刈割频度对普通野生稻实验种群的影响

本文通过考察普通野生稻(Oryza rufipogon)实验种群对不同频度刈割的反应，揭示刈割对该种群的密度、株高、生物量、单枝生物量和有性生殖份额等有明显的抑制作用，对累积株高增长和光合系统份额则有一定的促进作用。刈割频度越大，作用越大。但对后两者的促进是以消耗地下部分的物质和能量为前提的，超过一定频度的刈割不仅可使其有性生殖份额降至零，还可导致种群消亡。提示过频破坏普遍野生稻地上部分是该种部分种群发生地方性绝灭的重要原因之一。

EFFECTS OF CUTTING FREQUENCY ON THE EXPERIMENTAL POPULATION OF COMMON WILD RICE ORYZA RUFIPOGON

The effects of cutting frequency on the growth and reproduction of common wold rice (Oryza rufipogon), an endangered species, were studied with an experimental population cultivated in Wuhan (114˚18′E, 30˚32′N). Cutting above-ground part inhibited obviously shoot density, height, above-ground biomass, biomass per shoot and percentage of sexual reproduction while it promoted to some extent the accumulated shoot height and the percentage of photosynthesis system. The more frequently the cutting was made, the stronger the effects were. The Promotion, however, was promised at the expense of material and energy from the below-ground stems and roots. An excessive cutting would reduce not only the sexual reproduction but also the growth to such a large extent that the population could be no longer existence. This indicates that over-frequent destroying the above-ground part of common wold rice might be one of the most important reasons for local extinction of some populations of the species.