Experimental warming shifts coupling of carbon and nitrogen cycles in an alpine meadow. (31st January 2021)

• Record Type: Journal Article
• Authors: Wang, Song; Quan, Quan; Meng, Cheng; Chen, Weinan; Luo, Yiqi; Niu, Shuli
• Editors: Yang, Yuanhe
• Is Part Of: Journal of plant ecology. Volume 14:Number 3(2021)
• Page Start: 541
• Page End: 554
• Publication Date: 2021-01-31
• Subjects: Bayesian probabilistic inversion -- Markov-Chain Monte-Carlo (MCMC) -- warming -- carbon and nitrogen cycles -- stoichiometry -- alpine meadow; 贝叶斯反演 -- 马尔可夫链蒙特卡尔理论(MCMC) -- 增温 -- 碳氮循环 -- 化学计量 -- 高寒草甸; Plant ecology -- Periodicals; Phytogeography -- Periodicals; 581.705
• DOI: 10.1093/jpe/rtab008
• Languages: English
• ISSNs: 1752-9921

Abstract

Abstract: Aims: Terrestrial ecosystem carbon (C) uptake is remarkably regulated by nitrogen (N) availability in the soil. However, the coupling of C and N cycles, as reflected by C:N ratios in different components, has not been well explored in response to climate change. Methods: Here, we applied a data assimilation approach to assimilate 14 datasets collected from a warming experiment in an alpine meadow in China into a grassland ecosystem model. We attempted to evaluate how experimental warming affects C and N coupling as indicated by constrained parameters under ambient and warming treatments separately. Important Findings: The results showed that warming increased soil N availability with decreased C:N ratio in soil labile C pool, leading to an increase in N uptake by plants. Nonetheless, C input to leaf increased more than N, leading to an increase and a decrease in the C:N ratio in leaf and root, respectively. Litter C:N ratio was decreased due to the increased N immobilization under high soil N availability or warming-accelerated decomposition of litter mass. Warming also increased C:N ratio of slow soil organic matter pool, suggesting a greater soil C sequestration potential. As most models usually use a fixed C:N ratio across different environments, the divergent shifts of C:N ratios under climate warming detected in this study could provide a useful benchmark for model parameterization and benefit models to predict C–N coupled responses to future climate change.