Endemic Juniperus Montane Species Facing Extinction Risk under Climate Change in Southwest China: Integrative Approach for Conservation Assessment and Prioritization.

Biodiversity is severely threatened by habitat destruction. As a consequence of habitat destruction, the remaining habitat becomes more fragmented. This results in time-lagged population extirpations in remaining fragments when these are too small to support populations in the long term. If these time-lagged effects are ignored, the long-term impacts of habitat loss and fragmentation will be underestimated. We quantified the magnitude of time-lagged effects of habitat fragmentation for 157 nonvolant terrestrial mammal species in Madagascar, one of the biodiversity hotspots with the highest rates of habitat loss and fragmentation. We refined species' geographic ranges based on habitat preferences and elevation limits and then estimated which habitat fragments were too small to support a population for at least 100 years given stochastic population fluctuations. We also evaluated whether time-lagged effects would change the threat status of species according to the International Union for the Conservation of Nature (IUCN) Red List assessment framework. We used allometric relationships to obtain the population parameters required to simulate the population dynamics of each species, and we quantified the consequences of uncertainty in these parameter estimates by repeating the analyses with a range of plausible parameter values. Based on the median outcomes, we found that for 34 species (22% of the 157 species) at least 10% of their current habitat contained unviable populations. Eight species (5%) had a higher threat status when accounting for time-lagged effects. Based on 0.95-quantile values, following a precautionary principle, for 108 species (69%) at least 10% of their habitat contained unviable populations, and 51 species (32%) had a higher threat status. Our results highlight the need to preserve continuous habitat and improve connectivity between habitat fragments. Moreover, our findings may help to identify species for which time-lagged effects are most severe and which may thus benefit the most from conservation actions.

Drivers and trends in the extinction risk of New Zealand's endemic birds

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.

Endemism increases species' climate change risk in areas of global biodiversity importance

Biodiversity indices often combine data from different species when used in monitoring programs. Heuristic properties can suggest preferred indices, but we lack objective ways to discriminate between indices with similar heuristics. Biodiversity indices can be evaluated by determining how well they reflect management objectives that a monitoring program aims to support. For example, the Convention on Biological Diversity requires reporting about extinction rates, so simple indices that reflect extinction risk would be valuable. We developed 3 biodiversity indices that are based on simple models of population viability that relate extinction risk to abundance. We based the first index on the geometric mean abundance of species and the second on a more general power mean. In a third index, we integrated the geometric mean abundance and trend. These indices require the same data as previous indices, but they also relate directly to extinction risk. Field data for butterflies and woodland plants and experimental studies of protozoan communities show that the indices correlate with local extinction rates. Applying the index based on the geometric mean to global data on changes in avian abundance suggested that the average extinction probability of birds has increased approximately 1% from 1970 to 2009.Conectando Índices para el Monitoreo de la Biodiversidad con la Teoría de Riesgo de ExtinciónResumenLos índices de biodiversidad combinan frecuentemente los datos de diferentes especies cuando se usan en los programas de monitoreo. Las propiedades heurísticas pueden sugerir índices preferidos, pero carecemos de medios objetivos para discriminar a los índices con propiedades heurísticas similares. Los índices de biodiversidad pueden evaluarse al determinar qué tan bien reflejan los objetivos de manejo que un programa de monitoreo busca apoyar. Por ejemplo, la Convención sobre la Diversidad Biológica requiere reportar las tasas de extinción, así que los índices que reflejan el riesgo de extinción serían valiosos. Desarrollamos 3 índices de biodiversidad que se basan en modelos sencillos de viabilidad de población y que relacionan el riesgo de extinción con la abundancia. Basamos el primer índice en la media geométrica de la abundancia de especies, y el segundo en una media de poder más general. En el tercer índice integramos la media geométrica y la tendencia. Estos índices requieren los mismos datos que índices previos, pero también se relacionan directamente con el riesgo de extinción. La información de campo sobre mariposas y plantas de bosque, y los estudios experimentales de comunidades protozoarias, muestran que los índices se correlacionan con las tasas locales de extinción. Al aplicar el índice basado en la media geométrica sobre los datos globales de los cambios en la abundancia de aves, sugirió que la probabilidad de extinción promedio de aves ha incrementado aproximadamente 1% desde 1970 hasta 2009.Palabras ClaveÍndice de biodiversidad, media geométrica, medida de la biodiversidad, riesgo de extinción

