Extinction Risk Research Articles

Diversity and conservation status of palms (Arecaceae) in two hotspots of biodiversity in Colombia and Ecuador

Societal Impact StatementPalms provide vital plant resources and ecosystem services to people across the tropics. To improve conservation guidance, a “health check” of palms in two highly threatened biodiversity hotspots in Colombia and Ecuador was undertaken. Palms are very diverse in these regions, but over one third are threatened with extinction now, especially among endemic species. Widespread and useful palms are also under intense human pressure and need to be prioritized in terms of sustainable management practices. Given the importance of palms for humans, inclusive conservation actions should be continued in both countries in order to safeguard this resource.Summary Palms provide central plant resources to societies in the tropics, especially in the Global South. The western Pacific and Andean regions of Colombia and Ecuador host two hotspots of biodiversity. To prioritize conservation policies towards palms, we undertook a conservation assessment of species in the region. We compiled a taxonomically verified database of specimens collected in both hotspots. We inferred preliminary conservation assessments using International Union for Conservation of Nature (IUCN) Criteria B. In addition, we evaluated the level of exposure of palms to human use and population density using the anthrome concept. We documented 144 native palm species in 33 genera occurring in both hotspots of Colombia and Ecuador. Of these, 55 are endemic to this region. We recorded 133 species for Colombia, 43 endemic, and 71 species for Ecuador, 9 endemic. A third of all palm species in the region are potentially threatened with extinction (50/144) and 12 as preliminary Critically Endangered. Aiphanes and Geonoma have the highest number of threatened species. In total, 60% of palm specimens were collected in the “low human impact” anthrome type. In contrast, 41% of specimens occur in high human density areas. The two hotspots of biodiversity in Colombia and Ecuador are very diverse in palms. However, we show that this diversity is under threat and is predominantly found in areas impacted by human activities. Extinction risk is highest in endemic species in both countries. Widespread and useful palm species also face threats linked to overexploitation or habitat loss. Inclusive conservation measures should be designed to conserve, together with communities, this plant resource.

Response of Extremely Small Populations to Climate Change-A Case of Trachycarpus nanus in Yunnan, China.

Climate change affects the geographical distribution of plant species. Rare Trachycarpus nanus with a narrow distribution range, high medicinal value and extremely small population is facing increasing extinction risks under global climate change. In this study, 96 recorded occurrences and 23 environmental factors are used to predict the potential suitable area of T. nanus based on the optimized MaxEnt (3.4.4) model and ArcGIS (10.7) software. The results show that when the parameters are FC = LQ and RM = 1, the MaxEnt model is optimal and AUC = 0.946. The distribution patterns were predicted in the past, present, and four future phases, i.e., 2021-2040 (2030), 2041-2060 (2050), 2061-2080 (2070), and 2081-2100 (2090). The main factors are the annual precipitation (bio12), mean temperature of the coldest quarter (bio11), temperature seasonality (bio4), precipitation of the wettest quarter (bio16), and isothermality (bio3). The potential distribution of T. nanus is primarily concentrated in central Chuxiong, encompassing a total potential suitable area of 5.65 × 104 km2. In historical periods, the total habitat area is smaller than that in the present. In the future, the potential suitable area is generally increased. The centroid analysis shows that T. nanus will move to a high-altitude area and to the southeast. But its dispersal capacity may not keep up with the climate change rate. Therefore, additional protection sites for this species should be appropriately established and the habitat connectivity should be enhanced.

It is hot and cold here: the role of thermotolerance in the ability of spiders to colonize tree plantations in the southern Atlantic Forest.

