Europäische Süßwassersysteme im Klimawandel: die Effekte hydrologischer und thermischer Regimeveränderungen, Gewässerverbauung und Autökologie thermisch sensitiver Arten auf die Vulnerabilität von aquatischen Ökosystemen
Zusammenfassung der Projektergebnisse
Habitat conditions across the European freshwater are being drastically altered by human activities such as unsustainable land use, overutilization of resources, introduction of alien species, and connectivity disruption by barriers. Climate change is expected to amplify existing threats within freshwater ecosystems, alongside causing novel shifts in the hydrological, thermal and biotic conditions. The protection and preservation of freshwater and the services they provide requires comprehensive knowledge of the combined consequences of climate change, connectivity and species traits on vulnerability of freshwater under climate change. Using several modelling and analysis approaches, in this project we addressed the research questions of (i) how will species respond to climate change in view of the environmental shifts, anthropogenic pressures on water resources and dispersal barriers, (ii) how will the physiological performance of species change considering various future distribution scenarios, and (iii) how vulnerable are European freshwater ecosystems to climate change. Derived from these main research questions, we designed a novel framework for assessing the vulnerability of European freshwater catchments, investigated the thermal responses of species from different taxonomic groups, estimated the thermal performance changes across freshwater species’ life stages and identified priority catchments for conservation measures to mitigate climate change impacts. Analyses of freshwater systems and species under climate change have uncovered important suggestions for renewed and adjusted conservation actions. The current European protected area network covers less than 25% of the most vulnerable catchments implying the need for new efforts in ecosystem protection. The biodiversity hotspots - the ancient Balkan Lakes Ohrid and Prespa emerged as most vulnerable to climate change. Predicted poleward shifts of species’ ecological niches underline the importance of movement throughout the freshwater system network to suitable habitats and areas where higher physiological performances for all life stages may be possible. However, anthropogenic disturbances like habitat fragmentation additionally aggravate the impacts of changing climatic environments and unveil the need for sustainable solutions enhancing stakeholder cooperation at the major basin scale and maintaining connectivity among catchments. Within this project, we have contributed to the ongoing study area of investigating climate change impacts on freshwater ecosystems. We have successfully developed different quantitative catchmentbased assessments for estimating the impacts on freshwater systems and species and provided substantial advances in methodological aspects of predictive multi-scale species distribution modelling and in understanding of the biology of climate change. The European freshwater catchments identified as most climate change vulnerable provide preliminary targets for identification of opportunities towards increasing their climate change resilience and for development of climate change conservation management and mitigation strategies.
Projektbezogene Publikationen (Auswahl)
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(2017). Vulnerability of European freshwater catchments to climate change. Global Change Biology, 23: 3567–3580
Markovic, D., Carrizo, S. F., Kärcher, O., Walz, A., and David, J. N.
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(2019). Freshwater species distributions along thermal gradients. Ecology and Evolution, 9: 111–124
Kärcher, O., Hering, D., Frank, K., and Markovic, D.
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(2019). Model-based assessments of freshwater ecosystems and species under climate change.
Kärcher, O.
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(2019). Scale effects on the performance of niche-based models of freshwater fish distributions. Ecological Modelling, 405: 33–42
Kärcher, O., Frank, K., Walz, A., and Markovic, D.
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(2019). Scale effects on the performance of niche-based models of freshwater fish distributions: Local vs. upstream area influences. Ecological Modelling, 411: 108818
Markovic, D., Walz, A., Kärcher, O.
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(2020). Chlorophyll a – Nutrient and Temperature Relationships, and Predictions for Lakes across Mountain Regions. Inland Waters, 10: 29–41
Kärcher, O., Filstrup, C. T., Brauns, M., Tasevska, O., Patceva, S., Hellwig, N., Walz, A., Frank, K., and Markovic, D.
