Biology subjects

Guisan, A.

Publications and source records attributed to Guisan, A..

12 recordsLinked to original sources

bioRxiv2026

GLACIAL SPECIALIST SPECIES ARE MORE VULNERABLE TO CLIMATE CHANGE THAN GENERALIST SPECIES (DRAWING PARELLELS BETWEEN EMPIRICAL AND ECOLOGICAL DISTINCTIONS)

In Switzerland, glaciers are projected to shrink to minimal size by the end of the century. Thus, climate change puts pressure on glacial specialist plant species, as generalist plant species colonise their habitat. As bare areas are revealed by glacier retreat, glacial specialists can likewise shift their distributions to higher altitude, however, there will be no habitat for them to colonise. Thus, Swiss mountain floral biodiversity and ecosystem services will likely be locally extirpated. In this article, we use Species Distribution Models of 369 plants occurring in Swiss proglacial areas fitted using bioclimatic, lithological and topographic variables and compare the covariates that most strongly predict the distributions of glacial specialist and generalist species. In addition, we use two methods of defining glacial specialist species and separating them from specialists: empirical (degree of prevalence of species in proglacial areas) and ecological (using Landolt values). We find that both approaches yield similar results: the distributions of both generalist and glacial specialist species are most strongly predicted by bioclimatic variables, however, they are significantly stronger for glacial specialists. On the other hand, distributions of generalist species are more strongly predicted by topographical and lithological variables.

ecology↗

bioRxiv2026

Future-proofing agrobiodiversity: climate and niche-aware conservation planning using reinforcement learning.

Despite substantial global commitments to expand protected-area networks, the strategic allocation of limited resources remains challenging. Spatial conservation planning helps identify priority regions that maximise conservation benefits per unit area. Yet, they also tend to neglect two fundamental aspects of conservation: climate-driven range shifts and the representation of environmentally distinct populations within species. Here, we propose a continental-scale conservation planning framework that explicitly accounts for both processes through novel routines implemented in the conservation planning software CAPTAIN. We apply this framework to European crop wild relatives (CWR), for which niche coverage is a focal priority, as it underpins their potential to support agricultural adaptation to future environmental stressors through breeding programs. Comparative analyses on a subset of 186 CWR associated with five focal crops show that accounting for range shifts and niche coverage leads to substantially different conservation priorities from those obtained with a baseline model based on current distributions only. These additions reduced the number of non-protected species by 64%, increased the average protected distribution range by 43%, increased mean niche coverage from 75.8% to 84.5% and reduced the number of species with less than half of their niche protected from 35 to 10. Applied to a more comprehensive checklist of 1,140 European CWRs, the final framework identifies continental-scale priority areas representing 93.5% of these taxa and includes 94.4% of its critically endangered species. Our results highlight the importance of incorporating both temporal dynamics and within-species environmental representation when designing conservation strategies under climate change. RepositoryThe repository will be made publicly accessible after publication at doi: https://10.5281/zenodo.19855597

ecology↗

bioRxiv2025

Spatial Biodiversity Indicators and a Composite Index for Conservation Prioritization in Switzerland

Spatially explicit indicators that quantify to which extent landscapes support biodiversity are essential for guiding evidence-based conservation planning. Here, we present a 25-meter resolution dataset for Switzerland, encompassing three key biodiversity indicators-- Complementarity, Extinction Risk, and Ecological Connectivity--developed across 17 major taxonomic groups, using habitat suitability maps for approximately 7,500 individual species. These three indicators capture (1) the contribution of landscapes to taxonomic, functional, and phylogenetic diversity, (2) species vulnerability to extinction and (3) ecological connectivity. Outputs are provided for both terrestrial and aquatic realms, including versions adjusted for species richness, and integrated into composite indices. In total, 272 spatial layers were produced and made openly accessible. Relationships among the three indicators were analyzed to assess their distinct contributions, and expert-based validations were performed to evaluate their ecological plausibility and relevance for conservation applications. This dataset provides a robust foundation to support spatial planning and conservation decision-making in Switzerland and can be used as a blueprint for analogue integration in other countries.

ecology↗

bioRxiv2025

Ecological indicators predict functional diversity dynamics following glacier retreat

