摘要
以草原生态系统顶级群落羊草样地(1979年围封)为对照,研究了同一生境下长期放牧后围封2年的新羊草样地的大针茅种群生殖器官和营养器官的变异。结果表明:新羊草样地大针茅植株变矮,丛幅显著减小,营养枝和生殖枝减少,且生殖枝减少更为显著,说明大针茅放牧后个体小型化,有性繁殖降低,新枝条形成时间提前,但也提前结束。此外,其种子长变短,芒柱变短、变细,芒针变弱但长度基本没有变。
Variations of vegetative organs and reproduction organs was observed at the Stipa grandis Yangcao sample plot(pasture was enclosed in 1979) and Xinyangcao sample plot which was overgrazed for a long period and just fenced 2 years ago.The result suggested that morphological variations were significant with plant height decreasing,either small,media and big plant circumference decreased.Reproductive shoot and new shoot were also decreased,and there was a significant decrease in reproductive shoot,which means after years of overgrazing,not only the plant individual miniaturized,the reproductive ability also decreased.The formation of new shoot appeared early and finished early too.In addition, the seed length and awn length became short,the awn and needle also became thinner,but the length of needle keep steady.
出处
《中国草地》
CSCD
2003年第2期13-17,共5页
Grassland of China
基金
国家自然科学基金(30060015)
内蒙古自然科学基金(20001303)资助项目
关键词
大针茅
放牧
形态变异
Stipa grandis
Grazing
Morphological variation
