Biology subjects

Casagrandi, R.

Publications and source records attributed to Casagrandi, R..

17 recordsLinked to original sources

bioRxiv2026

Exploring the value of thematic urban ecosystem accounts in Western Balkan Countries to inform urban greening actions

Urban ecological health is increasingly prioritized in Europe, as reflected in the EU Biodiversity Strategy 2030, the Nature Restoration Regulation, and the amendment to the Regulation on Environmental-Economic Accounts. Translating this ambition into greening actions that halt and reverse urban ecological degradation requires standardized, spatially explicit indicators. This study explores the utility of the System of Environmental-Economic Accounting-Ecosystem Accounting (SEEA-EA) framework for developing thematic urban ecosystem accounts as integrated metrics to inform urban greening in the Western Balkans. We constructed pilot accounts for the Western Balkans for 2018, with particular focus on Horizon-funded CROSS-REIS countries, where local accounts were also developed for representative municipalities (Kranj, Rijeka, Ni[s], Podgorica, Tirana). The accounts quantify ecosystem extent, four condition metrics (imperviousness, green space, tree cover, and PM concentration), and the service air filtration using PM deposition onto vegetation as a proxy. Results were benchmarked nationally against EU/EFTA/UK countries and locally against Italian municipalities of the National Biodiversity Future Centre project. The analysis reveals that urban ecosystems in the Western Balkans exist on a continuum with other European countries but exhibit a distinct, more homogeneous profile shaped by geography, climate, and policy legacies. The accounts identify ecological degradation hotspots (e.g., high soil sealing) and areas of high service-delivery capacity, supporting translation of spatial diagnosis into targeted greening priorities. Overall, the study shows that thematic urban ecosystem accounts offer a standardized, multi-scale evidence base to inform and monitor urban greening policies, supporting the Western Balkans environmental management needs on their path toward EU integration.

ecology↗

bioRxiv2025

Electrophysiological monitoring of plants: an exploratory study on drought stress

Climate change is increasing environmental stress, particularly rising temperatures and water scarcity, in both natural and human-managed systems such as agroecosystems and urban environments. Traditional methods for monitoring plant health in human-managed systems remain limited, underscoring the need for novel approaches. This study explores the potential of plant electrophysiological signals (EPS) and derived statistical features for the early detection of drought stress. The two main objectives of this research are: i) to identify EPS features that are both ecologically relevant and statistically robust for detecting drought stress, and ii) to develop statistical models that integrate these features. EPS data was collected from two drought-stress experiments, one on tomato plants and one on apricot trees. Sixteen features from both time and frequency domains were selected and evaluated. Two models, a logistic and a machine learning classifier, were developed and compared using accuracy, precision, and recall metrics. In apricots, ten time-domain features (Frequency Center, Generalized Hurst Exponent, Hjorth Complexity, Hjorth Mobility, Kurtosis, Root Mean Squared Frequency, Root Variance Frequency, Shape Factor, Skewness and Standard Deviation) showed significant differences between stressed and control groups. In tomatoes, four frequency-domain features (Frequency Centre, Root Variance Frequency, Root Mean Squared Frequency, and Power Law Distribution Exponent) were significantly different. Model accuracy was approximately 50% for apricots and 66% for tomatoes, insufficient for practical deployment but indicative of potential. This study illustrates the potential value of plant EPS data, its derived statistical features, and models for developing early drought stress detection systems in both agricultural and urban plant management contexts.

