An interdisciplinary synthesis of floodplain ecosystem dynamics in a rapidly deglaciating watershed.

Autor: Sergeant CJ; Flathead Lake Biological Station, University of Montana, 32125 Bio Station Ln, Polson, MT 59860-6815, USA. Electronic address: cjser@uw.edu., Moore JW; Earth2Ocean Research Group, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada. Electronic address: jwmoore@sfu.ca., Whited DC; Flathead Lake Biological Station, University of Montana, 32125 Bio Station Ln, Polson, MT 59860-6815, USA. Electronic address: diane.whited@flbs.umt.edu., Pitman KJ; Earth2Ocean Research Group, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6, Canada., Connor M; Lands, Resources, and Fisheries, Taku River Tlingit First Nation, P.O. Box 132, Atlin, BC V0W 1A0, Canada. Electronic address: fisheries.coord@gov.trtfn.com., Sexton EK; Flathead Lake Biological Station, University of Montana, 32125 Bio Station Ln, Polson, MT 59860-6815, USA. Electronic address: erin.sexton@flbs.umt.edu.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Feb 20; Vol. 912, pp. 169245. Date of Electronic Publication: 2023 Dec 10.
DOI: 10.1016/j.scitotenv.2023.169245
Abstrakt: Glacier retreat is rapidly transforming some watersheds, with ramifications for water supply, ecological succession, important species such as Pacific salmon (Oncorhynchus spp.), and cultural uses of landscapes. To advance a more holistic understanding of the evolution of proglacial landscapes, we integrate multiple lines of knowledge starting in the early 1900s with contemporary data from the Taaltsux̱éi (Tulsequah) Watershed in British Columbia, Canada. Our objectives were to: 1) synthesize recent historical geography and Indigenous Knowledge, including glacier dynamics, and hydrology; 2) describe the limnology of a proglacial lake; 3) quantify decadal-scale downstream physical floodplain change; and 4) characterize riverine physical, chemical, and biological differences relative to distance from the proglacial lake. Since 1982, the Tulsequah Glacier has receded 0.07 km/yr, exposing a cold, deep, and growing proglacial lake. The downstream floodplain is rapidly changing; satellite imagery analysis revealed a 14 % increase in vegetation from 2003 to 2017 and Indigenous Knowledge described increases in vegetation and wildlife habitat over the last century. Contemporary measurements of physical-chemical water properties differed across sites representing the upper and lower watershed, and mainstem and off-channel habitats. Catches of juvenile salmonids in the upper watershed (closer to the glacier) were mostly limited to warmer, clearer groundwater-fed channels, whereas in the lower watershed there were salmonids in both groundwater-fed and mainstem habitats. There was limited zooplankton taxa diversity from the proglacial lake and benthic macroinvertebrates in the river. Collectively, our synthesis suggests that the transformation of proglacial landscapes experiencing rapid ice loss can be influenced by interlinked abiotic processes of glacier retreat, lake formation, and altered hydrology, as well as corresponding biological processes such as beaver repopulation, wetland formation, and riparian vegetation growth. These factors, along with expected increases to proglacial lake productivity and salmon habitat suitability, are an important consideration for forward-looking watershed management of glacier-fed rivers.
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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