Temporal dynamics of climate sensitivity of litter decomposition in a semi-arid grassland
Zhen Li,
Fuwei Wang,
Yue Wen,
Chenglong Ye,
Peng Wang,
Tongshuo Bai,
Xudong Gu,
Liang Guo,
Yunpeng Qiu,
Yi Zhang,
Yi Wang,
Shuijin Hu
Affiliations
Zhen Li
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Fuwei Wang
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Yue Wen
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Chenglong Ye
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Peng Wang
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Tongshuo Bai
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Xudong Gu
Ningxia Yunwu Mountains Grassland Natural Reserve Administration, Guyuan 756000, China
Liang Guo
State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling, Shaanxi 712100, China; Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi 712100, China; University of Chinese Academy of Sciences, Beijing 100049, China
Yunpeng Qiu
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Yi Zhang
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
Yi Wang
State Key Laboratory of Loess and Quaternary, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China
Shuijin Hu
Ecosystem Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA; Corresponding author at: Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, NC 27695-7616, USA.
Climate warming, precipitation changes, and reactive nitrogen (N) input are important environmental changes that can critically affect litter decomposition and soil carbon (C) dynamics. However, it remains unclear whether and how their effects and/or relative contribution vary across different decomposition stages. We assessed the effects of warming, precipitation changes and N addition, alone and in combination, on litter loss at various stages of the decomposition process in a semi-arid grassland. We found that warming inhibited litter decomposition in the early stage (1–2 years) and promoted it in the later stage (3–4 years). The temperature sensitivity of decomposition was affected by both soil moisture and N addition. Increased precipitation significantly accelerated litter decomposition initially, but not in the later stages. In the litter-soil incubation experiment, we observed that high-quality litter, characterized by low carbohydrate C:methoxyl C (CC:MC) ratio and/or CN ratios, displayed greater sensitivity to changes in moisture. In comparison, low-quality litter exhibits high temperature sensitivity of microbial respiration. Overall, our findings show that the climate sensitivity of litter decomposition exhibited distinct temporal dynamics, with increasing warming sensitivity of decomposition and decreasing moisture sensitivity of decomposition over time. Given that many current decomposition models use a constant sensitivity parameter (e.g., Q10 value = 2.0) throughout the decay process, our results suggest that incorporation of such temporal dynamics into decomposition models may enhance their predictive power.
