Extinction Risk Research Articles

Genetic Attributes and Conservation of an Endangered Giant Water Bug Species, Diplonychus esakii Miyamoto and Lee, 1966 (Hemiptera: Belostomatidae).

Diplonychus esakii, a water bug from the family Belostomatidae, plays an important role in freshwater ecosystems as one of the top predators. In this study, we investigated the genetic diversity and population structure of D. esakii by analyzing 318 specimens across 27 sites in South Korea. We found that the populations of D. esakii possess 11 haplotypes with a haplotype diversity of 0.623. This represents a relatively low level of genetic diversity compared to other known belostomatids and endangered species. AMOVA and FST analyses revealed significant genetic differentiation among populations, with most populations harboring only 1-2 haplotypes, suggesting restricted gene flow between populations and a low level of genetic diversity. This low genetic diversity and limited gene flow suggest a potential vulnerability to environmental changes and an increased risk of extinction, indicating that D. esakii should be designated as a protected species in South Korea as part of future conservation efforts. Based on the results of this study, Upo Wetland, which maintains relatively high levels of genetic diversity and Jeju Island, which, despite its lower genetic diversity compared to the mainland, does not share haplotypes with other regions, should be considered key conservation units for this species. This study highlights the importance of incorporating genetic information into conservation status assessments under the Red List Categories and Criteria and also emphasizes the need to evaluate this species on the Korean Red List. The data provided here will serve as essential baseline information and valuable resources for the development of effective conservation strategies.

Habitat availability decline for waterbirds in a sensitive wetland: Climate change impact on the Ebro Delta

The highly biodiverse, productive and vulnerable areas, such as coastal wetlands, are increasingly threatened by human-induced disturbances, resulting in habitat loss. This habitat loss is a critical driver of biodiversity decline and significantly impacts species distribution and behavior, increasing the risk of extinctions. To address these concerns, we developed a Species Distribution Model (SDM) using a decade-long dataset of waterbird functional group occurrences in the Ebro Delta, with a particular focus on the Ardeidae family, which represents the most prominent species in the wetland. This model aims to predict potential habitat loss under various climate change scenarios, specifically those outlined in the Intergovernmental Panel on Climate Change (IPCC) Representative Concentration Pathways (RCP) 4.5 and 8.5, across three distinct time periods.Our SDM revealed that habitat suitability for waterbirds was notably influenced by temperature variations, increased cumulative precipitation, and lower terrain elevation. Predictions indicate an increase in available habitat for these waterbird species over the study periods considering the specified climate scenarios. However, the incorporation of sea-level rise and flooded areas into the models unveiled a dramatic decline in available areas for waterbirds in the long-term, reaching up to 50 % (RCP 4.5) and 70 % (RCP 8.5) reduction.Our study highlights the urgent need for conservation efforts to mitigate the substantial reduction in available habitat for waterbirds. This need is especially crucial due to the Ebro Delta's importance as a vital coastal wetland for many thousands of waterbirds throughout their entire life cycle. Immediate and targeted conservation actions are imperative to safeguard the essential habitats for these species.

Rapidly Evaluating Species at Risk Using Endemic Plants of Kosrae, Federated States of Micronesia

The International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species is regarded as the primary source of global extinction risk for species. Despite this importance, the IUCN has assessed less than 20% of the world′s estimated 400,000 flowering plants due to issues like insufficient data or a lack of experts. Thousands of conservation status assessments were generated recently in response to the call to action by the revised Target 2 of the Global Strategy for Plant Conservation (GSPC), “An assessment of the conservation status of all known plant species, as far as possible, to guide conservation action.” Accelerated extinction risk assessments are needed to identify species that are most at risk of extinction, which can then be thoroughly evaluated by the Red List assessment procedure. The land area in the Pacific Islands is significantly smaller than in other parts of the world. Plant species restricted to these islands may be identified as “At Risk” due to the limited land area of these islands, despite being widespread locally. Distribution and abundance data of single-island endemic plant taxa of Kosrae, Federated States of Micronesia, are analyzed and combined with digital elevation model files from this island, ArcGIS, and herbarium data, to calculate the percentage of land area that is available within a species′ elevational occurrence, a metric we have coined the Extent of Inhabitable Elevation of Island Occurrence (EIEIO). This metric can be used as a streamlined system to rapidly identify species that need plant conservation attention and allows for a swifter response to Target 2 of the GSPC.

