Species richness and temporal partitioning in the beetle fauna of oak trees (Quercus robur L.) in Richmond Park, UK

Abstract

1. Species richness, abundance, body size, biomass, guild structure and temporal partitioning were examined in samples of 150 beetle species from oaks (Quercus robur L.) in southern Britain. 2. Abundance, species richness and biomass were highest in late June when leaves are in full flush, similar through much of the year for oak specialist beetle species, but were highest in July for generalists. Body size did not appear to vary significantly during the sampling period. 3. Temporal partitioning of feeding guilds was evident; predators and herbivores, peaked earlier in May-June, and fungivores and scavengers peaked in July-August. 4. Groups of closely related species, in Carabidae, Cantharidae and Curculionidae, often had similar seasonal patterns suggesting that temporal variation in both overall species richness and abundance for different guilds may be driven by resource availability rather than competition between closely related species. 5. Multidimensional scaling ordination shows an almost circular pattern in the beetle community underpinned by the most abundant species occurring throughout the year; vector analysis indicates that as temperatures increase and food resources become available, other species become abundant and influence patterns of similarity. 6. These patterns are also influenced by species that (i) have life cycles of 2 or more years, (ii) move between the ground, tree trunks and the canopy during the year and (iii) move from other tree species to oaks as these tree species lose their leaves earlier in Autumn. 7. The hypothesis that temporal patterns for invertebrate species in temperate trees are more coordinated than those in tropical trees is not supported.