Responses of mass loss and nutrient release in litter decomposition to ultraviolet radiation

Abstract

Ultraviolet (UV) radiation plays an important role in litter decomposition, but the direction and magnitude of its effect remain inconsistent. To determine the responses of litter decomposition and C and nutrient release to UV radiation, a meta-analysis that comprised 544 observations in field experiments was performed. The change in UV radiation had significant effects on litter mass loss and litter nitrogen (N) and phosphorus (P) release in field studies, and litter types affected only the magnitude of UV radiation changes on mass loss and nutrient release. In addition, mass loss and nutrient release varied as the decomposition process continued: UV enhancement accelerated litter decomposition only after 4 months of decomposition, whereas the effect of UV attenuation on litter decomposition decreased with decomposition time. The inhabitation of UV attenuation on litter decomposition increased with a decrease in precipitation. Overall, the different responses of mass loss and nutrient release in litter decomposition to changes in ultraviolet radiation may cause different C and nutrient cycling in terrestrial ecosystems in the Southern Hemisphere and Northern Hemisphere.