Rahil J. Amin, Jessie C. Buettel, Matthew W. Fielding, Peter M. Vaughan, Barry W. Brook
Modelling the spread of introduced ecosystem engineers is a conservation priority due to their potential to cause irreversible ecosystem-level changes. While existing models predict potential distributions and spread capacities, new approaches that simulate the trajectory of a species' spread over time are needed. We developed novel simulations that predict spatial and temporal spread, capturing both continuous diffusion-dispersal and occasional long-distance leaps. We focused on the introduced population of superb lyrebird Menura novaehollandiae in Tasmania, Australia. Initially introduced as an insurance population, lyrebirds have become novel bioturbators, spreading across key natural areas and becoming ‘unwanted but challenging to eradicate'. Using multi-scale ecological data, our research 1) identified broad and fine-scale correlates of lyrebird occupation and 2) developed a spread simulation guided by a pattern-oriented framework. This occurrence-based modelling framework is useful when demographic data are scarce. We found that the cool, wet forests of western Tasmania with open understoreys offer well-connected habitats for lyrebird foraging and nesting. By 2023, lyrebirds had reached quasi-equilibrium within a core range in southern Tasmania and were expanding northwest, with the frontier reaching the western coast. Our model forecasts that by 2085, lyrebirds will have spread widely across suitable regions of western Tasmania. By pinpointing current and future areas of lyrebird occupation, we provide land managers with targeted locations for monitoring the effects of their expansion. Further, our area of applicability (AOA) analysis identified regions where environmental variables deviate from the training data, guiding future data collection to improve model certainty. Our findings offer an evidence-based approach for future monitoring and provide a framework for understanding the dynamics of other range-expanding species with invasive potential.
{"title":"A pattern-oriented simulation for forecasting species spread through time and space: a case study on an ecosystem engineer on the move","authors":"Rahil J. Amin, Jessie C. Buettel, Matthew W. Fielding, Peter M. Vaughan, Barry W. Brook","doi":"10.1111/ecog.07597","DOIUrl":"https://doi.org/10.1111/ecog.07597","url":null,"abstract":"Modelling the spread of introduced ecosystem engineers is a conservation priority due to their potential to cause irreversible ecosystem-level changes. While existing models predict potential distributions and spread capacities, new approaches that simulate the trajectory of a species' spread over time are needed. We developed novel simulations that predict spatial and temporal spread, capturing both continuous diffusion-dispersal and occasional long-distance leaps. We focused on the introduced population of superb lyrebird <i>Menura novaehollandiae</i> in Tasmania, Australia. Initially introduced as an insurance population, lyrebirds have become novel bioturbators, spreading across key natural areas and becoming ‘unwanted but challenging to eradicate'. Using multi-scale ecological data, our research 1) identified broad and fine-scale correlates of lyrebird occupation and 2) developed a spread simulation guided by a pattern-oriented framework. This occurrence-based modelling framework is useful when demographic data are scarce. We found that the cool, wet forests of western Tasmania with open understoreys offer well-connected habitats for lyrebird foraging and nesting. By 2023, lyrebirds had reached quasi-equilibrium within a core range in southern Tasmania and were expanding northwest, with the frontier reaching the western coast. Our model forecasts that by 2085, lyrebirds will have spread widely across suitable regions of western Tasmania. By pinpointing current and future areas of lyrebird occupation, we provide land managers with targeted locations for monitoring the effects of their expansion. Further, our area of applicability (AOA) analysis identified regions where environmental variables deviate from the training data, guiding future data collection to improve model certainty. Our findings offer an evidence-based approach for future monitoring and provide a framework for understanding the dynamics of other range-expanding species with invasive potential.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"36 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wang Cai, Maximilian Pichler, Jeremy Biggs, Pascale Nicolet, Naomi Ewald, Richard A. Griffiths, Alex Bush, Mathew A. Leibold, Florian Hartig, Douglas W. Yu
Technological advances are enabling ecologists to conduct large-scale and structured community surveys. However, it is unclear how best to extract information from these novel community data. We metabarcoded 48 vertebrate species from their eDNA in 320 ponds across England and applied the ‘internal structure' approach, which uses joint species distribution models (JSDMs) to explain compositions as the result of four metacommunity processes: environmental filtering, dispersal, species interactions, and stochasticity. We confirm that environmental filtering plays an important role in community assembly, and find that species' estimated environmental preferences are consistent with known ecologies. We also detect negative biotic covariances between fish and amphibians after controlling for divergent environmental preferences, consistent with predator–prey interactions (likely mediated by predator avoidance behaviour), and we detect high spatial autocorrelation for the palmate newt, consistent with its hypothesised relict distribution. Promisingly, ecologically and spatially distinctive sites are better explained by their environmental covariates and geographic locations, respectively, revealing sites where environmental filtering and dispersal limitation act more strongly. These results are consistent with the recent proposal that applying JSDMs to species distribution patterns can help reveal the relative importance of environmental filtering, dispersal limitation, and biotic interaction processes for individual sites and species. Our results also highlight the value of the modern interpretation of metacommunity ecology, which embraces the fact that assembly processes differ among species and sites. We discuss how novel community data allow for several study design improvements that will strengthen the inference of metacommunity assembly processes from observational data.
