Earthquake, floods and changing land use history: A 200-year overview of environmental changes in Selenga River basin as indicated by n-alkanes and related proxies in sediments from shallow lakes.

Autor: C Martins C; Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK. Electronic address: ccmart@ufpr.br., Adams JK; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK; Biology Department, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada. Electronic address: j24adams@uwaterloo.ca., Yang H; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK., Shchetnikov AA; Institute of the Earth's Crust, Siberian Branch of the Russian Academy of Sciences, Irkutsk 664033, Russia; Vinogradov Institute of Geochemistry, Siberian Branch of Russian Academy of Sciences, Irkutsk 664033, Russia; Irkutsk State University, Irkutsk, 664025, Russia., Di Domenico M; Centro de Estudos do Mar, Campus Pontal do Paraná, Universidade Federal do Paraná, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil., Rose NL; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK., Mackay AW; Environmental Change Research Centre, Department of Geography, University College London, Gower Street, London WC1E 6BT, UK.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2023 May 15; Vol. 873, pp. 162245. Date of Electronic Publication: 2023 Feb 18.
DOI: 10.1016/j.scitotenv.2023.162245
Abstrakt: The Selenga River basin, located in southern Siberia, is an important component of the Lake Baikal ecosystem, and comprises approximately 80 % of the Baikal watershed. Within the Selenga River basin, two localized study regions were chosen. The first, the Selenga Delta, is one of the largest inland freshwater floodplains in the world and plays an important role in the ecosystem functioning of Baikal. It purifies the river waters before they enter the lake and acts as a refuge for many of Baikal's endemic species. The second location, the Gusinoozersk region, is southwest of Lake Baikal and the Selenga Delta, and was chosen as a more heavily industrialized region within the Selenga River basin. Anthropogenic activities, including industry, urban settlements, aquaculture and agriculture, have historically increased ecological damage within this area. We assessed possible drivers of changes in sedimentary organic matter (OM) composition within two shallow lakes (SLNG04 and Black Lake), located in the Selenga Delta and the Selenga watershed, respectively. We focused on individual n-alkanes, one of the most abundant and common lipids used to provide information on past vegetation and used multivariate statistics to disentangle changes in the sources of sedimentary OM over time. The depositional OM history of SLNG04B core can be divided in four zones: (i) major influence of non-emergent vascular plants, typically found in transitional environments (ca. 1835 to ca. 1875); (ii) increased influence of grasses/herbs (ca. 1880 to ca. 1910); (iii) transition from non-emergent vascular plants and grasses/herbs to submerged and floating macrophytes and phytoplankton (ca. 1915 to ca. 1945); (iv) maintenance of autochthonous OM from submerged and floating macrophytes and phytoplankton (ca. 1945 to ca. 2014). The depositional OM history of the Black Lake core can be divided in two main zones: (i) major influence of non-emergent vascular plants and submerged and floating macrophytes (ca. 1915 to ca. 1980); (ii) increased influence of grasses/herbs and phytoplankton (ca. 1980 to ca. 2010). Natural events (e.g., an earthquake in 1862 caused flooding and subsidence of much of the land surrounding SLNG04 lake and a further catastrophic flood event in 1897) and anthropogenic activities (e.g., nutrient pollution from expansion of agricultural and livestock population) changed the composition of sedimentary OM resulting in ecological shifts across trophic levels in the Selenga River basin.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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