Substrate and climate determine terrestrial litter decomposition
Abstract
Litter decomposition is a fundamental biogeochemical process for carbon flux and nutrient cycling in terrestrial ecosystems, yet the global variation in decomposition rates and their covariations with climate and substrate are not fully understood. Here, we synthesized a global dataset of 6,733 independent observations across six continents to illustrate the climatic and substrate controls over litter decomposition. The average decomposition rates of various litter types ranged from 0.74 to 4.01 y −1 across polar to tropics, showing a large geographical span. Litter substrate and climate directly explained 36 and 30% of the variations in decomposition rates, with the carbon-to-nitrogen ratio identified as the best predictor. In the absence of climate variables, litter substrate can effectively explain the variation, while the model’s predictive capacity decreased significantly after litter substrate was excluded. Our synthesis highlights that a fundamental constraint on litter substrate leads to predictable global-scale patterns of terrestrial litter decomposition rates. Integrating litter chemistry parameters should be prioritized for parameter optimization in Earth system models.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (12)
Qiuxia Wu
Key Laboratory of Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University
Xiangyin Ni
Key Laboratory of Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University
Xinyao Sun
College of Energy, Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, China.
Zihao Chen
Department of Materials Science and Engineering
Songbai Hong
School of Urban Planning and Design, Shenzhen Graduate School, Peking University
Björn Berg
Department of Forest Sciences, University of Helsinki
Mianhai Zheng
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences
Ji Chen
Jingjing Zhu
State Key Laboratory of Advanced Fiber Materials, College of Chemistry and Chemical Engineering
Ling Ai
Key Laboratory of Humid Subtropical Eco-Geographical Processes of the Ministry of Education, School of Geographical Sciences, Fujian Normal University
Yichen Zhang
Institute of Carbon Neutrality, Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University
Fuzhong Wu