Impacts Of Human Disturbance On Leaf Litter Decomposition In A Mid-subtropical Evergreen Broad-leaved Forest

Anthropogenic disturbance, such as,deforestation and Global warming havedirectly impacts on forest ecosystem. Litter decomposition is an important ecosystemprocess that plays a key role in global carbon dynamics and balance. Processes indecomposition can influence soil carbon cycling and carbon sequestration, andconsequently feedback into ecosystem climate change responses. Based on theresearch object of mid-subtropical evergreen broad-leaved forest, we chose fourdifferent type of forest with different human disturbance in the Gutianshan Naturalreserve in Zhe Jiang to study the impacts of the above forest on the litterdecomposition of Cunningnamia lanceolata, Schiam superb, Castanopsis eyrei andCyclobalanopsis glauca and the soil factors controlled with leaf litter bag method.Cunningnamia lanceolata, Schiam superb, Castanopsis eyrei and Cyclobalanopsis glaucadecomposed respectively42.41%、61.54%、56.86%and45.24%during April2011to Oct2012with total21month, meanwhile the content of soil environmental factors, soilnutrient and soil microbial biomass had significantly changed. Different forest typeand initial nutrient content of leaf litter have interaction on litter decomposition rate.The dominance species showed home-field advantage （HFA） in their livingcommunities during the process of decomposition which increased theirdecomposition rate as well. The initial C:N of leaf litter had significant negative effecton decomposition rate. Although there had discrepancy with soil factors due todifferent forest type, the decomposition rate of all the species had significant negativecorrelation with soil temperature, soil pH and soil respiration and positive correlationwith soil water content and soil C:N. The microbial communities were significantlydifferent under different forest type, meanwhile, the litter decomposition rate of all thespecies had a significantly positive relationship with PLFA biomass in all the foresttype. Cunningnamia lanceolata’s decomposition rate had also had a positiverelationship with the fungi under the plantation forest.