DOI: 10.1029/2019GB006241
论文题名: A Spatially Explicit, Empirical Estimate of Tree-Based Biological Nitrogen Fixation in Forests of the United States
作者: Staccone A. ; Liao W. ; Perakis S. ; Compton J. ; Clark C.M. ; Menge D.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2020
卷: 34, 期: 2 语种: 英语
英文关键词: 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
学科: biogeochemistry
; nitrogen fixation
; nutrient cycling
; temperate forest
中文摘要: 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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160065
Appears in Collections: 气候变化与战略
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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
Recommended Citation:
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]. Global Biogeochemical Cycles,2020-01-01,34(2)