{"title":"Assembly processes inferred from eDNA surveys of a pond metacommunity are consistent with known species ecologies","authors":"Wang Cai, Maximilian Pichler, Jeremy Biggs, Pascale Nicolet, Naomi Ewald, Richard A. Griffiths, Alex Bush, Mathew A. Leibold, Florian Hartig, Douglas W. Yu","doi":"10.1111/ecog.07461","DOIUrl":"https://doi.org/10.1111/ecog.07461","url":null,"abstract":"Technological advances are enabling ecologists to conduct large-scale and structured community surveys. However, it is unclear how best to extract information from these novel community data. We metabarcoded 48 vertebrate species from their eDNA in 320 ponds across England and applied the ‘internal structure' approach, which uses joint species distribution models (JSDMs) to explain compositions as the result of four metacommunity processes: environmental filtering, dispersal, species interactions, and stochasticity. We confirm that environmental filtering plays an important role in community assembly, and find that species' estimated environmental preferences are consistent with known ecologies. We also detect negative biotic covariances between fish and amphibians after controlling for divergent environmental preferences, consistent with predator–prey interactions (likely mediated by predator avoidance behaviour), and we detect high spatial autocorrelation for the palmate newt, consistent with its hypothesised relict distribution. Promisingly, ecologically and spatially distinctive sites are better explained by their environmental covariates and geographic locations, respectively, revealing sites where environmental filtering and dispersal limitation act more strongly. These results are consistent with the recent proposal that applying JSDMs to species distribution patterns can help reveal the relative importance of environmental filtering, dispersal limitation, and biotic interaction processes for individual sites and species. Our results also highlight the value of the modern interpretation of metacommunity ecology, which embraces the fact that assembly processes differ among species and sites. We discuss how novel community data allow for several study design improvements that will strengthen the inference of metacommunity assembly processes from observational data.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"28 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benoit Penel, Christine N. Meynard, Laure Benoit, Axel Boudonne, Anne-Laure Clamens, Laurent Soldati, Alain Migeon, Marie-Pierre Chapuis, Sylvain Piry, Gael Kergoat, Julien Haran
In a context of unprecedented insect decline, it is critical to have reliable monitoring tools to measure species diversity and their dynamic at large-scales. High-throughput DNA-based identification methods, and particularly metabarcoding, were proposed as an effective way to reach this aim. However, these identification methods are subject to multiple technical limitations, resulting in unavoidable false-positive and false-negative species detection. Moreover, metabarcoding does not allow a reliable estimation of species abundance in a given sample, which is key to document and detect population declines or range shifts at large scales. To overcome these obstacles, we propose here a human-assisted molecular identification (HAMI) approach, a framework based on a combination of metabarcoding and image-based parataxonomic validation of outputs and recording of abundance. We assessed the advantages of using HAMI over the exclusive use of a metabarcoding approach by examining 492 mixed beetle samples from a biodiversity monitoring initiative conducted throughout France. On average, 23% of the species are missed when relying exclusively on metabarcoding, this percent being consistently higher in species-rich samples. Importantly, on average, 20% of the species identified by molecular-only approaches correspond to false positives linked to cross-sample contaminations or mis-identified barcode sequences in databases. The combination of molecular methodologies and parataxonomic validation in HAMI significantly reduces the intrinsic biases of metabarcoding and recovers reliable abundance data. This approach also enables users to engage in a virtuous circle of database improvement through the identification of specimens associated with missing or incorrectly assigned barcodes. As such, HAMI fills an important gap in the toolbox available for fast and reliable biodiversity monitoring at large scales.