Food web structure affects the extinction risk of species in ecological communities

A single adverse environment event can threaten the survival of small-ranged species while random fluctuations in population size increase the extinction risk of less-abundant species. The abundance-range-size relationship (ARR) is usually positive, which means that smaller-ranged species are often of low abundance and might face both problems simultaneously. The ARR has been reported to be negative on tropical islands, perhaps allowing endemic species in such environments to remain extant. But there is a need to understand how endemism and land-use interact to shape ARR. Using 41 highly replicated transects along the full elevational gradient of Sri Lanka, we determined the following: (a) the direction of ARR, (b) if endemism affects ARR and (c) if land-use (rainforest, buffer and agriculture) changes ARR differently for endemics and non-endemics. Additionally, (d) we identified endemics that had both lower abundances and smaller range sizes, and ranked them from most threatened (specific to rainforests) to least threatened using a weighted-interaction nestedness estimator. (a) We found a positive relationship between species abundances and range size. This positive ARR was maintained among endemic and non-endemic species, across land-use types and at local and regional scales. (b) The ARR interacted with endemicity and land-use. Endemics with smaller range sizes had higher abundances than non-endemics, and particularly higher in rainforests compared to agriculture. In contrast, species with larger range sizes had similar abundances across endemicity and land-use categories. Many endemics with smaller range sizes are globally threatened; therefore, higher abundances may buffer them from extinction risks. (c) Nine (29%) endemics had both below average abundance and elevational range size. The nestedness estimator ranked the endemics Sri Lanka Whistling Thrush Myophonus blighi, Red-faced Malkoha Phaenicophaeus pyrrhocephalus, Sri Lanka Thrush Zoothera imbricata and White-faced Starling Sturnornis albofrontus as the four most vulnerable species to local extinction risk, which corresponds to their global extinction risk. We demonstrate that ARR can be positive on tropical islands, but it is influenced by endemism and land-use. Examining shifts in ARR is not only important to understand community dynamics but can also act as a tool to inform managers about species that require monitoring programmes.

Predicting climate change impact on the habitat of Ethiopia’s spot-breasted lapwing using ensemble model

Comparative lists of species’ extinction risk are increasingly being used to prioritise conservation resources. Extinction risk is most rigorously assessed using quantitative data on species’ population trajectories, but in the absence of such data, assessments often rely on qualitative estimates based on expert opinion of species abundances, distributions and threats. For example, one-third of coral species are classified as threatened and another third as near threatened on the IUCN Red List, despite a lack of data at the population level for the vast majority of species. Since many taxa show a strong correlation between species traits and extinction risk, an alternate approach is to identify traits associated with extinction in other groups and apply them to the taxon of interest. Here, we examine whether life-history traits associated with stress tolerance, fecundity and habitat specialisation are correlated with Red List conservation status in reef corals. We found no relationship between conservation status and life-history traits, suggesting that either traits identified as important predictors of extinction risk in other taxa are not important in corals, or that conservation status does not accurately reflect species’ relative extinction risk. Therefore, using global-scale extinction risk assessments to inform conservation of coral reefs presents a high risk of ‘silent extinctions’ of undescribed species. We argue that the conservation status for the vast majority of coral species should be ‘data deficient’ and is likely to remain so for the foreseeable future, and that the status and trends of coral populations can only be reliably assessed at relatively small scales.

