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Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland

Changes in the biosphere carbon (C) sink are of utmost importance given rising atmospheric CO(2) levels. Concurrent global changes, such as increasing nitrogen (N) deposition, are affecting how much C can be stored in terrestrial ecosystems. Understanding the extent of these impacts will help in pre...

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Autores principales: Wilcots, Megan E., Schroeder, Katie M., DeLancey, Lang C., Kjaer, Savannah J., Hobbie, Sarah E., Seabloom, Eric W., Borer, Elizabeth T.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9545222/
https://www.ncbi.nlm.nih.gov/pubmed/35593000
http://dx.doi.org/10.1111/gcb.16272
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author Wilcots, Megan E.
Schroeder, Katie M.
DeLancey, Lang C.
Kjaer, Savannah J.
Hobbie, Sarah E.
Seabloom, Eric W.
Borer, Elizabeth T.
author_facet Wilcots, Megan E.
Schroeder, Katie M.
DeLancey, Lang C.
Kjaer, Savannah J.
Hobbie, Sarah E.
Seabloom, Eric W.
Borer, Elizabeth T.
author_sort Wilcots, Megan E.
collection PubMed
description Changes in the biosphere carbon (C) sink are of utmost importance given rising atmospheric CO(2) levels. Concurrent global changes, such as increasing nitrogen (N) deposition, are affecting how much C can be stored in terrestrial ecosystems. Understanding the extent of these impacts will help in predicting the fate of the biosphere C sink. However, most N addition experiments add N in rates that greatly exceed ambient rates of N deposition, making inference from current knowledge difficult. Here, we leveraged data from a 13‐year N addition gradient experiment with addition rates spanning realistic rates of N deposition (0, 1, 5, and 10 g N m(−2) year(−1)) to assess the rates of N addition at which C uptake and storage were stimulated in a temperate grassland. Very low rates of N addition stimulated gross primary productivity and plant biomass, but also stimulated ecosystem respiration such that there was no net change in C uptake or storage. Furthermore, we found consistent, nonlinear relationships between N addition rate and plant responses such that intermediate rates of N addition induced the greatest ecosystem responses. Soil pH and microbial biomass and respiration all declined with increasing N addition indicating that negative consequences of N addition have direct effects on belowground processes, which could then affect whole ecosystem C uptake and storage. Our work demonstrates that experiments that add large amounts of N may be underestimating the effect of low to intermediate rates of N deposition on grassland C cycling. Furthermore, we show that plant biomass does not reliably indicate rates of C uptake or soil C storage, and that measuring rates of C loss (i.e., ecosystem and soil respiration) in conjunction with rates of C uptake and C pools are crucial for accurately understanding grassland C storage.
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spelling pubmed-95452222022-10-14 Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland Wilcots, Megan E. Schroeder, Katie M. DeLancey, Lang C. Kjaer, Savannah J. Hobbie, Sarah E. Seabloom, Eric W. Borer, Elizabeth T. Glob Chang Biol Research Articles Changes in the biosphere carbon (C) sink are of utmost importance given rising atmospheric CO(2) levels. Concurrent global changes, such as increasing nitrogen (N) deposition, are affecting how much C can be stored in terrestrial ecosystems. Understanding the extent of these impacts will help in predicting the fate of the biosphere C sink. However, most N addition experiments add N in rates that greatly exceed ambient rates of N deposition, making inference from current knowledge difficult. Here, we leveraged data from a 13‐year N addition gradient experiment with addition rates spanning realistic rates of N deposition (0, 1, 5, and 10 g N m(−2) year(−1)) to assess the rates of N addition at which C uptake and storage were stimulated in a temperate grassland. Very low rates of N addition stimulated gross primary productivity and plant biomass, but also stimulated ecosystem respiration such that there was no net change in C uptake or storage. Furthermore, we found consistent, nonlinear relationships between N addition rate and plant responses such that intermediate rates of N addition induced the greatest ecosystem responses. Soil pH and microbial biomass and respiration all declined with increasing N addition indicating that negative consequences of N addition have direct effects on belowground processes, which could then affect whole ecosystem C uptake and storage. Our work demonstrates that experiments that add large amounts of N may be underestimating the effect of low to intermediate rates of N deposition on grassland C cycling. Furthermore, we show that plant biomass does not reliably indicate rates of C uptake or soil C storage, and that measuring rates of C loss (i.e., ecosystem and soil respiration) in conjunction with rates of C uptake and C pools are crucial for accurately understanding grassland C storage. John Wiley and Sons Inc. 2022-06-02 2022-08 /pmc/articles/PMC9545222/ /pubmed/35593000 http://dx.doi.org/10.1111/gcb.16272 Text en © 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd. https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ (https://creativecommons.org/licenses/by-nc-nd/4.0/) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.
spellingShingle Research Articles
Wilcots, Megan E.
Schroeder, Katie M.
DeLancey, Lang C.
Kjaer, Savannah J.
Hobbie, Sarah E.
Seabloom, Eric W.
Borer, Elizabeth T.
Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
title Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
title_full Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
title_fullStr Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
title_full_unstemmed Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
title_short Realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
title_sort realistic rates of nitrogen addition increase carbon flux rates but do not change soil carbon stocks in a temperate grassland
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9545222/
https://www.ncbi.nlm.nih.gov/pubmed/35593000
http://dx.doi.org/10.1111/gcb.16272
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