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Land-use changes and the expansion of protected areas (PAs) have fostered increased interactions between humans and wildlife, resulting in an escalation of human-wildlife conflict (HWC) globally. However, HWC spatiotemporal pattern variation and its associations with PAs and land-use change remain poorly understood. To address this knowledge gap, we mapped and analyzed HWCs from 1990 to 2022 across China. We comprehensively mapped the spatiotemporal dynamics of HWCs in ArcGIS with data sets stratified by county, year, and species; assessed the impact of PAs through propensity score matching; and analyzed the effects of habitat transformation with linear mixed models. As PA increased from 0 to 20,000 km2, the likelihood of HWCs initially increased (50%) before declining (20%). Conversely, as the distance from a PA grew, the likelihood of HWC gradually decreased (0 beyond 65 km). There was a temporal lag between the establishment of a PA and the occurrence of HWC. Habitat loss catalyzed HWCs, whereas decreased levels of habitat fragmentation sometimes initially caused a temporary increase in HWCs. In general, the distribution of PAs greatly affected HWC occurrence, and habitat loss and fragmentation were critical drivers of HWCs, both of which exhibited time-lagged effects. HWC has become more challenging to address as conservation initiatives have led to significant recovery of the habitats and populations of wild animals. Further measures to address the HWCs are needed to ensure the preservation of animal welfare while fostering the mutually beneficial coexistence of humans and animal species. Finally, our study provides an important starting point for informing future HWC research and conservation planning on a global scale.
Efectos de la expansión de las áreas protegidas y la transformación del hábitat sobre la variación espaciotemporal en el conflicto humanofauna Resumen Los cambios en el uso del suelo y la expansión de las áreas protegidas (AP) han fomentado un aumento de las interacciones entre los humanos y la vida silvestre, lo que ha dado lugar a una escalada de los conflictos entre humanos y la fauna (CHF)) en todo el mundo. Sin embargo, todavía conocemos poco sobre la variación de los patrones espaciotemporales de estos conflictos y su relación con las áreas protegidas y los cambios en el uso del suelo. Para abordar este vacío de conocimiento, mapeamos y analizamos los CHF desde 1990 hasta 2022 en toda China. Mapeamos de forma exhaustiva la dinámica espaciotemporal de los CHF en ArcGIS con conjuntos de datos estratificados por condado, año y especie; evaluamos el impacto de las AP mediante el emparejamiento de puntuaciones de propensión y analizamos los efectos de la transformación del hábitat con modelos lineales mixtos. A medida que la superficie protegida aumentaba de 0 a 20,000 km2, la probabilidad de CHF aumentaba inicialmente (50%) antes de disminuir (20%). Por el contrario, a medida que aumentaba la distancia a un AP, la probabilidad de CHF disminuía gradualmente (de 0 a más allá de 65 km). Hubo un desfase temporal entre el establecimiento de un AP y la aparición de CHF. La pérdida de hábitat catalizó los CHF, mientras que la disminución de los niveles de fragmentación del hábitat a veces causó inicialmente un aumento temporal de los CHF. En general, la distribución de las áreas protegidas afectó en gran medida a la aparición de los CHF y la pérdida y fragmentación del hábitat fueron factores determinantes en los CHF, ambos con efectos retardados. Los conflictos entre el hombre y la fauna se han vuelto más difíciles de abordar, ya que las iniciativas de conservación han llevado a una recuperación significativa de los hábitats y las poblaciones de animales salvajes. Es necesario adoptar nuevas medidas para abordar estos conflictos, a fin de preservar el bienestar de los animales y fomentar al mismo tiempo una coexistencia de beneficio mutuo entre los humanos y la fauna. Por último, nuestro estudio ofrece un importante punto de partida para fundamentar futuras investigaciones sobre los CHF y la planificación de su conservación a escala mundial.
