Biology subjects

Losapio, G.

Publications and source records attributed to Losapio, G..

16 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

Glacier retreat reshapes trophic networks: interaction turnover outpaces species turnover over space-time

As glaciers retreat worldwide, newly exposed terrains are rapidly colonized by plants and their associated animal communities. Although plant-animal interactions are key for biodiversity maintenance and ecosystem functioning, the ecological processes underlying the assembly and development of trophic interactions over space-time remain poorly understood. Here, we investigated the trophic niche structure of plant-arthropod interactions along a 140-year primary succession at Mont Mine glacier foreland (Switzerland). Using arthropod gut-content DNA metabarcoding, we reconstructed trophic interactions at the food web level, revealing numerous previously undetected links among 284 arthropod taxa feeding on 263 plant taxa. Trophic niche overlap among arthropods increased following glacier retreat, indicating decreasing resource partitioning and suggesting increased resource competition. Trophic niche breadth became narrower and diet species richness declined, indicating increased trophic specialization. Notably, changes in trophic interactions occurred more rapidly than shifts in species diversity or community composition of plants and arthropods. These results demonstrate that glacier retreat reorganizes trophic networks beyond simple species turnover, reshaping biotic interactions during ecosystem development. Our findings highlight trophic interactions as sensitive indicators of biodiversity change and suggest that the stability of emerging food webs may be strongly affected as glaciers vanish worldwide.

ecology↗

bioRxiv2025

Long-term impacts of tree monoculture plantations on biodiversity are mediated by soil acidification

Reforestation efforts have sought to counteract deforestation and to provide a nature-based solution against climate change. However, they often involve monoculture plantations of non-native species, which may have unintended ecological consequences. Yet, the long-term impacts of planting trees have been poorly estimated. Leveraging historical reforestation conducted in northern Italy during the 1920s by the fascist regime, we assessed the long-term impacts of red spruce (Picea abies) monoculture plantations on biodiversity of plants and soil fauna. We found that plant diversity in tree plantations was 50.3% lower than in native forests and 74.5% lower than in grasslands. Additionally, functional evenness was reduced by 30% in spruce plantations, suggesting lower ecological stability. In tree plantations, soil pH was significantly more acid and organic carbon content was 25% higher due to litter deposition and slower decomposition rates. Soil fauna diversity was marginally less affected, suggesting a faster recover over the last one-hundred years of arthropods as compared to plants. These findings highlight the need for monitoring reforestation interventions, suggesting strategies that incorporate diverse tree species rather than planting tree monocultures to support functionally and resilient ecosystems.

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

Harmonising digitised herbarium data to enhance biodiversity knowledge: creating an updated checklist for the flora of Greenland.

International efforts to digitise herbarium specimens provide the building blocks for a global digital herbarium. However, taxonomic changes and errors can result in inconsistencies when amalgamating specimen metadata, that compromise the assignment of occurrence records to correct taxa, and the subsequent interpretation of patterns in biodiversity. We present a novel workflow to mass-curate digital specimens. By employing existing digital taxonomic backbones, we aggregate specimen names by their accepted name and flag remaining cases for manual review. We then validate names using site-specific floras, balancing automation with taxonomic expert-based curation. Applying our workflow to the vascular plants of Greenland, we harmonised 175,266 digitised herbarium specimens and observations from 92 data providers from the Global Biodiversity Information Facility (GBIF). The harmonised metacollection for the Greenland flora contains 780 plant species. Our workflow increases the number of species known from Greenland compared to other currently available species checklists and increases the mean number of occurrences per species by 42.6. Our workflow illustrates the integration required in order to create a global, universally accessible digital herbarium, and shows how previous obstacles to database curation can be overcome through a combination of automation and expert curation. From the specific perspective of the Greenland flora, our approach arrives at a new checklist of taxa, a new curated metacollection of occurrence data, and revised estimates of plant richness. The list of taxa and their prevalence allow a new basis for biodiversity assessment and conservation planning. Societal Impact StatementDigitising plant collections has allowed for data to be aggregated across multiple collections, forming a single harmonised resource of unprecedented scale. This resource is only accurate once the database names are assigned to one accepted name per species. We established a semi-automated workflow for processing plant name data, leveraging taxonomic backbones and employing taxonomic expertise at key stages. Applying our workflow to the flora of Greenland, we developed a curated checklist of 780 species, capturing greater species richness than previously published, while also curating 175,266 plant records. Our findings redefine our knowledge of Greenlandic plant diversity, while harmonising a vast digital collection for further research.

