封育对盐生假木贼荒漠和博乐绢蒿荒漠群落特征的影响

以盐生假木贼荒漠和博乐绢蒿荒漠为对象,采用野外简单取样的方法,探讨两种荒漠中围栏内外群落数量特征和植物多样性对短期封育的响应及封育效果,结果表明:(1)与自由放牧区相比,盐生假木贼荒漠短期封育(6a)后植物群落地上生物量、盖度、高度、丰富度指数、均匀度指数和多样性指数显著提高(P<0.05),但密度显著降低(P<0.05);博乐绢蒿荒漠群落数量特征和植物多样性对短期封育(5a)的响应较小。(2)从类型上看,盐生假木贼荒漠封育区高度、盖度、多样性指数和均匀度指数比博乐绢蒿荒漠封育区高28.3%~47.5%,差异显著(P<0.05);而盐生假木贼荒漠自由放牧区高度、丰富度指数、Margalef指数比博乐绢蒿荒漠低23.3%~49.5%,差异显著(P<0.05)。总之,短期封育有利于退化盐生假木贼荒漠草地的恢复和植物多样性的维持,但对博乐绢蒿荒漠影响较小,表明围栏封育效果与荒漠草地类型有密切关系。

Effects of Short-term Enclosure on Community Characteristics in Anabasis salsa Desert and Seriphidium borotalense Desert

In order to investigate the effect of short-term non-grazing on community characteristics,we used the method of combination field survey with the laboratory analysis to explore the quantitative characteristics of the community inside and outside the fence in Anabasis salsa desert(6 years of enclosure)and Seriphidium borotalense desert(5 years of enclosure)and the response of plant diversity to short-term enclose.The results showed that:(1)Compared with the free grazing area,the aboveground biomass,coverage,height,richness index,evenness index and diversity index of the plant community increased significantly after short-term enclosure(6a)of the A.salsa desert(P<0.05),but the density decreased significantly(P<0.05);the population characteristics and plant diversity of S.borotalense desert responded to short-term enclosure(5a)was lesser.(2)From the perspective of type,the height,coverage,diversity index and evenness index of the enclosure area of A.salsa desert were significantly higher by 28.3%~47.5% than those of S.borotalense desert;while the height,richness index and Margalef index of the free grazing of A.salsa desert were significantly lower by 23.3%~49.5% than those of S.borotalense desert.In conclusion,short-term enclosure was beneficial to the restoration of vegetation and the maintenance of plant diversity of the degraded A.salsa desert,but had little effect on S.borotalense desert,indicating that the enclosure effect was closely related to the type of desert grassland.