Worldwide, with the decline of natural habitats, species with reduced niche breadth (specialists) are at greater risk of extinction as they cannot colonise or persist in disturbed habitat types. However, the role of thermal tolerance as a critical trait in understanding changes in species diversity in disturbed habitats, e.g., due to forest replacement by tree plantations, is still understudied. To examine the role of thermal tolerance on the responses of specialist and generalist species to habitat disturbances, we measured and compared local temperature throughout the year and thermotolerance traits [upper (CTmax) and lower (CTmin) thermal limits] of the most abundant species of spiders from different guilds inhabiting pine tree plantations and native Atlantic Forests in South America. Following the thermal adaptation hypothesis, we predicted that generalist species would show a wider thermal tolerance range (i.e., lower CTmin and higher CTmax) than forest specialist species. As expected, generalist species showed significantly higher CTmax and lower CTmin values than specialist species with wider thermal tolerance ranges than forest specialist species. These differences are more marked in orb weavers than in aerial hunter spiders. Our study supports the specialisation disturbance and thermal hypotheses. It highlights that habitat-specialist species are more vulnerable to environmental changes associated with vegetation structure and microclimatic conditions. Moreover, thermal tolerance is a key response trait to explain the Atlantic Forest spider's ability (or inability) to colonise and persist in human-productive land uses.

Species diversity and conservation status of ornamental fish traded in Kupang, East Nusa Tenggara, Indonesia

Abstract. Usman Z, Hariyadi DR, Serihollo LGG. 2024. Species diversity and conservation status of ornamental fish traded in Kupang, East Nusa Tenggara, Indonesia. Biodiversitas 25: 1116-1126. The high demand for ornamental fish native to Indonesia has the potential to be used as a source of foreign exchange income. In addition to increasing the national income, the ornamental fish trade must also be considered to preserve the population of the fish species being sold. The study aimed to determine ornamental fish diversity and conservation status in Kupang City, East Nusa Tenggara. This research was conducted in Kupang City, East Nusa Tenggara, Indonesia, from August to September 2023. The research was conducted using survey (non-experiment) and observation methods. The survey method was carried out using a form to conduct interviews with sellers in 11 ornamental fish shops. At the same time, the observation method was used to identify the types of fish being traded. The study's results recorded 18 families, 39 genera, and 46 fish species (Include 1 species is hybrid fish). The highest species diversity came from the Cichlidae family with 9 species (1 species (Amphilophus citrinellus x Cichlasoma trimaculatum) is hybrid fish), followed by Cyprinidae with 7 species, whereas each species of the Characidae and Poecilidae families were 5 species. Conservation status shows 4 status groupings, namely Least Concern (LC), Vulnerable (VU), Endangered (EN), and Not Evaluated (NE). Based on these groupings, there were 32 species in the Least Concern (LC) category, 3 species in the Endangered (EN) category, 2 species in the Vulnerable (VU) category, and 8 species in the Not Evaluated (NE) and 1 unclassified category. There is only 1 species that is included in the Appendix I category, namely Scleropages formosus, and other species are Not evaluated. This is the first study conducted in Kupang City to reveal the types of ornamental fish species sold and their conservation status. The study will be useful information to the government, researchers, and other stakeholders on the potential extinction risk of each type of fish being traded.

Sex ratio distorting microbes exacerbate arthropod extinction risk in variable environments

AbstractMaternally‐inherited sex ratio distorting microbes (SRDMs) are common among arthropod species. Typically, these microbes cause female‐biased sex ratios in host broods, either by; killing male offspring, feminising male offspring, or inducing parthenogenesis. As a result, infected populations can experience drastic ecological and evolutionary change. The mechanism by which SRDMs operate is likely to alter their impact on host evolutionary ecology; despite this, the current literature is heavily biased towards a single mechanism of sex ratio distortion, male‐killing. Furthermore, amidst the growing concerns surrounding the loss of arthropod diversity, research into the impact of SRDMs on the viability of arthropod populations is generally lacking. In this study, using a theoretical approach, we model the epidemiology of an understudied mechanism of microbially‐induced sex ratio distortion—feminisation—to ask an understudied question—how do SRDMs impact extinction risk in a changing environment? We constructed an individual‐based model and measured host population extinction risk under various environmental and epidemiological scenarios. We also used our model to identify the precise mechanism modulating extinction. We find that the presence of feminisers increases host population extinction risk, an effect that is exacerbated in highly variable environments. We also identified transmission rate as the dominant epidemiological trait responsible for driving extinction. Finally, our model shows that sex ratio skew is the mechanism driving extinction. We highlight feminisers and, more broadly, SRDMs as important determinants of the resilience of arthropod populations to environmental change.