plant biology↗

bioRxiv2025

Reactive persistence of riverine metapopulations

Understanding the conditions that favor the persistence of metapopulations inhabiting riverine landscapes (riverscapes) is critical to guiding conservation and restoration efforts aimed at preserving biodiversity and ecological integrity in freshwater environments. In this study, we present a modeling framework to examine the transient persistence of fluvial metapopulations---the temporary occupation of riverscape patches by a metapopulation expected to become extinct in the long run. Our approach is theoretically grounded in the concept of ecological reactivity, which effectively complements asymptotic stability analysis in the study of the short-term response of ecological systems to impulsive perturbations of otherwise stable steady states. Our results suggest that, under ecohydrological conditions conducive to reactive metapopulation extinction equilibria, a metapopulation asymptotically bound to extinction can still colonize parts of the riverscape for significant periods of time. We also find that, in the presence of repeated positive perturbations of the extinction equilibrium, the temporal scales associated with these transient phenomena may allow for reactive pseudo-persistence. This phenomenon involves an arbitrarily long delay in the eventual extinction of the metapopulation, which may occur well below the deterministic extinction threshold. Identifying the ecohydrological drivers of reactivity-driven metapopulation persistence and the riverscape patches that contribute most to transient metapopulation dynamics over different temporal scales may provide valuable suggestions for the spatial prioritization of conservation and restoration efforts.

ecology↗

bioRxiv2025

Do urban ecosystem service assessments account for ecosystem condition and biodiversity?

Urban ecosystems provide essential ecosystem services (ES), a supply that is dependent on ecosystem condition (EC). Statistical frameworks like the UN SEEA-EA explicitly link ES flows to the extent and condition of ecosystem assets. Yet, the concrete role of EC in shaping ES supply remains only partially understood, as their relationship is complex and varies across services. Consequently, the operational integration of EC into urban ES assessments remains fragmented. Through a systematic review of 110 studies (2005-2024), we evaluated how and to what extent EC has been incorporated into urban ES assessments. For each study, we examined ES assessment methods, types of condition variables, spatial and temporal explicitness, flow types (potential vs. actual), and sustainability considerations. We find that integration is decisively underway, with most studies (87%) using EC variables as inputs, predominantly for regulating services. However, this integration is narrow: it relies on static methods, focuses on potential over actual flows, and favors easily measurable abiotic and structural state variables over functional, compositional, or landscape ones. While spatial explicitness is common (45%), dynamic models are rare (20%), and assessments seldom leverage EC to evaluate ES flow sustainability. Addressing these gaps, by broadening types of EC variables, increasing temporal dynamism, and linking condition to both actual flows and sustainability, will enhance the capacity of urban ES assessments to support the planning and adaptive management of urban greening. It will also help advance the development of urban ecosystem condition and service accounts, thereby increasing the relevance of urban ES assessment knowledge.

ecology↗

bioRxiv2025

Does generalism drive pollinators' abundance, persistence and regional distribution? Insights from an ecological model

The functioning of plant-pollinator mutualistic networks is crucial for ecosystem service provisioning and biodiversity maintenance. However, multiple drivers of global change are causing an alarming decline of wild pollinators abundance and richness. We propose an ecological, process-based mathematical model describing the dynamics of pollinators and plants, properly mediated by reward resources. Our model explicitly accounts for the main interactions of both facilitative and competitive nature that occur both within and between the two guilds. We apply our model to a broad set of real communities in fragmented landscapes to investigate the mechanisms that link the architecture of the interaction networks, the pollinators temporal persistence and abundance at the community level, and their rarity at the landscape level. Our results suggest that few generalist pollinators form a core of abundant, persistent and widely distributed species, while a lower number of mutualistic partners is generally associated with low abundance, low persistence and high turnover between patches. Specialists, however, are crucial to maintaining high levels of biodiversity within the community. This finding highlights the importance of ecological connectivity, through which local extinctions can be counter-balanced by recolonizations. Our analysis shows how a mechanistic model accounting for the structure of plant-pollinator networks can serve as a tool to investigate important ecological mechanisms driving community composition, dynamics and the resulting species distribution patterns.

ecology↗

bioRxiv2025

An individual, mechanistic and dynamical model to simulate urban tree growth and ecosystem services supply under future scenarios

