气候变化领域集成服务门户(CCPortal): Multiple anthropogenic drivers behind upward trends in organic carbon concentrations in boreal rivers

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DOI	10.1088/1748-9326/ab4fa9
	Multiple anthropogenic drivers behind upward trends in organic carbon concentrations in boreal rivers
	Asmala E.; Carstensen J.; Raike A.
发表日期	2019
ISSN	17489318
卷号	14 期号:12
英文摘要	Increases of riverine organic carbon concentrations have been observed across the northern hemisphere over the past few decades. These increases are the result of multiple environmental drivers, but the relative importance of the drivers is still unclear. We analyzed a dataset of >10 000 observations of riverine total organic carbon (TOC) concentrations and associated water chemistry and hydrological observations from 1993 to 2017. The observations span a ∼600 km north-south gradient from 30 individual river systems in Finland. Our data show significantly increasing TOC concentrations in 25 out of 30 systems, with an average increase from 12.0 to 15.1 mg l-1. The observed increase in riverine TOC concentrations led to an increase of 0.28 Mt in annual TOC load to the Baltic Sea from 1993 level to 2017 level. We analyzed the role of three putative environmental drivers of the observed TOC trends. Multiple regression analysis revealed that the most common driver was discharge, which alone explained TOC increases in 13 rivers, whereas pH and temperature were less important drivers (sole predictor in one and zero rivers, respectively). Different permutations of these three drivers were also found to be significant; the combination of discharge and pH being the most common (4 rivers). Land use was not in general linked with trends in TOC, except for the proportion of ditched land in the catchment, which was significantly correlated with increases in TOC concentration. Land use showed significant relationships with trends in discharge and pH. We also found that catchment characteristics are regulating the extent of these regional or global environmental changes causing the upward trends of riverine organic carbon. © 2019 The Author(s). Published by IOP Publishing Ltd.
英文关键词	ditching; land use; riverine export; total organic carbon
语种	英语
scopus关键词	Catchments; Chemical analysis; Land use; Regression analysis; Rivers; Runoff; Carbon concentrations; Catchment characteristics; ditching; Global environmental change; Multiple regression analysis; Northern Hemispheres; riverine export; Total Organic Carbon; Organic carbon; catchment; concentration (composition); estuarine front; land use; river system; total organic carbon; water chemistry; Atlantic Ocean; Baltic Sea; Finland
来源期刊	Environmental Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/154315
作者单位	Tvarminne Zoological Station, University of Helsinki, Hanko, Finland; Department of Bioscience, Aarhus University, Roskilde, Denmark; Marine Research Centre, Finnish Environment Institute, Helsinki, Finland
推荐引用方式 GB/T 7714	Asmala E.,Carstensen J.,Raike A.. Multiple anthropogenic drivers behind upward trends in organic carbon concentrations in boreal rivers[J],2019,14(12).
APA	Asmala E.,Carstensen J.,&Raike A..(2019).Multiple anthropogenic drivers behind upward trends in organic carbon concentrations in boreal rivers.Environmental Research Letters,14(12).
MLA	Asmala E.,et al."Multiple anthropogenic drivers behind upward trends in organic carbon concentrations in boreal rivers".Environmental Research Letters 14.12(2019).