Response of diademed sifaka (Propithecus diadema) to fosa (Cryptoprocta ferox) predation in the Betampona Strict Nature Reserve, Madagascar.

Large-bodied mammals living in fragmented habitats are at higher risk of extinction, and such risk can be influenced by ecological factors such as predator-prey system dynamics. These dynamics can be particularly complex for conservation management when one endangered species preys on another endangered species in an isolated or poor-quality habitat. Here we describe predation events observed over 19 months that involved two threatened species: the largest carnivore in Madagascar, the fosa (Cryptoprocta ferox), and three groups of diademed sifaka (Propithecus diadema) in the Betampona Strict Nature Reserve. This site is a 22 km2 low-altitude rainforest that is surrounded by agricultural land and isolated from larger forest corridors. We aim to (1) assess the behavioral changes of P. diadema in response to fosa attacks and identify any antipredator strategies that they adopted, and (2) quantify the frequency of fosa attacks and the predation impact on the sifaka population. We report five direct observations of fosa predation attempts (one successful), the discovery of a dead sifaka with evidence of fosa predation, and the disappearance of three individuals. We describe the observed attacks and compare the sifaka activity budgets and movement patterns before and after the events. To escape the predator, sifakas fled short distances, hid, and remained vigilant. The impact of predation, combined with low reproductive rates and potentially high inbreeding of this isolated diademed sifaka population, could affect the survival of this species in Betampona.Given the compounding effects of habitat isolation and high hunting pressure, community-specific conservation strategies should incorporate predator-prey dynamics via longitudinal monitoring of predator and prey population densities and quantifying the predation pressure between them.

Species motif participation provides unique information about species risk of extinction.

Loss of species in food webs can set in motion a cascade of additional (secondary) extinctions. A species' position in a food web (e.g. its trophic level or number of interactions) is known to affect its ability to persist following disturbance. These simple measures, however, offer only a coarse description of how species fit into their community. One would therefore expect that more detailed structural measures such as participation in three-species motifs (meso-scale structures which provide information on a species' direct and indirect interactions) will also be related to probability of persistence. Disturbances affecting the basal resources have particularly strong effects on the rest of the food web. However, how disturbances branch out and affect consumer persistence depends on the structural pattern of species interactions in several steps. The magnitude, for example, the proportion of basal resources lost, will likely also affect the outcome. Here, we analyse whether a consumer's risk of secondary extinction after the removal of basal resources depends on the consumer's motif participation and how this relationship varies with the severity of disturbance. We show that consumer species which participate more frequently in the direct competition motif and less frequently in the omnivory motif generally have higher probability of persistence following disturbance to basal resources. However, both the strength of the disturbance and the overall network structure (i.e. connectance) affect the strength and direction of relationships between motif participation and persistence. Motif participation therefore captures important trends in species persistence and provides a rich description of species' structural roles in their communities, but must be considered in the context of network structure as a whole and of the specific disturbance applied.

Amphibian conservation status in Brazil: Spatial patterns, threats, and challenges

Extinction risk assessments are valuable conservation tools, especially for sensitive groups like amphibians, which are facing escalating threats from habitat loss and degradation. In this scenario, Brazil stands out as a pivotal player in amphibian conservation due to its exceptional amphibian diversity. Between 2010 and 2014, 973 amphibian species were assessed in Brazil. More recently, from 2017 to 2018, this number increased to 1096. In this study, we (1) compare the extinction risk status of Brazilian amphibians between the 1st and 2nd assessments; (2) evaluate the reasons for changes in status; (3) identify the main threats and research recommendations; and (4) analyze the spatial patterns of threatened species in relation to protected areas and ecoregions in Brazil. Our findings reveal an increase in the number of threatened species from the first to the second assessment. The categories of Least Concern and Critically Endangered experienced the most significant increases, with 169 and 16 more species, respectively, while the count of Data Deficient species dropped by 71. The primary factor contributing to these changes is the availability of new, more precise information, affecting 134 species, or 85.4% of the cases. Threatened species are predominantly clustered within the Atlantic Forest biome, itself the most endangered biome in Brazil, hosting 46 species, or 78% of the total. Notably, one-third of threatened species in Brazil do not inhabit protected areas and thus require immediate conservation attention. While substantial progress has been made in understanding Brazilian amphibians in recent years, an urgent need persists for fundamental research. This research should encompass taxonomy, natural history, and the evaluation of threat impacts, providing a robust foundation for more effective conservation efforts concerning this group.

