退化程度对紫花针茅花期种群构件生长及生物量分配的影响

Effects of Degradation Degree on Modules Growth and Biomass Allocation of Stipa purpurea Population at Flowering Stage

以新疆巴音布鲁克高寒草原建群种紫花针茅种群为研究对象,采用野外调查和室内分析相结合的方法,分析了退化程度对紫花针茅种群构件形态生长和生物量分配的影响。结果表明:随着退化程度的增加,紫花针茅种群高度和个体生物量显著降低(P<0.05),分蘖节和茎的直径呈现增加的趋势,而根长、茎长、叶长、花序长呈现减少的趋势。未退化草地生物量分配趋势为营养分配>繁殖分配>贮藏分配,而退化草地为营养分配>贮藏分配>繁殖分配。紫花针茅花序生物量与个体生物量呈显著线性正相关关系(P<0.05),随着退化程度的增加,花序生物量的增长速率显著降低。紫花针茅种群在不同退化程度的草地中具有较强的形态可塑性。

The effects of different degradation degree on modules morphdlogical growth and biomass allocation of Stipa purpurea population were analyzed using sampling method and indoor experiment method. The results showed that： with the increase of the degree of degradation, the height and individual biomass of Stipa purpurea population significantly reduced（P〈0.05）, the diameter of tiller node and stern of Stipa purpurea showed a trend of increase, but the length of root, stem, leaf and inflorescence showed a trend of decrease. The above biomass al- location of non--degraded grassland showed nutrition allocation 〉reproduction allocation〉storage allocation, but degraded grassland showed nutrition allocation〉 storage allocation 〉reproduction allocation. And there was a lin- ear and positive correlation between inflorescence biomass and individual biomass, With the increase of the degree of degradation, increasing rate of inflorescence biomass showed remarkably reduced. Stipa purpurea showed a strong morphological plasticity in grassland of different degraded degree.