Biology subjects

Visconti, P.

Publications and source records attributed to Visconti, P..

18 recordsLinked to original sources

bioRxiv2026

Land use and climate warming interact to reshape global avian biodiversity through ecological filtering and homogenisation

Land-use and climate change are dominant drivers of terrestrial biodiversity change, yet are usually analysed separately although they co-occur and may interact. We integrated global bird assemblage records from PREDICTS with temperature anomalies and species' ecological characteristics to test how land use modifies biodiversity responses to climate warming across three dimensions: local abundance and richness, compositional dissimilarity among assemblages, and species occurrence across ecological groups. Land use modified warming associations for both abundance and richness. Relative to primary vegetation, warming associations were more positive in low-intensity agriculture for both responses, but more negative for richness in high-intensity agriculture and urban land. Predicted richness remained below the reference, defined as primary vegetation at temperature anomaly 0, across all modified land uses, with the largest declines in high-intensity agriculture (-17.9%) and urban land (-21.8%). Within land-use classes, greater warming exposure was generally associated with higher compositional similarity, consistent with warming associated biotic homogenisation. Occurrence models revealed ecological filtering: broad-niched generalists were favoured in warmer modified habitats, whereas range-restricted habitat specialists were filtered out under intensive land use and warming. Conservation assessments should therefore integrate land-use-warming interactions with changes in assemblage composition and ecological strategies, particularly in agricultural and urban landscapes where warming further disadvantaged range-restricted specialists.

ecology↗

bioRxiv2026

Small patches dominate the Natura 2000 network of protected areas in Europe

The Natura 2000 network for protected areas is one of Europes main tool to address the loss of biodiversity. Voluntary commitments of all 27 Member States aim for an extension towards a coherent network of protected land and sea area by 2030 that covers at least 30% of each realm in an ecologically representative and spatially coherent way. Spatial coherence refers to addressing issues brought about by small size of protected patches and their fragmentation in the Natura 2000 network, which, however have not been analysed in depth. This study presents an analysis of the full Natura 2000 data set of terrestrial and marine protected areas in Europe, to which extent documented sites are split up into smaller fragments, how their spatial configuration and shape might mitigate or invite edge effects, and which edge effects might be expected based on the surrounding land cover and land use matrix. Our results show a substantial fragmentation of the network, with four times more individual patches than recorded sites, and 75% of these patches being smaller than 1 km2. Across four size categories between smaller than 1 km2 and larger than 100 km2, about a quarter of patches show a spatial configuration that is likely to cause substantial edge effects due to a suboptimal ratio between area and perimeter. At the same time, many of the smallest patches are surrounded by a large share of sealed surfaces and agricultural areas within a 500m radius. Considering fragmentation and edge effects in future reporting, monitoring and planning of additional designations and restoration activities could close an important gap in understanding causes for continuing declines of Europes biodiversity and highlight pathways to mitigate them. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/730078v2_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@3744faorg.highwire.dtl.DTLVardef@91b8ccorg.highwire.dtl.DTLVardef@fb6193org.highwire.dtl.DTLVardef@1c32267_HPS_FORMAT_FIGEXP M_FIG C_FIG

ecology↗

bioRxiv2026

Global vertebrate hotspots

Effective biodiversity conservation requires tools that can identify priority areas under growing human pressures. Building on the concept of global biodiversity hotspots, we present a transparent and repeatable approach to mapping conservation priorities using data for 33,604 species of terrestrial vertebrates from the IUCN Red List. This framework expands the taxonomic scope of previous efforts and integrates updated information on key human-driven threats to biodiversity. We identify that around 13% of Earths terrestrial surface qualifies as vertebrate conservation hotspots, often shaped by distinct combinations of species groups and threats. These results highlight the need for tailored, context-specific conservation strategies. By providing a robust method to guide spatial prioritization, our work supports more effective implementation of conservation targets in a rapidly changing world.