{"title":"The best of two worlds: toward large-scale monitoring of biodiversity combining COI metabarcoding and optimized parataxonomic validation","authors":"Benoit Penel, Christine N. Meynard, Laure Benoit, Axel Boudonne, Anne-Laure Clamens, Laurent Soldati, Alain Migeon, Marie-Pierre Chapuis, Sylvain Piry, Gael Kergoat, Julien Haran","doi":"10.1111/ecog.07699","DOIUrl":"https://doi.org/10.1111/ecog.07699","url":null,"abstract":"In a context of unprecedented insect decline, it is critical to have reliable monitoring tools to measure species diversity and their dynamic at large-scales. High-throughput DNA-based identification methods, and particularly metabarcoding, were proposed as an effective way to reach this aim. However, these identification methods are subject to multiple technical limitations, resulting in unavoidable false-positive and false-negative species detection. Moreover, metabarcoding does not allow a reliable estimation of species abundance in a given sample, which is key to document and detect population declines or range shifts at large scales. To overcome these obstacles, we propose here a human-assisted molecular identification (HAMI) approach, a framework based on a combination of metabarcoding and image-based parataxonomic validation of outputs and recording of abundance. We assessed the advantages of using HAMI over the exclusive use of a metabarcoding approach by examining 492 mixed beetle samples from a biodiversity monitoring initiative conducted throughout France. On average, 23% of the species are missed when relying exclusively on metabarcoding, this percent being consistently higher in species-rich samples. Importantly, on average, 20% of the species identified by molecular-only approaches correspond to false positives linked to cross-sample contaminations or mis-identified barcode sequences in databases. The combination of molecular methodologies and parataxonomic validation in HAMI significantly reduces the intrinsic biases of metabarcoding and recovers reliable abundance data. This approach also enables users to engage in a virtuous circle of database improvement through the identification of specimens associated with missing or incorrectly assigned barcodes. As such, HAMI fills an important gap in the toolbox available for fast and reliable biodiversity monitoring at large scales.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"76 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexandra C. Coconis, Kenneth E. Nussear, Rebecca J. Rowe, Angela D. Hornsby, Marjorie D. Matocq
The relative importance of abiotic and biotic factors in determining species distributions has long been of interest to ecologists but is often difficult to assess due to the lack of spatially and temporally robust occurrence records. Furthermore, locating places where potentially highly competitive species co-occur may be challenging but would provide critical knowledge into the effects of competition on species ranges. We built species distribution models for two closely related species of small mammals (Neotoma) that are largely parapatric along mountainsides throughout the Great Basin Desert, USA using extensive modern occurrence records. We hindcasted these models to the mid-Holocene to compare the response of each species to dramatic climatic change and used paleontological records to validate our models. Model results showed species co-occurrence at mid-elevations along select mountain ranges in this region. We confirmed our model results with fine-scale field surveys in a single mountain range containing one of the most extensive survey datasets across an elevational gradient in the Great Basin. We found close alignment of realized distributions to the respective abiotic species distribution model predictions, despite the presence of the congener, indicating that climate may be more influential than competition in shaping distribution at the scale of a single mountain range. Our models also predict differential species responses to historic climate change, leading to reduced probability of species interactions during warmer and dryer climatic conditions. Our results emphasize the utility of examining species distributions with regard to both abiotic variables and species interactions and at various spatial scales to make inferences about the mechanisms underlying distributional limits.
