DOI: 10.1016/j.foreco.2014.03.044
Scopus记录号: 2-s2.0-84898800160
论文题名: Forest harvest effects on mercury in streams and biota in Norwegian boreal catchments
作者: De Wit H.A. ; Granhus A. ; Lindholm M. ; Kainz M.J. ; Lin Y. ; Braaten H.F.V. ; Blaszczak J.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2014
卷: 324 起始页码: 52
结束页码: 63
语种: 英语
英文关键词: Bioaccumulation
; Catchment manipulation
; Clear-cutting
; Forest management
; Methylmercury
; Primary consumers
Scopus关键词: Bioaccumulation
; Biochemistry
; Experiments
; Forestry
; Frost effects
; Harvesting
; Mercury (metal)
; Nitrates
; Nutrients
; Runoff
; Soil mechanics
; Boreal catchments
; Clear-cutting
; Dissolved organic matters
; Fatty acid contents
; Forest harvesting
; Methyl mercury
; Primary consumers
; Stream invertebrates
; Catchments
; bioaccumulation
; biomarker
; clearcutting
; dissolved organic matter
; food web
; forest management
; harvesting
; mercury (element)
; methylmercury
; nutrient budget
; streamwater
; Norway
英文摘要: Forest harvesting practices can potentially increase mercury run-off from catchments. A paired catchment experiment was conducted in a boreal forest in southern Norway, to test effects of forest harvest operations on (i) concentrations and fluxes of methylmercury (MeHg), total mercury (HgT), nutrients and dissolved organic matter (TOC), and on (ii) MeHg bioaccumulation in stream foodwebs.Thirty percent of a catchment was harvested in winter time with snow cover but no soil frost, resulting in wheel tracks and soil compaction. Pre-harvest differences included higher streamwater MeHg, HgT and TOC, and lower pH in the treated catchment compared to the reference.No significant treatment effects on concentrations of MeHg, HgT and TOC were detected, whereas concentrations of nutrients (ammonium, nitrate, phosphorus (P)) increased significantly. Estimated catchment export of nitrate and ammonium increased fourfold, as a combined effect of changed discharge and concentrations. Export of MeHg and HgT increased weakly, primarily because of an increase in discharge.Levels of MeHg in stream invertebrates mirrored differences in aquatic MeHg between the two streams, resulting in higher MeHg in biota in the harvest catchment in pre-harvest conditions. After harvest, MeHg levels in primary consumers (herbivorous stoneflies) were no longer different between the two streams, despite continued exposure to higher aqueous MeHg in the harvested catchment. Simultaneously, dietary biomarkers (δ15N signature, lipid- and algal fatty acid content) in the stoneflies had changed significantly, consistent with higher nutrient loadings and associated higher diet availability in the harvested stream.The results of our experiment do not support that forest management has a strong impact on catchment MeHg production. Catchment disturbance through forest harvesting may decrease MeHg in aquatic biota, because of higher stream productivity and associated higher quality of dietary sources, at least in the short-term. Other studies on catchment MeHg production to disturbance have shown a range in responses, from strong to none. So far, no factor has emerged to explain such range in responses. Predictions of forest management effects on MeHg in streamwater and aquatic food webs are hampered by limited understanding of catchment controls on MeHg production. © 2014 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/65939
Appears in Collections: 影响、适应和脆弱性
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作者单位: Norwegian Institute for Water Research, Gaustadalléen 21, NO-0349 Oslo, Norway; Norwegian Forest and Landscape Institute, Mailbox 115, NO-1431 Ås, Norway; Inter-University Center for Aquatic Ecosystem Research WasserCluster Lunz, Dr. Carl Kupelwieser Promenade 5, A-3293 Lunz am See, Austria; Biology Department, Duke University, Durham, NC 27708, United States
Recommended Citation:
De Wit H.A.,Granhus A.,Lindholm M.,et al. Forest harvest effects on mercury in streams and biota in Norwegian boreal catchments[J]. Forest Ecology and Management,2014-01-01,324