ecology↗

bioRxiv2025

Risk to European birds from collisions with wind-energy facilities

In line with Europes decarbonization goals, wind-power capacity is projected to increase in future years. However, wind-energy facilities can affect biodiversity; flying animals can fatally collide with wind-energy infrastructure. Here, we assessed the reported risk posed by collisions to 108 European birds, comparatively across species. We drew risk maps to assess current hotspots of risk. We employed a customised risk approach, considering that risk emerged from the interaction between (1) reported impacts (the total estimated number of fatalities at the species-level, accounting for current exposure to wind turbines) and (2) vulnerability to these impacts (the degree to which species may be affected by collision mortality). We used a quantitative synthesis of fatality numbers at wind-energy facilities to quantify collision-mortality rates at the species-level. We derived (1) by further combining these with information on species suitable areas and on current wind-turbine deployment. We estimated species vulnerability from ecological characteristics (generation length, clutch size, and estimates of European suitable area) assumed to reflect species ability to cope with disturbances. Overlapping vulnerability with estimated impacts, we classified species into different risk categories, considering species to be at higher relative risk when more vulnerable and more impacted. We assessed where species falling into the risk categories might occur, and where possible conflicts with wind-energy deployment might arise. We found several risk hotspots notably located in the Iberian Peninsula and Northern Europe. Our work helps inform wind-power deployment and spatial planning at the European scale with the aim of minimising negative biodiversity impacts.

ecology↗

bioRxiv2025

Synergies and trade-offs between maintaining climate niche variability and preserving climate stability

The impact of climate change on biodiversity accelerates, calling for climate resilient conservation strategies such as protecting areas of high climatic stability (i.e. climate refugia) or protecting the variability of species climatic niches (to preserve adaptive potential). Developing a spatial framework that integrates both strategies, we identify priorities to protect climatic niche components of 1,207 European vertebrates. Priority areas for protecting climatic niches under low climate velocity or low magnitude were respectively found in mountainous/southern regions and in northern/eastern Europe. These synergy areas overlapped by 48-73% with single-objective prioritizations focused on either niche components or climatic stability. Trade-offs occur where climatic niches diversity is high but climate stability is low, such as eastern Europe (velocity) or the Mediterranean and North Fennoscandia (magnitude). Our results reveal spatial mismatches between climate refugia and spatial priorities to preserve adaptive potential, emphasizing the need to combine both strategies in conservation planning.

ecology↗

bioRxiv2025

Improving the classification of wildlife conservation status to support nature protection in the European Union

Ensuring that species of conservation concern achieve favorable conservation status (FCS) is central to European Union (EU) biodiversity conservation targets. A key criterion for FCS is exceeding the favorable reference range (FRR)--the range extent needed for long-term species stability and full ecological variation. However, due to data limitations, FRRs are often unknown, undermining their applicability. We developed a machine-learning approach to estimate and standardize FRRs across the EU. Applied to amphibians, mammals, and reptiles, our method provided FRRs for 99.5% of species of conservation concern, compared to 17.5% previously available (with satisfactory modelling performance: R2 0.75). We reassessed conservation status using the estimated FRRs, finding that species in FCS (34.8%) are notably fewer than reported in official documentation (69.1%). The average proportional distance to FRR for species in unfavorable conservation status is -64.4%. Our approach may support periodic FCS reassessments and help refine the targets of EU conservation policies.

ecology↗

bioRxiv2025

Sperm meet the elevated energy demands to attain fertilization competence by increasing flux through aldolase

Prior to ejaculation, sperm are stored in the epididymis in a resting metabolic state. Upon ejaculation, sperm must alter their metabolism to generate the energy needed to support the motility and maturation process known as capacitation to reach and fertilize the oocyte. How sperm regulate the capacitation-induced increase in carbon flux is unknown. Here, we use 13C stable isotope labeling to follow glucose metabolism through sperm central carbon metabolic network before and after sperm activation. We identify regulatory steps which sperm use to alter their metabolic state from resting to highly active. In activated sperm, glucose flux through glycolysis is increased at the expense of the pentose phosphate pathway to increase energy yield. Increased glycolytic activity seems to be due to capacitation-induced stimulation of flux through aldolase. In the mitochondria-containing midpiece, glycolytically generated pyruvate feeds the TCA cycle to further maximize energy yield via oxidative phosphorylation. In the mitochondria-free principal piece of the tail, pyruvate produced from glycolysis is reduced to lactate by lactate dehydrogenase. Reduction to lactate regenerates oxidized NAD+ ensuring a sufficient supply to support glycolysis. The resultant lactate is at least partially secreted. Finally, we find evidence that there is an as yet unknown endogenous source of energy in sperm feeding the upregulation of TCA cycle intermediates. These studies provide the most complete picture of the metabolic shift which occurs in capacitating sperm. Significance statementA rapid switch from a quiescent to a high energy-demanding state during ejaculation is essential for sperm to reach and fertilize the oocyte. Somatic cells also undergo bioenergetic switches from low to very high energy demand. However, because metabolic processes essential for proliferation are going on in parallel, it is difficult to identify the molecular mechanisms regulating the increase in ATP production. This study represents the first complete picture of the metabolic reprogramming that happens in sperm upon ejaculation. Using stable isotope labeling, we identify rate-limiting enzymatic steps and points of regulation directing the changes in metabolic flux. Our sperm metabolic studies allow us to identify conserved mechanisms of metabolic regulation that are crucial for the survival of mammalian cells.