Mitigating the extinction risk of globally threatened and endemic mountainous Orthoptera species: Parnassiana parnassica and Oropodisma parnassica

Abstract Orthoptera species are vulnerable to extinction on a global scale. Greece hosts 35% (380 species) of the European Orthoptera fauna with a high degree of endemic (37%) and threatened species (37%). We sampled 46 plots (100 m2) to investigate the distribution and ecological requirement of two Greek mountain endemic and red‐listed species: Parnassiana parnassica (Ramme, 1926; Orthoptera: Tettigoniidae; Critically Endangered [CR]) and Oropodisma parnassica (Scudder, 1897; Orthoptera: Caelifera; Endangered [EN]). Species had a restricted geographical range, with two isolated populations confined to high altitudes (1527–2320 m) of Mts. Parnassos and Elikonas. Species distribution models showed that slope affected their suitable habitat, together with the topographic position index and the annual temperature range (P. parnassica), and the amount of green vegetation and evapotranspiration (O. parnassica). Connectivity analysis showed that P. parnassica‐suitable habitat consisted of few larger and well‐connected patches (26 patches: effective mesh size of 1.57 km2) and that O. parnassica‐suitable habitat consisted of more but smaller and less connected patches (56 patches: effective mesh size of 0.3 km2). Generalised linear models showed that the population density of P. parnassica was negatively influenced by the height of herbaceous vegetation and that of O. parnassica was positively influenced by altitude. The species face three main imminent threats: land take, wildfires and global warming, whereas livestock grazing seems to have a positive impact and skiing a neutral impact on their populations. We assessed both species as EN after International Union for Conservation of Nature (IUCN) criteria and a suite of conservation measures are suggested for their status improvement.

The rarest of rarities in the flora of Mexico

Background: Endemism can originate from multiple biogeographic and evolutionary processes that promote the formation or persistence of species with restricted distributions (rare species). Understanding rare species’ distributions is a central question in biogeography and is crucial for biodiversity conservation. Questions: What are the rarest plant species in Mexico? How are they distributed? Under what risk categories should they be classified? Studied species: Vascular species considered rare in the flora of Mexico. Study site: Mexico. Methods: “Rare species” were defined as species endemic to Mexico whose distribution is restricted to a single 1 × 1° cell. We analyzed rare species’ distributions and proposed the risk category for each according to IUCN criteria. For some of the species distributed in the cell with the highest number of rare species, we compared the proposed category with published evaluations. Results: We identified 2,705 rare species. The richest cells in terms of rare species are in southern Mexico. Only 302 species had been previously evaluated under IUCN criteria. The remaining 2,403 qualify for the Near Threatened (NT) category or higher. The cell with the highest rare species richness, located in the Sierra Norte of Oaxaca, contained only 10 species with an existing IUCN risk category; for another 81 species, the categories of Vulnerable (VU), Endangered (EN) or Critically Endangered (CR) are indicated. Conclusions: Recognizing the rarity of these 2,705 species will increase attention on them, allowing more precise appraisal of their extinction risk and possible strategies for their conservation.

The role of protected areas in the Balkan freshwater biodiversity conservation: The case of Blidinje Nature Park (Southwestern Bosnia-Herzegovina)

Freshwaters of the Balkan Peninsula show high levels of endemism and relict species, which are still little studied and are threatened by numerous anthropogenic stressors. Protected areas could give special opportunities to improve knowledge of their biodiversity and develop proper conservation measures for the most at-extinction risk species. The aims of this research were to: i) fill the knowledge gap regarding fish and crustaceans occurring in the main water bodies of the Blidinje Nature Park (Southwestern Bosnia-Herzegovina); ii) assess the population abundance and growth, for the species of conservational interest; iii) identify fish biodiversity hotspots in Bosnia-Herzegovina; iv) identify anthropogenic pressures and suggest proper conservation measures. Fish and crayfish data were collected in four sampling sites located on the main water bodies, using electrofishing and gillnets, in three sampling phases over the period July 2022-August 2023. The presence of three species at high extinction risk has been detected: Squalius tenellus, Aulopyge huegelii and Astacus astacus. Their populations were abundant, with balanced age structure and good growth performance. A spatial analysis allowed to quantify the fractions of the endemic species range covered by the Blidinje Nature Park, which were 6.1% and 2.3% for S. tenellus and A. huegelii, respectively. The presence of invasive Atlantic trout and overharvesting of crayfish seem to represent the main anthropogenic pressures on freshwater biota. The obtained information allowed to expand the knowledge on the distribution and population status of threatened species and to highlight diversity hotspots as valuable tools for their conservation and management.