ecology↗

bioRxiv2024

Glacier Retreat Effects On Ecosystem Development And Carbon Dynamics

One of the clearest indicators of global warming is the retreat of Alpine glaciers. Organisms rapidly colonize bare ground free from ice, and in less than a century complex ecosystems can develop in a process of primary succession, where community changes as terrain age increases and interactions within species change over time. When glaciers retreat the resulting ice-free soil is exposed to new forms of chemical and biological weathering, with initiating soil formation as an important driver of evolving ecosystems. Soils play an important role in the global carbon (C) cycle, serving as the largest reservoir of carbon. CO2 is removed from the atmosphere by plant photosynthesis, then stored in biomass and soils, and released again to the atmosphere via plant and soil respiration. Soil respiration includes CO2 production by heterotrophic soil organisms (e.g., bacteria, fungi, invertebrates) that metabolize plant litter and soil organic matter, and autotrophs (e.g. plant roots). However, little is known about the development of soils, their physico-chemical changes, and their influence on plant diversity and soil carbon emission (CO2) after glacier retreat. This study aims to investigate how the retreat of the Mont Mine and Ferpecle glaciers (Valais Alps, Switzerland) influences soil functioning and vegetation development. For this purpose, we carried out soil analyses and vegetation surveys on 5 ice-free stages deglaciated between 1864 and 2023. Soil physico-chemical properties (pH, soil organic matter, organic carbon and nitrogen, granulometry, available elements, total elements), soil CO2 respiration fluxes, and plant communities (composition, diversity, richness, biomass) were studied in 20 plots along the glacier forefield. Our results show that vegetation develops according to the principles of primary succession, going further from glacier front: from pioneer vegetation 7 years after glacier retreat, progressing through early vegetation at 20 years, then to intermediate vegetation, and ultimately culminating in a climax coniferous forest, 140 years after glacier retreat. Over 140 years, the increase in vegetation productivity results in a greater transfer of organic matter (SOM) to the soil, which increases organic carbon, nitrogen, and nutrient levels, and decreases pH values as it releases organic acids. Aboveground plant biomass (i.e. carbon storage) increases over the succession, however, plant diversity and richness peak at the intermediate stages and then level off due to the dominance of few species in the late stages. At the intermediate stage, there is also a peak observed in soil respiration (CO2 flux), which in turn promotes plant colonization and diversity. Thus, the soil, along with its development stages and properties, plays a critical role in carbon accumulation, leading to an increased potential for carbon release as organic matter storage increases. This project aims to contribute to the understanding of the consequences of global warming on recently deglaciated ecosystems, which remain still poorly overlooked.

ecology↗

bioRxiv2024

Ongoing local adaptation to climate change in yarrow (Achillea millefolium L.)

Climate change threatens biodiversity as populations can persist if they migrate or adapt to the rapidly changing conditions of the Anthropocene. However, little is known about the persistence of plant populations under the long-term trends of increasing temperature and drought. We explore whether historical populations of yarrow (Achillea millefolium L.) surveyed in the 1920s have persisted locally or undergone local extinction after 100 years. We resurveyed historical sites spanning a broad climatic gradient (from 1 m to 3,200 m a.s.l.), examined to what extent plant growth signature (height) has changed over time, and analyzed metabolic diversity. Nine out of ten populations persisted locally and showed phenotypic and metabolic differentiation. The only population potentially extirpated is that of the hottest and driest site. Populations from warm sites in coastal and mountain regions had grown taller than 100 years ago. In contrast, populations from dry sites in lowlands and foothills became shorter. Furthermore, we document differentiation in metabolic diversity involving plant defenses and signaling. Ongoing local adaptation is constrained by changing both temperature and precipitation as well as by biotic interactions. Preserving locally adapted populations and metabolic diversity is key for conservation efforts.