{"title":"The role of climate and species interactions in determining the distribution of two elevationally segregated species of small mammals through time","authors":"Alexandra C. Coconis, Kenneth E. Nussear, Rebecca J. Rowe, Angela D. Hornsby, Marjorie D. Matocq","doi":"10.1111/ecog.07556","DOIUrl":"https://doi.org/10.1111/ecog.07556","url":null,"abstract":"The relative importance of abiotic and biotic factors in determining species distributions has long been of interest to ecologists but is often difficult to assess due to the lack of spatially and temporally robust occurrence records. Furthermore, locating places where potentially highly competitive species co-occur may be challenging but would provide critical knowledge into the effects of competition on species ranges. We built species distribution models for two closely related species of small mammals (<i>Neotoma</i>) that are largely parapatric along mountainsides throughout the Great Basin Desert, USA using extensive modern occurrence records. We hindcasted these models to the mid-Holocene to compare the response of each species to dramatic climatic change and used paleontological records to validate our models. Model results showed species co-occurrence at mid-elevations along select mountain ranges in this region. We confirmed our model results with fine-scale field surveys in a single mountain range containing one of the most extensive survey datasets across an elevational gradient in the Great Basin. We found close alignment of realized distributions to the respective abiotic species distribution model predictions, despite the presence of the congener, indicating that climate may be more influential than competition in shaping distribution at the scale of a single mountain range. Our models also predict differential species responses to historic climate change, leading to reduced probability of species interactions during warmer and dryer climatic conditions. Our results emphasize the utility of examining species distributions with regard to both abiotic variables and species interactions and at various spatial scales to make inferences about the mechanisms underlying distributional limits.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"40 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafael de Oliveira, Elisa Barreto, Thais B. Zanata, Francisco Tobar, Tatiana Santander, María José Gavilanes, Catherine H. Graham, Isabela G. Varassin
Tropical mountains often harbour high species richness. Yet the mechanisms behind such high richness remain poorly understood. One prominent hypothesis for high species richness is niche partitioning, which reduces competition and promotes coexistence. Here, we evaluate niche structure and specialisation of plant species based on the floral traits related to pollination interactions across an elevational gradient in the northern Andes. Niche structure can vary among sites, either expanding or contracting, or becoming more or less packed. We sampled eleven communities of hummingbird-visited plants along an elevation gradient in the Ecuadorian Andes and measured a series of functional traits associated with hummingbird pollination. We used the traits of all co-occurring species to calculate community weighted means, functional richness, and mean nearest neighbour distances and evaluated how they varied across elevation. Additionally, we measured specialisation based on plant–hummingbird interaction records to assess if packing is associated with narrower resource use or greater niche overlap. Species and functional richness were constant along the elevation gradient; however, niche packing was stronger at mid-elevation. We found changes in network specialisation, where the least specialised communities were those with higher niche packing. These results suggest that traits related to pollination and plant reproduction help to explain species co-occurrence and specialisation.
{"title":"Niche packing, but not niche expansion, explains the co-occurrence of hummingbirds-visited plants","authors":"Rafael de Oliveira, Elisa Barreto, Thais B. Zanata, Francisco Tobar, Tatiana Santander, María José Gavilanes, Catherine H. Graham, Isabela G. Varassin","doi":"10.1111/ecog.07440","DOIUrl":"https://doi.org/10.1111/ecog.07440","url":null,"abstract":"Tropical mountains often harbour high species richness. Yet the mechanisms behind such high richness remain poorly understood. One prominent hypothesis for high species richness is niche partitioning, which reduces competition and promotes coexistence. Here, we evaluate niche structure and specialisation of plant species based on the floral traits related to pollination interactions across an elevational gradient in the northern Andes. Niche structure can vary among sites, either expanding or contracting, or becoming more or less packed. We sampled eleven communities of hummingbird-visited plants along an elevation gradient in the Ecuadorian Andes and measured a series of functional traits associated with hummingbird pollination. We used the traits of all co-occurring species to calculate community weighted means, functional richness, and mean nearest neighbour distances and evaluated how they varied across elevation. Additionally, we measured specialisation based on plant–hummingbird interaction records to assess if packing is associated with narrower resource use or greater niche overlap. Species and functional richness were constant along the elevation gradient; however, niche packing was stronger at mid-elevation. We found changes in network specialisation, where the least specialised communities were those with higher niche packing. These results suggest that traits related to pollination and plant reproduction help to explain species co-occurrence and specialisation.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"7 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ben C. Scheele, Geoffrey W. Heard, Richard P. Duncan, Simon Clulow, Jarrod Sopniewski
Quantifying how species' distributions contract in response to threats can reveal pathways of decline and the role of environmental conditions in moderating threat impacts. Two general patterns of niche contraction have been described: ecological marginalization, where species contract away from threat impacts to peripheral, sub-optimal areas of their niche, and; contraction to the core, where species contract toward their niche center where their fitness and capacity to withstand threat impacts is highest. Recent work has described widespread ecological marginalization in declining mammal species, for which land use change and overexploitation are key threats. Different threatening processes could result in contrasting patterns of niche contraction, although this has not been well-studied. Here, we examine patterns of realized niche contraction in Australian frog species impacted by the emergence of chytrid fungus Batrachochytrium dendrobatidis, a pathogen that has driven catastrophic amphibian declines globally. We quantified changes in species' environmental niche space following chytrid emergence and documented a pattern of contraction toward the niche core in declining species. We develop and apply a novel approach to show that these niche contractions are driven by losses in a subset of niche space, suggesting population extinctions due to chytrid are driven by factors shaping both pathogen fitness (threat impact) and host fitness (threat tolerance). Species declines have been concentrated in high elevation areas with cooler temperatures, which are more physiologically suitable for the pathogen and constrain the resilience of frog hosts at both individual and population levels. Given the contrast between our results and widespread ecological marginalization in mammals, we propose that while a given threat may result in common patterns of decline among affected species, patterns of decline may vary considerably between threatening processes and among taxa.