A haplotype-resolved genome assembly of Coptis teeta, an endangered plant of significant medicinal value

Coptis teeta Wall. (Ranunculaceae), an endangered plant species of significant medicinal value, predominantly undergoes clonal propagation, potentially compromising the species’ evolutionary potential and ultimately increase its risk of extinction. In this study, we successfully assembled two sets of haploid genomes (Hap1 and Hap2) for C. teeta, comprising nine homologous chromosome pairs, by employing Illumina and PacBio sequencing technologies. The genome annotation identified a total of 43,979 and 46,311 protein-coding genes in Hap1 and in Hap2, and most of them were functionally annotated. The high-quality reference genome will serve as an indispensable genomic resource for conservation and comprehensive exploitation of this endangered species. Between the two haploid genomes, numerous structural alterations were detected within the nine homologous chromosome pairs, potentially resulting in aberrant synapsis and irregular chromosomal segregation and thus contributing to the sustained preservation of clonal propagation in C. teeta. The findings offer new perspective for elucidating the genetic mechanism underlying the compromised sexual reproductive capacity of C. teeta, thereby facilitating its enhancement though molecular breeding and genetic improvement.

Cumulative human impacts on global marine fauna highlight risk to biological and functional diversity.

Anthropogenic stressors to marine ecosystems from climate change and human activities increase extinction risk of species, disrupt ecosystem integrity, and threaten important ecosystem services. Addressing these stressors requires understanding where and to what extent they are impacting marine biological and functional diversity. We model cumulative risk of human impact upon 21,159 marine animal species by combining information on species-level vulnerability and spatial exposure to a range of anthropogenic stressors. We apply this species-level assessment of human impacts to examine patterns of species-stressor interactions within taxonomic groups. We then spatially map impacts across the global ocean, identifying locations where climate-driven impacts overlap with fishing, shipping, and land-based stressors to help inform conservation needs and opportunities. Comparing species-level modeled impacts to those based on marine habitats that represent important marine ecosystems, we find that even relatively untouched habitats may still be home to species at elevated risk, and that many species-rich coastal regions may be at greater risk than indicated from habitat-based methods alone. Finally, we incorporate a trait-based metric of functional diversity to identify where impacts to functionally unique species might pose greater risk to community structure and ecosystem integrity. These complementary lenses of species, function, and habitat provide a richer understanding of threats to marine biodiversity to help inform efforts to meet conservation targets and ensure sustainability of nature's contributions to people.

A landscape conservation perspective of state Species of Greatest Conservation Need

AbstractState Wildlife Action Plans (SWAPs), including lists of Species of Greatest Conservation Need (SGCN), outline state strategies for protecting species and habitats in the United States. In developing the current, second revision SWAPs, states are increasingly pursuing coordinated landscape conservation approaches. Analyzing SGCN lists in the first revision SWAPs, we found evidence that they already support multistate conservation. Most states address a common set of vertebrate and invertebrate groups, include most of the imperiled species from these groups, do not prioritize endemics over non‐endemics, and often include most imperiled species that are shared with neighboring states. Also, a regional SGCN coordination effort was successful. Although 65% of animals on each SGCN list were assessed as at elevated risk of extirpation by state authorities, only 43% of the combined national list were at elevated risk of global extinction. Over 40% of the combined animal SGCNs are considered globally apparently secure. Plants, snails, freshwater shrimps, and freshwater insects were poorly represented in SGCN lists. For the current SWAP revisions, we recommend improving foundational data on taxonomy, range‐wide distribution, and conservation status; expanded taxonomic coverage in SGCN lists; supporting existing and establishing new interstate initiatives; and diversifying funding mechanisms that target regional cooperation.

Age truncation due to disease shrinks metapopulation viability for amphibians.