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Identifying the main predictors of species' extinction risk while accounting for the effects of spatial and phylogenetic structures in the data is key to preventing species loss in tropical forests through adequate conservation practices. We recorded 22 705 precise geographical locations of primate occurrence across four major geographic realms (Neotropics, mainland Africa, Madagascar and Asia) to assess predictors of threat status using a novel Bayesian spatio-phylogenetic approach. We estimated the relative contributions of fixed factors (forest amount, body mass, home range, diel activity, locomotion, evolutionary distinctiveness and climatic instability) and random factors (space and phylogeny) to primate extinction risk. Precipitation instability increased the extinction risk in the Neotropics but decreased it in mainland Africa and Madagascar. Forest amount was negatively associated with extinction risk in all realms except Madagascar. Body mass increased the extinction risk in the Neotropics and Madagascar, whereas home range increased the extinction risk in mainland Africa and decreased it in Asia. Evolutionary distinctiveness negatively influenced extinction risk only in mainland Africa. Our findings highlight the importance of climate change mitigation and forest protection strategies. Increasing the protection of large primates and reducing hunting are also essential.
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Cambio Climático , Extinción Biológica , Primates , Animales , Primates/fisiología , Filogenia , Conservación de los Recursos Naturales , Teorema de Bayes , Bosques , África , Asia , MadagascarRESUMEN
Habitat loss is one of the primary drivers of large felid decline. The leopard (Panthera pardus), a generalist large felid species, has the behavioural and dietary flexibility to exploit different habitat types of varying human influence. Understanding habitat selection in a shared landscape is critical for the development of conservation strategies and managing negative human-leopard interactions. The development of conservation policy requires data on large spatial scales, which is mostly lacking, especially within shared landscapes in India. This study aims to determine habitat selection by Indian leopards and the anthropogenic, environmental, and climatic variables contributing to this selection. Leopard occurrence records were obtained from an occupancy survey conducted in the five administrative districts in Karnataka (28,375 km2). 267 randomly selected 30 km2 grids were each walked for 10 km and all leopard signs were recorded. Environment variables were chosen to reflect land use, climatic, topographic, and human disturbances that could affect habitat selection at a resolution of 0.1 km2. The mean ensemble model was projected to the state of Karnataka. Habitat selection predicted by the ensemble model was driven by proximity to forest cover and rocky outcrops, higher precipitation, and negatively by distance to cropland and roads. Protected Areas and Reserved Forests in the study covered 47% of the predicted habitat, while 25% is within human-use areas such as human habitation and croplands. This study predicts that half of the habitat selected by leopards is outside of protected areas and reserved forests. The selection of human-use areas is predicted because of the availability of cover from irrigated croplands and the proximity to natural cover that provides refuge. Livestock density did not drive large-scale habitat selection. The preservation of natural cover and rocky outcrops that provide refuge between protected areas is paramount for leopard conservation.
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Human disturbance compromises the ecological integrity of forests, negatively affecting associated species. Assessing the impact of forest integrity on biodiversity is complex due to the interplay of various human activities, ecological factors, and their interactions. Current large-scale indices assess forest integrity but often lack a direct connection to the biotic environment. We tested the effectiveness of the global Forest Landscape Integrity Index (FLII) in evaluating aspects of anthropogenic forest degradation on the biotic community. We analyzed the relationship between changes in the ecological integrity of Finnish forests and variations in mammal species abundance, using the number of tracks from 17 different species collected during the winter seasons between 2016 and 2020 in south-central Finland. Beyond the FLII, we analyzed forest and canopy cover to enhance the accuracy of habitat preference assessments. We found that the FLII captures the varying degrees of forest integrity, as reflected by the correlation between the abundance of winter tracks and the FLII for most mammals. Species that were positively associated with forest integrity were all native to the boreal forest, while mammals that adapt well to human-disturbed environments including two invasive species were more common in lower FLII forests. Significant differences in habitat preferences were also observed in relation to forest and canopy cover, revealing additional nuances that the FLII alone did not capture. This study demonstrates that the FLII, when combined with a comprehensive dataset and supplemented with region-specific factors, can assess species' adaptability to human-modified forests, aiding in the development of conservation strategies.