{"title":"An invasive pathogen generally contracts species to their niche cores, not margins","authors":"Ben C. Scheele, Geoffrey W. Heard, Richard P. Duncan, Simon Clulow, Jarrod Sopniewski","doi":"10.1111/ecog.07612","DOIUrl":"https://doi.org/10.1111/ecog.07612","url":null,"abstract":"Quantifying how species' distributions contract in response to threats can reveal pathways of decline and the role of environmental conditions in moderating threat impacts. Two general patterns of niche contraction have been described: ecological marginalization, where species contract away from threat impacts to peripheral, sub-optimal areas of their niche, and; contraction to the core, where species contract toward their niche center where their fitness and capacity to withstand threat impacts is highest. Recent work has described widespread ecological marginalization in declining mammal species, for which land use change and overexploitation are key threats. Different threatening processes could result in contrasting patterns of niche contraction, although this has not been well-studied. Here, we examine patterns of realized niche contraction in Australian frog species impacted by the emergence of chytrid fungus <i>Batrachochytrium dendrobatidis</i>, a pathogen that has driven catastrophic amphibian declines globally. We quantified changes in species' environmental niche space following chytrid emergence and documented a pattern of contraction toward the niche core in declining species. We develop and apply a novel approach to show that these niche contractions are driven by losses in a subset of niche space, suggesting population extinctions due to chytrid are driven by factors shaping both pathogen fitness (threat impact) and host fitness (threat tolerance). Species declines have been concentrated in high elevation areas with cooler temperatures, which are more physiologically suitable for the pathogen and constrain the resilience of frog hosts at both individual and population levels. Given the contrast between our results and widespread ecological marginalization in mammals, we propose that while a given threat may result in common patterns of decline among affected species, patterns of decline may vary considerably between threatening processes and among taxa.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"12 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143050868","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alejandro López-de Sancha, Lluís Benejam, Dani Boix, Lars Briggs, Maria Cuenca-Cambronero, Thomas A. Davidson, Luc De Meester, Julie C. Fahy, Pieter Lemmens, Beatriz Martin, Thomas Mehner, Beat Oertli, Marzenna Rasmussen, Helen M. Greaves, Carl Sayer, Meryem Beklioğlu, Rein Brys, Sandra Brucet
Amphibians are commonly occurring inhabitants of most lentic freshwater ecosystems, yet their global populations are in alarming decline. Ponds in particular play a crucial role in supporting amphibian biodiversity. In this study, we identified the main drivers influencing amphibian species richness by conducting a comprehensive ecological characterization in 201 ponds across seven European countries spanning a large latitudinal and longitudinal gradient. The amphibian species richness in each of these ponds was assessed using environmental DNA metabarcoding on water samples. The relative influence of climatic, local abiotic and biotic, and land use variables on variation in species richness across ponds was quantified using boosted regression trees. Our results suggest that local factors, particularly chlorophyll-a concentration, but also pond area and depth, are the main drivers of amphibian richness, together with climatic variables such as annual mean precipitation and temperature. The highest richness was observed in low-nutrient, fishless, intermediate-sized, shallow ponds, located in warmer regions with higher precipitation rates. These potential drivers of amphibian richness should be considered in the planning and implementation of amphibian conservation and management actions.