Urban trees represent a key nature-based solution and an essential component of green infrastructures, providing multiple ecosystem services but increasingly subjected to environmental stressors. Here we present a dynamic, mechanistic, and individual-based model designed to simulate growth of urban trees and the associated provision of ecosystem services under varying climate conditions. The model is modular, runs at daily time steps and incorporates key biological processes such as photosynthesis, water limitation and biomass allocation. It simulates single-tree growth and quntifies ecosystem services, such as carbon sequestration, air filtration, and local climate regulation using species-specific parameters and local climate forcing. The model was calibrated and tested in a pilot application in Milan, simulating the long-term growth of three of three common broadleaved species (Platanus x acerifolia, Populus nigra and Robinia pseudoacacia) across different planting ages and climate scenarios. A multi-objective calibration was used to fit stem diameter and crown width, and sensitivity analyses were conducted to assess parameter robustness and uncertainty propagation. Results show realistic growth trajectories with clear species-age contrasts. Tree growth declines under stronger climate forcing, and ecosystem service provision scales non-linearly with age, with mature trees delivering far greater benefits. Carbon sequestration and air filtration decrease under more extreme scenarios, whereas local climate regulation exhibits a compensatory response: lower productivity is offset by higher evaporative demand, yielding stable or slightly increased evapotranspiration-based cooling. The model offers a promising tool for supporting urban forestry decisions related to planning, species selection, and long-term ecosystem service provision.

ecology↗

bioRxiv2025

Advancing the global statistical standard for urban ecosystem accounts

The System of Environmental-Economic Accounting-Ecosystem Accounting (SEEA-EA), adopted by UNSD, provides a standardized global framework for measuring and monitoring ecosystems extent, condition, and services. However, its application to urban ecosystems faces conceptual and operational challenges. Building on SEEA-EA, we propose advancing the framework for thematic urban ecosystem accounting, identifying main challenges and framing potential solutions based on existing lessons and approaches. Through a literature review on ecosystem accounting and urban science, we identified 24 challenges, with lessons and approaches suggested for 17 of them. Results show that many challenges are highly interconnected and shared with accounts for other ecosystem types. Urban-specific challenges include a lack of consensus in defining urban ecosystems, their specific assets, and their classifications. Additionally, findings highlight the need for defining appropriate methods to capture socio-ecological degradation, impacts, and dependencies of urban ecosystems. Suggested solutions include adapting the accounting structure and prioritizing the resolution of urban- specific challenges.

ecology↗

bioRxiv2025

Shifting ecological niches of Prunus species under climate change

Climate change is strongly impacting agriculture, reducing crop production and shifting the geographic distribution of suitable areas for crop cultivation. To safeguard future global yield and feed a growing world population, the migration of crop production areas to new suitable sites represents a way to adapt to a changing climate. Here, we aim to identify the ecological niche of Prunus species, namely peach, plum, almond, apricot and sweet cherry, and examine their expected future shifts under climate change. For each Prunus species, we selected from the literature processed-based phenological models for dormancy break, blooming and fruit ripening, whose fulfillment determines whether an area is suitable for crop cultivation. Historically, the ecological niche of Prunus species spans mid-low European latitudes, while higher latitudes fail satisfying the forcing requirements for blooming and fruit ripening. In future, this constraint is expected to become less restrictive with a northwards expansion of the suitable areas. However, this will be contrasted by a contraction of the niche at low latitudes due to dormancy break failures. While bridging established mechanistic knowledge on the climatic effects of plant phenological traits with citizen science observations, our work brings new insights into how fruit crops will respond to global warming.

ecology↗

bioRxiv2023

Phenological and epidemiological impacts of climate change on peach production

Agricultural food security is threatened by climate change impacts, which can distress crop growth and favor the spread of infectious diseases. Here, we examined the synergism of the two potentially most disruptive causes of future yield failure in peach production: the effects of global climate change on fruit growth and on the spread of fungal diseases. Coupling a phenological and epidemiological model across the French continental territory, we provided projections of yield losses for four peach cultivars (early, mid-early, mid-late, and late) in the XXI century under different climate change scenarios. Global warming is expected to impair fruit phenology with blooming failure events in the south-western part of the country. This will be less extreme under the more moderate emission scenario, even though sporadic blooming failures will still occur. In contrast, future warmer and drier conditions will decrease brown rot-induced yield loss in the historical locations devoted to peach cultivation. To adapt to these changes, the benefits of shifting peach production sites to new suitable areas are evaluated. Thanks to this strategy, the peach national yield could still be fulfilled even under the most extreme climate change scenario. Comprehensive mathematical frameworks, that concomitantly consider the climatic effects on the plant hosts and on their pathogens, are required to provide reliable future predictions of crop yields and to inform control and adaptation strategies to guarantee food security under global warming.

