Intra- and interspecific interactions and environmental factors determine spatial–temporal species assemblages of rodents in arid grasslands

Abstract

Many factors have been shown to affect species assemblages of a community, but studies using long-term spatial–temporal community data are still lacking. In this study, by using population abundance data of 14 rodent species over 25 years in 21 sampling sites, we investigated the effects of taxonomic relation, density dependency, species interaction and climate variation in determining spatial–temporal species assemblages of rodents in arid grasslands of Inner Mongolia in China. By the use of GAMM analysis, we found that intraspecific interactions were more common and more significant than interspecific interactions. Negative interactions between species of the same genus were more common than negative interactions between species of different genera. Dominant species show negative interactions on less abundant or rare species. Positive interactions often occur within rare or less abundant species. Through cluster analysis, we found species assemblages of rodent communities are well explained by assemblages of environmental variables, and species of same genus tend not to occur together as compared to species of the same family. Our results indicate that resource partitioning through intra- or interspecific competition and environmental filtering by climate and vegetation are important forces in shaping the spatial–temporal community structure and the dynamics of small mammal populations in an arid grassland landscape.