Prioritizing conservation areas to mitigate connectivity loss and local extinction risk of a small carnivore (Leopardus guttulus) in South America

Effective conservation management depends on the maintenance of key areas that allow population connectivity across the landscape. However, the lack of knowledge of how habitat conversion affects species movement hinders the identification of these areas. Here, we analyzed the impact of habitat fragmentation on landscape connectivity for Leopardus guttulus, a small Neotropical felid threatened by the high habitat fragmentation across the Atlantic Forest, and mapped and ranked the most important core areas and corridors for conservation actions. We also estimated genetic diversity indices and predicted the viability of the current core areas in the future. Our analyses suggest that L. guttulus populations are fragmented, and connectivity links between populations are few and weak. We predict that due to their size, estimated density and low connectivity, some current core areas may not maintain viable populations in the long-term. Also, ongoing land-use changes may further isolate remaining populations, leading to progressive reductions in the populations they support. In this study, we spatially prioritize the most critical areas for L. guttulus conservation and highlighted the urge that exists in the adoption of management measures for its conservation.

GnRH analogue triptorelin acetate induces ovulation in jennies during oestrus.

Most of the northern hemisphere donkey breeds are faced with the risk of extinction, thus donkey reproduction is considered an emerging branch of theriogenology, and the management of artificial insemination and induction of ovulation is a crucial point in setting up preservation protocols. For four consecutive cycles, six jennies' ovarian activity was routinely monitored; an ultrasound examination was performed daily from the evidence of a follicle diameter ≥27 mm until ovulation. Upon reaching a follicular diameter ≥32 ± 2 mm (Hour 0), oestrous jennies were treated alternatively with 0.1 mg triptorelin acetate, sc, (TRIP), 0.4 mg/sc of buserelin acetate (BUS) or saline, sc, (CTRL) and examined ultrasonographically at Hours 14, 24, 38, 42, 48, 62 and every 24 h until ovulation. Induction of ovulation was considered successful if ovulation occurred from 24 to 48 h after treatment. 11/12 cycles resulted in ovulation for TRIP and 12/12 for BUS and CTRL groups, respectively. Mean ± SD ovulation time after treatment was 37.3 ± 8.3, 47.1 ± 21.0 and 66.8 ± 25.9 h for BUS, TRIP and CTRL, respectively (p = .0032). Ovulation rates between h24 and h48 were 10/12 (83.3%) for both TRIP/BUS and 2/12 (16.7%) for CTRL, respectively (p = .003). Buserelin and triptorelin-treated jennies had a 25 times higher probability to ovulate between Hours 24 and 48 than controls (p = .003), while there were no jenny and cycle effects on the ovulatory rate. The results of this study show how triptorelin successfully induced ovulation in jennies, like other GnRH analogues previously evaluated.