ecology↗

bioRxiv2023

Helminth ecological requirements shape the impact of climate change on the hazard of infection

Outbreaks and spread of infectious diseases are often associated with seasonality and changes caused by global warming. Free-living stages of soil-transmitted helminths are highly susceptible to environmental drivers, however, how multiple climatic variables affect helminth species, and the long-term consequences of these interactions, is poorly understood. We used experiments on nine trichostrongylid species to develop a temperature- and humidity-dependent model of infection hazard, which was then implemented at the European scale under climate change scenarios. Intestinal and stomach helminths exhibited contrasting climatic responses, with the former group strongly affected by temperature while the latter primarily impacted by humidity. These differences generated seasonal changes in the timing and intensity of the infection hazard and spatial heterogeneities within and between the two groups. A future range expansion of both groups toward northern latitudes is expected to create new opportunities for the co-circulation of the studied helminth species.

ecology↗

bioRxiv2022

Modeling the contribution of antibodies to the within-host dynamics of single and dual helminth infections in a natural system

Within-host models of infection can provide important insights into the processes that affect parasite spread and persistence in host populations. However, modeling is often limited by the availability of empirical data, a problem commonly encountered in natural systems. Here, we used six years of immune-infection observations of two gastrointestinal helminths (Trichostrongylus retortaeformis and Graphidium strigosum) from a population of European rabbits (Oryctolagus cuniculus) to develop an age-dependent, within-host mathematical model that explicitly included species-specific and cross-reacting antibody (IgA and IgG) responses to each helminth in hosts with single or dual infections. Different models of single infection were formally compared to test alternative mechanisms of parasite regulation. The two models that best described single infections of each helminth species were then coupled through antibody cross-immunity to examine how the presence of one species could alter the host immune response to, and the within-host dynamics of, the other species. For both single infections, model selection suggested that either IgA or IgG responses could equally explain the observed parasite intensities at different host age. However, the strength of this response drastically changed between the two helminths, being stronger against T. retortaeformis than against G. strigosum and causing contrasting age-intensity profiles. When the two helminths coinfect the same host, we found a decrease of the species-specific immune response to both species together with an asymmetric cross-immune response driven by IgG. Changes in the level and affinity of antibodies from single to dual infections contributed to the significant increase of both helminth abundances. By combining mathematical modeling with immuno-infection data, our work provides a model framework for disentangling some of the complexities generated by host-parasite and parasite-parasite interactions from natural systems. Our approach thus offers a tractable general tool to examine immune-infection relationships within hosts. Author summaryThe host immune response often plays a critical role in regulating parasite dynamics and transmission. We developed a mathematical model to evaluate whether and how the observed variation in host antibody responses could explain the relative differences in the abundance of two parasite species in hosts with single and dual infections from a natural rabbit population. Our results indicated that either IgA or IgG could describe the contrasting trends of the two parasites in rabbits with single infections. Specifically, antibodies appeared to control T. retortaeformis, while the effect was less clear for G. strigosum. For dual infections, we found a weaker specific antibody response against both helminths and an asymmetric cross-immunity, which could explain the significantly greater intensities observed for T. retortaeformis and, secondly, for G. strigosum. Our within-host mathematical framework provides a plausible mechanism for the mediated role of antibodies in hosts with single and dual parasite infections, and how the strength of these infection-immune interactions changes with host age. This model framework offers a way forward to our understanding of the within-host processes that generate individual variation in infection and is relatively flexible to be applied to other natural systems.

immunology↗

bioRxiv2022

A climate-driven compartmental model for fungal diseases in fruit orchards: The impacts of climate change on a brown rot-peach system

