short term (one two growing seasons after burning). Head fires had greater flame height rate spread than fires. However, were more intense exceeded 100°C at ground level. Botanical composition little influenced by both head fires, though fire a drastic basal cover tuft die-back. Basal still 28% 11% respectively lower that unburnt grassland, one burning. Those grass species normally forming large tufts, such as Cymbopogon plurinodis Themeda triandra, greatest percentage die-back per tuft. Defoliation up to during October, rested for full season burning, significantly (P ≤ 0.01) lowered production subsequent seasons. For sustainable in this semi-arid area, it seems gr...