Decomposition of aboveground and root litter for three desert herbs: mass loss and dynamics of mineral nutrients

Abstract

Litter decomposition is an important process in terrestrial C and N cycling, but it is still unclear which factors are controlling litter decomposition and nutrient release in arid and semiarid environments. Litterbag experiment was carried out to evaluate the mass loss and nutrient dynamics of aboveground and belowground litter of three desert plants with different life form (ephemeral herbs and perennials). The decomposition rates of Erodium oxyrrhynchum and Eremurus inderiensis (ephemeral herbs) were faster than that of Seriphidium santolinum (perennial) after 2 years. The content of neutral soluble detergent positively correlated with mass loss and was responsible for the faster rates in the primary decomposition phase. Additionally, differences in mass loss and N release between aboveground and belowground litter depended on litter type. Decomposition of the aboveground litter was mainly affected by initial nutrient content and C component of litter, whereas root decomposition was primarily determined by the content of recalcitrant compounds of litter. Only stem generally exhibited N accumulation, whereas there was no relationship between the initial N content and net N immobilization during decomposition of leaf and root litter. Our results suggest that the decomposition rate and nutrient release in temperate desert are closely linked to initial nutrients and C contents of litters, and decomposition of desert litters depended on plant life form.