Progressive nitrogen limitation across the Tibetan alpine permafrost region

• Published in: Nature Communications
• Main Authors: Kou, Dan, Yang, Guibiao, Li, Fei, Feng, Xuehui, Zhang, Dianye, Mao, Chao, Zhang, Qiwen, Peng, Yunfeng, Ji, Chengjun, Zhu, Qiuan, Fang, Yunting, Liu, Xueyan, Xu-Ri, Li, Siqi, Deng, Jia, Zheng, Xunhua, Fang, Jingyun, Yang, Yuanhe
• Format: Article in Journal/Newspaper
• Language: English
• Published: NATURE PUBLISHING GROUP 2020
• Subjects: Multidisciplinary Sciences; SOIL ORGANIC-CARBON; MYCORRHIZAL FUNGI; CLIMATE-CHANGE; BIOMASS ALLOCATION; USE EFFICIENCY; TUNDRA; AVAILABILITY; ECOSYSTEM; PRODUCTIVITY; METAANALYSIS; Science & Technology - Other Topics; permafrost; Tundra
• Online Access: http://ir.ibcas.ac.cn/handle/2S10CLM1/21691; https://doi.org/10.1038/s41467-020-17169-6

The ecosystem carbon (C) balance in permafrost regions, which has a global significance in understanding the terrestrial C-climate feedback, is significantly regulated by nitrogen (N) dynamics. However, our knowledge on temporal changes in vegetation N limitation (i.e., the supply of N relative to plant N demand) in permafrost ecosystems is still limited. Based on the combination of isotopic observations derived from a re-sampling campaign along a similar to 3000 km transect and simulations obtained from a process-based biogeochemical model, here we detect changes in ecosystem N cycle across the Tibetan alpine permafrost region over the past decade. We find that vegetation N limitation becomes stronger despite the increased available N production. The enhanced N limitation on vegetation growth is driven by the joint effects of elevated plant N demand and gaseous N loss. These findings suggest that N would constrain the future trajectory of ecosystem C cycle in this alpine permafrost region.