Angesichts der schnellen Landschaftsveränderungen, insbesondere im urbanen Raum, haben innovative, gemeinsam erarbeitete Ideen zu einer verbesserten Umsetzung von ökologischer Infrastruktur höchste Priorität. Zwei Workshops mit unterschiedlichen Teilnehmenden haben eine Plattform geboten, um sich über die Herausforderungen und Herangehensweisen rund um die ökologische Infrastruktur auszutauschen. Es scheinen besonders Hürden in Bezug auf Koordination über die verschiedenen Sektoren hinweg, Ausbildung als auch Finanzierung zu bestehen. Es wird auch klar, dass alle Akteure aus verschiedenen Bereichen der Praxis und Wissenschaft gefragt sind, um gemeinsam das Ziel einer ökologischen Infrastruktur zur Förderung und Erhaltung der Biodiversität langfristig zu realisieren.

Eu égard aux modifications rapides du paysage, en particulier dans l'espace urbain, il est urgent de produire des idées collaboratives et innovantes afin d'améliorer la mise en oeuvre de l'infrastructure écologique. Deux ateliers accueillant des profils différents ont servi de plateforme d'échange sur le thème des difficultés et des approches en lien avec l'infrastructure écologique. Les obstacles rencontrés concernent principalement la coordination intersectorielle, la formation et le financement. Tous les acteurs des différents domaines de la pratique et de la recherche sont appelés à conjuguer leurs efforts afin de concrétiser en commun l'objectif durable d'une infrastructure écologique capable de promouvoir et de préserver la biodiversité.

Im Rahmen der Forschungsinitiative «Blau-grüne Biodiversität» von Eawag und WSL diskutierten an zwei Workshops verschiedenste Interessenvertretende über die Herausforderungen rund um die ökologische Infrastruktur. Die Teilnehmenden betonten die Notwendigkeit, die interdisziplinäre Zusammenarbeit zu verbessern, und erkundeten Hindernisse wie Interessenkonflikte, politische Trägheit und wenig genutztes Potenzial. Der an den Workshops vielfach geäusserte Wunsch nach verstärkter Zusammenarbeit unterstreicht die Bedeutung solcher Veranstaltungen für die Umweltpolitik und eine nachhaltige Entwicklung.

Clownfish (subfamily Amphiprioninae) are an iconic group of coral reef fish that evolved a mutualistic interaction with sea anemones, which triggered the adaptive radiation of the clade. Within clownfishes, the "skunk complex" is particularly interesting. Besides ecological speciation, interspecific gene flow and hybrid speciation are thought to have shaped the evolution of the group. We investigated the mechanisms characterizing the diversification of this complex. By taking advantage of their disjunct geographical distribution, we obtained whole-genome data of sympatric and allopatric populations of the three main species of the complex (Amphiprion akallopisos, A. perideraion and A. sandaracinos). We examined population structure, genomic divergence and introgression signals and performed demographic modelling to identify the most realistic diversification scenario. We excluded scenarios of strict isolation or hybrid origin of A. sandaracinos. We discovered moderate gene flow from A. perideraion to the ancestor of A. akallopisos + A. sandaracinos and weak gene flow between the species in the Indo-Australian Archipelago throughout the diversification of the group. We identified introgressed regions in A. sandaracinos and detected in A. perideraion two large regions of high divergence from the two other species. While we found that gene flow has occurred throughout the species' diversification, we also observed that recent admixture was less pervasive than initially thought, suggesting a role of host repartition or behavioural barriers in maintaining the genetic identity of the species in sympatry.

Der Aufbau einer blau-grünen Infrastruktur erfordert die Koordination zwischen ganz verschiedenen gesellschaftlichen Akteurinnen und Akteuren. Es ist daher essenziell, die sozio-ökologischen Netzwerke zu analysieren sowie die Herausforderungen für alle Beteiligten bei der Planung und Umsetzung zu verstehen.

Primary considerations for urban blue-green infrastructure (BGI) encompass sustainable stormwater/urban heat management while biodiversity conservation is often considered an inherent benefit rather than a core planning requirement. However, ecological function of BGI as 'stepping stones' or linear corridors for otherwise fragmented habitats is undisputed. While quantitative approaches for modelling ecological connectivity in conservation planning are well established, mismatches in scope and scale with models that support the planning of BGI makes their adoption and integration difficult across disciplines. Technical complexities have led to ambiguity around circuit and network-based approaches, focal node placement, spatial extents, and resolution. Furthermore, these approaches are often computationally intensive, and considerable gaps remain in their use for identifying local-scale critical "pinch-points" that urban planners may respond to with the integration of BGI interventions that address biodiversity enhancement among other ecosystem services. Here, we present a framework that simplifies and integrates the merits of regional connectivity assessments with a focus on urban areas to prioritise BGI planning interventions while reducing computational demands. Our framework facilitates: (1) modelling potential ecological corridors at a coarse regional scale, (2) prioritising local-scale BGI interventions based on the relative contribution of individual nodes in this regional network, and (3) inferring connectivity hot- and cold-spots for local-scale BGI interventions. We illustrate this in the Swiss lowlands, demonstrating how, compared to previous work, we are able to identify and rank different priority locations across the region for BGI interventions in support of biodiversity enhancement and how their local-scale functional design may be benefited by addressing specific environmental variables.