evolutionary biology↗

bioRxiv2024

Glacier retreat decreases plant-pollinator network robustness over space-time

Glaciers are retreating worldwide at an ever-increasing rate, exposing new ice-free areas to ecological succession. This process leads to changes in biodiversity and potentially to species interactions. However, we still have a limited understanding of how glacier retreat influences species interaction networks, particularly the structure and robustness of mutualistic networks. After reconstructing plant-pollinator networks along a glacier foreland, we address the effects of glacier retreat on pollination network structure and robustness. Our results show that the prevalence of different network motifs changes over space-time. With glacier retreat, pollination networks shift from being highly connected with specialist interactions to loosely connected with generalist interactions. Furthermore, network robustness decreased with glacier retreat. Despite the turnover of plant species, we find that structural roles played by different plant species stay constant over space-time. Our findings suggest that glacier retreat pushes pollination networks towards a loss of specialist interactions and low robustness, leading to increased fragility in the long term. Monitoring network motifs may provide valuable insights into the ability of novel pollination networks to withstand disturbances and preserve functionality in the face of glacier extinction.

ecology↗

bioRxiv2024

Impact of Spruce Plantation on Plant Diversity

1As the effects of climate change are becoming more evident, different countries around the world are adopting new policies to intervene on the regulation of greenhouse gasses emission. Recent frameworks acknowledge the potential contribution that forest ecosystems can give to carbon sequestration. These are indicating reforestation programmes as effective climate change mitigation options. Yet, there are possibilities that reforestation may have counteractive effects on biodiversity. However the long term consequences of reforestation for biodiversity are poorly understood. Reforestation policies have already been widely implemented around the world. For instance, in northern Italy and central Europe plantations of spruce trees (Picea abies) have been highly promoted during the last century. The objective of our research is to address the long term consequences of reforestation by answering the following questions. What is the spruce plantations impact on plant diversity? Does the spruce plantation impact environmental factors like luminosity and ground surface temperature and do these environmental factors affect plant diversity? We hypothesize that the spruce plantation causes a reduction of plant diversity. Indeed, we expect that the spruce plantation affects different environmental factors that have an important role in determining plant composition and abundance. To answer our research questions, we have conducted a study in two different sites of the Como Prealps. The potential vegetation of the selected area is represented by mixed forests of deciduous trees dominated by beech trees (Fagus sylvatica). Historically, the land has also been used for grazing and mowing. However, some stands of the potential vegetation are here replaced by spruce plantations, the presence of which is linked to national forestry policies of the twentieth century. For our research we have conducted a total of 100 vegetation surveys to collect data on plant diversity and environmental factors, namely luminosity and ground surface temperature. We then compared plant diversity among land-use treatments (i.e., habitat types): the spruce plantation, the natural mixed forest and the semi-natural grassland-pasture. For our analysis we have used linear regression models to test the impact of the different habitat types on plant diversity. We have also measured covariance and correlation to analyse the relationship between the environmental factors and plant diversity. The analysis on plant diversity reveals the long-lasting impact of spruce monoculture plantation on plant diversity. The number of plant species decreases by 57percent from the grassland-pasture to the spruce plantation and by 41percent compared to the natural mixed forest. Likewise, the diversity of plant functional forms decreases in the spruce plantation as compared to mixed forests and grassland-pasture. At last, although luminosity and ground surface temperature do not vary from the mixed forest to the spruce plantation, we have measured a positive relationship between the number of plant species and the two environmental parameters. Our research provides novel evidence that the spruce plantation negatively impacts plant diversity still one hundred years after. As biodiversity loss and climate change are two interwoven processes, they must not be treated separately. For what concerns future reforestation programmes, we recommend that they include biodiversity-friendly measures and address win-win solutions, for their effectiveness in climate change mitigation would otherwise be compromised.

