期刊
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
卷 127, 期 3, 页码 -出版社
AMER GEOPHYSICAL UNION
DOI: 10.1029/2021JG006670
关键词
iron biogeochemistry; freshwater browning; atmospheric sulfur deposition; paleolimnology; X-ray absorption spectroscopy
资金
- Swedish Research Council [2015-05450, 201604561, 201604153]
- Formas [2019-00889]
- Knut and Alice Wallenberg Foundation [2013.0073]
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-76SF00515]
- DOE Office of Biological and Environmental Research
- National Institutes of Health, National Institute of General Medical Sciences [P41GM103393]
- Swedish Research Council [2015-05450] Funding Source: Swedish Research Council
- Formas [2019-00889] Funding Source: Formas
The study found that the increase in iron concentrations in lakes may be due to increased loading from the terrestrial catchment rather than changes in the distribution between sediments and the water column. Investigations in Lake Bolmen in southern Sweden revealed that the changes in iron sulfide in sediments were independent of iron accumulation and speciation.
Increasing iron (Fe) concentrations are found in lakes on a wide geographical scale but exact causes are still debated. The observed trends might result from increased Fe loading from the terrestrial catchment, but also from changes in how Fe distributes between the water column and the sediments. To get a better understanding of the causes we investigated whether there has been any change in the sediment formation of Fe sulfides (FeS) as an Fe sink in response to declining atmospheric sulfur (S) deposition during recent decades. For our study, we chose Lake Bolmen in southern Sweden, a lake for which we confirmed that Fe concentrations in the water column have strongly increased along with water color during 1966-2018. Our investigations showed that Fe accumulation and speciation varied independently of S accumulation patterns in the Lake Bolmen sediment record. Thus, we were not able to relate the positive trend in Fe concentrations to reduced FeS binding in the sediments. Furthermore, we found that Fe accumulation rates increased along with lake water Fe concentrations, indicating that increased catchment loading rather than a change in the distribution between the sediments and the water column has driven the increase in Fe concentrations. The increased loading may be due to land-use change in the form of an extensive expansion of coniferous forest during the past century. Altered forest management practices and increased precipitation may have led to enhanced weathering and erosion of organic soil layers under aging coniferous forest.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据