Metapopulations often exist in a fragile balance between local extinctions and (re)colonisations, in which case emerging threats that alter species vital rates may drastically increase metapopulation extinction risk. We combined empirical data with metapopulation simulations to examine how demographic shifts associated with amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) have altered metapopulation viability for threatened amphibians in Australia. Comparing the ages of museum specimens collected before Bd emerged in Australia with individuals from geographically matched remnant populations revealed significant truncation of age structures post-Bd, with a halving of annual adult survival probabilities. Spatially realistic metapopulation modelling demonstrated that reduced adult survival led to major reductions in the parameter space over which persistence was possible for the focal species, with contractions to landscapes with higher landscape connectivity, lower environmental stochasticity and considerably higher recruitment rates. Metapopulation persistence post-Bd required greater landscape connectivity than pre-Bd. This arises from a landscape-level analogue of compensatory recruitment at the population level, in which higher (re)colonisation rates can offset more frequent local extinctions, enabling persistence of amphibians susceptible to Bd. Interactions between recruitment rate, environmental stochasticity and landscape connectivity were also more important for metapopulation persistence post-Bd. Higher recruitment was required to mitigate the impacts of environmental stochasticity, and higher landscape connectivity was required to mitigate the impacts of environmental stochasticity and poor recruitment. Increased reliance on these interdependencies shrunk the parameter space over which metapopulations could persist post-Bd. Our study demonstrates that emerging threats that alter species vital rates can drastically reduce the capacity of certain environments to support metapopulations. For our focal species, reductions in adult survival rates due to Bd produced major reductions in the conditions under which persistence was possible, providing a mechanistic insight into the processes underpinning observed range and niche contractions of amphibians impacted by this pathogen. More broadly, our study illustrates how environmentally mediated host resilience can enable persistence following the emergence of novel pathogens. This pathway to persistence is worthy of greater attention on both conceptual and applied grounds.

Increased incidences of cervical ribs in deer indicate extinction risk

Mammals as a rule have seven cervical vertebrae, a number which remains remarkably conserved. Occasional deviations of this number are usually due to the presence of cervical ribs on the seventh vertebra, indicating a homeotic transformation from a cervical rib-less vertebra into a thoracic rib-bearing vertebra. These transformations are often associated with major congenital abnormalities or pediatric cancers (pleiotropic effects) that are, at least in humans, strongly selected against. Based on data from Late Pleistocene mammoths (Mammuthus primigenius) and woolly rhinoceroses (Coelodonta antiquitatis) from the North Sea, we hypothesized that high incidences of cervical ribs in declining populations are due to inbreeding and/or adverse conditions impacting early pregnancies. In this study, we investigated the incidence of cervical ribs in an extinct Late Pleistocene megaherbivore, giant deer (Megaloceros giganteus) from Ireland and in the extant highly inbred Père David deer (Elaphurus davidianus) and in twenty other extant species. We show that the incidence of cervical ribs is exceptionally high in both the Irish giant deer and the Père David deer and much higher than in extant outbred deer. Our data support the hypothesis that inbreeding and genetic drift increase the frequencies of maladaptive alleles in populations at risk of extinction. The high incidence of cervical ribs indicates a vulnerable condition, which may have contributed to the extinction of megaherbivore species in the Late Pleistocene. We argue that cervical rib frequency may be a good proxy for extinction risk in inbred populations.

POPULATION STUDY AND REASSESSMENT OF CONSERVATION STATUS OF AN ENDEMIC DIPTEROCARP, Hopea bilitonensis

Hopea bilitonensis is a rare, endemic Dipterocarp species in the Malesian Region. It has a disjunct distribution pattern, where main populations occur on the sandy soils of Bangka Belitung Islands of Indonesia and some on limestone forest in Perak, Peninsular Malaysia. Current global status of this species based on the IUCN Red List is Critically Endangered (CR) A1c+2c, B1+2c (1998) whilst in Malaysia it is assessed as CR A4c, B1ab(iii) (2010). A reassessment of the conservation status of this species is needed to provide the most current population status and its extinction risk, especially in Indonesia using the IUCN Red List Categories and Criteria version 3.1. This study was conducted to survey and assess the current populations of this species in Belitung Island where most population occurred and subsequently to recommend its current conservation status. The species is in fact still common in the island, stretching along the main roads and surrounding forests. Using the purposive sampling method, we developed a total of 16 plots of 20x20m each in 10 different locations across the Belitung Island. A total of 730 individuals were found with stem diameter at breast height ranged from 2cm to more than 30cm. For global reassessment, based on the current distribution and herbarium records, the calculated extent of occurrence (EOO) is 108,128.642km2, whilst the area of occupancy (AOO) is 84 km2. However, the species clearly has a restricted distribution and is facing high threats due to frequent timber harvesting and continuing decline of the EOO and AOO. The species extinction risk was then assessed by using five quantitative criteria of the IUCN. Therefore, we propose H. bilitonensis category is considered to be Endangered (EN) based on A2c, B2ab(i,ii,iii,iv,v) and C2a(i) criteria.