ecology↗

bioRxiv2023

Glacier extinction homogenizes functional diversity

QuestionsThe disappearance of glaciers threatens biodiversity and the functioning of ecosystems. To date, questions remain about the response of functional diversity to glacier extinction and its potential for adaptation to climate change. How does glacier retreat and extinction affect plant functional diversity? How do mean and variation of plant traits change with glacier retreat and extinction? LocationFour glacier ecosystems in Italian Alps. Plant communities spanning 0 to ca 5,000 years on average after glacier retreat. MethodsWe quantify how glacier retreat affects functional diversity of plant communities analysing twelve functional traits of 117 plant species across 170 plots. First, we addressed the impact of glacier retreat on functional divergence and functional homogeneity, analysing both trait average and trait variation. Next, we explored how biodiversity (i.e., plant species richness) influenced functional diversity and how glacier retreat affected such relationship. Finally, we explored the effects of glacier retreat on mean and variation of single traits associated to carbon and nitrogen cycling and resource allocation. ResultsGlacier retreat homogenizes functional diversity by reducing trait variation and making communities more functionally similar. While biodiversity positively contributes to trait heterogeneity, glacier retreat erodes the support of species richness to functional diversity. We also show how glacier extinction has medium to large negative effects on the average and variation of key functional traits associated to carbon economy, but small positive effects on leaf nitrogen content. ConclusionsOur results demonstrate the pervasive impact of glacier extinction on the functioning of plant communities. We stress that functional diversity and trait variation should be the focus of adaptation and mitigation actions.

ecology↗

bioRxiv2023

Impact of glacier retreat on biodiversity and plant-insect interaction dynamics

With the retreat and extinction of glaciers worldwide, new areas are exposed for colonization by diverse plants and associated insects. Yet, glacier retreat is also followed by the loss of plants and insects from local communities, causing changes in species diversity, species composition and plant-insect interactions. However, the impact of glacier retreat and extinction on pollination networks remains poorly understood. An integrative understanding of pollination network dynamics following glacier retreat is therefore of major importance to biodiversity maintenance and ecosystem functioning and services. Here, we addressed how glacier retreat affects directly and indirectly through biodiversity the frequency, complexity, and diversity of plant-insect interactions. After reconstructing the geochronology of glaciers (Mont Mine glacier, Swiss Alps), we surveyed plant-insect interactions and analyzed network dynamics. We observed sharp changes in the diversity of both plant and insect communities. We found an increase in the frequency of their interactions following glacier retreat, but an ultimate decrease with glacier extinction. Yet, after controlling for the effects of flower diversity, interaction frequency showed a regular, universal pattern. Accordingly, the complexity of pollination networks and interaction diversity tended to change at constant rates with glacier retreat. Our results indicate that, in the long-term, glacier retreat decreases biodiversity and influence the stability of ecological networks. The good news is that increasing flower diversity would counteract these impacts by increasing interaction diversity and complexity. Supporting plant and flower diversity may therefore be a key strategy for halting the erosion of ecological networks while increasing ecosystem functioning.

ecology↗

bioRxiv2022

Assessing the accuracy of paired and random sampling for quantifying plant-plant interactions in natural communities

Interactions among plant species in extreme ecological systems are often inferred from spatial associations and quantified by means of paired sampling. Yet, this method might be confounded by habitat-sharing effects, in particular when microenvironmental heterogeneity and stress are high. Here, we address whether paired and random sampling methods provide similar results at varying levels of environmental heterogeneity. Furthermore, we investigate how the relationship between species preferences and abiotic severity influences the outcome of these two methods. We quantified spatial associations with the two methods at three sites that encompass different micro-environmental heterogeneity and stress levels: semi-arid environments in Canary Islands, Spain and Sardinia, Italy and a cold alpine environment in Hokkaido (Japan). Then, we simulated plant communities with different levels of species micro-habitat preferences, environmental heterogeneity and stress levels. We found that differences in species associations between paired and random sampling were indistinguishable from zero in our model simulations. At each site, there were strong differences between beneficiary species in their spatial association with benefactor species, and associations became more positive with increasing stress in Spain. Most importantly, there were no differences in the results yielded by the two methods at any of the different stress levels at the Spanish and Japanese sites. At the Italian site, although micro-environmental heterogeneity was low, we found weakly significant differences between methods that were unlikely due to habitat-sharing effects. We conclude that the paired sampling method can provide significant insights into net, long-term effects of plant interactions in spatially conspicuous environments.

ecology↗

bioRxiv2021

The impact of multiple species invasion on soil and plant communities increases with invader diversity