The role of food value on host use by the herbivorous amphipod Sunamphitoe pelagica

Mesograzers often use macrophytes as both food and habitat and may have strong effects on primary producers. In this context, understanding the factors mediating their interaction with macrophytes, such as host food value, is an important step to predict the impacts of these herbivores on aquatic ecosystems. The amphipod Sunamphitoe pelagica is a mesograzer with distribution restricted to a few brown macroalgal hosts, however it is unclear if food value drives host use by this mesograzer. Herein, we investigated the distribution of S. pelagica and the food value of its hosts. For that, the abundance of S. pelagica on the macroalgae Sargassum filipendula, Padina gymnospora, and Dichotomaria marginata was evaluated seasonally in a subtidal rocky shore at Fortaleza Beach (23°32′S, 45°10′W), state of São Paulo, Brazil. Furthermore, we conducted laboratory experiments to test feeding preference and rate, as well as the performance (e.g. survival, growth, and reproductive potential) of S. pelagica using the same macroalgal hosts used in the field abundance investigation. Overall, the mesograzer was more abundant on the brown macroalgae Sargassum and Padina than on the red macroalga Dichotomaria. In both feeding preference and rate experiments, S. pelagica consumed more Sargassum and Padina than Dichotomaria. Moreover, the consumption of Padina and Sargassum resulted in high performance of this mesograzer, while juveniles raised on Dichotomaria had a low survival, perishing within few days of experiment. These results suggest the host use by S. pelagica is strongly driven by the food value of macroalgal hosts and are in accordance with the narrow host breadth of this mesograzer. Therefore, considering the vulnerability of large macroalgae to climate change and habitat alterations, the restricted host use by S. pelagica to few brown macroalgae may increase its risk of local extinction.

Population structure, genetic diversity and evolutionary history of the narrow endemic squirrel Sciurus meridionalis

Endemic species and their genetic diversity are critical components of global biodiversity, yet they usually face a higher risk of decline and extinction than species with broader distributions. Loss of genetic diversity within geographically restricted and fragmented ranges plays a significant role in driving endemic species to extinction, threatening their ability to adapt to environmental challenges. Hence, considering genetic diversity and its spatial distribution within populations is mandatory in planning conservation actions for narrow endemic species. Here, we investigated the population genetic diversity, structure and evolutionary history of the Calabrian black squirrel Sciurus meridionalis, a species endemic to the Calabrian region in the south of the Italian peninsula. A fine-scale sampling procedure was carried out throughout the whole species range, and genetic variation was assessed from multiple mitochondrial and nuclear markers. Phylogeographic and population structure analyses showed three evolutionary significant units within the current species range, each characterised by extremely low levels of genetic diversity. Bayesian phylogeographic analyses suggested that Calabrian black squirrel populations experienced a range fragmentation during the Last Glacial Maximum (∼20 ka), which geographically mirrors the three main mountain massifs within the species range. Historical demographic reconstructions revealed a recent and still ongoing demographic expansion for Calabrian black squirrel populations, likely promoted by a concurrent expansion of the Calabrian black pine in this area. Overall, our findings clarify the designation of the evolutionary significant units for a narrow endemic squirrel and underscore the importance of analysing range-wide population genetic data and considering species interactions when defining management strategies for narrow endemic species’ conservation.

Estimating the extinction risk from climate change

Estimating the extinction risk from climate change

Management and research efforts are failing dolphins, porpoises, and other toothed whales

Despite being subject to intensive research and public interest many populations of dolphins, porpoises, and other toothed whales (small cetaceans) continue to decline, and several species are on the verge of extinction. We examine small cetacean status, human activities driving extinction risk, and whether research efforts are addressing priority threats. We estimate that 22% of small cetaceans are threatened with extinction, with little signs of improvement in nearly thirty years. Fisheries and coastal habitat degradation are the main predictors of extinction risk. Contrary to popular belief, we show that the causal impact of small-scale fisheries on extinction risk is greater than from large-scale fisheries. Fisheries management strength had little influence on extinction risk, suggesting that the implementation of existing measures have been largely ineffective. Alarmingly, we find research efforts for priority threats to be vastly underrepresented and so a major shift in research focus is required. Small cetaceans are among the lower hanging fruits of marine conservation; continued failure to halt their decline bodes poorly for tackling marine biodiversity loss and avoiding an Anthropocene mass extinction.