As a well-known driving force of diseases in crops, climate change is likely to impact future crop yields. In the present work, we account for climate-related influences on the key parameters of a SIR-type epidemiological model for fungal diseases in stone fruit aimed at simulating different observed epidemic patterns, and, eventually, evaluating the possible impacts of climate change on the disease-induced yield loss. Brown rot disease in peach orchards is used here as a study system. We contrasted simulation results with epidemiological measures collected from an experimental orchard in Avignon (southern France) in two consecutive years, characterized by dissimilar brown rot outbreaks. The capacity of our climate-driven model to adequately reproduce the observed disease patterns suggests temperature and precipitation as key drivers of brown rot epidemics. Overall, the model predicts a potential decrease of brown rot severity under warmer and drier climatic conditions. To comprehensively understand the effect of future climate change on peach yield, alterations of crop phenology must also be accounted for. We thus build a model that considers the synergism between the two factors: vulnerability to the pathogen and varying phenology. Using plausible climate change scenarios, we find that the peach yield in the considered Mediterranean region will be considerably impaired: although brown rot-related yield losses are expected to decrease in warmer and drier climatic conditions, climate change will hinder fruit blooming and consequently the yield because milder winters will impede the achievement of dormancy. By deepening our understanding of climatic impacts on crop fungal infections, the present study may serve as a useful tool to plan and implement suitable adaptation strategies for peach cultivation.

plant biology↗

bioRxiv2021

The Enemy of my Enemy is my Friend: Immune-Mediated Facilitation Contributes to Fitness of Co-Infecting Helminths

Our conceptual understanding of immune-mediated interactions between parasites is rooted in the theory of community ecology. One of the limitations of this approach is that most of the theory and empirical evidence has focused on resource or immune-mediated parasite competition and yet, there is ample evidence of positive interactions between species that could be generated by immune-mediated facilitation. Here, we develop an immuno-epidemiological framework and apply it to longitudinal infection data of two gastrointestinal helminths that infect a population of free-living rabbits to investigate, through model testing, the mechanisms of immune-mediated facilitation in dual infections. Simulations show that weakened, species-specific IgA antibody responses and unequal, albeit low, IgA cross-reactions explain higher parasite intensities in dual compared to single infections, for both helminths. Simulations also show that rabbits with dual infections shed more free-living stages that survive fort longer in the environment, implying greater onward transmission than hosts with single infections. These findings support the hypothesis that the two helminths interact through immune-mediated facilitation which contributes to greater fitness and the long-term co-circulation of both species in the host population.

ecology↗

bioRxiv2021

Analysis of amino acid change dynamics reveals SARS-CoV-2 variant emergence

Since its emergence in late 2019, the diffusion of SARS-CoV-2 is associated with the evolution of its viral genome1,2. The co-occurrence of specific amino acid changes, collectively named virus variant, requires scrutiny (as variants may hugely impact the agents transmission, pathogenesis, or antigenicity); variant evolution is studied using phylogenetics3-6. Yet, never has this problem been tackled by digging into data with ad hoc analysis techniques. Here we show that the emergence of variants can in fact be traced through data-driven methods, further capitalizing on the value of large collections of SARS-CoV-2 sequences. For all countries with sufficient data, we compute weekly counts of amino acid changes, unveil time-varying clusters of changes with similar - rapidly growing - dynamics, and then follow their evolution. Our method succeeds in timely associating clusters to variants of interest/concern, provided their change composition is well characterized. This allows us to detect variants emergence, rise, peak, and eventual decline under competitive pressure of another variant. Our early warning system, exclusively relying on deposited sequences, shows the power of big data in this context, and concurs to calling for the wide spreading of public SARS-CoV-2 genome sequencing for improved surveillance and control of the COVID-19 pandemic.

bioinformatics↗

bioRxiv2020

Shifts in the thermal niche of fruit trees under climate change: the case of peach cultivation inFrance.

