DOI: 10.1029/2017GB005840
论文题名: Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution
作者: Olson C. ; Jiskra M. ; Biester H. ; Chow J. ; Obrist D.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2018
卷: 32, 期: 7 语种: 英语
英文关键词: active layer
; concentration (composition)
; mercury (element)
; Northern Hemisphere
; pollutant source
; soil horizon
; soil pollution
; spatial distribution
; temperate environment
; tundra soil
; Alaska
; Arctic
; Arctic Ocean
; United States
学科: Alaska
; Arctic
; mercury
; pollution
; soils
; tundra
中文摘要: Tundra soils serve as major sources of mercury (Hg) input to the Arctic Ocean via river runoff and coastal erosion; yet little information is available on tundra soil Hg concentrations, pool sizes, origins, and dynamics. We present a detailed investigation of Hg in the active layer (upper ~100 cm subject to seasonal thaw) of tundra soils across 11 sites in Alaska. Soil Hg concentrations in organic horizons (151 ± 7 μg/kg) were in the upper range of temperate soil organic horizons, and concentrations in mineral horizons (98 ± 6 μg/kg) were much higher than in temperate soils. Soil Hg concentrations declined from inland to coastal sites, in contrast to a hypothesized northward increase expected because of proximity to coastal atmospheric mercury depletion events. Principle component analyses and elemental ratios results show that exogenic sources dominated over geogenic sources—in A-horizons (66 ± 4%) and mineral B-horizons (51 ± 1%). 14C age-dating suggested recent origins of Hg in surface soils but showed that mineral soils (more than 7,300 years old) must have accumulated atmospheric inputs across millennia leading to high soil concentrations and pools. We estimated a total Northern Hemisphere active-layer tundra soil Hg pool of 184 Gg (range of 136 to 274 Gg), suggesting a globally important Hg storage pool. Tundra soils are subject to seasonal thaw and freeze dynamics, thereby providing large inputs to rivers, lakes, and the Arctic Ocean. Understanding processes that mobilize Hg from tundra soils will be critical to understanding future Arctic wildlife and human Hg exposures. ©2018. 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/160214
Appears in Collections: 气候变化与战略
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作者单位: Desert Research Institute, Reno, NV, United States; Geosciences Environment Toulouse, CNRS, Toulouse, France; Environmental Geochemistry, Technische Universität Braunschweig, Braunschweig, Germany; Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts, Lowell, MA, United States
Recommended Citation:
Olson C.,Jiskra M.,Biester H.,et al. Mercury in Active-Layer Tundra Soils of Alaska: Concentrations, Pools, Origins, and Spatial Distribution[J]. Global Biogeochemical Cycles,2018-01-01,32(7)