{"title":"Drivers of amphibian species richness in European ponds","authors":"Alejandro López-de Sancha, Lluís Benejam, Dani Boix, Lars Briggs, Maria Cuenca-Cambronero, Thomas A. Davidson, Luc De Meester, Julie C. Fahy, Pieter Lemmens, Beatriz Martin, Thomas Mehner, Beat Oertli, Marzenna Rasmussen, Helen M. Greaves, Carl Sayer, Meryem Beklioğlu, Rein Brys, Sandra Brucet","doi":"10.1111/ecog.07347","DOIUrl":"https://doi.org/10.1111/ecog.07347","url":null,"abstract":"Amphibians are commonly occurring inhabitants of most lentic freshwater ecosystems, yet their global populations are in alarming decline. Ponds in particular play a crucial role in supporting amphibian biodiversity. In this study, we identified the main drivers influencing amphibian species richness by conducting a comprehensive ecological characterization in 201 ponds across seven European countries spanning a large latitudinal and longitudinal gradient. The amphibian species richness in each of these ponds was assessed using environmental DNA metabarcoding on water samples. The relative influence of climatic, local abiotic and biotic, and land use variables on variation in species richness across ponds was quantified using boosted regression trees. Our results suggest that local factors, particularly chlorophyll-a concentration, but also pond area and depth, are the main drivers of amphibian richness, together with climatic variables such as annual mean precipitation and temperature. The highest richness was observed in low-nutrient, fishless, intermediate-sized, shallow ponds, located in warmer regions with higher precipitation rates. These potential drivers of amphibian richness should be considered in the planning and implementation of amphibian conservation and management actions.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"11 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Borja Rodríguez-Lozano, Emilio Rodríguez-Caballero, and Yolanda Cantón
Water scarcity poses a significant life constraint in global drylands that determines species adaptations and mosaic of exposed bare areas and vegetation patches. Runoff-water redistribution resulting from this spatial configuration has been suggested as a key process controlling water availability for vegetation and ecosystem functioning. However, the potential of this process to ameliorate the negative impacts of aridification in drylands remains unclear, and there is no empirical evidence of its relevance on natural ecosystems under different levels of aridity and disturbance regimes. To address this gap, we analysed temporal series of the normalized vegetation index (NDVI, a proxy of vegetation functioning) along a regional aridity–disturbance gradient under current and future climatic conditions. We found that mean NDVI increases in areas of runoff water accumulation (calculated using a water redistribution index) until a certain threshold, above which vegetation patches are not able to retain extra runoff water. Once thresholds were identified, we analysed the role of water redistribution on vegetation dynamics by analysing temporal series of monthly NDVI in a space–for–time substitution approach. The obtained results provided further evidence of the runoff water redistribution on vegetation, triggering a positive feedback between water accumulation and vegetation growth. Results obtained by the combination of the obtained model with climatic data from the 6th IPCC report suggest that this feedback could ameliorate the expected negative effects of aridification in drylands. However, this effect is partially counterbalanced in scenarios of high human disturbance and in areas where vegetation is not able to trap and retain the extra amount of resources given by runoff. Overall, our results provide empirical evidence of the relevance of runoff redistribution as a key process linking vegetation patterns to climate resistance in drylands that underscores its importance in the analysis and modelling of drylands' responses to aridification.
{"title":"Resource redistribution mediated by hydrological connectivity modulates vegetation response to aridification in drylands","authors":"Borja Rodríguez-Lozano, Emilio Rodríguez-Caballero, and Yolanda Cantón","doi":"10.1111/ecog.07650","DOIUrl":"https://doi.org/10.1111/ecog.07650","url":null,"abstract":"Water scarcity poses a significant life constraint in global drylands that determines species adaptations and mosaic of exposed bare areas and vegetation patches. Runoff-water redistribution resulting from this spatial configuration has been suggested as a key process controlling water availability for vegetation and ecosystem functioning. However, the potential of this process to ameliorate the negative impacts of aridification in drylands remains unclear, and there is no empirical evidence of its relevance on natural ecosystems under different levels of aridity and disturbance regimes. To address this gap, we analysed temporal series of the normalized vegetation index (NDVI, a proxy of vegetation functioning) along a regional aridity–disturbance gradient under current and future climatic conditions. We found that mean NDVI increases in areas of runoff water accumulation (calculated using a water redistribution index) until a certain threshold, above which vegetation patches are not able to retain extra runoff water. Once thresholds were