A stage-based life cycle implementation for individual-based population viability analyses of grey wolves (Canis lupus) in Europe

Population viability analyses (PVA) are important tools for decision-making and planning of adaptive wildlife management actions. While earlier approaches on individual based PVAs have often been age-based, analyses of species with strong social structure might benefit from a stage-based model approach. In this study, we designed an individual-based and stage-based PVA within the software Vortex. As a case study, we applied our model to the German part of the European wolf population, making use of comprehensive data sets originating from the German monitoring regime including individual genotypes. Genetic diversity and inbreeding were important considerations in our analysis, as they could greatly impact population dynamics. We aimed to assess the population's trajectory, extinction risk, and genetic integrity under different scenarios while analyzing factors that could affect its survival. We found that mortality rates at different life cycle stages had varying effects on population growth. Higher mortality rates among pups and dispersers led to negative growth and increased the risk of extinction. In comparison, higher mortality rates among yearlings and subdominant wolves still resulted in positive growth but at a slower rate. Mortality among the breeding individuals within the pack (territorials) had the highest impact on population trajectory. Although the German wolves represent a rather recently founded population, our simulations predicted generally good genetic diversity as long as the population was not held at artificially low numbers.Ultimately, we present a generic, easy-to-use-and-adapt model built within the Vortex environment, that after appropriate modification, calibration and testing could be used within conservation practice and management in collaboration with scientific research. Our study highlights the importance of stage-based modeling for understanding the demographic traits of social species like wolves.

Predicting the effects of climate and land use changes on small rattlesnakes in central Mexico: Insights for conservation planning

Anthropogenic changes pose a significant threat to global biodiversity, especially in reptiles. Mexico, renowned for its diverse reptile population, is experiencing habitat disturbance and fragmentation, endangering rattlesnakes in particular due to their specific habitat requirements and limited mobility. The loss of structural connectivity further increases the risk of extinction for reptiles. Our study focuses on predicting the distribution and connectivity of nine Crotalus species in the Trans-Mexican Volcanic Belt (TMVB), using environmental modeling. We used climate models (CNRM-CM5 and MPI-ESM-LR) for the year 2050 and Representative Concentration Pathways (RCP 85) alongside changes in vegetation cover and land use. The Maxent modeling method in ENMeval helped assess distribution patterns and to identify key environmental variables influencing these species’ distributions and niche overlap. We also conducted an analysis of the structural connectivity of the different Crotalus species. Our findings indicate reductions in suitable habitats due to changes in agriculture, urbanization, and forest cover. The Maxent models showed high accuracy in predicting species distributions. The most influential variables varied among species and included forest types and climatic factors. We observed limited connectivity among small Crotalus species, although some species exhibited greater connectivity than others. Future models suggest potential distribution reductions for all species, with C. armstrongi facing the greatest reduction (78%) according to the cn85 global climate model. Protected areas do not encompass the majority of potential distribution for these small rattlesnake species. These findings highlight the urgency of conservation efforts and the need to mitigate the impacts of future environmental changes on reptile populations.

Spatial dynamic simulation of beetles in biodiversity hotspots

IntroductionColeoptera is the most species-rich order of animals with the widest distribution area; however, little is known about its global suitability distribution, and a substantial number of species are experiencing silent extinction. Most of Earth’s biocommunities are concentrated in biodiversity hotspots, and these hotspots receive the largest investment of conservation funds. The survival of beetles is closely related to the richness of biodiversity, so habitat loss in hotspots results in a high extinction risk for beetles.MethodsWe used the MaxEnt model to simulate the spatial suitable distribution in six time periods (1970-1980, 1980-1990, 1990-2000, 2000-2010, 2010-2020, and 1970-2020). Furthermore, we determined the priority suitable regions in hotspots after coupling the current biodiversity zones and evaluated the congruence between the suitable habitat of beetles and hotspots.ResultsThe results revealed that less than 30% of suitable regions were located in hotspots, and approximately 49.08% of the suitable habitat remained constant in all six periods, and can be regarded as climatically stable refugia. The Mediterranean Basin had the largest suitable area in each period and was always ranked first; other regions, such as Indo-Burma, Irano-Anatolian, and Mesoamerica, also had large areas of suitable habitat. Nine excellent, ten stable, and seventeen lower hotspots were identified based on their dynamic changes in 36 hotspots.DiscussionBased on these results, corresponding planning and management measures should be implemented in different biodiversity hotspots according to the changes in geographic distribution. In this paper, we propose practical advice for different regions to improve isolated and fragmented habitats, which will support the conservation of Coleoptera taxa and the restoration of biodiversity.

