阿拉善地区人为干扰下啮齿动物群落的β多样性

Beta diversity of rodent community exposed to human disturbances in Alxa area

采用标志重捕法对阿拉善荒漠区2002—2010年4种不同人为干扰生境(禁牧区、轮牧区、过牧区和开垦区)中的啮齿动物进行了调查,计算不同生境梯度中啮齿动物群落的Jaccard、Sorenson和Cody指数,分析其在不同生境梯度中的β多样性变化特征.结果表明,3种指数均表现为过牧区到开垦区、禁牧区到开垦区、轮牧区到开垦区的β多样性指数变化较大,且与其他各梯度的差异具有高度统计学意义(p<0.01).对各生境鼠种的主成分分析结果表明,不同生境中组成啮齿动物群落的优势种不同,尤其是原生基底荒漠景观被开垦为农田后,其β多样性变化最大,这主要是由于原生植被破碎化后,原有优势鼠种消失和新物种增加所致.

Rodent community in four human disturbed habitats（prohibited-grazing,rotational-grazing,over-grazing and reclamation area）of the Alxa desert was investigated from 2002 to 2010 by mark-recapture method. Jaccard,Sorenson and Cody indices were used to analyze the variation characteristics of β diversity in different habitat gradients. The results showed that three β diversities indices in prohibited-grazing to reclamation area,rotational-grazing to reclamation area and over-grazing to reclamation area changed greatly,which showed statistically significant difference（p〈0.01）with other gradients.The rodent species in each habitats were analyzed by the principal component analysis（PCA）,and the result suggested that the dominant rodent species in communities were various in different habitats. Especially the greatest change of the β diversities occurred after the native matrix landscape of desert was converted to farmland,mainly due to the native vegetation fragmentation which leaded to the disappearance of dominant species and immigration of new species.