|
Nitrate is an important nitrogen source for Arctic tundra plantsNitrate is an important nitrogen source for Arctic tundra plants |
"/Liu, Xue-Yan/"Liu, Xue-Yan ,
"/Koba, Keisuke/"Koba, Keisuke ,
"/Koyama, Lina A./"Koyama, Lina A. ,
"/Hobbie, Sarah E./"Hobbie, Sarah E. ,
"/Weiss, Marissa S./"Weiss, Marissa S. ,
"/Inagaki, Yoshiyuki/"Inagaki, Yoshiyuki ,
"/Shaver, Gaius R./"Shaver, Gaius R. ,
"/Giblin, Anne E./"Giblin, Anne E. ,
"/Hobara, Satoru/"Hobara, Satoru ,
"/Nadelhoffer, Knute J./"Nadelhoffer, Knute J. ,
"/Sommerkorn, Martin/"Sommerkorn, Martin ,
"/Rastetter, Edward B./"Rastetter, Edward B. ,
"/Kling, George W./"Kling, George W. ,
"/Laundre, James A./"Laundre, James A. ,
"/Yano, Yuriko/"Yano, Yuriko ,
"/Makabe, Akiko/"Makabe, Akiko ,
"/Yano, Midori/"Yano, Midori ,
"/Liu, Cong-Qiang/"Liu, Cong-Qiang
115
(
13
)
, pp.3398
-
3403 , 2018-03-27 , National Academy of Sciences
ISSN:0027-8424
内容記述
ツンドラの生態系でも硝酸イオンは大切な窒素源だった --最先端の測定技術で「見えない」硝酸イオンの重要性を検証--. 京都大学プレスリリース. 2018-03-14.
Plant nitrogen (N) use is a key component of the N cycle in terrestrial ecosystems. The supply of N to plants affects community species composition and ecosystem processes such as photosynthesis and carbon (C) accumulation. However, the availabilities and relative importance of different N forms to plants are not well understood. While nitrate (NO3−) is a major N form used by plants worldwide, it is discounted as a N source for Arctic tundra plants because of extremely low NO3− concentrations in Arctic tundra soils, undetectable soil nitrification, and plant-tissue NO3− that is typically below detection limits. Here we reexamine NO3− use by tundra plants using a sensitive denitrifier method to analyze plant-tissue NO3−. Soil-derived NO3− was detected in tundra plant tissues, and tundra plants took up soil NO3− at comparable rates to plants from relatively NO3−-rich ecosystems in other biomes. Nitrate assimilation determined by 15N enrichments of leaf NO3− relative to soil NO3− accounted for 4 to 52% (as estimated by a Bayesian isotope-mixing model) of species-specific total leaf N of Alaskan tundra plants. Our finding that in situ soil NO3− availability for tundra plants is high has important implications for Arctic ecosystems, not only in determining species compositions, but also in determining the loss of N from soils via leaching and denitrification. Plant N uptake and soil N losses can strongly influence C uptake and accumulation in tundra soils. Accordingly, this evidence of NO3− availability in tundra soils is crucial for predicting C storage in tundra.
本文を読む
http://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/230345/1/pnas.1715382115.pdf
