The small-scale structure of a soil mite metacommunity

Abstract

The metacommunity theory has advanced our understanding of how local communities are structured at multiple scales. However, few studies have addressed the distribution patterns of the metacommunity at a small scale, particularly for those organisms living in belowground ecosystems. Using a combination of the elements of metacommunity structure (EMS) and the null model analyses, the small-scale (50 m) spatial pattern of a soil mite metacommunity was identified in a temperate forest in 2012 and 2013. This study evaluated whether species replace each other across consistent environmental gradients and whether a significant competitive structure exists in the entire community. According to the results of EMS analysis, the soil mite metacommunity showed a Clementsian structure (a grouped distribution of species along environmental gradients), which was significantly correlated with moisture in 2012 and associated with moisture and food resources in 2013. Moreover, the patterns of the soil mite metacommunity were similar in both years. Based on the results of the null model analysis, a non-random co-occurred pattern with more significantly aggregated species pairs and the Pianka's overlap index, which was significantly larger than the randomness model, were detected in each year, indicating a non-competitive community. In conclusion, the study indicated that the environmental filtering with moisture and food resources was an important driver in shaping the soil mite metacommunity into a small-scale Clementsian structure, while interspecific competition was likely not influential.