Soil microarthropod community structure and litter decomposition dynamics: A study of tropical and temperate sites

The influence of climate, substrate quality and microarthropods on decomposition was studied by comparing the mass loss of litter at three forested sites: two tropical and one temperate. At each site, litterbags containing a dominant local Litter were placed in the field in replicated plots. Half the bags were treated with naphthalene to reduce microarthropod 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 populations. The effect was minimal at the temperate site where the fauna tended to increase the decomposition rate only towards the end of the year. In contrast, the effect of the fauna at the tropical sites was marked 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.