荒漠草原马粪中粪金龟子组成及分解作用

Dung beetle species composition and decomposition function in horse dung in desert steppe of Inner Mongolia

2007年4—10月,采用野外和室内实验相结合的方法,研究了荒漠草原马粪中的粪金龟子群落组成和对马粪分解的影响。共捕获粪金龟子13528头,隶属于3科4属26种,优势种为符号蜉金龟(Aphodius comma),占总捕获量的88.5%,不同季节粪金龟子群落组成明显不同;在鲜马粪中活动的粪金龟子以粪居型蜉金龟为主,在鲜马粪堆置3d时种数和个体数达到最高,6d后全部离开;马粪经过136d分解,残留率为52.5%,残留粪样中氮和磷释放较慢,钾释放较快;结合室内分解实验的结果,认为粪金龟子主要通过在马粪中活动对其分解产生影响,并与风蚀作用成为荒漠草原马粪块破碎的重要动因,主要发生在春季和秋季。

Field investigation and microcosm experiment were conducted to study the dung beetle species composition and decomposition function in fresh horse dung pats in desert steppe of Inner Mongolia.A total of 13528 dung beetle individuals were collected,belonging to 26 species,4 genera,and 3 families,among which,Aphodius comma was the dominant species,with its individual number occupying 88.5% of the total.The species composition of the beetle varied obviously in different seasons.In the fresh horse dung pats,endocoprids（Aphodius spp.） were dominated,with the species number and individual number being the highest within 3 days of fresh horse dung pats deposit and nearly disappeared after 6 days.After 136 days decomposition,52.5% of the horse dung remained,and the release rates of N and P from the remained dung were lower than that of K.It was suggested that dung beetle affected the horse dung decomposition mainly through its activities in the dung,and the beetle＇s activities and wind erosion mainly occurred in spring and autumn were the important factors for the fragmentation of the horse dung pats.