TY - JOUR
T1 - Consequences of hydrological alteration for beta diversity of fish assemblages at multiple spatial scales
AU - Rolls, Robert J.
AU - Chessman, Bruce C.
AU - Heino, Jani
AU - Wolfenden, Ben
AU - Growns, Ivor O.
AU - Cheshire, Katherine J.M.
AU - Curwen, Graeme
AU - Ryan, David
AU - Butler, Gavin L.
N1 - Funding Information:
The fish and hydrology datasets used here were produced as part of the New South Wales (NSW) Integrated Monitoring of Environmental Flows program, funded and supplied by the former NSW Department of Land and Water Conservation. Brendan Ebner and Adam Kerezsy generously provided images used in the graphical abstract. An anonymous reviewer provided useful comments that improved the manuscript. This work was supported by the NSW Environmental Trust (reference: 2018/RD/0051). JH was funded by the Academy of Finland as part of the project ?Regoverning the existing hydropower system: integrating ecological, economic and societal aspects of sustainability?.
Funding Information:
This work was supported by the NSW Environmental Trust (reference: 2018/RD/0051 ). JH was funded by the Academy of Finland as part of the project “Regoverning the existing hydropower system: integrating ecological, economic and societal aspects of sustainability”.
Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - Effects of dam operation and extraction of water from rivers on spatial variation in hydrological regimes, and consequences for freshwater biodiversity, are widely predicted but seldom assessed empirically. Evidence of linkages between hydrology and beta diversity contributes to water-management decisions to support landscape-scale biodiversity and avoid inadvertently contributing to further biodiversity decline. Using six lowland rivers in Australia's Murray – Darling Basin that formed a gradient of hydrological alteration, we examined (1) spatial variation in hydrology under modelled scenarios of low water-resource development and flow modification by dams and extraction, (2) how beta diversity of fish among and within rivers was associated with spatial hydrological variation and whether patterns of overall beta diversity differed between native and non-native species, and (3) the associations of spatial and environmental variables and both recent and long-term hydrology with beta diversity. Spatial variation in hydrology among rivers was higher under the modified scenario than under the low-development scenario yet change in the magnitude of within-river (longitudinal) variation was inconsistent between rivers. Beta diversity among rivers was significantly associated with spatial variation in hydrology only in certain circumstances (native species assemblages in specific years). Within-river beta diversity varied among rivers yet was unrelated to longitudinal variation in modified hydrological regimes. Patterns of beta diversity did not differ appreciably if non-native species were included in or excluded from analyses. These findings contradict predictions adopted in ecohydrological science that water resource development homogenises hydrological regimes, in turn causing biotic homogenisation in lowland rivers.
AB - Effects of dam operation and extraction of water from rivers on spatial variation in hydrological regimes, and consequences for freshwater biodiversity, are widely predicted but seldom assessed empirically. Evidence of linkages between hydrology and beta diversity contributes to water-management decisions to support landscape-scale biodiversity and avoid inadvertently contributing to further biodiversity decline. Using six lowland rivers in Australia's Murray – Darling Basin that formed a gradient of hydrological alteration, we examined (1) spatial variation in hydrology under modelled scenarios of low water-resource development and flow modification by dams and extraction, (2) how beta diversity of fish among and within rivers was associated with spatial hydrological variation and whether patterns of overall beta diversity differed between native and non-native species, and (3) the associations of spatial and environmental variables and both recent and long-term hydrology with beta diversity. Spatial variation in hydrology among rivers was higher under the modified scenario than under the low-development scenario yet change in the magnitude of within-river (longitudinal) variation was inconsistent between rivers. Beta diversity among rivers was significantly associated with spatial variation in hydrology only in certain circumstances (native species assemblages in specific years). Within-river beta diversity varied among rivers yet was unrelated to longitudinal variation in modified hydrological regimes. Patterns of beta diversity did not differ appreciably if non-native species were included in or excluded from analyses. These findings contradict predictions adopted in ecohydrological science that water resource development homogenises hydrological regimes, in turn causing biotic homogenisation in lowland rivers.
KW - Beta diversity
KW - Biotic differentiation
KW - Biotic homogenisation
KW - Ecohydrology
UR - http://www.scopus.com/inward/record.url?scp=85111296096&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2021.149170
DO - 10.1016/j.scitotenv.2021.149170
M3 - Article
C2 - 34332378
AN - SCOPUS:85111296096
SN - 0048-9697
VL - 798
SP - 1
EP - 14
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 149170
ER -