|Title:||Nitrate is an important nitrogen source for Arctic tundra plants|
Koba, Keisuke https://orcid.org/0000-0003-1942-9811 (unconfirmed)
Koyama, Lina A.
Hobbie, Sarah E.
Weiss, Marissa S.
Shaver, Gaius R.
Giblin, Anne E.
Nadelhoffer, Knute J.
Rastetter, Edward B.
Kling, George W.
Laundre, James A.
|Author's alias:||木庭, 啓介|
|Keywords:||Arctic tundra plants|
|Publisher:||National Academy of Sciences|
|Journal title:||Proceedings of the National Academy of Sciences of the United States of America|
|Abstract:||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.|
|Description:||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.|
|Rights:||This open access article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).|
|Appears in Collections:||Journal Articles|
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