Abstract: Biotic interaction is considered as an important driver for community assembly. However, it is still unclear for the interspecific associations of soil animal communities at different spatial scales. To reveal species composition, diversity and interspecific associations of ground Coleoptera adults at small scale, and to verify whether negative interspecific associations are common in congeneric/coordinal species pairs, an experiment was conducted in a 9 hm² permanent plot in a broad-leaved Korean pine mixed forest in Xiaoxing’an Mountains, Heilongjiang Province, China. Traps were used to capture ground Coleoptera beetles in August and October 2015. The results showed that: (1) A total of 1394 Coleoptera adults were collected in the two months, belonging to nine families and 58 species, in which Carabidae and Staphylinidae beetles were dominant in abundance. The abundance and species richness of Coleoptera in October were significantly lower than those in August. Moreover, the community diversity was significantly different between the two months. (2) The associations among individuals in Carabidae, Silphidae and Staphylinidae communities were significantly positive. The overlaps of spatial niche between two species from different families were narrow and the species associations between them were almost random. For beetles from the same family, most species pairs were random associations and few species pairs were significantly positive/negative associations. Our results demonstrated that the species composition and diversity were significantly different for ground Coleoptera adults in summer and autumn at small scale. Random associations were detected for almost all species pairs, whereas negative associations were not common for congeneric/coordinal species pairs.

Key words: nitrogen deposition, three-dimensional fluorescence spectra, enzyme activity., soil dissolved organic matter (DOM)