Effects of UV-B radiation on the decomposition of Cunninghamia lanceolata leaf litter

A litterbag experiment was conducted to study the decomposition of Cunninghamia lanceolata leaf litter under ambient and reduced UV-B radiation(22.1% below ambient).Comparing with ambient treatment,the reduced treatment decreased the decomposition rate of C.lanceolata leaf litter by 69.6%(P0.001),making the relative contents of nitrogen(N),phosphorus(P),and lignin in the litter increased by 150%,83.3%,and 13.8%,respectively,and the release of potassium(K) and carbon(C) slowed down.In the process of litter decomposition,photo-degradation of lignin didn't play crucial role.The results suggested that UV-B radiation could accelerate the decomposition rate of C.lanceolata leaf litter,promote the release of N,P,K,and C from it,and increase the nutrients turnover rate in litter layer as well as the carbon flux on the ground,giving potential effects on the function of C.lanceolata forest as a carbon source or sink in humid subtropical China.