Do mangrove diversity and leaf litter decay promote meiofaunal diversity?

Abstract

The effects of mangrove diversity and the process of leaf litter decay on the diversity and community structure of meiofauna inhabiting leaf litter were investigated in a simple field experiment in a wet, tropical, soft sediment, mangrove forest in north-eastern Malaysia. Strings of freshly fallen leaves of Rhizophora apiculata and Bruguiera parviflora were placed on the mud surface in two adjacent subplots, each dominated by one of these tree species. The leaf strings were sampled weekly over five weeks and the nematodes and copepods found on the leaves were identified to species and enumerated. It is shown that, under similar conditions of sediment composition, salinity and tidal inundation, the species of mangrove tree or their leaves have little influence on leaf litter meiofaunal climax communities. Such differences as are apparent in the early part of the experiment are probably the result of differences in tree root structure, associated macrofauna and the initial chemical composition of the leaves. It is also shown that there are significant differences in the litter meiofaunal communities during the process of leaf litter decay. For the copepods, a distinct leaf litter community is characterized by the presence of members of the family Darcythompsoniidae and it is the completion of their lifecycle which is the principal feature of the community changes. Development of the nematode community is characterized by subtle shifts in the composition of species inhabiting the leaf litter. It is suggested that changes in the meiofauna community may be more intimately linked to successional changes in the chemistry and/or microflora of the leaf litter than to the physical breakdown of the substratum.