气候变化领域集成服务门户(CCPortal): A Spatially Explicit, Empirical Estimate of Tree-Based Biological Nitrogen Fixation in Forests of the United States

CCPortal

DOI	10.1029/2019GB006241
	A Spatially Explicit, Empirical Estimate of Tree-Based Biological Nitrogen Fixation in Forests of the United States
	Staccone A.; Liao W.; Perakis S.; Compton J.; Clark C.M.; Menge D.
发表日期	2020
ISSN	0886-6236
EISSN	1944-9224
卷号	34 期号:2
英文摘要	Quantifying human impacts on the nitrogen (N) cycle and investigating natural ecosystem N cycling depend on the magnitude of inputs from natural biological nitrogen fixation (BNF). Here, we present two bottom-up approaches to quantify tree-based symbiotic BNF based on forest inventory data across the coterminous United States and SE Alaska. For all major N-fixing tree genera, we quantify BNF inputs using (1) ecosystem N accretion rates (kg N ha−1 yr−1) scaled with spatial data on tree abundance and (2) percent of N derived from fixation (%Ndfa) scaled with tree N demand (from tree growth rates and stoichiometry). We estimate that trees fix 0.30–0.88 Tg N yr−1 across the study area (1.4–3.4 kg N ha−1 yr−1). Tree-based N fixation displays distinct spatial variation that is dominated by two genera, Robinia (64% of tree-associated BNF) and Alnus (24%). The third most important genus, Prosopis, accounted for 5%. Compared to published estimates of other N fluxes, tree-associated BNF accounted for 0.59 Tg N yr−1, similar to asymbiotic (0.37 Tg N yr−1) and understory symbiotic BNF (0.48 Tg N yr−1), while N deposition contributed 1.68 Tg N yr−1 and rock weathering 0.37 Tg N yr−1. Overall, our results reveal previously uncharacterized spatial patterns in tree BNF that can inform large-scale N assessments and serve as a model for improving tree-based BNF estimates worldwide. This updated, lower BNF estimate indicates a greater ratio of anthropogenic to natural N inputs, suggesting an even greater human impact on the N cycle. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	biogeochemistry; nitrogen fixation; nutrient cycling; temperate forest
语种	英语
scopus关键词	abundance; biogeochemistry; bottom-up approach; deciduous tree; dominance; empirical analysis; estimation method; forest ecosystem; forest inventory; human activity; nitrogen fixation; spatial variation; temperate forest; Alaska; United States; Alnus; Prosopis; Robinia
来源期刊	Global Biogeochemical Cycles
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/129670
作者单位	Ecology, Evolution, and Environmental Biology Department, Columbia University, New York, NY, United States; Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, United States; US Geological Survey Forest and Rangeland Ecosystem Science Center, Corvallis, OR, United States; US EPA, Center for Public Health and Environmental Assessment, Washington, DC, United States
推荐引用方式 GB/T 7714	Staccone A.,Liao W.,Perakis S.,et al. A Spatially Explicit, Empirical Estimate of Tree-Based Biological Nitrogen Fixation in Forests of the United States[J],2020,34(2).
APA	Staccone A.,Liao W.,Perakis S.,Compton J.,Clark C.M.,&Menge D..(2020).A Spatially Explicit, Empirical Estimate of Tree-Based Biological Nitrogen Fixation in Forests of the United States.Global Biogeochemical Cycles,34(2).
MLA	Staccone A.,et al."A Spatially Explicit, Empirical Estimate of Tree-Based Biological Nitrogen Fixation in Forests of the United States".Global Biogeochemical Cycles 34.2(2020).