Abstract

Biological invasions pose a major threat to biodiversity, ecosystem functioning, and human well-being. Non-native species can have severe ecological impacts that are transformative, affecting ecosystems across both short-term and long-term timescales. However, few studies have determined the temporal dynamics of impact between these scales, impeding future predictions as invasion rates continue to rise. Our study uses a meta-analytical approach to dissect the changing taxonomic and functional impacts of biological invasions on native macroinvertebrate populations and communities in freshwater ecosystems across Europe, using a recently collated European long-term time series spanning several decades. Our findings reveal a complex temporal pattern: while initial stages of invasion (i.e., five years after the first record of non-native species) often exhibited benign impacts on macroinvertebrate abundance, richness, or functional diversity, the long-term (i.e., the period following the early-invasion) effects became predominantly negative. This pattern was consistent between taxonomic and functional metrics for impact at both population and species levels, with taxonomic metrics initially positively affected by invasions and functional metrics more stable, before declining. These results suggest that even initially benign or positively perceived impacts could be eventually superseded by negative consequences. Therefore, understanding the magnitude of invasion effects increasingly requires long-term studies spanning several years or decades to offer insights into effective conservation strategies prioritising immediate and future biodiversity protection efforts. These findings also highlight the importance of integrating multiple taxonomic, functional, and temporal components to inform adaptive management approaches to mitigate the negative effects of current and future biological invasions.

Keywords: Invasive species; non-native; freshwater ecosystems; temporal dynamics; ecosystem functionality; management strategies

• Ismael Soto - University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic. ORCID: 0000-0002-7288-6336
• Rafael L. Macêdo - Graduate Program in Conservation and Ecotourism, Federal University of Rio de Janeiro State, Rio de Janeiro, RJ, Brazil; Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 310, 12587 Berlin, Germany; Institute of Biology, Freie Universität Berlin, Königin-Luise-Str. 1-3, 14195 Berlin, Germany. ORCID: 0000-0001-5086-0170
• Lais Carneiro - Université Paris-Saclay, CNRS, AgroParisTech, Ecologie Systématique Evolution, Gif sur Yvette, France.
• Elizabeta Briski - GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel, Wischhofstraße 1-3, 24148, Kiel, Germany. ORCID: 0000-0003-1896-3860
• Antonín Kouba - University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany
• Ross N. Cuthbert - Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, BT9 5DL, United Kingdom. ORCID: 0000-0003-2770-2544
• Phillip J. Haubrock - University of South Bohemia in České Budějovice, Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Zátiší 728/II, 389 25 Vodňany, Czech Republic; Department of River Ecology and Conservation, Senckenberg Research Institute and Natural History Museum Frankfurt, Gelnhausen, Germany; CAMB, Center for Applied Mathematics and Bioinformatics, Gulf University for Science and Technology, Kuwait. ORCID: 0000-0003-2154-4341

Corresponding authors: Ismael Soto

✝Senior Authors (Ross N. Cuthbert & Phillip J. Haubrock)

• R (version 4.0.0 or higher) --> I used v4.3.1

• How to us this repository

• Data: Contains the raw and processed data used in our analyses.

• Scripts: Includes all R scripts for replicating the study's results.

• Figures: Visual representations of key insights from our data.

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