放牧对星毛委陵菜(Potentilla acaulis)种群生殖对策的影响

<title>Effect of grazing on reproduction in Potentilla acaulis population

在种群水平上系统研究了不同放牧强度对内蒙古冷蒿小禾草退化草原星毛委陵菜(Potentillaacaulis)种群克隆生长、有性生殖的影响,结果表明:星毛委陵菜匍匐茎长度在轻牧处理最长,而重牧条件下显著缩短;分株密度随放牧强度增加而增加。种群营养枝密度在不放牧与放牧处理之间差异显著,尤其是不放牧与重牧之间,而相邻放牧强度之间差异不显著。星毛委陵菜生殖枝密度在放牧处理间差异不显著,但不放牧与重牧差异显著,与轻牧、中牧差异不显著。种群生殖枝分化率不放牧显著高于中牧和重牧,但与轻牧间差异不显著。随放牧强度的增加,生殖枝上花序数目增加,但差异不显著。

<Abstrcat>The experiment on the effect of grazing on the clonal growth and sexual reproduction in Potentilla acaulis population was conducted in the degraded rangeland of Artemisia frigida with shortgrasses in Inner Mongolia. The results showed that Potentilla acaulis had the longest internodes length under slight grazing while internodes lengths shorten significantly under heavy grazing. And shoots densities increased with the increase of grazing intensities. The vegetative shoots density under no grazing was significantly higher than that under any grazing intensities. Grazing also affected sexual reproduction. There was no significant difference in sexual shoot densities between grazing treatments. The number of inflorescences per flowering shoot increased insignificantly with the increase of grazing intensities.