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Plant nitrogen concentration, use efficiency, and contents in a tallgrass prairie ecosystem under experimental warming
Author(s) -
An Yuan,
Wan Shiqiang,
Zhou Xuhui,
Subedar Afzal A.,
Wallace Linda L.,
Luo Yiqi
Publication year - 2005
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/j.1365-2486.2005.01030.x
Subject(s) - biomass (ecology) , global warming , grassland , ecosystem , nitrogen , agronomy , forb , environmental science , chemistry , ecology , biology , climate change , organic chemistry
Plant nitrogen (N) relationship has the potential to regulate plant and ecosystem responses strongly to global warming but has not been carefully examined under warmed environments. This study was conducted to examine responses of plant N relationship (i.e. leaf N concentration, N use efficiency, and plant N content in this study) to a 4‐year experimental warming in a tallgrass prairie in the central Great Plains in USA. We measured mass‐based N and carbon (C) concentrations of stem, green, and senescent leaves, and calculated N resorption efficiency, N use efficiency, plant N content, and C : N ratios of five dominant species (two C 4 grasses, one C 3 grass, and two C 3 forbs). The results showed that warming decreased N concentration of both green and senescent leaves, and N resorption efficiency for all species. N use efficiencies and C : N ratios were accordingly higher under warming than control. Total plant N content increased under warming because of warming‐induced increases in biomass production that are larger than the warming‐induced decreases in tissue N concentration. The increases in N contents in both green and senescent plant tissues suggest that warming enhanced both plant N uptake and return through litterfall in the tallgrass ecosystem. Our results also suggest that the increased N use efficiency in C 4 grasses is a primary mechanism leading to increased biomass production under warming in the grassland ecosystem.