The power of citizen science to advance fungal conservation.

Fungal conservation is gaining momentum globally, but many challenges remain. To advance further, more data are needed on fungal diversity across space and time. Fundamental information regarding population sizes, trends, and geographic ranges is also critical to accurately assess the extinction risk of individual species. However, obtaining these data is particularly difficult for fungi due to their immense diversity, complex and problematic taxonomy, and cryptic nature. This paper explores how citizen science (CS) projects can be lever-aged to advance fungal conservation efforts. We present several examples of past and ongoing CS-based projects to record and monitor fungal diversity. These include projects that are part of broad collecting schemes, those that provide participants with targeted sampling methods, and those whereby participants collect environmental samples from which fungi can be obtained. We also examine challenges and solutions for how such projects can capture fungal diversity, estimate species absences, broaden participation, improve data curation, and translate resulting data into actionable conservation measures. Finally, we close the paper with a call for professional mycologists to engage with amateurs and local communities, presenting a framework to determine whether a given project would likely benefit from participation by citizen scientists.

Evolutionary correlates of extinction risk in Chinese angiosperm

China is widely known for its rich plant diversity, being a home for over 32,000 species of vascular plants. Approximately 11 % of them are threatened and require urgent conservation efforts. Although the major cause of species disappearance is known, the human activity does not affect all species equally. In our study we tested whether, at the family level, the risk of extinction is related to the evolutionary history and the total geographical range of the comprising family species. We gathered threat status data, evolutionary history information and range data for 27,102 Chinese angiosperm species representing 233 families. Using several Bayesian statistical approaches, we found that families with lower diversification rates had smaller geographic ranges, and that family diversification rate and geographic range size were strongly negatively associated with extinction risk. In contrast, the effect of family age on extinction risk, when its indirect effect through geographic range size was accounted for, was significantly positive. Our findings highlight the importance of considering evolutionary history in understanding the extinction dynamics and prioritization of species for protection. Our results imply that a special attention in conservation decisions should be given to species from the families with low diversification rates, old age and limited geographic ranges.

Alternative vegetation trajectories through passive habitat rewilding: opposite effects for animal conservation

ContextPassive habitat rewilding after rural abandonment can affect wildlife differently depending on the type of habitats that it generates.ObjectiveEvaluate and compare the effects of two alternative vegetation trajectories that occur through passive habitat rewilding in Mediterranean ecotone areas (crop-scrub and crop-pine forest transitions) on the long-term population dynamics of animal species.MethodsWe used the spur-thighed tortoise (Testudo graeca), a characteristic long-lived species of cultural landscapes, as study species. We applied a spatially explicit and individual-based model (STEPLAND) to simulate the movement and demographic processes in a long-term period, by comparing an “impact scenario” (i.e., historical land-use changes) to a “control scenario” (no land-use changes).ResultsThe two landscape scenarios resulted in different population trends. In the crop-scrub scenarios (control and impact), population densities increased similarly over time. However, the crop-pine forest scenario negatively affected population density throughout the simulation period, and showed a time-lag response of three decades. The extinction risk was 55% with a time-lag response of approximately 110 years.ConclusionsOur study highlights the need to analyse the legacy effects on long-lived ectotherms, using them as a proxy to understand the future effects of dynamic landscapes created by “passive habitat rewilding”. Our results showed how traditional agriculture in Mediterranean ecotone areas may generate “ecotone effects” (i.e. increase in demographical parameters), but also population extinction on long-lived ectotherms. Therefore, we consider it relevant to maintain traditional agricultural areas in Mediterranean landscapes, especially in ecotone areas associated with pine forests (generating mosaics with open habitats).