biochemistry↗

bioRxiv2024

Narratives for positive nature futures in Europe

O_LIThe Nature Futures Framework (NFF) is a novel tool for the development of positive scenarios centred on the relationship of nature and people, emphasising biodiversity as part of the solution to environmental challenges across various spatial and temporal scales, explicitly addressing a plurality of values for nature. C_LIO_LIIn this work, we describe the process that has led to the formulation of continental-scale positive narratives for conservation in Europe based on the NFF and its value perspectives (Nature for Nature; Nature for Society; Nature as Culture), through a stakeholder group elicitation. We focused on 6 topics in the narratives: Nature Protection and Restoration; Forestry; Freshwater Ecosystems; Urban Systems; Agriculture, and Energy. We analyse differences and similarities among the narratives across these topics. C_LIO_LIWe develop three novel Nature Futures narratives for Europe with contrasting perspectives and priorities for the six topics. Within the EU socioeconomic trends and policy framework, common solutions that simultaneously tackle biodiversity conservation and instrumental and cultural Natures Contributions to People (NCP) provision emerged. C_LIO_LIThis set of narratives may integrate preferences concerning EU-level conservation targets and plausible socio-ecological development pathways, supporting the modelling of positive scenarios for nature that can be crucial in guiding policy decisions towards recovery of nature. C_LI

ecology↗

bioRxiv2022

The global exposure of species ranges and protected areas to forest management

The majority of vertebrate species globally are dependent on forests, most of which require active protection to safeguard global biodiversity. Forests, however, are increasingly either being disturbed, planted or managed in the form of timber or food plantations. Because of a lack of spatial data, forest management has commonly been ignored in previous conservation assessments. Here we show - using a new global map of forest management - that disturbed and human managed forests cover the distributional ranges of most forest-associated species. Even more worrying, protected areas are increasingly being established in areas dominated by disturbed forests. Our results imply that species extinction risk and habitat assessments might have been overly optimistic with forest management practices being ignored. With forest restoration being in the centre of climate and conservation policies in this decade, we caution that policy makers should explicitly consider forest management.

ecology↗

bioRxiv2022

Assessing the global impact of targeted conservation actions on species abundance

In recent years, vertebrate population abundance has declined at unprecedented rates (WWF 2020). In response, targeted conservation measures - such as breeding programs or species-specific habitat management - have been applied to halt population declines, aid population recovery, and reduce and reverse the loss of biodiversity (Salafsky et al. 2008; Bolam et al. 2020). Until now, assessments of conservation actions have focused on the extent to which they reduce extinction risk, impact populations within protected areas, or increase the global area of land under protection (Hoffmann et al. 2010, 2015; Barnes et al. 2016; Maxwell et al. 2020; Bolam et al. 2020; Grace et al. 2021a). Here, we record and analyze conservation actions for 26,904 vertebrate populations from 4,629 species, to measure the impact of targeted conservation on vertebrate abundance. Using a counterfactual approach to represent population trends in the absence of conservation, we demonstrate that targeted actions have delivered substantial positive effects on the abundance of recipient vertebrate populations worldwide. We show that, in the absence of conservation, a global indicator of vertebrate abundance would have declined even more. Positive population trends were associated with vertebrate populations subject to species or habitat management. We demonstrate that targeted conservation actions can help to reverse global biodiversity loss and show the value of counterfactual analysis for impact evaluation - an important step towards reversing biodiversity declines.