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Biodiversidad , Ecosistema , Bosques , Mamíferos , Animales , Finlandia , HumanosRESUMEN
The distribution of species in a patchy habitat may be influenced by competitive interactions. The dominant and highly competitive boreal ant species belong to the Formica rufa group. A pair of species, Formica aquilonia and Formica polyctena, require extensive territories due to their multi-nest breeding habits. The coexistence and habitat patterns of these two wood ant species in the boreal forest landscape were investigated. Forest characteristics in the vicinity of nests in forest patches were similar for both species, but they did not coexist in the same sampling plots of 0.79 ha in forest patches, indicating competitive exclusion. The sampling plots in large forest patches were more occupied by F. aquilonia, while no such association was found for F. polyctena. At a larger spatial scale (78.5 ha), we found that F. polyctena was more tolerant of smaller forest patches than F. aquilonia suggesting that these two ant species can coexist in moderately fragmented forest landscapes. However, forest habitat loss, fragmentation and climate-induced changes in forest tree structure may shift the species balance in favour of F. polyctena over F. aquilonia in the future.
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Hormigas , Ecosistema , Bosques , Animales , Taiga , Territorialidad , Especificidad de la EspecieRESUMEN
Chemical pollution, land cover change, and climate change have all been established as important drivers of amphibian reproductive success and phenology. However, little is known about the relative impacts of these anthropogenic stressors, nor how they may interact to alter amphibian population dynamics. Addressing this gap in our knowledge is important, as it allows us to identify and prioritise the most needed conservation actions. Here, we use long-term datasets to investigate landscape-scale drivers of variation in the reproductive success and phenology of UK Common frog (Rana temporaria) populations. Consistent with predictions, we found that increasing mean temperatures resulted in earlier initialisation of spawning, and earlier hatching, but these relationships were not consistent across all sites. Lower temperatures were also linked to increased spawn mortality. However, temperature increases were also strongly correlated with increases in urban area, arable area, and nitrate levels in the vicinity of spawning grounds. As with spawning and hatching, there was marked spatial variation in spawn mortality trends, where some sites exhibited steady increases over time in the proportion of dead or diseased spawn. These findings support previous work linking warming temperatures to shifts in timing of amphibian breeding, but also highlight the importance of assessing the effect of land use change and pollution on wild amphibian populations. These results have implications for our understanding of the response of wild amphibian populations to climate change, and the management of human-dominated landscapes for declining wildlife populations.
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Cambio Climático , Rana temporaria , Reproducción , Temperatura , Animales , Reproducción/fisiología , Dinámica PoblacionalRESUMEN
BACKGROUND: Forestry and land-use change are leading causes of habitat loss, degradation, and fragmentation worldwide. The boreal forest biome is no exception, and only a small proportion of this forest type remains intact. Since forestry will remain a major land-use in this region, measures must be taken to ensure forest dependent biodiversity. Stand level features and structures promoting conservation relevant species have received much attention, but the landscape level perspective is often missing. Hence, we review the literature that has related fragmentation in the surrounding landscape to occurrence of threatened, declining, red-listed, rare, or deadwood dependent species as well as those considered to be indicator, flagship, umbrella, and/or keystone species in a given boreal forest stand. METHODS: A comprehensive search string was developed, benchmarked, and adapted for four bibliographic databases, two search engines, and 37 specialist websites. The online evidence synthesis tool Cadima was used for screening of both abstracts and full texts. All articles meeting the inclusion criteria were subject to study validity assessment and included in a narrative table. Studies reporting means and variance were included in quantitative meta-analysis when more than 3 comparable studies were available. RESULTS: The searches resulted in 20 890 unique articles that were reduced to 172 studies from 153 articles. These studies related stand level presence, abundance, species richness, and/or composition of conservation relevant species to landscape factors such as: categorical fragmentation intensity (higher vs. lower), amount of habitat or non-habitat, distance to habitat, and/or habitat configuration, on scales ranging from tens to tens of thousands of ha. Forty-three studies were suitable for meta-analysis. These showed a significant negative effect of fragmentation on both presence and abundance of conservation relevant species, as well as a near significant trend for species richness. This was particularly clear when fragmentation was measured as distance to surrounding habitat for presence, and as habitat amount for abundance. The organism groups with the strongest support for a negative effect of fragmentation were wood fungi and birds. CONCLUSION: As hypothesised, there is strong support for negative effects of fragmentation in boreal forest. These results emphasize the negative consequences of the intensive forestry and associated landscape transformation that has been the norm for the last century. We argue that this should have direct implications for policy makers to shift towards including a landscape perspective in all planning of harvesting, preserving, and restoring forest. In addition, we found that research effort has been very uneven between organism groups, that studies on landscape change over time were rare, and that many studies have not quantified the difference in fragmentation intensity among landscapes making it difficult to quantify the extent of the negative effect. One way forward would be to revisit the studies included here in to incorporate change over time, as well as a true quantification of landscape fragmentation. By doing so, the scale of the negative effects would be much better analysed, which would greatly assist conservation practitioners all throughout the boreal forest biome.
