Open AccessWarming decreased and grazing increased plant uptake of amino acids in an alpine meadow
Author(s) -
Ma Shuang,
Zhu Xiaoxue,
Zhang Jing,
Zhang Lirong,
Che Rongxiao,
Wang Fang,
Liu Hanke,
Niu Haishan,
Wang Shiping,
Cui Xiaoyong
Publication year - 2015
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/ece3.1646
Subject(s) - grazing , organic matter , nitrogen , mineralization (soil science) , chemistry , nitrogen cycle , agronomy , soil organic matter , plateau (mathematics) , environmental chemistry , environmental science , ecology , biology , soil water , organic chemistry , mathematical analysis , mathematics
Abstract Organic nitrogen (N) uptake by plants has been recognized as a significant component of terrestrial N cycle. Several studies indicated that plants have the ability to switch their preference between inorganic and organic forms of N in diverse environments; however, research on plant community response in organic nitrogen uptake to warming and grazing is scarce. Here, we demonstrated that organic N uptake by an alpine plant community decreased under warming with 13 C– 15 N‐enriched glycine addition method. After 6 years of treatment, warming decreased plant organic N uptake by 37% as compared to control treatment. Under the condition of grazing, warming reduced plant organic N uptake by 44%. Grazing alone significantly increased organic N absorption by 15%, whereas under warming condition grazing did not affect organic N uptake by the Kobresia humilis community on Tibetan Plateau. Besides, soil NO 3 –N content explained more than 70% of the variability observed in glycine uptake, and C:N ratio in soil dissolved organic matter remarkably increased under warming treatment. These results suggested warming promoted soil microbial activity and dissolved organic N mineralization. Grazing stimulated organic N uptake by plants, which counteracted the effect of warming.