Human impacts such as habitat loss, climate change and biological invasions are radically altering biodiversity, with greater effects projected into the future. Evidence suggests human impacts may differ substantially between terrestrial and freshwater ecosystems, but the reasons for these differences are poorly understood. We propose an integrative approach to explain these differences by linking impacts to four fundamental processes that structure communities: dispersal, speciation, species-level selection and ecological drift. Our goal is to provide process-based insights into why human impacts, and responses to impacts, may differ across ecosystem types using a mechanistic, eco-evolutionary comparative framework. To enable these insights, we review and synthesise (i) how the four processes influence diversity and dynamics in terrestrial versus freshwater communities, specifically whether the relative importance of each process differs among ecosystems, and (ii) the pathways by which human impacts can produce divergent responses across ecosystems, due to differences in the strength of processes among ecosystems we identify. Finally, we highlight research gaps and next steps, and discuss how this approach can provide new insights for conservation. By focusing on the processes that shape diversity in communities, we aim to mechanistically link human impacts to ongoing and future changes in ecosystems.

Aim: Evaluating the similarity of diversity patterns across micro- to macroevolutionary scales in natural communities, such as species–genetic diversity correlations (SGDCs), may inform on processes shaping community assembly. However, whether SGDCs not only hold across communities but also across lineages has never been explored so far. Here we investigated SGDCs across co-distributed taxa for different spatial components (α, β, γ), and formally tested the influence of dispersal traits on β-SGDCs.
Location: Western Indian Ocean.
Time period: 2016–2017.
Major taxa studied: Tropical reef fish species with contrasting dispersal traits.
Methods: Using double-digest restriction-site associated DNA sequencing (ddRADseq) Single Nucleotide Polymorphism data for 20 tropical reef fishes and distribution data of 2,446 species belonging to 12 families, we analysed the correlations between within-species genetic diversity and within-family species diversity (i.e., lineage diversity) for the three spatial components (α, β, γ-SGDCs). We then related the strength of β-SGDCs per species to proxies of larval dispersal abilities.
Results: We detected positive and significant lineage-based SGDC only for the β component, that is, the families showing the greatest level of species turnover among sites contain the species with the greatest levels of genetic differentiation. We showed that the Monsoon Drift mainly explained the β-diversity patterns at both intraspecific and interspecific levels. Higher β-SGDCs were found for species with short pelagic larval duration and weak larval swimming capacity.
Main conclusions: Our study reveals a strong correlation between genetic and species β-diversity, a result explained by the presence of a 'soft' barrier and mediated by larval dispersal processes. This suggests that vicariance and dispersal limitation are major processes shaping β-diversity patterns from microevolutionary to macroevolutionary scales in tropical reef fishes.

Increasing urbanization degrades quantity, quality, and the functionality of spatial cohesion of natural areas essential to biodiversity and ecosystem functioning worldwide. The uncontrolled pace of building activity and the erosion of blue (i.e., aquatic) and green (i.e., terrestrial) landscape elements threaten existing habitat ranges and movability of wildlife. Local scale measures, such as nature-inspired engineered Blue-Green Infrastructure (BGI) are emerging mitigation solutions. Originally planned to promote sustainable stormwater management, adaptation to climate change and improved human livability in cities, such instruments offer interesting synergies for biodiversity in support of existing ecological infrastructure. BGI are especially appealing for globally declining amphibians, a rich and diverse vertebrate assemblage sensitive to urbanization. We integrated biological and highly resolved urban-rural land-cover data, ensemble models of habitat suitability, and connectivity models based on circuit theory to improve multi-scale and multi-species protection of core habitats and ecological corridors in the Swiss lowlands. Considering a broad spectrum of amphibian biodiversity, we identified distributions of amphibian biodiversity hotspots and four landscape elements essential to amphibian movability at the regional scale, namely i) forest edges, ii) wet-forest habitats, iii) soils with variable moisture and iv) riparian zones. Our work shows that cities can make a substantial contribution (e.g., up to 15% of urban space in the study area) to wider landscape habitat connectivity. We highlight the importance of planning BGI locally in strategic locations across urban and peri-urban areas to promote the permeability and availability of ‘stepping stone’ habitats in densely populated landscapes, essential to the maintenance of regional habitat connectivity and thereby enhancing biodiversity and ecosystem functioning.

Intensiv genutzte Landschaften und Lebensraumfragmentierung sind mitverantwortlich für den Rückgang der Biodiversität, weil Lebensraumqualität und grundlegende biologische Prozesse wie z.B. die Ausbreitung gestört werden. Stetig wachsende Städte als überregionale Barrieren für die Vernetzung natürlicher Lebensräume stellen eine besondere Herausforderung dar (Abb. 1). Wir zeigen am Beispiel von Amphibien auf, wie eine gezielte Platzierung blaugrüner Infrastrukturen die Durchlässigkeit von Städten verbessern könnte und dadurch Lebensräume und Laichgebiete von regionaler Bedeutung besser vernetzt werden. Die Einrichtung blaugrüner Infrastrukturen ist eine vielversprechende Massnahme, um die Anpassung an den Klimawandel zu fördern und die Lebensqualität zu verbessern. Synergien zur Vernetzung der Biodiversität bieten sich auf lokaler und regionaler Ebene an.

L'utilisation intensive des paysages et la fragmentation des habitats sont en partie co-responsables du déclin de la biodiversité, dans la mesure où la qualité des habitats et des processus biologiques fondamentaux tels que la dispersion sont perturbés. L'urbanisation croissante constitue un défi particulier dans ce contexte, notamment en tant qu'obstacle transrégional à la connectivité des habitats naturels. En prenant l'exemple des amphibiens, nous montrons comment la planification ciblée d'infrastructures bleuesvertes pourrait améliorer la perméabilité des villes en reliant mieux les habitats naturels et les sites de reproduction d'importance régionale. L'installation d'infrastructures bleues-vertes est une mesure prometteuse qui est actuellement planifiée dans de nombreuses villes surtout pour promouvoir l'adaptation au changement climatique ainsi que pour l'amélioration de la qualité de vie. Cependant, des synergies pour la mise en réseau de la biodiversité sont aussi disponibles non seulement à niveaux local mais aussi régional.