identified, we analysed the role of water redistribution on vegetation dynamics by analysing temporal series of monthly NDVI in a space–for–time substitution approach. The obtained results provided further evidence of the runoff water redistribution on vegetation, triggering a positive feedback between water accumulation and vegetation growth. Results obtained by the combination of the obtained model with climatic data from the 6th IPCC report suggest that this feedback could ameliorate the expected negative effects of aridification in drylands. However, this effect is partially counterbalanced in scenarios of high human disturbance and in areas where vegetation is not able to trap and retain the extra amount of resources given by runoff. Overall, our results provide empirical evidence of the relevance of runoff redistribution as a key process linking vegetation patterns to climate resistance in drylands that underscores its importance in the analysis and modelling of drylands' responses to aridification.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"1 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
José P. Queirós, Philip R. Hollyman, Paco Bustamante, Diana Vaz, Mark Belchier, José C. Xavier
Food-webs are a major component of ecosystems and determinant for their functioning and structure. The food chain length (FCL) is a key feature of food-webs and it is crucial for the resistance of the community to external stressors. The Southern Ocean (SO) food-web is known for being short and dominated by an Antarctic krill Euphausia superba surplus, though recent studies proved the existence of different pathways. However, previous studies focused on the pelagic realm, with the deep-sea and benthopelagic coupling remaining poorly understood. Using stable isotopes of δ13C and δ15N in muscle from individuals collected during toothfish fishing seasons 2020, 2021 and 2022, we 1) studied the bathyal food-web structure at South Sandwich Islands; 2) evaluated the interannual variability of FCL; and 3) tested which FCL hypothesis better explains the variability at the SO deep-sea. Our results show that this food-web is composed of five trophic levels with both Patagonian Dissostichus eleginoides and Antarctic Dissostichus mawsoni toothfish as top predators. The 4th and 5th trophic levels are mostly composed of fish, while in the 3rd trophic level we mainly found cephalopods and crustaceans. The benthopelagic coupling occurs at different trophic levels, though mostly between the 3rd and 4th trophic level. The FCL varied between years, being in 2022 0.30 trophic levels shorter than in 2020. Our results suggest that food-webs including a benthic component are longer than pelagic and coastal SO food-webs. The FCL is positively related with net primary productivity, supporting that the productivity hypothesis explains the variability in FCL in SO bathyal food-webs in slope and seamount areas. With climate change, the productivity in the SO is expected to increase which will increase the length of the food-web. This change will affect the structure of the ecosystem, increasing assimilation losses, exposure to biomagnifying contaminants and changing nutrient cycles.
{"title":"Deep-sea food-web structure at South Sandwich Islands (Southern Ocean): net primary production as a main driver for interannual changes","authors":"José P. Queirós, Philip R. Hollyman, Paco Bustamante, Diana Vaz, Mark Belchier, José C. Xavier","doi":"10.1111/ecog.07263","DOIUrl":"https://doi.org/10.1111/ecog.07263","url":null,"abstract":"Food-webs are a major component of ecosystems and determinant for their functioning and structure. The food chain length (FCL) is a key feature of food-webs and it is crucial for the resistance of the community to external stressors. The Southern Ocean (SO) food-web is known for being short and dominated by an Antarctic krill <i>Euphausia superba</i> surplus, though recent studies proved the existence of different pathways. However, previous studies focused on the pelagic realm, with the deep-sea and benthopelagic coupling remaining poorly understood. Using stable isotopes of δ<sup>13</sup>C and δ<sup>15</sup>N in muscle from individuals collected during toothfish fishing seasons 2020, 2021 and 2022, we 1) studied the bathyal food-web structure at South Sandwich Islands; 2) evaluated the interannual variability of FCL; and 3) tested which FCL hypothesis better explains the variability at the SO deep-sea. Our results show that this food-web is composed of five trophic levels with both Patagonian <i>Dissostichus eleginoides</i> and Antarctic <i>Dissostichus mawsoni</i> toothfish as top predators. The 4th and 5th trophic levels are mostly composed of fish, while in the 3rd trophic level we mainly found cephalopods and crustaceans. The benthopelagic coupling occurs at different trophic levels, though mostly between the 3rd and 4th trophic level. The FCL varied between years, being in 2022 0.30 trophic levels shorter than in 2020. Our results suggest that food-webs including a benthic component are longer than pelagic and coastal SO food-webs. The FCL is positively related with net primary productivity, supporting that the productivity hypothesis explains the variability in FCL in SO bathyal food-webs in slope and seamount areas. With climate change, the productivity in the SO is expected to increase which will increase the length of the food-web. This change will affect the structure of the ecosystem, increasing assimilation losses, exposure to biomagnifying contaminants and changing nutrient cycles.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"1 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Don-Jean Léandri-Breton, Kyle H. Elliott, Arnaud Tarroux, Pierre Legagneux, William Jouanneau, Françoise Amélineau, Frédéric Angelier, Pierre Blévin, Vegard Sandøy Bråthen, Per Fauchald, Geir W. Gabrielsen, Aurélie Goutte, Sabrina Tartu, Børge Moe, Olivier Chastel
