Belowground/Aboveground Biodiversity Relationships in the Humid Forest Zone of Southern Cameroon.
Madong A. Birang, Institut de Recherche Agricole pour le Développement (IRAD), P.O. Box 2067 Messa, Yaounde, Cameroon and Lijbert Brussaard, Wageningen Univ and Research Centre, Dept of Soil Quality, P.O. Box 8005, 6700 EC, Wageningen, Netherlands.
A survey was undertaken from July to November 1999 in five land-use systems differing in disturbance levels in six villages along a land-use intensification gradient in the benchmark of the forest margins zone of southern Cameroon. Simultaneous samplings for earthworms, termites and ants were done in the same sites using transect samplings and hand-sorting of monoliths; soil sampling and vegetation structure and description were also performed in the same site in order to establish the relationships between the invertebrates and the environmental variables as well as the impact of land management on the distribution of these animals. Direct ordination (RDA) of the samples with the whole species structural variables and environmental variables yielded significant eigenvalues of 0.303 for the first axis and 0.191 for the second axis. We found low correlations between the parameters of the different groups of fauna. Species richness and diversity were clearly separated. Soil macrofaunal species richness and diversity were more responsive to soil and vegetation parameters than macrofaunal abundances. These results suggest that there is a positive relation between the complexity and production of the vegetation and the complexity of the faunal community in terms of species richness and diversity. Key words. Land-use intensification, land management, vegetation structure, soil invertebrates, faunal community, soil characteristics