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Amphibians are experiencing severe population declines, requiring targeted conservation action for the most threatened species and habitats. Unfortunately, we do not know the basic demographic traits of most species, which hinders population recovery efforts. We studied one of Madagascar's most threatened frog species, the harlequin mantella (Mantella cowanii), to confirm it is still present at historic localities and estimate annual survival and population sizes. We surveyed eleven of all thirteen known localities and were able to detect the species at eight. Using a naïve estimate of detection probability from sites with confirmed presence, we estimated 1.54 surveys (95% CI [1.10-2.37]) are needed to infer absence with 95% confidence, suggesting the three populations where we did not detect M. cowanii are now extirpated. However, we also report two new populations for the first time. Repeated annual surveys at three sites showed population sizes ranged from 13-137 adults over 3-8 years, with the most intensively surveyed site experiencing a >80% reduction in population size during 2015-2023. Annual adult survival was moderately high (0.529-0.618) and we recaptured five individuals in 2022 and one in 2023 first captured as adults in 2015, revealing the maximum lifespan of the species in nature can reach 9 years and beyond. Our results confirm M. cowanii is characterized by a slower life history pace than other Mantella species, putting it at greater extinction risk. Illegal collection for the international pet trade and continued habitat degradation are the main threats to the species. We recommend conservation efforts continue monitoring M. cowanii populations and reassess the International Union for Conservation of Nature (IUCN) Red List status because the species may be Critically Endangered rather than Endangered based on population size and trends.
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Anuros , Conservación de los Recursos Naturales , Especies en Peligro de Extinción , Densidad de Población , Animales , Madagascar , Extinción Biológica , Ecosistema , Dinámica Poblacional , Ranas VenenosasRESUMEN
Projections for deep decarbonization require large amounts of solar energy, which may compete with other land uses such as agriculture, urbanization, and conservation of natural lands. Existing capacity expansion models do not integrate land use land cover change (LULC) dynamics into projections. We explored the interaction between projected LULC, solar photovoltaic (PV) deployment, and solar impacts on natural lands and croplands by integrating projections of LULC with a model that can project future deployment of solar PV with high spatial resolution for the conterminous United States. We used scenarios of LULC projections from the Intergovernmental Panel on Climate Change Special Report on Emission Scenarios from 2010 to 2050 and two electricity grid scenarios to model future PV deployment and compared those results against a baseline that held 2010 land cover constant through 2050. Though solar PV's overall technical potential was minimally impacted by LULC scenarios, deployed PV varied by -16.5 to 11.6 % in 2050 from the baseline scenario. Total land requirements for projected PV were similar to other studies, but measures of PV impacts on natural systems depended on the underlying land change dynamics occurring in a scenario. The solar PV deployed through 2050 resulted in 1.1 %-2.4 % of croplands and 0.3 %-0.7 % of natural lands being converted to PV. However, the deepest understanding of PV impacts and interactions with land cover emerged when the complete net gains and losses from all land cover change dynamics, including PV, were integrated. For example, one of the four LULC projections allows for high solar development and a net gain in natural lands, even though PV drives a larger percentage of natural land conversion. This paper shows that integrating land cover change dynamics with energy expansion models generates new insights into trade offs between decarbonization, impacts of renewables, and ongoing land cover change.