Assessing population viability and management strategies for species recovery of the critically endangered Puerto Rican parrot

AbstractRecovery of endangered species is challenging and lengthy, especially when it involves reintroduction and dynamic environmental conditions. Because managers often need to decide between many management strategies with uncertain outcomes, periodically assessing progress toward recovery using population viability analysis (PVA) can help guide decision‐making. We developed a PVA for the critically endangered Puerto Rican parrot (Amazona vittata) to evaluate current status and potential future management strategies to reach goals set in the Recovery Plan. Having grown from their nadir of 13 birds in 1976 to 686 in 2021, the recovery effort has made great progress. Using 15 years of data, we built an individual‐based PVA that included interactions between two captive and three wild populations connected via annual releases. If management continues as planned, the wild populations have no to moderate risks of extinction (0–32%) over the next 100 years. However, wild populations remain dependent on releases to sustain growth, and recovery targets for stable population growth and connectivity have not yet been reached. Our analysis suggests that hurricanes are an impediment to reaching recovery targets and impact some wild populations more than others based on geography. Projections with climate‐change‐induced higher hurricane impact resulted in wild populations being less likely to stabilize. We identified demographic rates and associated management strategies that could positively impact wild populations: increasing reproduction (e.g., via increasing artificial nests, improving nest success) and decreasing first‐year mortality (e.g., via targeted predator control). Based on our current understanding of Puerto Rican parrot demographics, species recovery will continue to be management‐dependent unless demographic rates can be altered. As more data are gathered, especially for data‐sparse populations and in the face of environmental change, future iterations of this model can re‐evaluate progress, update management strategies, and provide support for deciding if and when to delist this iconic species.

Habitat fragmentation strongly restricts gene flow in endangered ectomycorrhizal fungal populations: Evidence from Rhizopogon togasawarius, specific to Pseudotsuga japonica, across the entire distribution range.

Habitat fragmentation reduces gene flow, causing genetic differentiation and diversity loss in endangered species through genetic drift and inbreeding. However, the impact of habitat fragmentation on ectomycorrhizal (ECM) fungi remains unexplored, despite their critical roles in forest ecosystems. Here, we investigated the population genetic structure and the demographic history of Rhizopogon togasawarius, the ECM fungus specifically colonizing the host tree Pseudotsuga japonica, across its entire distribution range (>200 km). These two species are designated as endangered species on the IUCN Red List since they are found only in small, fragmented forests in Japan. We analysed 236 R. togasawarius individuals from five remaining populations across the Kii Peninsula and the Shikoku Island, separated by a sea channel. Simple sequence repeat analyses using 20 loci revealed strong genetic differentiation among populations (FST = 0.255), even significant in the nearest population pair separated by a distance of only 8 km (FST = 0.075), indicating extremely limited gene flow between populations. DIYABC-RF analyses implied that population divergence occurred approximately 6000 generations ago between the two regions, and nearly 1500 generations ago between the nearest populations within Shikoku Island, related to past climate events. Because of prolonged genetic isolation, significant inbreeding was confirmed in four of five populations, where effective population sizes became very small (Ne = 9.0-58.0). Although evaluation of extinction risks for microorganisms is challenging, our conservation genetic results indicated that habitat fragmentation increases extinction risk through population genetic mechanisms, and therefore should not be overlooked in biodiversity conservation efforts.

Effects of trade and poaching pressure on extinction risk for cacti in the Atacama Desert.

