Open AccessIntensified plant N and C pool with more available nitrogen under experimental warming in an alpine meadow ecosystem
Author(s) -
Peng Fei,
Xue Xian,
You Quangang,
Xu Manhou,
Chen Xiang,
Guo Jian,
Wang Tao
Publication year - 2016
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.2583
Subject(s) - nitrification , environmental science , mineralization (soil science) , nitrogen cycle , ecosystem , global warming , biomass (ecology) , permafrost , agronomy , nitrogen , growing season , biogeochemical cycle , sink (geography) , carbon cycle , climate change , environmental chemistry , ecology , soil water , chemistry , soil science , biology , cartography , organic chemistry , geography
Nitrogen (N) availability is projected to increase in a warming climate. But whether the more available N is immobilized by microbes (thus stimulates soil carbon (C) decomposition), or is absorbed by plants (thus intensifies C uptake) remains unknown in the alpine meadow ecosystem. Infrared heaters were used to simulate climate warming with a paired experimental design. Soil ammonification, nitrification, and net mineralization were obtained by in situ incubation in a permafrost region of the Qinghai‐Tibet Plateau (QTP). Available N significantly increased due to the stimulation of net nitrification and mineralization in 0–30 cm soil layer. Microbes immobilized N in the end of growing season in both warming and control plots. The magnitude of immobilized N was lower in the warming plots. The root N concentration significantly reduced, but root N pool intensified due to the significant increase in root biomass in the warming treatment. Our results suggest that a warming‐induced increase in biomass is the major N sink and will continue to stimulate plant growth until plant N saturation, which could sustain the positive warming effect on ecosystem productivity.