SOIL MICROARTHROPOD COMMUNITY STRUCTURE AND LITTER DECOMPOSITION DYNAMICS - A STUDY OF TROPICAL AND TEMPERATE SITES

The influence of climate, substrate quality and microarthropods on dec omposition was studied by comparing the mass loss of litter at three f orested sites: two tropical and one temperate. At each site, litterbag s containing a dominant local Litter were placed in the field in repli cated plots. Half the bags were treated with naphthalene to reduce mic roarthropod abundance. The pattern of mass loss was markedly seasonal at the temperate site. The amount of mass remaining after 250 days was strongly related to the initial %N of the three litter types (r(2)=0. 997). The faunated litterbags lost more mass at all sites and for all litters studied than the litterbags with reduced microarthropod popula tions. The effect was minimal at the temperate site where the fauna te nded to increase the decomposition rate only towards the end of the ye ar. In contrast, the effect of the fauna at the tropical sites was mar ked within months of the start of the experiment. Species richness of microarthropods in samples of 300 cm(2) of leaf litter was similar at the three sites. However, diversity (measured using Fisher's or index) was greatest at the tropical sites. (C) 1998 Elsevier Science B.V.