气候变化领域集成服务门户(CCPortal): Differential subsurface mobilization of ambient mercury and isotopically enriched mercury tracers in a harvested and residue harvested hardwood forest in northern Minnesota

CCPortal

DOI	10.1007/s10533-021-00801-y
	Differential subsurface mobilization of ambient mercury and isotopically enriched mercury tracers in a harvested and residue harvested hardwood forest in northern Minnesota
	McCarter C.P.R.; Sebestyen S.D.; Eggert S.L.; Kolka R.K.; Mitchell C.P.J.
发表日期	2021
ISSN	1682563
起始页码	119
结束页码	138
卷号	154 期号:1
英文摘要	Mercury is a global pollutant of critical concern but its movement through terrestrial upland systems is poorly understood. We investigated whether forest harvesting practices and varying hydrological conditions resulted in different subsurface transport pathways, fluxes and proportions of recent vs. ambient mercury in runoff. In a multiyear field experiment, we measured subsurface lateral mercury fluxes at three adjacent hillslope plots, including one that was not harvested, one where all biomass was removed after harvest, and one where residual biomass was left after harvest. Two different enriched stable mercury isotopes (Hg tracer) were added to the hillslope plots (one pre-harvest and one post-harvest) to help differentiate between recently deposited mercury and ambient mercury in soils, as well as to identify changes between years. More Hg tracer was recovered in runoff post-harvest (16.2–54.0 μg) than pre-harvest (3.7–11.8 μg) from both harvested hillslopes, but differences between harvested hillslopes were not significant. The movement of Hg tracer was governed by periods of near surface preferential flow that was enhanced by forest harvesting. Runoff Hg tracer concentrations were significantly and inversely related to both event runoff magnitude (R2 = 0.85) and runoff ratio (R2 = 0.81). Insignificant relationships between Hg tracer concentrations and both DOC and precipitation pH suggest that for recently deposited mercury, the overarching controls on mobilization were hydrological rather than biogeochemical. The dependence of mercury mobilization on the routing of precipitation to different subsurface flow pathways suggests an important interaction between climate and the age of mercury pools for mercury transport from terrestrial landscapes. © 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
英文关键词	Biomass harvest; Dissolved organic carbon; Mercury; Silviculture; Soil; Throughflow
语种	英语
来源期刊	Biogeochemistry
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184597
作者单位	Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military Trail, Scarborough, ON M1C 1A4, Canada; USDA Forest Service Northern Research Station, Grand Rapids, MN 55744, United States
推荐引用方式 GB/T 7714	McCarter C.P.R.,Sebestyen S.D.,Eggert S.L.,et al. Differential subsurface mobilization of ambient mercury and isotopically enriched mercury tracers in a harvested and residue harvested hardwood forest in northern Minnesota[J],2021,154(1).
APA	McCarter C.P.R.,Sebestyen S.D.,Eggert S.L.,Kolka R.K.,&Mitchell C.P.J..(2021).Differential subsurface mobilization of ambient mercury and isotopically enriched mercury tracers in a harvested and residue harvested hardwood forest in northern Minnesota.Biogeochemistry,154(1).
MLA	McCarter C.P.R.,et al."Differential subsurface mobilization of ambient mercury and isotopically enriched mercury tracers in a harvested and residue harvested hardwood forest in northern Minnesota".Biogeochemistry 154.1(2021).