Understanding variation in animal distributions is a central and challenging question in ecology that has become particularly critical in the context of global environmental changes. While distributions are often studied for resident or breeding species, species range limits are equally important for migratory species in winter when population regulation may occur due to limited resources in the non-breeding season. A central hypothesis in several theories is that the density, fitness and performance of individuals decrease towards the edge of the range as organisms become maladapted when approaching the limit of their environmental tolerance (‘abundant centre hypothesis'). Energy is a critical resource, especially in winter when environmental conditions deteriorate, and this hypothesis predicts that high energy expenditure (low performance) at the range limit would lead to rapidly dwindling body mass and reduced fitness. We investigated this hypothesis in an Arctic-breeding seabird wintering in the North Atlantic, the black-legged kittiwake Rissa tridactyla. From 2008 to 2019, we tracked 117 adult kittiwakes (n = 176 tracks) with geolocation devices and saltwater immersion sensors to estimate the migratory strategies, time–activity budget and energy expenditure of individuals during winter, and estimated their reproductive success after their return to the colony during summer. Population density was indeed higher towards the centre of the range. However, contrary to the predictions, the energy expenditure of individuals was higher at the centre of the range and decreased towards the edge. In contrast, there were no spatial differences in the reproductive success of individuals wintering at the centre versus at the edge of their range. We conclude that performance and fitness did not increase towards the centre of the wintering range, implying that although resource acquisition was likely higher at the abundant centre, energy expenditure was also higher, so that individual fitness was constant across the winter range.
{"title":"Testing the abundant centre hypothesis in a seabird: higher energy expenditure at the wintering range centre does not reduce reproductive success","authors":"Don-Jean Léandri-Breton, Kyle H. Elliott, Arnaud Tarroux, Pierre Legagneux, William Jouanneau, Françoise Amélineau, Frédéric Angelier, Pierre Blévin, Vegard Sandøy Bråthen, Per Fauchald, Geir W. Gabrielsen, Aurélie Goutte, Sabrina Tartu, Børge Moe, Olivier Chastel","doi":"10.1111/ecog.07498","DOIUrl":"https://doi.org/10.1111/ecog.07498","url":null,"abstract":"Understanding variation in animal distributions is a central and challenging question in ecology that has become particularly critical in the context of global environmental changes. While distributions are often studied for resident or breeding species, species range limits are equally important for migratory species in winter when population regulation may occur due to limited resources in the non-breeding season. A central hypothesis in several theories is that the density, fitness and performance of individuals decrease towards the edge of the range as organisms become maladapted when approaching the limit of their environmental tolerance (‘abundant centre hypothesis'). Energy is a critical resource, especially in winter when environmental conditions deteriorate, and this hypothesis predicts that high energy expenditure (low performance) at the range limit would lead to rapidly dwindling body mass and reduced fitness. We investigated this hypothesis in an Arctic-breeding seabird wintering in the North Atlantic, the black-legged kittiwake <i>Rissa tridactyla</i>. From 2008 to 2019, we tracked 117 adult kittiwakes (n = 176 tracks) with geolocation devices and saltwater immersion sensors to estimate the migratory strategies, time–activity budget and energy expenditure of individuals during winter, and estimated their reproductive success after their return to the colony during summer. Population density was indeed higher towards the centre of the range. However, contrary to the predictions, the energy expenditure of individuals was higher at the centre of the range and decreased towards the edge. In contrast, there were no spatial differences in the reproductive success of individuals wintering at the centre versus at the edge of their range. We conclude that performance and fitness did not increase towards the centre of the wintering range, implying that although resource acquisition was likely higher at the abundant centre, energy expenditure was also higher, so that individual fitness was constant across the winter range.","PeriodicalId":51026,"journal":{"name":"Ecography","volume":"85 5 1","pages":""},"PeriodicalIF":5.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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