Decomposition regularities of leaf litter and fine roots of Cunninghamia lanceolata and their divergent drivers at different altitudes in the Wuyi Mountain

AimsLitter is an important source of organic matter in forest soils, and litter decomposition is crucial in the global carbon cycle.There is a large topographic relief that has formed various vegetation types and ecosystems along the altitudinal gradient in the Wuyi Mountain, China.Studying the differences in the decomposition regularities and driving factors of leaf litter and fine roots of Cunninghamia lanceolata at different altitudes can provide scientific theoretical basis for protecting and managing ecosystems in the study area.Methods In this study, C. lanceolata plantation forests at three altitudes in the Wuyi Mountain were selected as the research platform for climate change research.A 3.5-year-experiment on litter and fine root decomposition was conducted using the decomposition bag approach along the altitude gradient. Important findingsThe decomposition rate of leaf litter was higher than that of fine roots across the altitude gradient.The decomposition rates of leaf litter and fine roots decreased with increasing altitude, while we observed increased differences in decomposition rates between leaf litter and fine roots.Furthermore, the release rates of carbon, nitrogen, and phosphorus from leaf litter and fine roots reduced with increasing altitude, which had an inhibitory effect on lignin decomposition in litter and roots.The temperature was found to drive fine root decomposition and nutrient changes, while soil nutrient status and microbial communities across the altitudinal gradient acted primarily on leaf litter, suggesting divergent drivers controlling litter and root decomposition across the altitude gradient.Taken together, this study explores the impact of temperature, soil, and microorganisms on leaf litter and fine root decomposition, thereby deepening the understanding of differences in aboveground and ©植物生态学报 Chinese Journal of Plant Ecology