黄土高原沙打旺草地群落生态的研究

Study on Community Ecology Grassland of Astragalus Adsurgens in the Loess Plateau

试验于1981～1988年在黄土高原半干旱的固原县河川北山人工沙打旺草地进行。结果表明:沙打旺从兴到衰,出现一较快的演替系列,其重要值有显著的变化。生长3～6年沙打旺繁茂,但天然牧草受到抑制,由于沙打旺发达的根系,可充分利用土壤深层水分。衰败沙打旺草地水分渗透速率比天然草地和农地快,但上层土壤含水量恢复较好,这样其它野生植物在衰败地上生长较好。沙打旺的根有固氮能力,可改变土壤理化性质,培肥土壤,促进其它植物的生长。

The experiment was carried out at grassland Astragalus adsurgens from 1981 to 1988 years in Guyan county He Chuan North mountain semi--arid zones of the Loess Plateau. The result showed that the proless of A. adsurgens from thriveing to dwindling is a faster evolution system the important value changed obvious ly. A. adsurgens grew well between 3 and 6 years, but A. adsurgens of natural grassland grew bad. Because A. adsurgens has large roots system, it can absorbed larger deep water from the soil. The water permeated speed in degeneration A. adsurgens lands is higher than that in the natural grassland and farmland, but its water of up soil layer recover fast, there for the others natural plants grew very well. A. adsurgens root system have nitrogen fixation ability. That can change the composition of soil improve the soil feature and other plants growth.