In this era of a global biodiversity crisis, vascular plants are facing unprecedented extinction rates. We conducted an assessment of the extinction risk of 32 species and 7 subspecies of Copiapoa, a genus endemic to Chile's fog-dependent coastal Atacama Desert. We applied the International Union for Conservation of Nature Red List Categories and Criteria enhanced by expert insights and knowledge. Our primary aim was to analyze the impact of trade and poaching on their extinction risk. We employed machine learning models, including multinomial logistic regression (MLR), decision tree (DT), and random forest (RF), to analyze the relationships between conservation status and various factors. These factors encompassed trade and poaching activities, landscape condition, human footprint, monthly cloud frequency, and biological traits such as evolutionary distinctiveness and maximum diameter. Seven taxa had an area of occupancy (AOO) of <10km2, 10 additional taxa had an AOO of <20km2, and 16 taxa had an AOO of ≤100km2. This reassessment exposed a critical level of extinction risk for the genus; 92% of the taxa were classified as threatened, 41% as critically endangered, 41% as endangered, and 10% as vulnerable. MLR, DT, and RF exhibited accuracies of 0.784, 0.730, and 0.598, respectively, and identified trade and poaching pressure and landscape condition as the primary drivers of extinction risk. Our assessment of Copiapoa showed trade, poaching, habitat degradation, and their synergic impacts as the main drivers of the genus' extinction risk. Our results highlight the urgent need for nations to develop and enforce strategies to monitor and control trade and poaching pressure because these factors are crucial for the long-term persistence of desert plants.

Assessing the risk of overexploitation to a tarantula species in the pet trade.

The global pet trade in invertebrates remains poorly understood and underrepresented in policy and research. Tarantulas are a highly traded invertebrate group. Many individuals in trade are wild caught, and trade regulation is often lacking, raising concerns about the effect of trade on local ecosystems and populations. We addressed local concerns surrounding the international trade of Tapinauchenius rasti (Caribbean diamond tarantula), which is endemic to Saint Vincent and the Grenadines. We assessed the extinction risks associated with this widely traded species by analyzing supply of and demand for the species with the COM-B (capability, opportunity, motivation, behavior) model. This model breaks down decision-making into capability, opportunity, and motivation. We interviewed stakeholders throughout the supply chain and analyzed content of an online hobbyist forum and a time series of prices for this species and other tarantulas. In terms of motivation, there was limited preference for the Caribbean diamond tarantula due to its morphology and behavior. In terms of opportunity, the species was readily available, primarily through captive breeding. Collecting wild specimens is challenging due to enforcement measures and logistical difficulties, making it an unprofitable endeavor. In terms of capability, the species was relatively low in price, likely because it is easy to breed in captivity. As a result, the current wildlife trade does not pose a significant threat to the Caribbean diamond tarantula. Our methodology can serve as a valuable tool for assessing potential threats posed by trade to other spider species and possibly other invertebrates. Understanding these threats is crucial for promoting responsible and sustainable trade practices that minimize risks to wild populations while ensuring equitable benefits for communities coexisting with wildlife.

Synergies between price and life history enhance extinction risk in open‐access fisheries

AbstractThere have been few documented extinctions of fished species, but many bioeconomic models predict that open‐access incentives make extinction possible. Open‐access multi‐species fisheries can cause species' extinction if other, faster‐growing species maintain profits at fatal effort levels. Even target species can be profitably harvested to extinction if their prices rise sufficiently as they are depleted. Here, we explore interactions between these potential extinction mechanisms by modelling an open‐access multi‐species fishery with one or multiple fleets exploiting two species, each with different growth rates, ex‐vessel prices, and price dynamics. Increases in the strong stock's (the stock with higher productivity relative to fishing susceptibility) price as it is depleted increase the range of conditions under which the weak stock can be driven extinct and shrinks the range of bioeconomic parameters in which both species can coexist under open‐access. Catch hyperstability – whereby species become easier to catch as they are depleted – makes the weak stock weaker as it is depleted and further narrows the scope for coexistence. Fleet diversity in targeting ability can prevent weak stock extinction, as competition or switching balances species abundances. With few documented global fished‐species extinctions, our results raise important questions, which we discuss. Is the apparent lack of extinctions largely due to management? Are more species in lightly‐managed fisheries threatened with extinction than previously acknowledged? Have more extinctions than we realize already happened in data‐ and management‐poor fisheries? Or have fishes' high fecundity and the oceans' vastness provided protection against extinction that is uncaptured by existing theoretical models?

