气候变化领域集成服务门户(CCPortal): Seeing the Canopy for the Branches: Improved Within Canopy Scaling of Leaf Nitrogen

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DOI	10.1029/2020MS002237
	Seeing the Canopy for the Branches: Improved Within Canopy Scaling of Leaf Nitrogen
	Butler E.E.; Chen M.; Ricciuto D.; Flores-Moreno H.; Wythers K.R.; Kattge J.; Thornton P.E.; Reich P.B.
发表日期	2020
ISSN	19422466
卷号	12 期号:10
英文摘要	Transitioning across biological scales is a central challenge in land surface models. Processes that operate at the scale of individual leaves must be scaled to canopies, and this is done using dedicated submodels. Here, we focus on a submodel that prescribes how light and nitrogen are distributed through plant canopies. We found a mathematical inconsistency in a submodel implemented in the Community and Energy Land Models (CLM and ELM), which incorporates twigs, branches, stems, and dead leaves in nitrogen scaling from leaf to canopy. The inconsistency leads to unrealistic (physically impossible) values of the nitrogen scaling coefficient. The mathematical inconsistency is a general mistake, that is, would occur in any model adopting this particular submodel. We resolve the inconsistency by allowing distinct profiles of stems and branches versus living leaves. We implemented the updated scheme in the ELM and find that the correction reduces global mean gross primary production (GPP) by 3.9 Pg C (3%). Further, when stems and branches are removed from the canopy in the updated model (akin to models that ignore shading from stems), global GPP increases by 4.1 Pg C (3.2%), because of reduced shading. Hence, models that entirely ignore stem shading also introduce errors in the global spatial distribution of GPP estimates, with a strong signal in the tropics, increasing GPP there by over 200 g C m−2 yr−1. Appropriately incorporating stems and other nonphotosynthesizing material into the light and nitrogen scaling routines of global land models, will improve their biological realism and accuracy. © 2020 The Authors.
英文关键词	climate; land surface; modeling; nitrogen; photosynthesis; vegetation
语种	英语
scopus关键词	Plants (botany); Gross primary production; Land model; Land surface models; Leaf nitrogen; Plant canopies; Scaling coefficients; Strong signal; Updated model; Nitrogen; land surface; leaf area; leaf area index; net primary production; nitrogen; spatial distribution
来源期刊	Journal of Advances in Modeling Earth Systems
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/156604
作者单位	Department of Forest Resources, University of Minnesota, St. Paul, MN, United States; The High School Affiliated With Renmin University of China, Renmin University of China, Shenzhen, China; Environmental Sciences Division, Climate Change Science Institute, Oak Ridge National Laboratory, Oak Ridge, TN, United States; Biological Sciences, George Washington University, Washington, DC, United States; Max Planck Institute for Biogeochemistry, Jena, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany; Hawkesbury Institute for the Environment, University of Western Sydney, Penrith, NSW, Australia
推荐引用方式 GB/T 7714	Butler E.E.,Chen M.,Ricciuto D.,et al. Seeing the Canopy for the Branches: Improved Within Canopy Scaling of Leaf Nitrogen[J],2020,12(10).
APA	Butler E.E..,Chen M..,Ricciuto D..,Flores-Moreno H..,Wythers K.R..,...&Reich P.B..(2020).Seeing the Canopy for the Branches: Improved Within Canopy Scaling of Leaf Nitrogen.Journal of Advances in Modeling Earth Systems,12(10).
MLA	Butler E.E.,et al."Seeing the Canopy for the Branches: Improved Within Canopy Scaling of Leaf Nitrogen".Journal of Advances in Modeling Earth Systems 12.10(2020).