Response of soil macrofauna to desertification in Stipa breviflora desert steppe
Soil fauna is an important component of grassland ecosystems and plays a key role in maintaining the stability of ecosystem structure and functioning.Studying the response of soil fauna to desertification may reveal the ecological linkage between aboveground and belowground processes,and improve our understanding of the ecological consequences of desertification.A survey of the soil macrofauna community was conducted by hand sorting at No-desertification (Ⅰ),Lightdesertification (Ⅱ),Moderate-desertification (Ⅲ),Heavy-desertification (Ⅳ),and Extreme-desertification (Ⅴ) habitats in Stipa breviflora steppe.A total of 25 fauna groups belonging to 6 orders,2 classes and 1 phylum were found.The dominant groups were Formicidae and Scarabaeidae larvae with 8 common groups.Soil macrofauna communities in the Stipa breviflora steppe were similar to those in other areas in temperate prairies.As desertification progressed,the dominant groups (Formicidae and Scarabaeidae larvae) did not change.However,the structure of soil macrofauna communities became simpler with total individual density and number of soil animal groups (P ＜ 0.01,P ＜ 0.01),biodiversity (P ＜0.01),richness (P ＜ 0.01)and evenness indices (P ＜ 0.05) decreasing significantly.Soil fauna communities and soil animal groups in different habitats along a degradation gradient showed different preferences and responses to habitat factors.Desertification in the Stipa breviflora steppe affected the vertical distribution of soil fauna,with first affected individuals and then groups.The first effects were seen in the top layers and later in the deeper layers of the soil,but the highest faunal abundances were found in the top soil layers.The Light-desertification (Ⅱ) habitat was most preferred by the Formicidae,but food shortage resulting from desertification led to a decrease in Formicidae abundance.Soil total nitrogen,organic matter and aboveground dry biomass were the main factors affecting individual densities of Carabidae and Curculionidae larvae,which did not survive in Heavy-desertification (Ⅳ) and extreme-desertification (Ⅴ) habitats.Desertification had little effect on the total individual density of Scarabaeidae and Araneida.The degradation of grassland ecosystems was reflected by the relations among soil fauna,habitat factors,and desertification.
国家科技期刊平台
NSTL
万方数据
维普