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Habitat loss and change are often implicated as the primary causes of species extinction. Although any population can be instantly imperiled by catastrophe, most habitat loss occurs gradually, thus enabling affected individuals an adaptive advantage to occupy the best of their dwindling opportunities. I demonstrate how to infer the advantage between two habitats for any density and frequency-dependent strategy of habitat selection. I explore the concept of an Adaptive Dispersal Strategy Landscape to reveal the Evolutionarily Stable Strategy separately for ideal-free and ideal preemptive habitat selectors. Both solutions reveal an initially counterintuitive expectation that individuals living at high density gain insufficient adaptive advantage to disperse from a deteriorating habitat. Adaptive dispersal is constrained at high density because habitats of better quality are fully occupied. I test the theory with measures of movement and foraging in crossover experiments on a seminatural population of meadow voles. The experiment allowed the voles to choose among patches and between enclosures in which I differentially manipulated food and shelter. Although photographs from an infrared camera documented voles venturing from one habitat to the other, none became resident. Voles preferentially foraged in the richer of the two enclosures, even when I reversed treatments, and they foraged more in patches protected by mulched straw. The adaptive advantage of dispersal using a surrogate fitness proxy based on the voles' giving-up densities mirrored that generated by theory. The convergence between theory and experiment yields much-needed insight into our ability to test, predict, and hopefully resolve, the ecological, evolutionary, and conservation consequences of habitat loss.
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Ecosistema , Animales , Arvicolinae/fisiología , Adaptación Fisiológica , Modelos BiológicosRESUMEN
Recent international agreements have strengthened and expanded commitments to protect and restore native habitats for biodiversity protection ("area-based biodiversity conservation"). Nevertheless, biodiversity conservation is hindered because how such commitments should be implemented has been strongly debated, which can lead to suboptimal habitat protection decisions. We argue that, despite the debates, there are three essential principles for area-based biodiversity conservation. These principles are related to habitat geographic coverage, amount, and connectivity. They emerge from evidence that, while large areas of nature are important and must be protected, conservation or restoration of multiple small habitat patches is also critical for global conservation, particularly in regions with high land use. We contend that the many area-based conservation initiatives expected in the coming decades should follow the principles we identify, regardless of ongoing debates. Considering the importance of biodiversity for maintenance of ecosystem services, we suggest that this would bring widespread societal benefits.
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Biodiversidad , Conservación de los Recursos Naturales , Conservación de los Recursos Naturales/métodos , EcosistemaRESUMEN
Protected areas (PAs) serve as effective means for biodiversity conservation but face threats from habitat loss and fragmentation. Current research on the impact of habitat loss or habitat fragmentation on biodiversity in PAs mostly focuses on individual PA or regional scales. At the global scale, the extent of habitat loss and fragmentation in PAs and their effects on biodiversity remains unclear. Therefore, we investigated the degree of habitat loss and fragmentation in global PAs from 2000 to 2020, analyzed the impact of habitat loss and fragmentation on biodiversity in PAs, identified hotspot PAs of severe habitat loss or fragmentation, and highlighted critically endangered species within these PAs. Our study reveals that, between 2000 and 2020, 19 % of global PAs experienced habitat loss, and 34 % experienced habitat fragmentation, with large PAs and South American tropical PAs exhibiting the most severe levels of habitat loss and fragmentation. The impact of habitat loss and fragmentation on biodiversity was most significant in small PAs and African tropical PAs. There are 10 global hotspot PAs of habitat loss or fragmentation, posing a serious threat to the survival of endangered species within PAs. Biodiversity conservation remains a prominent research focus globally, and the issues of habitat loss and fragmentation in PAs may impact the achievement of the COP15 biodiversity conservation goals. Therefore, this study aims to provide data support and scientific guidance for the management and development of global PAs.