Despite increasing evidence indicating that invasive species are harming ecological systems and processes, impacts of multiple invasions, and the linkages between these events and changes in vegetation and soil are inadequately documented and remain poorly understood. Addressing multiple invasions would help to highlight high priority invaders and would aid in designing more effective control strategies, contributing to environmental restoration and sustainability. In this work, we tested the impact of three concurring invasive plant species, Amorpha fruticosa, Fraxinus pennsylvanica and Acer negundo, on soil conditions and native plant diversity. The research was conducted in riparian ecosystem and included the following treatments: (1) co-occurrence of the three invasive plant species, (2) occurrence of a single invasive species, and (3) control, i.e., absence of invasive species. Our findings revealed that the impact of invasive plants on soil properties and native plant diversity is magnified by their co-occurrence. Soil in mixed plots (those populated with all three invaders) contained much higher levels of nitrifying bacteria (NB), organic matter (Om), nitrogen (N), and carbon (C) as well as lower carbon to nitrogen ratio (C:N) levels, compared to single species invaded plots and control plots. Mixed plots were also characterized by reduced native plant diversity compared to single species invaded and control plots. Differences in soil conditions and native plant diversity revealed the interactive potential of invasive plants in depleting biodiversity, and thus in affecting ecological and biogeochemical processes. Our results highlight the need to study the impact of multispecies invasion and suggest that sites in riparian areas affected by co-occurring invaders, should be prioritized for ecosystem restoration.

ecology↗

bioRxiv2020

Facilitation and biodiversity jointly drive mutualistic networks

O_LIFacilitation by nurse plants increases understorey diversity and supports ecological communities. In turn, biodiversity shapes ecological networks and enhances ecosystem functioning. However, whether and how facilitation and increased biodiversity jointly influence community structure and ecosystem functioning remains unclear. C_LIO_LIWe performed a field experiment disentangling the relative contribution of nurse plants and increasing understorey plant diversity in driving pollination interactions. Both the presence of nurse shrubs as well as increased understorey plant diversity increased pollinator diversity and visitation rates. While nurse and understorey diversity effects on pollinator visitation rates did not interact, the effects of increasing understorey plant diversity on pollinator diversity were stronger in the absence than in the presence of shrubs, meaning that nurse shrubs attenuated the effects of high understorey diversity and buffered the effects of low understorey diversity. C_LIO_LIWe also found positive complementarity effects among understorey species as well as complementarity between nurse plants and understorey species at high diversity. Results also indicate negative selection effects, suggesting that species with generally few pollinators benefit the most in the polyculture, while a species (possibly the nurse plant) with generally lots of pollinators does not. The corresponding changes in pollination networks with the experimental treatments were due to both changes in the frequency of visits and turnover in pollinator community composition. C_LIO_LISynthesis Plant-plant facilitative systems, where a nurse plant increases understorey plant diversity, are common in stressful environments. Here, we show that these facilitative systems positively influence mutualistic interactions with pollinators via both direct nurse effects and indirect positive effects of increasing plant diversity. C_LIO_LIConserving and supporting nurse plant systems is crucial not only for maintaining plant diversity but also for supporting ecosystem functions and services. C_LI

ecology↗

bioRxiv2017

Facilitation between plants shapes pollination networks

SignificanceAlthough it is known that plant-plant and plant-pollinator interactions can strongly influence biodiversity and its effects on ecosystem functioning, the details of how competition and facili-tation among plants scale up to mutualistic interactions with pollinators and thus affect pollina-tion networks are poorly understood. We introduce a simple experimental system in which we control local plant interactions, measure pollinator responses and characterize plant-pollinator networks. We find that facilitation among plants produces synergistic and antagonistic effects on the pollinator community affecting the architecture and robustness of plant-pollinator net-works. Our results provide evidence for bottom-up non-additive effects of plant interactions on pollination networks and have implications for the way we study and manage ecosystems.

ecology↗

bioRxiv2017

Positive interactions support the formation of complex spatial networks

Ecologists have recognised the effects of biotic interactions on the spatial distribution of living organisms. Yet, the spatial structure of plant interaction networks in real-world ecosystems has remained elusive so far. Using spatial pattern and network analyses, we found that alpine plant communities are organised in spatially variable and complex networks. Specifically, the cohesiveness of complex networks is promoted by short-distance positive plant interactions. At fine spatial scale, where positive mutual interactions prevailed, networks were characterised by a large connected component. With increasing scale, when negative interactions took over, network architecture became more hierarchical with many detached components that show a network collapse. This study highlights the crucial role of positive interactions for maintaining species diversity and the resistance of communities in the face of environmental perturbations.

ecology↗