Climate influences plant phenological traits, thus playing a key role in defining the geographical range of crops. Foreseeing the impact of climate change on fruit trees is essential to inform policy decisions to guide the adaptation to new climatic conditions. To this end, we propose and use a phenological process-based model to assess the impacts of climate change upon the phenology, the suitability and the distribution of economically important cultivars of peach (Prunus persica), across the entire continental France. The model combines temperature dependent sub-models of dormancy, blooming, fruit survival and ripening, using chilling units, forcing units, frost occurrence and growing degree days, respectively. We find that climate change will have divergent impacts upon peach production. On the one hand, blooming will occur earlier, warmer temperatures will decrease spring frost occurrence and fruit ripening will be easily achieved before the start of fall. On the other hand, milder winters will impede the plant buds from breaking endodormancy, with consequent abnormal patterns of fruit development or even blooming failure. This latter impact will dramatically shift the geographic range of sites where peach production will be profitable. This shift will mainly be from the south of France (Languedoc-Roussillon, Rhone-Alpes and Provence-Alpes-Cote dAzur), to northwestern areas where the winter chilling requirement will still be fulfilled. Our study provides novel insights for understanding and forecasting climate change impacts on peach phenology and it is the first framework that maps the ecological thermal niche of peach at national level.

plant biology↗

bioRxiv2019

Modelling plastics exposure for the marine biota: Risk maps for fin whales in the Pelagos Sanctuary (North-Western Mediterranean)

The Mediterranean basin is among the most impacted marine ecoregions globally, being at the same time semi-enclosed by densely populated countries and crossed by trafficked maritime routes. Such anthropogenic pressure threatens both the qual-ity of its waters and the high biodiversity living in them, making the role of Marine Protected Areas (MPAs) crucial for pre-serving species suitable habitats. Under the European Union Marine Strategy Framework Directive, marine litter has been recognized as one of the principal causes of marine pollution, and public awareness on its environmental and biological impacts is raising. Using a quantitative and data-driven modelling approach, here we assess the presence of plastic waste within the feeding grounds of the fin whale Balaenoptera physalus, an endangered cetacean for which there is increasing evidence of impacts due to microplastic ingestion. To this end, we analyze a decade (2000 - 2010) of advection patterns of marine plastic litter, modelled with a Lagrangian approach. Particles are released in the MPA Pelagos, the International Sanctuary for the Protection of Mediterranean Marine Mammals (North-Western Mediterranean, between France, Italy and Monaco), from different sources (i.e., untreated waste along coasts, plastic discharged from rivers and plastic pollution released along maritime shipping routes). Risk of exposure of fin whales to microplastic pollution is evaluated by interlacing plastic litter distribution maps obtained through modelling with maps of suitable habitats obtained from the elaboration of satellite chlorophyll-a data in species-specific visited areas. Our modelling results show that all the three main sources of plastic litter taken into account clearly contribute to impacting cetaceans in the Sanctuary, yet in a different manner. The procedure formalized here can be extended to assess the risk caused by plastic pollution in other MPAs as well as to evaluate possible impacts on other taxa, thus informing targeted actions to tackle the complex issue of marine litter.

ecology↗

bioRxiv2018

Prawn aquaculture as a method for schistosomiasis control and poverty alleviation: a win-win approach to address a critical infectious disease of poverty

Recent evidence suggests crustacean snail predators may aid schistosomiasis control programs by targeting the environmental component of the parasites life cycle through predation of the snail species that serve as intermediate hosts of the parasite. We evaluate costs, benefits, and potential synergies between schistosomiasis control and aquaculture of giant prawns using an integrated bio-economic-epidemiologic model. We identified combinations of stocking density and aquaculture cycle length that maximize profit and offer disease control benefits for sustainable schistosomiasis control. We consider two prawn species in sub-Saharan Africa: the endemic, non-domesticated Macrobrachium vollenhovenii, and the non-native, domesticated Macrobrachium rosenbergii. We find that, at profit-optimal densities, both M. rosenbergii and M. vollenhovenii can complement conventional control approaches (mass drug treatment of people) and lead to sustainable schistosomiasis control. We conclude that integrated aquaculture strategies can be a win-win strategy in terms of health and sustainable development in schistosomiasis endemic regions of the world.

epidemiology↗