DOI: 10.1002/2015GB005316
Scopus记录号: 2-s2.0-84973497222
论文题名: Forest harvest contribution to Boreal freshwater methyl mercury load
作者: Kronberg R ; -M ; , Drott A ; , Jiskra M ; , Wiederhold J ; G ; , Björn E ; , Skyllberg U
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2016
卷: 30, 期: 6 起始页码: 825
结束页码: 843
语种: 英语
英文关键词: cycling model
; forest harvest
; forest soil
; mercury
; methyl mercury
; stream export
Scopus关键词: biogeochemical cycle
; clearcutting
; coniferous tree
; flux measurement
; forest soil
; harvesting
; mercury (element)
; methylmercury
; peatland
; runoff
; streamwater
; terrain
; topsoil
; transport process
; watershed
; Atlantic Ocean
; Baltic Sea
; Sweden
; Picea abies
英文摘要: Effects of Boreal forest harvest on mercury (Hg) and methyl mercury (MeHg) soil pools and export by stream runoff were quantified by comparing 10 reference watersheds (REFs) covered by >80 year old Norway spruce (Picea abies Karst.) forests with 10 similar watersheds subjected to clear-cutting (CCs). While total Hg soil storage did not change, MeHg pools increased seven times (p = 0.006) in the organic topsoil 2 years after clear-cutting. In undulating terrain, situated above the postglacial marine limit (ML) of the ancient Baltic Sea, the mass ratio between flux-weighted MeHg and dissolved organic carbon (MeHg/DOC) in stream runoff increased 1.8 times (p < 0.004) as a consequence of forest harvest. When recalculated to 100% clear-cutting of the watershed, the annual MeHg stream export increased 3.8 times (p = 0.047). Below the ML, where the terrain was flatter, neither the MeHg/DOC ratio nor the annual export of MeHg differed between REFs and CCs, likely because of the larger contribution of MeHg exported from peaty soils and small wetlands. The most robust measure, MeHg/DOC, was used to calculate MeHg loadings to Boreal headwaters. If the forest harvest effect lasts 10 years, clear-cutting increases MeHg runoff by 12–20% in Sweden and 2% in the Boreal zone as a whole. In Sweden, having intensely managed forests, 37% and 56% of MeHg are exported from peatlands and forest soils, respectively, and forest clear-cutting is adding another 6.6%. In the Boreal zone as a whole peatlands and forests soils contribute with 53% and 46%, respectively, and clear-cutting is estimated to add another 1.0%. An expected rapid increase in Boreal forest harvest and disturbance urge for inclusion of land use effects in mercury biogeochemical cycling models at different scales. ©2016. 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/77847
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden; Department of Chemistry, Umeå University, Umeå, Sweden; Soil Chemistry Group, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zurich, Switzerland; Isotope Geochemistry Group, Institute of Geochemistry and Petrology, ETH Zurich, Zurich, Switzerland
Recommended Citation:
Kronberg R,-M,, Drott A,et al. Forest harvest contribution to Boreal freshwater methyl mercury load[J]. Global Biogeochemical Cycles,2016-01-01,30(6)