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Lookup NU author(s): Dr Fredric WindsorORCiD
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
The unique hydrology and physicochemistry of alpine streams provide an important influence on the structure and function of inhabiting biological communities. A substantial body of research exists on alpine streams across many regions of the globe (e.g. Europe, North and South America and Greenland). To date, however, there have been few studies investigating the environmental conditions present in alpine streams across the Japanese archipelago. The lack of information on alpine streams in Japan is problematic as unique regional climates, e.g. some of the highest levels of snowfall globally, are likely to have repercussions for morphological, hydrological, physicochemical and metabolic signatures, causing them to differ from those observed in other regions. In this study we compare the morphology, hydrology, physicochemistry and metabolic activity of snowmelt and groundwater fed streams in the Kamikochi region of the Japanese Alps. Stream discharge, water chemistry (major ions, silica, dissolved oxygen), water temperature and channel stability were measured over a period of 16 months in 2017–2018. Metabolic activity was determined using Resazurin-Resorufin (Raz-Rru) Smart Tracer and variation in the Raz transformation rate was assessed to understand the effects of hydrology and physicochemistry on ecosystem functioning. Snowmelt streams were characterised by higher variability of water temperature, water chemistry and stream discharge, both, within and between sites. Indeed, two of the snowmelt streams experienced no flow conditions for several periods and also floods. In comparison, water chemistry, water temperature and stream discharge in groundwater fed streams were more temporally stable. Metabolic activity was higher in one groundwater fed stream, attributed to significant growth of macrophytes. These findings indicate that the patterns of morphology, hydrology, physicochemistry and metabolic activity across streams in the Japanese Alps largely resemble those identified elsewhere, although there were higher levels of inter-stream variation. The diversity and inter-site variation of hydrological and physicochemical conditions are likely responsible for the unique flora and fauna in the streams. This study therefore indicates the potential importance of habitat templates for the aquatic biodiversity hotspot in this region.
Author(s): Windsor FM, Docherty CL, Brekenfeld N, Tojo K, Krause S, Milner AM
Publication type: Article
Publication status: Published
Journal: Journal of Hydrology
Year: 2021
Volume: 600
Print publication date: 01/09/2021
Online publication date: 10/06/2021
Acceptance date: 08/06/2021
Date deposited: 23/06/2021
ISSN (print): 0022-1694
Publisher: Elsevier
URL: https://doi.org/10.1016/j.jhydrol.2021.126560
DOI: 10.1016/j.jhydrol.2021.126560
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