Nutrient consumption over time in plant litter decomposition in drylands: effects of different species mixtures and Photodegradation

Abstract

Plant litter decomposition in soil is a dynamic process that is affected and regulated by several factors. Soil microbial activity, light intensity, litter composition and habitat all affect the rate of decomposition of litter. In this study we aimed to elucidate the effect of photodegradation, and different litter species mixtures on decomposition rate of nitrogen and carbon. Plant leaf litter of Conocarpus lancifolius and Avicennia marina, mixture of two species (Conocarpus lancifolius and Ziziphus spina-christi) and mixture of four species (Conocarpus lancifolius, Avicennia marina, Ziziphus spina-christi, and Acacia ehrenbergiana) were placed in litter bags to degrade below ground and on the surface. Samples were harvested after 50, 100, 205, and 345 days after which nitrogen and carbon concentration of the litter was analyzed. The study revealed that nitrogen and carbon on the surface decomposed faster for A. marina and the four species mixture compared to the one below ground which shows that sunlight exposure increases the rate of decomposition of nitrogen irrespective of its species. The species composition also influences the N % and C % decomposition in the plant litter. The study revealed that N and C on the surface decomposed faster for four species mixture as compared to the one below ground which shows that sunlight exposure increases the decomposition of C compared to N of plant litter irrespective of its species. The study also revealed that the mixture of different species can influence the decomposition of N % and C %