Plant Litter Diversity Effects On Decomposition:a Comparison Study Of Subtropical Karst Limestone Soil And Sandstone Soil

One of the most striking features of the earth’s biota is its extraordinary diversity. The understanding of when and where changes in species diversity are most likely to influence functioning in real world ecosystems, relative to other biotic variables, remains limited. To study the relationships between biodiversity and ecosystem is crucial for biodiversity conservation and understanding how the shifts of species number could affect ecosystem functioning. Litter decomposition plays a vital role in the (re-)cycling of carbon and other nutrients, thereby driving other ecosystem processes, such as net primary productivity. In natural or managed ecosystems, plant residues from more than one species usually mix and decompose together. Litter chemical and Physical quality changes from monocultures to mixtures of litter. The decomposition rates of plant litter mixtures usually differ from the rates of their component plant litter species decomposed separately in monocultures. Here we ask how altering litter species diversity affects species-specific decomposition rates, soil faunal community, soil microbial community and soil physic-chemic properties between two different soil types. Our results show that:(1) For mass lossThe non-additive effects of leaf litter mixtures accelerated decomposition rates of litter on limestone soil. Decomposition rates of each mixtures have not been affected by soil types, even though the soil indicators tested are significantly different. Higher species richness presents positive effects on decomposition rates of Japanese Cassia, and the rates in each mixture does not vary with soil types.(2) For soil faunaSoil fauna are dominated by collambola and mites in this study. Mixture with diverse physical and chemical properties of litter might provide diverse habitats for soil invertebrate communities. Litter species richness strongly affected abundance of soil fauna. For both two soil types, the mixtures4、8、16observed higher fauna abundance than other mixtures. This is correlated with the higher decomposition rates of the3mixtures. But the responses to litter species richness are varied in different groups.(3) For soil microbes The occurrence of leaf litter could make hardly contribution to shape the structure of microbial communities. The structure can also be affected by Litter species richness and soil types.(4) For soil propertiesPlant litter decomposition drives the return of nutrients from the leaf litter to the soil. Decomposition of litter increased soil TC and TP of both two soil types. The influences of litter decomposition on soil pH、EC and TK are different in the two soil types. There’re some relationship between decomposition in each mixture and soil properties.In conclusion, in our study, the mixture of leaf litter makes non-additive influences on process of decomposition. Mixtures have higher decomposition rates, decomposer communities can be influenced by leaf litter diversity, the non-additive effects are driven by many factors, soil properties are related with decomposition rates.