It is commonly accepted that species should move toward higher elevations and latitudes to track shifting isotherms as climate warms. However, temperature might not be the only limiting factor determining species distribution. Species might move to opposite directions to track changes in other climatic variables. Here, we used an extensive occurrence data set and an ensemble modelling approach to model the climatic niche and to predict the distribution of the seven baobab species (genus Adansonia) present in Madagascar. Using climatic projections from three global circulation models, we predicted species' future distribution and extinction risk for 2055 and 2085 under two representative concentration pathways (RCPs) and two dispersal scenarios. We disentangled the role of each climatic variable in explaining species range shift looking at relative variable importance and future climatic anomalies. Four baobab species (Adansonia rubrostipa, Adansonia madagascariensis, Adansonia perrieri¸ and Adansonia suarezensis) could experience a severe range contraction in the future (>70% for year 2085 under RCP 8.5, assuming a zero-dispersal hypothesis). For three out of the four threatened species, range contraction was mainly explained by an increase in temperature seasonality, especially in the North of Madagascar, where they are currently distributed. In tropical regions, where species are commonly adapted to low seasonality, we found that temperature seasonality will generally increase. It is, thus, very likely that many species in the tropics will be forced to move equatorward to avoid an increase in temperature seasonality. Yet, several ecological (e.g., equatorial limit, or unsuitable deforested habitat) or geographical barriers (absence of lands) could prevent species to move equatorward, thus increasing the extinction risk of many tropical species, like endemic baobab species in Madagascar.

Over 750 native bird species reside in or regularly migrate to Australia, many of which have experienced rapid changes in habitat extent over the past two centuries. By 2020, eight taxa were considered Extinct and 10% threatened with extinction. Understanding the underlying extrinsic and intrinsic factors that increase extinction risk can allow prioritisation of conservation management and research. Here, we use state-of-the-art phylogenetic comparative models to reveal the most important biological traits that predispose Australian bird species to elevated extinction risk. We use an extensive database of their biological traits and relate these to each species’ national and global IUCN extinction risk status as assessed over the past three decades (in 1990, 2000, 2010, and 2020). We show that high evolutionary distinctiveness (uniqueness), island endemism, and an inability to take advantage of agricultural habitats were the most important traits explaining elevated extinction risk in species when phylogeny is controlled for, suggesting that extinction risk is disproportionately high in species with high evolutionary distinctiveness. Extinct taxa were characterised by large body mass and island endemism compared to taxa extant in 2020. Our study provides the largest and most up-to-date analysis of the intrinsic traits of Australian birds in relation to their extinction risk, and can be used as a baseline in future studies, for prioritisation of conservation actions, and for policy advice on a broad scale.

There has been an increasing number of studies on species extinction because of global warming based on estimations of changes in species distributions. Life cycle impact assessment methods do not have a biodiversity damage factor for global warming that uses the extinction risk index. In this study, a method for determining the extinction risks of individual species per unit CO2 emission was proposed and test calculations of the extinction risks of 216 species of Japanese vascular plants were performed. We also examined the possibility of determining local and global extinction risk factors using this method. This method uses the Expected Increase in the Number of Extinction Species (EINES), which is defined as the inverse of the time to extinction, as the extinction risk index. Procedures for determining the extinction risks of individual species per unit CO2 emission (EINES/species/kg) are as follows. First, based on the base scenario of CO2 emission, a niche-based species distribution model is used to estimate species distribution areas in 2000 and 2100 and calculate the distribution area decrease over 100 years. The number of years before the zero distribution area is then determined by assuming that the decrease is constant. Extinction risk is defined as the inverse of this time. The final step is to determine the extinction risk at specific CO2 emissions in addition to the base emission scenario and divide the difference in the extinction risk by the additional amount of CO2 emissions. The distribution areas of 216 species of Japanese vascular plants having southern distribution limits were estimated to decrease by 40–85% in 100 years. The accuracy of the estimation was sufficient according to the value of area under the curve (AUC). Considering climate models and migration conditions, the extinction risk per unit CO2 emission was estimated between −0.6 × 10−18 and 4.7 × 10−18 (EINES/species/kg). We converted the normalization values of the extinction risk of Japan for the 216 species to compare impact of land use changes and waste processing with that of global warming on the species. We found that global warming has smaller impact compared with land use changes and larger impact compared with waste processing. A method for estimating the extinction risks of species per unit CO2 emission was proposed, and it can be used to determine the local and global extinction risk factors of CO2.