Quantifying the Capacity for Assisted Migration to Achieve Conservation and Forestry Goals Under Climate Change

ABSTRACTAimMany tree species may be threatened with declines in range and biomass, or even extinction, if they cannot disperse or adapt quickly enough to keep pace with climate change. One potential, and potentially risky, strategy to mitigate this threat is assisted migration (AM), the intentional movement of species to facilitate population range shifts to more climatically suitable locations under climate change. The ability for AM to minimise risk and maximise conservation and forestry outcomes depends on a multi‐faceted decision process for determining, what, where and how much to move. We provide an assessment on how the benefits and risks of AM could affect the decision‐making process.LocationMountainous coastal western United States.TaxonTrees.MethodsWe used a dynamic vegetation model parameterised with 23 tree species.ResultsWe found that most of the modelled species are likely to experience a substantial decline in biomass, with many potentially facing regional extinction by 2100 under the high‐emission SSP5‐85 climate‐change scenario. Though simulations show AM had little effect on the forestry goal of total biomass across all species, its effects on the conservation goal of promoting individual species' persistence were far more substantial. Among eight AM strategies (differing in the life cycle stage of movement and target destination selection criteria), the approach that conserved the highest biomass for individual species involved relocating target seedlings to areas that recently experienced fire. Although this strategy significantly reduced extinction risk for six at‐risk species compared with no action, it also slightly reduced biomass of four species, due to increasing competition. Species with relatively weak tolerance to drought, fire or high temperature were the most likely candidate groups for AM.Main ConclusionsOur simulations indicate that AM can aid conservation by reducing extinction risks for species vulnerable to climate change, but it has limited impact on forestry‐specific goals, affecting overall biomass minimally. This model framework could be applied to other forest ecosystems to evaluate the efficacy of AM globally.

Cloudy with a chance of survival: Simulating the effects of climate, habitat, and management on the population viability of an at-risk lizard species

The spot-tailed earless lizards (STEL) are small, phrynosomatid lizards in the Holbrookia genus. Historically, these were considered two subspecies, the Plateau (Holbrookia lacerata lacerata) and Tamaulipan STEL (Holbrookia lacerata subcaudalis); however, each are now recognized as a distinct species (i.e., H. lacerata (plateau STEL) and H. subcaudalis (Tamaulipan STEL)). Recently, the plateau STEL was considered but not awarded federal protection under the Endangered Species Act by the U.S. Fish and Wildlife Service; however, much uncertainty remains about the status of the Tamaulipan STEL and a conclusive policy decision has not been made. In this study, we developed a hybrid theoretic-empirical demographic model and conducted a population viability analysis (PVA) of the Tamaulipan STEL (H. subcaudalis). We evaluated the role of multiple demographic, environmental, and anthropogenic parameters and assessed population-level effects and extinction risks via sensitivity experiments. The baseline simulation demonstrated that Tamaulipan STEL have a relatively low probability of extinction under best case scenario conditions; however, results of elasticity analysis of the baseline simulation and sensitivity analysis of demographic parameters demonstrated that increases in juvenile mortality had the greatest effect on population growth rate and extinction risk. Simulations of anthropogenic impacts showed that small increases in habitat loss (e.g., 2 %) had drastic negative effects on population size and persistence. Results from this study demonstrate the need for conservation and management actions aimed at protecting and increasing populations of young individuals (i.e., decreasing juvenile mortality) and promoting the conservation of available and suitable habitat for STEL throughout their range. These results must be considered in future conservation initiatives focused on this species to achieve successful conservation outcomes.

Additions to and revisions of the endemic and near-endemic Acanthaceae of Ethiopia

Taxonomic studies in the Acanthaceae of Ethiopia and neighbouring countries reveal the presence of several previously overlooked endemic and near-endemic taxa. The Isoglossa somalensis Lindau complex is revised, resulting in the description of a new species, Isoglossa recurva Hanny &amp; I.Darbysh. from the forests of southwest Ethiopia, and a new variety of I. somalensis, var. glandulosa Hanny, G.Hoban &amp; I.Darbysh. from montane southeast Ethiopia. Barleria induta C.B.Clarke from Ethiopia and Eritrea, treated as B. prionitis L. subsp. induta (C.B.Clarke) Brummitt &amp; J.R.I.Wood in the Flora of Ethiopia and Eritrea (FEE), is reevaluated and found to represent two species, with B. praetermissa I.Darbysh. described from the Tigray region of northwest Ethiopia. Finally, Hypoestes microphylla Nees is resurrected as a good species, separate from the widespread H. triflora (Forssk.) Roem. &amp; Schult. under which it was treated as a synonym in FEE. Descriptions, tables of comparison and notes on the habitat, ecology and extinction risk for these taxa are provided. The first record of I. gregorii (S.Moore) Lindau for Ethiopia is also noted and a revised key to Isoglossa in Ethiopia is presented. The endemic Acanthaceae of Ethiopia now stands at 21 species (23 taxa), whilst an additional 23 species (24 taxa) are considered to be range-restricted near-endemics.