DOI: 10.1111/gcb.12422
论文题名: Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle
作者: Gundale M.J. ; From F. ; Bach L.H. ; Nordin A.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2014
卷: 20, 期: 1 起始页码: 276
结束页码: 286
语种: 英语
英文关键词: 15N labeling
; Carbon sequestration
; Carbon sink
; Dwarf shrubs
; Feather mosses
; Nitrogen deposition
; Productivity
; Soil nitrogen uptake
; Understory vegetation
Scopus关键词: anthropogenic source
; atmospheric deposition
; biomass allocation
; boreal forest
; carbon cycle
; carbon sequestration
; carbon sink
; emission inventory
; forest cover
; nitrogen
; temperate forest
; understory
; Sweden
; Bryophyta
; nitrogen
; 15N labeling
; article
; biomass
; carbon sequestration
; carbon sink
; chemistry
; dwarf shrubs
; feather mosses
; growth, development and aging
; human activities
; metabolism
; moss
; nitrogen deposition
; Poaceae
; productivity
; soil
; soil nitrogen uptake
; spruce
; Sweden
; tree
; understory vegetation
; Vaccinium myrtillus
; 15N labeling
; carbon sequestration
; carbon sink
; dwarf shrubs
; feather mosses
; Nitrogen deposition
; productivity
; soil nitrogen uptake
; understory vegetation
; Biomass
; Bryophyta
; Carbon Sequestration
; Human Activities
; Nitrogen
; Picea
; Poaceae
; Soil
; Sweden
; Trees
; Vaccinium myrtillus
英文摘要: It is proposed that increases in anthropogenic reactive nitrogen (Nr) deposition may cause temperate and boreal forests to sequester a globally significant quantity of carbon (C); however, long-term data from boreal forests describing how C sequestration responds to realistic levels of chronic Nr deposition are scarce. Using a long-term (14-year) stand-scale (0.1 ha) N addition experiment (three levels: 0, 12.5, and 50 kg N ha-1 yr-1) in the boreal zone of northern Sweden, we evaluated how chronic N additions altered N uptake and biomass of understory communities, and whether changes in understory communities explained N uptake and C sequestration by trees. We hypothesized that understory communities (i.e. mosses and shrubs) serve as important sinks for low-level N additions, with the strength of these sinks weakening as chronic N addition rates increase, due to shifts in species composition. We further hypothesized that trees would exhibit nonlinear increases in N acquisition, and subsequent C sequestration as N addition rates increased, due to a weakening understory N sink. Our data showed that understory biomass was reduced by 50% in response to the high N addition treatment, mainly due to reduced moss biomass. A 15N labeling experiment showed that feather mosses acquired the largest fraction of applied label, with this fraction decreasing as the chronic N addition level increased. Contrary to our hypothesis, the proportion of label taken up by trees was equal (ca. 8%) across all three N addition treatments. The relationship between N addition and C sequestration in all vegetation pools combined was linear, and had a slope of 16 kg C kg-1 N. While canopy retention of Nr deposition may cause C sequestration rates to be slightly different than this estimate, our data suggest that a minor quantity of annual anthropogenic CO2 emissions are sequestered into boreal forests as a result of Nr deposition. © 2013 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62130
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden; Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, Umeå, SE-901 83, Sweden; Department of Ecology and Environmental Science, Umeå University, Umeå, SE-90187, Sweden
Recommended Citation:
Gundale M.J.,From F.,Bach L.H.,et al. Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle[J]. Global Change Biology,2014-01-01,20(1)