The retreat of glaciers due to climate change is reshaping mountain landscapes and biodiversity. While previous research has documented vegetation succession after glacier retreat, our understanding of functional diversity dynamics is still limited. In this case study, we address the effects of glacier retreat on plant functional diversity by integrating plant traits with ecological indicator values across a 140-year chronosequence in a subalpine glacier landscape. We reveal that functional richness and functional dispersion decrease with glacier retreat, while functional evenness and functional divergence increase, suggesting a shift towards more specialized and competitive communities. Our findings highlight the critical role of ecological factors related to soil moisture, soil nutrients, and light availability in shaping plant community dynamics. The integrative approach of this case study provides novel insights into the potential response of alpine plant communities to climate change, offering a deeper understanding of how to predict and anticipate the effects of glacier extinction on biodiversity in rapidly changing environments.

ecology↗

bioRxiv2024

LEVERAGING CITIZEN SCIENCE TO ASSESS RICHNESS, DIVERSITY, AND ABUNDANCE IN ANT COMMUNITIES

AO_SCPLOWBSTRACTC_SCPLOWCitizen science is a key resource in overcoming the logistical challenges of monitoring biodiversity. While datasets collected by groups of volunteers typically have biases, recent methodological and technological advances provide approaches for accounting for such biases, particularly in the context of modelling species distributions and diversity. Specifically, data integration techniques allow for the combination of scientifically collected datasets with haphazardly sampled presence-only datasets created by most citizen science initiatives. Here, we use a hierarchical Bayesian framework to integrate a set of ant presences collected by citizen scientists in the Vaud canton (Switzerland) with ant colony density data collected concurrently in the same region following a scientific sampling design. The community-level Poisson point process model included species-specific responses to the local (1.2 m2) and regional (1 km2) environment, with the presence-only samples incorporated at the regional scale to predict local and regional ant communities. At the regional scale, species richness followed a hump-shaped pattern and peaked near 1000 m while abundance increased with elevation. Low elevation and montane ant communities were composed of distinct species assemblages. At the local scale, the link between elevation and richness, diversity, and abundance was weak. At low elevations, local plots varied both in total abundance and species composition, while at higher elevations, the species composition was less variable. The citizen science dataset showed a general tendency toward under-representation of certain species, and heavy spatial sampling bias. Nonetheless, the inclusion of the citizen science data improved predictions of local communities, and also reduced susceptibility to over-fitting. Additionally, the citizen science dataset included many rare species not detected in the structured abundance dataset. The model described here illustrates a framework for capitalizing on the efforts of citizen scientists to better understand the patterns and distribution of biodiversity.

ecology↗

bioRxiv2023

Biodiversity in mountain soils above the treeline

Despite the importance of healthy soils for human livelihood, wellbeing, and safety, current gaps in our knowledge and understanding of biodiversity in soil are numerous, undermining conservation efforts. These gaps are particularly wide in mountain regions where healthy soils are especially important for human safety and yet evidence is accumulating of ongoing degradation, posing significant threats to ecosystem functioning and human settlements. To analyse these gaps in detail, we synthesise current research on the global diversity of microorganisms, cryptogams, and invertebrates in mountain soils above the treeline. This synthesis is based on a semi-quantitative survey of the literature and an expert-based analysis. Our work reveals not only deficiencies in geographic cover but also significant gaps in taxonomic coverage, particularly among soil protists and invertebrates, and a lack of (functional and ecological) description of the uncultivated majority of prokaryotes, fungi, and protists. We subsequently build on this overview to highlight opportunities for research on mountain soils as systems of co-occurring species that interact in complex environmental matrices to fulfil critical functions and make essential contributions to life on land. Closing gaps in biodiversity research in mountain soil is crucial to enhance our understanding and to promote laws and guidelines advancing international soil biodiversity conservation targets in mountains. Addressing sparse and biased data, recognizing the impact of environmental changes on mountain ecosystems, and advocating dedicated policies are essential strategies to safeguard mountain soils and their biodiversity. GLOSSARY O_TBL View this table: org.highwire.dtl.DTLVardef@16682fdorg.highwire.dtl.DTLVardef@121b9feorg.highwire.dtl.DTLVardef@139eadeorg.highwire.dtl.DTLVardef@16abd74org.highwire.dtl.DTLVardef@bc3da9_HPS_FORMAT_FIGEXP M_TBL C_TBL

ecology↗

bioRxiv2023

Implementation of biotic interactions in niche analyses unravels the patterns underneath community composition in clownfishes