ecology↗

bioRxiv2021

Capacity of countries to reduce biological invasions

The extent and impacts of biological invasions on biodiversity are largely shaped by an array of socio-ecological predictors, which exhibit high variation among countries. Yet a global synthetic perspective of how these factors vary across countries is currently lacking. Here, we investigate how a set of five socio-ecological predictors (Governance, Trade, Environmental Performance, Lifestyle and Education, Innovation) explain i) country-level established alien species (EAS) richness of eight taxonomic groups, and ii) country capacity to prevent and manage biological invasions and their impacts. Trade and Governance together best predicted the average EAS richness, increasing variance explained by up to 54% compared to models based on climatic and spatial variables only. Country-level EAS richness increased strongly with Trade, whereas high level of Governance resulted in lower EAS richness. Historical (1996) levels of Governance and Trade better explained response variables than current (2015) levels. Thus, our results reveal a historical legacy of these two predictors with profound implications for the future of biological invasions. We therefore used Governance and Trade to define a two-dimensional socio-economic space in which the position of a country captures its capacity to address issues of biological invasions. Our results provide novel insights into the complex relationship between socio-ecological predictors and biological invasions. Further, we highlight the need for designing better policies and management measures for alien species, and for integrating biological invasions in global environmental scenarios.

ecology↗

bioRxiv2020

Deficient spermiogenesis in mice lacking Rlim

The X-linked gene Rlim plays major roles in female mouse development and reproduction, where it is crucial for the maintenance of imprinted X chromosome inactivation in extraembryonic tissues of embryos. However, while females carrying a systemic Rlim knockout (KO) die around implantation, male Rlim KO mice appear healthy and are fertile, raising questions as to the pressures driving Rlim gene selection during evolution. Here we report an important role for Rlim in testis where it is highly expressed in post-meiotic round spermatids as well as in Sertoli cells. Systemic deletion of the Rlim gene leads to lower numbers of mature sperm that contains excess cytoplasm, leading to decreased sperm motility and in vitro fertilization rates. Targeting the conditional Rlim cKO specifically to the spermatogenic cell lineage largely recapitulates this phenotype. These results reveal functions of Rlim in male reproduction specifically in round spermatids during spermiogenesis with likely evolutionary implications.

developmental biology↗

bioRxiv2020

Global trends in biodiversity and ecosystem services from 1900 to 2050

Despite the scientific consensus on the extinction crisis and its anthropogenic origin, the quantification of historical trends and of future scenarios of biodiversity and ecosystem services has been limited, due to the lack of inter-model comparisons and harmonized scenarios. Here, we present a multi-model analysis to assess the impacts of land-use and climate change from 1900 to 2050. During the 20th century provisioning services increased, but biodiversity and regulating services decreased. Similar trade-offs are projected for the coming decades, but they may be attenuated in a sustainability scenario. Future biodiversity loss from land-use change is projected to keep up with historical rates or reduce slightly, whereas losses due to climate change are projected to increase greatly. Renewed efforts are needed by governments to meet the 2050 vision of the Convention on Biological Diversity. One Sentence SummaryDevelopment pathways exist that allow for a reduction of the rates of biodiversity loss from land-use change and improvement in regulating services but climate change poses an increasing challenge.

ecology↗

bioRxiv2020

Only 40% of the world's forests are in good health

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remains poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate the first globally-consistent, continuous index of forest condition as determined by degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) have high landscape level integrity (mostly found in Canada, Russia, the Amazon, Central Africa and New Guinea) and only 27% of this area is found in nationally-designated protected areas. Of the forest in protected areas, only 56% has high landscape level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally.

ecology↗

bioRxiv2019

Conservation attention necessary across at least 44% of Earth’s terrestrial area to safeguard biodiversity

