摘要
根据对大针茅（Ｓｔｉｐａｇｒａｎｄｉｓ）繁殖的研究和分析，本文提出：生殖枝分化比例低，种子产量和埋藏率低，幼苗成活率低是大针茅有性繁殖微弱的主要原因。这种情况在退化群落更加严重。大针茅在春季不形成分蘖芽，１个分蘖枝条在秋季可在基部形成２～４个分蘖芽，枝条分蘖比率和每个枝条形成的分蘖数在群落退化后变化不明显。但株丛的大小，种群的密度和大针茅的竞争力都大大降低。围栏保护后大针茅依赖营养繁殖迅速恢复。
Based on the investigation on characteristics of sexual reproduction andvegetative propagation of Stipa grandis,this paper puts forward that the low rates ofreproductive shoots differentiation,seed yieles,buried seeds and seedlings survival arethe reasons for the weak sexual reproduction of Stipa grandis.It was most severe in thedegenerated community.Stipa grandis cannot form tillers in spring.A reproductivetiller can produce 2-4 tillering buds in Autumm.The rate of reproductive tiller and thenumber of tillering buds produced by a reproductive shoot do not change significantlywith degeneration severitmes.The size of stands,population density and thecompetitivity in the degenerated community are much lower than those in the controlcommunity.After protected the population of Stipa grandis renews rapidly throughvegetative propagation.
基金
国家自然科学基金
