Temporal dynamics of ultraviolet radiation impacts on litter decomposition in a semi-arid ecosystem
作 者：Wang J, Yang S, Zhang BB, Liu WX, Deng MF, Chen SP, Liu LL*
影响因子:3.052
刊物名称:Plant and Soil
出版年份:2017
卷:419期:1-2 页码:71-81
文章摘要:Background and aims
The emerging consensus posits that ultraviolet (UV) radiation accelerates litter decomposition in xeric environments mainly by preconditioning litter for subsequent microbial decomposition. However, how UV radiation affects the interactions among litter chemistry, microbes, and eventually litter mass during different decomposition stages is still poorly understood.
Methods
Here, we conducted a 29-month in situ decomposition experiment with litter exposed to ambient and reduced UV in a semi-arid grassland.
Results
The decomposition rate forCleistogenes squarrosaandStipa kryloviiunder ambient UV was 82 and 111% greater than that under reduced UV, respectively. UV’s positive effect showed three-stage temporal dynamics. During the early stage, UV had no impact on either litter chemistry or mass loss. During the intermediate stage, UV decreased litter carbon concentration and increased dissolved organic carbon concentration, but still had no effect on litter mass. During the late stage, UV exposure increased microbial population size in the surface soil and significantly increased litter mass loss.
Conclusions
Overall, our study suggested that UV exposure accelerated litter decomposition first by improving litter biodegradability during the intermediate stage and then by enhancing microbial decomposition during the late stage. More long-term photodegradation experiments are needed to explore the biotic and abiotic interactions during different decomposition stages.