More ambitious conservation efforts are needed to stop the global biodiversity crisis. Here, we estimate the minimum land area to secure important sites for terrestrial fauna, ecologically intact areas, and the optimal locations for representation of species ranges and ecoregions. We discover that at least 64 million km2 (44% of terrestrial area) requires conservation attention. Over 1.8 billion people live on these lands so responses that promote agency, self-determination, equity, and sustainable management for safeguarding biodiversity are essential. Spatially explicit land-use scenarios suggest that 1.3 million km2 of land requiring conservation could be lost to intensive human land-uses by 2030, which requires immediate attention. However, there is a seven-fold difference between the amount of habitat converted under optimistic and pessimistic scenarios, highlighting an opportunity to avert this crisis. Appropriate targets in the post-2020 Global Biodiversity Framework to ensure conservation of the identified land would contribute substantially to safeguarding biodiversity.

ecology↗

bioRxiv2019

Targeted expansion of Protected Areas to maximise the persistence of terrestrial mammals

Over a quarter of species assessed by the IUCN Red List are threatened with extinction. A global commitment to protect 17% of land and 10% of the oceans by 2020 is close to being achieved, but with limited ecological impacts due to its inadequacy and poor enforcement. Here, we reverse-engineer IUCN Red List criteria to generate area-based conservation targets and spatial conservation priorities to minimize the extinction risk of the world terrestrial mammals. We find that approximately 60% of the Earths non-Antarctic land surface would require some form of protection. Our results suggest that global conservation priority schemes, among which the Aichi targets, will be inadequate to secure the persistence of terrestrial mammals. To achieve this goal, international cooperation is required to implement a connected and comprehensive conservation area network, guided by high priority regions outlined in this study.

ecology↗

bioRxiv2018

Putting species back on the map: devising a robust method for quantifying the biodiversity impacts of land conversion

AimQuantifying connections between the global drivers of habitat loss and biodiversity impact is vital for decision-makers promoting responsible land-use. To that end, biodiversity impact metrics should be able to report linked trends in specific anthropogenic activities and changes in biodiversity state. However, for biodiversity, it is challenging to deliver integrated information on its multiple dimensions (i.e. species richness, endemicity) and keep it practical. Here, we developed a biodiversity footprint indicator that can i) capture the status of different species groups, ii) link biodiversity impact to specific human activities, and iii) be adapted to the most applicable scale for the decision context.\n\nLocationCerrado Biome, Brazil\n\nMethodsWe illustrate this globally-applicable approach for the case of soybean expansion in the Brazilian Cerrado. Using species-specific habitat suitability models, we assessed the impact of soy expansion and other land uses over 2,000 species of amphibians, birds, mammals and plants for three time periods between 2000 and 2014.\n\nResultsOverall, plants suffered the greatest reduction of suitable habitat. However, among endemic and near-endemic species - which face greatest risk of global extinction from habitat conversion in the Cerrado - birds were the most affected group. While planted pastures and cropland expansion were together responsible for most of the absolute biodiversity footprint, soy expansion via direct conversion of natural vegetation had the greatest impact per unit area. The total biodiversity footprint over the period was concentrated in the southern states of Minas Gerais, Goias and Mato Grosso, but the soy footprint was proportionally higher in those northern states (such as Bahia and Piaui) which belong to the new agricultural frontier.\n\nMain conclusionsThe ability and flexibility of our approach to examine linkages between biodiversity loss and specific human activities has substantial potential to better characterise the pathways by which habitat loss drivers operate.

ecology↗

bioRxiv2018

The actin cytoskeleton of the mouse sperm flagellum is organized in a helical structure

Conception of a new mammalian organism is determined by the fusion of a sperm cell with an oocyte during fertilization. Motility is one of the features of sperm that allows them to succeed in fertilization, and their flagellum is essential for this function. Longitudinally, the flagellum divides into the midpiece, the principal piece, and the end piece. A precise cytoskeletal architecture of the sperm tail is key for the acquisition of fertilization competence. It has been proposed that the actin cytoskeleton plays essential roles in the regulation of sperm motility, however, actin organization in sperm remains elusive. In the present work, we found different types of actin structures in the sperm tail, using stochastic optical reconstruction microscopy (STORM). In the principal piece, actin is radially distributed between the axoneme and the plasma membrane. The actin-associated proteins spectrin and adducin are also found in these structures. Strikingly, polymerized actin in the midpiece forms a double-helix that accompanies mitochondria. Our findings illustrate a novel specialized structure of actin filaments in a mammalian cell.

cell biology↗