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Biodiversidad , Conservación de los Recursos Naturales , Ecosistema , Especies en Peligro de Extinción , Conservación de los Recursos Naturales/métodosRESUMEN
The endangered and poorly known Swamp Grass-babbler, Laticilla cinerascens (Passeriformes: Pellorneidae), confronts critical threats and vulnerability due to its specific habitat requirements and restricted populations in the northeastern region of the Indian Subcontinent. This study investigates the distribution of the species, habitat quality, geometry and shape complexity of connectivity among the protected areas (PAs), and responses to climate change in Northeast India under different climate change pathways by utilizing ensemble distribution models, and ecological metrics. From the total distribution extent (1,42,000 km2), approximately 9366 km2 (6.59 %) is identified as the suitable habitat for this threatened species. Historically centered around Dibru Saikhowa National Park (DSNP), the species faced a drastic decline due to anthropogenic activities and alteration in land use and lover cover. The study also reveals a significant decline in suitable habitat for L. cinerascens in future climate scenarios, with alarming reductions under SSP126 (>10 % in the timeframe 2041-2060 and > 30 % from 2061 to 2080), SSP245 (>90 % in both time periods), and SSP585 (>90 % in both timeframes) from the present scenario. At present, DSNP has the most suitable habitat within the distribution range but is projected to decline (>90 %) under more severe climate change scenarios, as observed in other PAs. Landscape fragmentation analysis indicates a shift in habitat geometry, highlighting the intricate impact of climate change. It predicts a substantial 343 % increase (in the SSP126) in small habitat patches in the future. Connectivity analysis among PAs shows a significant shift, with a decline exceeding 20 %. The analysis of shape complexity and connectivity geometry reveals a significant increase of over 220 % in the fragmentation of connectivity among PAs between 2061 and 2080 under the SSP585 climate change scenario compared to the present conditions. The study underscores the urgent need for conservation actions, emphasizing the complex interplay of climate change, habitat suitability, and fragmentation. Prioritizing PAs with suitable habitats and assessing their connectivity is crucial. Adaptive management strategies are essential to address ongoing environmental changes and safeguard biodiversity. Future research in critical areas is needed to establish long-term monitoring programs to lead/extend effective conservation strategies.
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Understanding how human-modified landscapes maintain biodiversity and provide ecosystem services is crucial for establishing conservation practices. Given that responses to land-use are species-specific, it is crucial to understand how land-use changes may shape patterns of species diversity and persistence in human-modified landscapes. Here, we used a comprehensive data set on bird distribution from the Brazilian Atlantic Forest to understand how species richness and individual occurrences of frugivorous bird species responded to land-use spatial predictors and, subsequently, assess how ecological traits and phylogeny modulated these responses. Using Bayesian hierarchical modeling, we reveal that the richness of frugivorous birds was positively associated with the amount of native forest and negatively with both agriculture and pasture amount at the landscape scale. Conversely, the effect of these predictors on species occurrence and ecological traits was highly variable and presented a weak phylogenetic signal. Furthermore, land-use homogenization (i.e., the conversion of forest to pasture or agriculture) led to pervasive consequences for forest-dependent bird species, whereas several generalist species thrived in deforested areas, replacing those sensitive to habitat disturbances.
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Agricultura , Biodiversidad , Aves , Animales , Aves/fisiología , Brasil , Clima Tropical , Conservación de los Recursos Naturales/métodos , Bosques , FrutasRESUMEN
Moroccan wetlands host up to half a million wintering birds and provide a stopover for tens of thousands of migrants, while they are inhabited by few nesting species. Most of this avifauna prefers to use the large coastal wetlands or reservoirs, while many species are dispersed across hundreds of small inland wetlands of various types. In this study, we monitored the wintering avifauna of 11 wetlands of the Saïss plain and its adjacent Atlas Mountains (north-center of Morocco), during six wintering seasons (2017-2018 to 2022-2023), with the objective of assessing the importance of this region as a waterbird wintering area. Using the richness of the species, we determine the bird population changes during this pentad and between the different types of wetlands (natural, human-made, and natural wetlands). During this study, we recorded 51 species, belonging to 17 families, among which exist four remarkable birds: the endangered Oxyura leucocephala, the vulnerable Aythya ferina and the near-threatened Aythya nyroca and Limosa limosa. Bird diversity is higher in human-made ecosystems than in peri-urban and natural ecosystems, while the populations' size is similar in urban and non-urban wetlands. With regard to bird conservation, these inland wetlands, mainly the small ones, are threatened by recurrent droughts and various anthropic stressors, which we describe using our observations of the two last decades (2003-2023). The loss of habitat is significant, reaching 348.5 hectares, while the impacts of reduced precipitation and temperature increase are particularly evident in the mountainous natural lakes.
