Abstract:
Litter quality and diversity are major factors structuring decomposer communities.
However, little is known on the relationship between litter quality and
the community structure of soil protists in tropical forests. We analyzed the
diversity, density, and community structure of a major group of soil protists of
tropical montane rainforests, that is, testate amoebae. Litterbags containing
pure and mixed litter of two abundant tree species at the study sites (Graffenrieda
emarginata and Purdiaea nutans) differing in nitrogen concentrations were
exposed in the field for 12 months. The density and diversity of testate amoebae
were higher in the nitrogen-rich Graffenrieda litter suggesting that nitrogen
functions as an important driving factor for soil protist communities. No additive
effects of litter mixing were found, rather density of testate amoebae was
reduced in litter mixtures as compared to litterbags with Graffenrieda litter
only. However, adding of high-quality litter to low-quality litter markedly
improved habitat quality, as evaluated by the increase in diversity and density
of testate amoebae. The results suggest that local factors, such as litter quality,
function as major forces shaping the structure and density of decomposer
microfauna that likely feed back to decomposition processes.
