Changes in oribatid mite community structure associated with the succession from heather ( Calluna vulgaris) moorland to birch ( Betula pubescens) woodland

• Published in: Pedobiologia Vol. 50; no. 4; pp. 323 - 330
• Main Authors: Osler, Graham H.R., Cole, Lisa, Keith, Aidan M.
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01-01-2006
• Subjects: Oribatid mites; Secondary succession; Species richness; Oribatid mites; Secondary succession; Species richness
• ISSN: 0031-4056; 1873-1511
• DOI: 10.1016/j.pedobi.2006.05.001

Factors determining the total and relative abundance of oribatid mite communities have been well described. In contrast, the factors that determine species composition and species richness of this fauna are far less understood. We tested the hypothesis that oribatid species richness would increase in the secondary succession from heather moorland to birch woodland. This secondary succession is associated with a change in humus form from mor to mull and a complete change in the composition of the understorey vegetation. However, in contrast to most studies of the response of oribatid mites to secondary succession, the invasion of birch can occur without large-scale physical disturbance of the moorland. Our study examined oribatid communities in three replicates of heather moorland, 49- and 58-year-old birch stands at two sites in the Scottish uplands. There was a clear increase in population density and species richness of the oribatids per unit area, and a change in relative abundance of the species, in the birch compared with the heather moorland. However, multivariate analyses indicated that only a few species contributed to the separation of samples based upon changes in relative abundance. Overall, just two and four more oribatid species were found in the oldest birch compared with the heather moorland at the two sites. Some of these species have been found in heather moorland elsewhere in the United Kingdom. Consequently, our results suggest that many oribatid species are able to persist in two distinctly different habitats in this area. Further, a gradual onset of secondary succession arising from tree invasion, as opposed to, for example, the cessation of agriculture or tree harvesting, may not lead to an overall increase in oribatid species richness in this environment. Our results support synecology studies conducted in Europe that indicate that many oribatid species are able to persist in a wide range of humus forms and vegetation types.