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Climate change and land use change are two main drivers of global biodiversity decline, decreasing the genetic diversity that populations harbour and altering patterns of local adaptation. Landscape genomics allows measuring the effect of these anthropogenic disturbances on the adaptation of populations. However, both factors have rarely been considered simultaneously. Based on a set of 3660 SNPs from which 130 were identified as outliers by a genome-environment association analysis (LFMM), we modelled the spatial turnover of allele frequencies in 19 localities of Pinus leiophylla across the Avocado Belt in Michoacán state, Mexico. Then, we evaluated the effect of climate change and land use change scenarios, in addition to evaluating assisted gene flow strategies and connectivity metrics across the landscape to identify priority conservation areas for the species. We found that localities in the centre-east of the Avocado Belt would be more vulnerable to climate change, while localities in the western area are more threatened by land conversion to avocado orchards. Assisted gene flow actions could aid in mitigating both threats. Connectivity patterns among forest patches will also be modified by future habitat loss, with central and eastern parts of the Avocado Belt maintaining the highest connectivity. These results suggest that areas with the highest priority for conservation are in the eastern part of the Avocado Belt, including the Monarch Butterfly Biosphere Reserve. This work is useful as a framework that incorporates distinct layers of information to provide a more robust representation of the response of tree populations to anthropogenic disturbances.
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Cambio Climático , Flujo Génico , Persea , Pinus , Polimorfismo de Nucleótido Simple , Pinus/genética , Persea/genética , México , Frecuencia de los Genes , Adaptación Fisiológica/genética , Genética de Población , Conservación de los Recursos Naturales , Ecosistema , Variación GenéticaRESUMEN
The response of coastal wetlands to sea-level rise (SLR) largely depends on the tolerance of individual plant species to inundation stress and, in brackish and freshwater wetlands, exposure to higher salinities. Phragmites australis is a cosmopolitan wetland reed that grows in saline to freshwater marshes. P. australis has many genetically distinct haplotypes, some of which are invasive and the focus of considerable research and management. However, the relative response of P. australis haplotypes to SLR is not well known, despite the importance of predicting future distribution changes and understanding its role in marsh response and resilience to SLR. Here, we use a marsh organ experiment to test how factors associated with sea level rise-inundation and seawater exposure-affect the porewater chemistry and growth response of three P. australis haplotypes along the northern Gulf of Mexico coast. We planted three P. australis lineages (Delta, European, and Gulf) into marsh organs at five different elevations in channels at two locations, representing a low (Mississippi River Birdsfoot delta; 0-13 ppt) and high exposure to salinity (Mermentau basin; 6-18 ppt) for two growing seasons. Haplotypes responded differently to flooding and site conditions; the Delta haplotype was more resilient to high salinity, while the Gulf type was less susceptible to flood stress in the freshwater site. Survivorship across haplotypes after two growing seasons was 42% lower at the brackish site than at the freshwater site, associated with high salinity and sulfide concentrations. Flooding greater than 19% of the time led to lower survival across both sites linked to high concentrations of acetic acid in the porewater. Increased flood duration was negatively correlated with live aboveground biomass in the high-salinity site (χ2 = 10.37, p = 0.001), while no such relationship was detected in the low-salinity site, indicating that flood tolerance is greater under freshwater conditions. These results show that the vulnerability of all haplotypes of P. australis to rising sea levels depends on exposure to saline water and that a combination of flooding and salinity may help control invasive haplotypes.
