Local environment and fragmentation by drought and damming shape different components of native and non-native fish beta diversity across pool refuges

Joana Martelo; Christos Gkenas; Diogo Ribeiro; M Judite Alves; Filipe Ribeiro; Julien Cucherousset; João Gago; M Filomena Magalhães

doi:10.1016/j.scitotenv.2024.172517

Local environment and fragmentation by drought and damming shape different components of native and non-native fish beta diversity across pool refuges

Sci Total Environ. 2024 Apr 17:930:172517. doi: 10.1016/j.scitotenv.2024.172517. Online ahead of print.

Authors

Joana Martelo¹, Christos Gkenas², Diogo Ribeiro², M Judite Alves³, Filipe Ribeiro², Julien Cucherousset⁴, João Gago⁵, M Filomena Magalhães⁶

Affiliations

¹ cE3c- Centre for Ecology, Evolution and Environmental Changes & CHANGE - Global Change and Sustainability Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal; MARE, Marine and Environmental Sciences Centre & ARNET - Aquatic Research Network Associated Laboratory, Faculty of Sciences, University of Lisbon, Lisbon, Portugal. Electronic address: jmmartelo@fc.ul.pt.
² MARE, Marine and Environmental Sciences Centre & ARNET - Aquatic Research Network Associated Laboratory, Faculty of Sciences, University of Lisbon, Lisbon, Portugal.
³ cE3c- Centre for Ecology, Evolution and Environmental Changes & CHANGE - Global Change and Sustainability Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal; Museum of Natural History and Sciences, University of Lisbon, Lisbon, Portugal.
⁴ Laboratoire EDB (UMR 5174), CNRS, University Toulouse III, Paul Sabatier, France.
⁵ MARE, Marine and Environmental Sciences Centre & ARNET - Aquatic Research Network Associated Laboratory, Faculty of Sciences, University of Lisbon, Lisbon, Portugal; Escola Superior Agrária de Santarém, Instituto Politécnico de Santarém, Santarém, Portugal; CERNAS, Research Centre for Natural Resources, Environment and Society, Portugal.
⁶ cE3c- Centre for Ecology, Evolution and Environmental Changes & CHANGE - Global Change and Sustainability Institute, Faculty of Sciences, University of Lisbon, Lisbon, Portugal.

PMID: 38641092
DOI: 10.1016/j.scitotenv.2024.172517

Abstract

Pool refuges are critical for maintaining stream fish diversity in increasingly intermittent streams. Yet, the patterns and drivers of beta diversity of native and non-native fish in pool refuges remain poorly known. Focusing on Mediterranean streams, we decomposed beta diversity of native and non-native fish into richness difference (RichDiff) and species replacement (Repl), and local (LCBD, LCBD_RichDiff and LCBD_Repl) and species (SCBD) contributions. We assessed the influence of environmental and spatial factors associated with drought and damming fragmentations on beta diversity components and LCBDs, and of local species richness and occupancy on LCBDs and SCBD, respectively. Overall, non-native species showed a more limited occupancy of pool refuges than native fish. RichDiff dominated beta diversity, though it was influenced by drought and damming fragmentations for native fish and local environment for non-native fish. Repl for native fish was slightly influenced by local environment, but for non-native fish was largely driven by drought and damming, albeit with a contribution of local environment as well. LCBD and LCBD_RichDiff increased in pools in low order streams for native fish and at low elevations for non-native fish, and with high or low species richness. SCBD was higher for native species with intermediated pool occupancy, but for non-native species with low occupancy. Our results suggest that stream fragmentation may drive native species loss and non-native species replacement in pool refuges, and that environmental filtering may shape non-native species loss. Pools in lower order streams harbouring unique species-rich or species-poor assemblages should be prioritize for conservation and restoration, respectively, and pools at low elevation with unique non-native assemblages should deserve control efforts. We encourage the partitioning of beta diversity and individual analysis of native and non-native fish in intermittent streams, which may be key in stressing the importance of pool refuges in safeguarding native fish diversity.

Keywords: Biodiversity conservation; Dispersal limitation; Environmental filtering; Intermittent streams; Metacommunities.