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Warming decreased and grazing increased plant uptake of amino acids in an alpine meadow.

Ma S, Zhu X, Zhang J, Zhang L, Che R, Wang F, Liu H, Niu H, Wang S, Cui X - Ecol Evol (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences University of Chinese Academy of Sciences Beijing 100049 China.

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.

No MeSH data available.


Mean uptake rates of the amino acid glycine under CK, G, W, WG treatments, expressed as μmol·N·g−1DW h−1 (DW, dry weight). Amino acid uptake was significantly decreased by warming (P < 0.05). Bars represent the mean of four replicates per treatment with error bars denoting ±SE. Different lowercase letters indicate a significant difference in uptake rate among treatments (P < 0.05).
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ece31646-fig-0004: Mean uptake rates of the amino acid glycine under CK, G, W, WG treatments, expressed as μmol·N·g−1DW h−1 (DW, dry weight). Amino acid uptake was significantly decreased by warming (P < 0.05). Bars represent the mean of four replicates per treatment with error bars denoting ±SE. Different lowercase letters indicate a significant difference in uptake rate among treatments (P < 0.05).

Mentions: The uptake rate of organic N by K. humilis meadow under different treatments lay in the range of 0.11–0.33 μmol·g−1·h−1 (Fig. 4). Glycine uptake rate was significantly lower under warming treatments (P < 0.05; Fig. 4). Compared to control treatment, warming decreased glycine uptake rate by 37% (P < 0.05; Fig. 4). Under the condition of grazing, warming reduced plant organic N uptake by 44% (P < 0.05; Fig. 4). Grazing itself increased glycine uptake rate (between CK and G treatments, t‐test, P < 0.05; Fig. 4), whereas under warming condition grazing did not affect organic N uptake by the K. humilis community (i.e., between W and WG treatments).


Warming decreased and grazing increased plant uptake of amino acids in an alpine meadow.

Ma S, Zhu X, Zhang J, Zhang L, Che R, Wang F, Liu H, Niu H, Wang S, Cui X - Ecol Evol (2015)

Mean uptake rates of the amino acid glycine under CK, G, W, WG treatments, expressed as μmol·N·g−1DW h−1 (DW, dry weight). Amino acid uptake was significantly decreased by warming (P < 0.05). Bars represent the mean of four replicates per treatment with error bars denoting ±SE. Different lowercase letters indicate a significant difference in uptake rate among treatments (P < 0.05).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4588656&req=5

ece31646-fig-0004: Mean uptake rates of the amino acid glycine under CK, G, W, WG treatments, expressed as μmol·N·g−1DW h−1 (DW, dry weight). Amino acid uptake was significantly decreased by warming (P < 0.05). Bars represent the mean of four replicates per treatment with error bars denoting ±SE. Different lowercase letters indicate a significant difference in uptake rate among treatments (P < 0.05).
Mentions: The uptake rate of organic N by K. humilis meadow under different treatments lay in the range of 0.11–0.33 μmol·g−1·h−1 (Fig. 4). Glycine uptake rate was significantly lower under warming treatments (P < 0.05; Fig. 4). Compared to control treatment, warming decreased glycine uptake rate by 37% (P < 0.05; Fig. 4). Under the condition of grazing, warming reduced plant organic N uptake by 44% (P < 0.05; Fig. 4). Grazing itself increased glycine uptake rate (between CK and G treatments, t‐test, P < 0.05; Fig. 4), whereas under warming condition grazing did not affect organic N uptake by the K. humilis community (i.e., between W and WG treatments).

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Sciences University of Chinese Academy of Sciences Beijing 100049 China.

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.

No MeSH data available.