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Blind mole rats (genus Nannospalax) attract a great deal of attention because of their cancer resistance and longevity. Due to the high rate of chromosome rearrangements, 74 Nannospalax chromosomal forms have been discovered. The convergence of their external morphology complicates their taxonomy, and many cryptic species remain unrecognized. Thus, the European N. leucodon supersp. is listed in the IUCN Red List of Threatened Species with "Data Deficient" status. It is crucial for the conservation of biodiversity to clarify its taxonomy, to recognize each cryptic species, and assign to them the correct conservation status. Of the more than 20 chromosomal forms described within N. leucodon, five cryptic species occur in Serbia. The most threatened among them-N. l. syrmiensis, described and named 50 years ago in the regions of Srem, Belgrade and Macva-has been declared extinct in the literature, which may have negative consequences for the conservation of wildlife genetic diversity. Through five years of fieldwork and comparison of 16SrRNA and MT-CYTB gene segments between old, archived teeth and recently collected material, we show that N. l. syrmiensis is not extinct. However, its habitat has been fragmented and reduced, owing primarily to anthropogenic impact. Therefore, detailed surveillance, population-structure studies, risk assessment, and appropriate conservation measures are needed.
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Forest loss and degradation due to land cover changes imperil biodiversity worldwide. Subtropical and tropical ecosystems experience high deforestation rates, negatively affecting species like primates. Madagascar's endemic lemurs face exceptionally high risks of population declines and extirpation. We examined how short-term land cover changes within a fragmented landscape in southeastern Madagascar impacted the density of lemur species. Using line transects, we assessed density changes in nine lemur species across five forest fragments. Diurnal surveys were conducted monthly from 2015 to 2019 on 35 transects (total effort = 1268 km). Additionally, 21 transects were surveyed nocturnally in 2015 and 2016 (total effort = 107.5 km). To quantify forest cover changes, we generated land use/land cover (LULC) maps from Sentinel-2 imagery using supervised classification for each year. For the LULC maps, we overlayed species-specific buffers around all transects and calculated the proportion of land cover classes within them. We observed declines in the annual densities of four diurnal and cathemeral lemur species between 2015 and 2019, with species-specific declines of up to 80% (Varecia variegata). While the density of two nocturnal species decreased, one increased fivefold (Cheirogaleus major) between 2015 and 2016. By 2019, Grassland was the dominant land type (50%), while Paddy Fields had the smallest coverage (1.03%). Mature Agricultural Land increased the most (63.37%), while New Agricultural Land decreased the most (-66.36%). Unexpectedly, we did not find evidence that higher forest cover supported a higher lemur population density within sampled areas, but we found support for the negative impact of degraded land cover types on three lemur species. Our study underscores the urgent need to address land-use changes and their repercussions for primate populations in tropical ecosystems. The diverse responses of lemur species to modified habitats highlight the complexity of these impacts and emphasize the importance of targeted conservation efforts.
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Habitat loss and fragmentation per se have been shown to be a major threat to global biodiversity and ecosystem function. However, little is known about how habitat loss and fragmentation per se alters the relationship between biodiversity and ecosystem function (BEF relationship) in the natural landscape context. Based on 130 landscapes identified by a stratified random sampling in the agro-pastoral ecotone of northern China, we investigated the effects of landscape context (habitat loss and fragmentation per se) on plant richness, above-ground biomass, and the relationship between them in grassland communities using a structural equation model. We found that habitat loss directly decreased plant richness and hence decreased above-ground biomass, while fragmentation per se directly increased plant richness and hence increased above-ground biomass. Fragmentation per se also directly decreased soil water content and hence decreased above-ground biomass. Meanwhile, habitat loss decreased the magnitude of the positive relationship between plant richness and above-ground biomass by reducing the percentage of grassland specialists in the community, while fragmentation per se had no significant modulating effect on this relationship. These results demonstrate that habitat loss and fragmentation per se have inconsistent effects on BEF, with the BEF relationship being modulated by landscape context. Our findings emphasise that habitat loss rather than fragmentation per se can weaken the positive BEF relationship by decreasing the degree of habitat specialisation of the community.