Biotic interactions shape the ecology of species and communities, yet their integration into ecological niche modeling methods remains challenging. Despite being a central topic of research for the past decade, the impact of biotic interactions on species distributions and community composition is often overlooked. Mutualistic systems offer ideal case studies for examining the effects of biotic I nteractions on species niches and community dynamics. This study presents a novel approach to incorporating mutualistic interactions into niche modeling, using the clownfish-sea anemone system. By adapting existing niche quantification frameworks, we developed a method to estimate the partial effects of known interactions and refine ecological niche estimates. This approach allows for a more comprehensive understanding of how mutualistic relationships influence species distributions and community assembly patterns. We also used mutualistic information to investigate the resource-use overlap, identitying patterns of competition within clownfish communities. Our results reveal significant deviations in niche estimates when biotic interactions are considered, particularly for specialist species. Host partitioning among clownfish species reduces resource-use overlap, facilitating coexistence in species-rich habitats and highlighting mutualisms role in promoting and maintaining diversity. We uncover complex dynamics in resource-use overlap among clownfish species, influenced by factors such as species richness, ecological niche overlap, and host specialization. Specialist-generalist interactions strike an optimal balance, supporting high species richness while minimizing competition. These insights enhance our understanding of clownfish biodiversity patterns, demonstrating how diverse mutualistic strategies contribute to diversity build-up and mitigate competitive exclusion in saturated communities. The analytical framework presented has broad applications beyond the clownfish-sea anemone system, potentially extending to a broader range of interactions. It enables a more comprehensive understanding of biodiversity maintenance in complex ecosystems and constitutes a valuable tool for conservation planning and ecosystem management.

ecology↗

bioRxiv2023

Conserving genetic diversity during climate change:Niche marginality and discrepant monitoring capacity in Europe

Genetic monitoring of populations currently attracts interest in the context of the Convention on Biological Diversity but needs long-term planning and investments. Genetic diversity has been largely neglected in biodiversity monitoring, and when addressed is treated separately, detached from other conservation issues, such as habitat alteration due to climate change. Genetic monitoring supports the conservation and management of fisheries, game, and threatened populations. It also can contribute to the assessment of predicted and realized impacts of climate change, and their management. We report the first accounting of genetic monitoring efforts among countries in Europe (their genetic monitoring capacity, GMC) to determine where GMC suggests the combination of national infrastructure, political support and resources for continued and expanded monitoring. Overlaying GMC with areas where species ranges approach current and future climate niche limits (i.e., niche marginality) helps identify whether GMC coincides with anticipated climate change effects on biodiversity. Our analysis suggests that country area extent, financial resources, and conservation policy influence GMC, high values of which inconsistently match joint species patterns of climate niche marginality. Populations at niche margins likely hold genetic diversity that is important to adaptation to changing climate, and our results illuminate the need in Europe for expanded genetic monitoring across the climate gradients occupied by species, a need arguably greatest in southeastern European countries.

ecology↗

bioRxiv2022

Microbial landscape ecology: landscape structure better predicts soil protist diversity than local edaphic variables in alpine meadows

ContextHuman-induced changes in landscape structure are among the main causes of biodiversity loss. Despite their important contribution to biodiversity and ecosystem functioning, microbes - and particularly protists - remain spatially understudied. Soil microbiota are most often driven by local soil properties, but the influence of the surrounding landscape is rarely assessed. ObjectivesWe assessed the effect of landscape structure on soil protist alpha and beta diversity in meadows in the western Swiss Alps. MethodsWe sampled 178 plots along an elevation gradient representing a broad range of environmental conditions and land-use. We measured landscape structure around each plot at 5 successive spatial scales (i.e. neighbourhood windows of increasing radius, ranging from 100 to 2000 m around a plot). We investigated the changes of protist alpha and beta diversity as a function of landscape structure, local environmental conditions and geographic distance. ResultsLandscape structures played a key role for protist alpha and beta diversity. The percentage of meadows, forests, or open habitats had the highest influence among all landscape metrics. The importance of landscape structure was comparable to that of environmental conditions and spatial variables, and increased with the size of the neighbourhood window considered. ConclusionsOur results suggest that dispersal from neighbouring habitats is a key driver of protist alpha and beta diversity which highlight the importance of landscape-scale assembly mechanisms for microbial diversity. Landscape structure emerges as a key driver of microbial communities which has profound implications for our understanding of the consequences of land-use change on soil microbial communities and their associated functions.

ecology↗

bioRxiv2021

Determinants of haemosporidian single and co-infections risks in western paleartic birds