The successful implementation of the Convention on Biological Diversity's post‐2020 Global Biodiversity Framework will rely on effective translation of targets from global to national level and increased engagement across diverse sectors of society. Species conservation targets require policy support measures that can be applied to a diversity of taxonomic groups, that link action targets to outcome goals, and that can be applied to both global and national data sets to account for national context, which the species threat abatement and restoration (STAR) metric does. To test the flexibility of STAR, we applied the metric to vascular plants listed on national red lists of Brazil, Norway, and South Africa. The STAR metric uses data on species’ extinction risk, distributions, and threats, which we obtained from national red lists to quantify the contribution that threat abatement and habitat restoration activities could make to reducing species’ extinction risk. Across all 3 countries, the greatest opportunity for reducing plant species’ extinction risk was from abating threats from agricultural activities, which could reduce species’ extinction risk by 54% in Norway, 36% in South Africa, and 29% in Brazil. Species extinction risk could be reduced by a further 21% in South Africa by abating threats from invasive species and by 21% in Brazil by abating threats from urban expansion. Even with different approaches to red‐listing among countries, the STAR metric yielded informative results that identified where the greatest conservation gains could be made for species through threat‐abatement and restoration activities. Quantifiably linking local taxonomic coverage and data collection to global processes with STAR would allow national target setting to align with global targets and enable state and nonstate actors to measure and report on their potential contributions to species conservation.

Around the world, endemic species with restricted ranges seem to be at particular risk of extinction. When range size is controlled, lowland continental species may be especially at risk, more so than island or montane species. Our study aimed to investigate reasons behind the high vulnerability of endemic species. In Sri Lanka, large‐scale national surveys and intensive localized fieldwork established that endemic plant and animal species are mostly associated with undisturbed rainforest habitats. On the other hand, non‐endemic species used both forest and non‐forest habitats almost equally, suggesting they are less likely to suffer from deleterious edge effects. To understand the different distribution of endemic and non‐endemic species, our study focused on rats. Compared to the widespread species, the endemic rat species had a larger home range and fed on fewer species of forest fruit, possibly indicating greater specialization. The abundance of the endemic species was also negatively correlated with the abundance of the non‐endemic species, to which it was behaviourally subordinate. Greater specialization and competitive inferiority could both contribute to the vulnerability of endemic species.

Mountain forest ecosystems provide us with life-supporting ecosystem services that are valuable for local, regional, and global communities. Ecological niche-based models have been used extensively, with remarkable success, in understanding the influence of climate change on potential distribution of species. In this study, we used maximum entropy (MaxEnt) modelling to predict the potential distribution of ecologically important tree species, Abies, Picea, and Juniperus, at the eastern edge of the Tibetan Plateau in China. The potential distribution of tree species was modelled and predicted on genus level for current and three representative concentration pathway (RCPs) based future (2050s and 2070s) climate conditions. The model performed well and gave reliable results for current and potential species’ distribution. Precipitation of wettest month was the most important environmental variable for determining the habitat suitability of all tree species, with 30.3% (Abies), 51.2% (Picea), and 57% (Juniperus) contribution to model output, respectively. Temperature seasonality, temperature annual range, and soil type also made the most significant contribution to model outputs. Model projections under current climate highlight that the total suitable habitats, which included regions with different probability of species occurrence, for Abies (3234.2 km2) was much higher than Picea (2003.7 km2) and Juniperus (1784.8 km2). However, projections of habitat suitability under current climate scenario projected onto future climate change scenarios for all concentration pathways in 2050s and 2070s, showed a clear decline in potentially suitable habitats for all three species. The shifts in geographic distributions under future climate scenarios showed an unusual pattern, with slight downward shift of the mean elevation with high habitat suitability for the occurrence of tree species in most RCPs, accompanied by a decrease in the elevational range of suitable habitats. The results of this study highlight the urgent need for forest management strategies to conserve the habitats of these species. Our study offers base-line information on the impact of climate-change on major tree species which can aid in guiding adaptation strategies for forest conservation and management in order to sustain the delivery of ecosystem services in the future.