title: The effects of forest disturbance on diversity of tropical soil nematodes.
abstract: We provide the first account of the effects of forest disturbance on species richness of nematodes in tropical forest soils, from 24 sites along gradients of disturbance and regeneration in the Mbalmayo Forest Reserve, Cameroon. Species richness was very high. Samples of 200 nematodes from individual soil cores contained a maximum of 89 and an average of 61 species; in total we recorded 431 species and approximately 194 genera. The model of Siemann et al. (1996), predicting that species richness scales as the number of individuals I0.5, underestimates nematode diversity 4-6 fold in these samples. Over 90% of specimens cannot be assigned to known species. Although nematode species richness declined with forest disturbance, statistically significant effects were detectable only under the most extreme conditions (active slash-and-burn agriculture and complete mechanical forest clearance) and even here remained at 40% of the richness of near primary sites. Impacts on trophic structure were also small, and there were no significant changes in the maturity index (MI) (Bongers 1990) with disturbance (mean MI across all treatments was very high, at 3.58). In the light of this study, the problems of completing reliable all-taxon inventories in tropical forests are briefly discussed.
authors.affiliation: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK, , , , , , GB.
authors.forename: G F
authors.initials: GF
authors.lastname: Bloemers
authors.affiliation: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK, , , , , , GB.
authors.forename: M
authors.initials: M
authors.lastname: Hodda
authors.affiliation: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK, , , , , , GB.
authors.forename: P J D
authors.initials: PJ
authors.lastname: Lambshead
authors.affiliation: NERC Centre for Population Biology, Imperial College, Silwood Park, Ascot SL5 7PY, UK, , , , , , GB.
authors.forename: J H
authors.initials: JH
authors.lastname: Lawton
authors.affiliation: Department of Zoology, Natural History Museum, Cromwell Road, London SW7 5BD, UK, , , , , , GB.
authors.forename: F R
authors.initials: FR
authors.lastname: Wanless
keywords: Key words Nematodes; Population abundance; Species richness; Trophic groups