临时公路干扰对高寒荒漠草原草地群落的影响——以阿里地区沙生针茅型草地为例

Influence of Temporarily Road Disturbance on High and Cold Desolate Grassland Community---Taking the Stipa Glareosa Grassland in Ali Tibet as an Example

通过对临时公路干扰下西藏阿里地区温性荒漠草原草地的调查研究,从群落特征、多样性、生产能力和有性更新能力几个方面分析其对干扰的响应和作用规律。结果表明,不同程度的干扰群落特征具有明显的变化,中度干扰下第一优势种(沙生针茅)重要值增加,第二优势种(轮叶棘豆)下降,群落中开始有新的物种入侵(高原芥、灌木亚菊)。重度干扰下第一优势种(沙生针茅)重要值迅速降低而被高原芥取代,群落特征发生质的变化。中度干扰下群落多样性程度最高,重度干扰下最低。中度干扰下群落生产能力下降显著,地面生物量仅为原始群落的50.97％,经济类群变化不大;重度干扰下群落地面生物量为原始群落的45.14％,同时其经济类群发生显著变化。中度干扰下群落保持了相当的有性繁殖能力,重度干扰则使群落基本丧失了原有的有性繁殖能力。

A study on the high and cold desolate grassland of Stipa glareosa in Ali Tibet was conducted. The result shown that the community character depends on the degree of disturb,the Ⅳ(importance value)of Stipa glareosa increased under middle level disturb and decreased under heavy disturb, at the same time the superior spice is became Christolea crassifolia. The spice diversity of the middle disturbing community is highest, it is decreased greatly under heavy disturb. The yield of middle and heavy disturb community are decreased both, but the quality of heavy one is changed much. The number of germinated seed of no disturbing community is the most, the second is the middle one, the heavy one almost lost the ability of reproduce through seed.