Co-infections with multiple pathogens are common in the wild and may act as a strong selective pressure on both host and parasite evolution. Yet, contrary to single infection, the factors that shape co-infection risk are largely under-investigated. Here, we explored the extent to which bird ecology and phylogeny impact single and co-infection probabilities by haemosporidian parasites using large datasets from museum collections and a Bayesian phylogenetic modelling framework. While both phylogeny and species attributes (e.g. size of the geographic range, life-history strategy, migration) were relevant predictors of co-infection risk, these factors were less pertinent in predicting the probability of being single infected. Our study suggests that co-infection risk is under a stronger deterministic control than single-infection risk. These results underscore the combined influence of host evolutionary history and species attributes in determining single and co-infection pattern providing new avenues regarding our ability to predict infection risk in the wild.

ecology↗

bioRxiv2020

Beyond range size: drivers of species' geographic range structure in European plants

AimTo assess if and how species range size relates to range structure, if the observed geographic range properties can be retrieved from predicted maps based on species distribution modeling, and whether range properties are predictable from biogeophysical factors. LocationEurope Time periodCurrent Major taxa studied813 vascular plant species endemic to Europe MethodsWe quantified the size and spatial structure of species geographic ranges and compared ranges currently occupied with those predicted by species distribution models (SDMs). SDMs were constructed using complete occurrence data from the Atlas Florae Europaeae and climatic, soil and topographic predictors. We used landscape metrics to characterize range size, range division and patch shape structure, and analysed the phylogenetic, geographic and ecological drivers of species range size and structure using phylogenetic generalized least squares (pGLS). ResultsRange structure metrics were mostly decoupled from species range size. We found large differences in range metrics between observed and predicted ranges, in particular for species with intermediate observed range size and occupied area, and species with low and high observed patch size distribution, geographic range filling, patch shape complexity and geographic range fractality. Elevation heterogeneity, proximity to continental coasts, Southerly or Easterly geographic range positions and narrow ecological niche breadth constrained species observed range size and range structure to different extents. The strength and direction of the relationships differed between observed and predicted ranges. Main conclusionsSeveral range structure metrics, in addition to range size, are needed to adequately describe and understand species ranges. Species range structure can be well explained by geophysical factors and species niche width, albeit not consistently for observed and predicted ranges. As range structure can have important ecological and evolutionary consequences, we highlight the need to develop better predictive models of range structure than provided by current SDMs, and we identify the kinds of species for which this is most necessary.

ecology↗

bioRxiv2019

Soil protist diversity in the Swiss western Alps is better predicted by topo-climatic than by edaphic variables

AimGeneral trends in spatial patterns of macroscopic organisms diversity can be reasonably well predicted from correlative models, using for instance topo-climatic variables for plants and animals allowing inference over large scales. By contrast, soil microorganisms diversity is generally considered as mostly driven by edaphic variables and, therefore, difficult to extrapolate on a large spatial scale based on predictive models. Here, we compared the power of topo-climatic vs. edaphic variables for predicting the diversity of various soil protist groups at the regional scale.\n\nLocationSwiss western Alps.\n\nTaxaFull protist community and nine clades belonging to three functional groups: parasites (Apicomplexa, Oomycota, Phytomyxea), phagotrophs (Sarcomonadea, Tubulinea, Spirotrichea) and phototrophs (Chlorophyta, Trebouxiophyceae, Bacillariophyta).\n\nMethodsWe extracted soil environmental DNA from 178 sites along a wide range of elevations with a random-stratified sampling design. We defined protist Operational Taxonomic Units assemblages by metabarcoding of the V4 region of the ribosomal RNA small sub-unit gene. We assessed and modelled the diversity (Shannon index) patterns of all selected groups as a function of topo-climatic and edaphic variables using Generalized Additive Models.\n\nResultsThe respective significance of topo-climatic and edaphic variables varied among taxonomic and - to a certain extent - functional groups: while many variables explained significantly the diversity of phototrophs this was less the case for parasites. Generally, topo-climatic variables had a better predictive power than edaphic variables, yet predictive power varied among taxonomic and functional groups.\n\nMain conclusionsTopo-climatic variables are, on average, better predictors of protist diversity at the landscape scale than edaphic variables, which opens the way to wide-scale sampling designs avoiding costly and time-consuming laboratory protocols. However, predictors of diversity differ considerably among taxonomic and functional groups; such relationships may be due to direct and/or indirect, e.g. biotic influences. Future prospects include using such spatial models to predict hotspots of diversity or pathogens outbreaks.

ecology↗