Areas Of Potential Habitat Research Articles

Combining species distribution modeling and distance sampling to assess wildlife population size: A case study with the northern yellow-cheeked gibbon (Nomascus annamensis).

Population size and distribution data for wildlife species play an important role in conservation and management, especially for endangered species. However, scientists seriously lack data on the population status of many species. The northern yellow-cheeked gibbon (Nomascus annamensis) is found in southern Lao PDR, central Vietnam, and northeastern Cambodia. The population of the species has significantly declined due to hunting, habitat loss, and the wildlife trade. To examine the population size and distribution of N. annamensis, we conducted a field survey in Song Thanh Nature Reserve, Quang Nam Province, central Vietnam from February to April 2019 using the audio point count method. We combined Distance Sampling and Ecological Niche Modeling to estimate the population of the gibbons. Results showed that the total suitable area for the gibbons was about 302.32 km2 , with the two most important variables of the habitat model being the distance-to-villages and forest type. We detected 36 gibbon groups through field surveys and estimated 443 (95% CI, 278-707) gibbon groups in Song Thanh Nature Reserve. Our results indicate that the gibbon population in Song Thanh Nature Reserve is the largest known population of N. annamensis in Vietnam. In addition, our study was the first to combine species distribution modeling with distance sampling to estimate gibbon density and population size. This approach might be useful in surveying and monitoring gibbon populations because it takes imperfect detection probability into account in estimating gibbon population density while estimating the area of potential habitat using environmental variables.

Incorporating Landscape Character in Cork Oak Forest Expansion in Sardinia: Constraint or Opportunity?

Cork oak (Quercus suber) is a declining woodland species across the island of Sardinia, despite its former economic importance for wine production and its significance for biodiversity. In particular, cork oak forests (COFs) on the island have seen a 29% decrease in the past 45 years. A spatial GIS model was developed to determine suitability for the expansion of cork oak forests on the island. The model uses a set of simple spatial decision rules based on principles of landscape ecology and expert opinion to assign a suitability score for pure cork oak forests to every land use parcel in Sardinia. These rules include the type of existing land parcel, its size, distance to existing cork oak forest, and the area of seminatural habitats in its neighborhood. This was coupled with a map of landscape types to assist with the development of policy for the protection of cork oak forests across Sardinia. The results show that there is an area of 116,785 ha potentially suitable for cork oak forest expansion in Sardinia, with the largest area of potential habitat on granitic mountains. There is a substantial overall agreement (Cohen’s kappa = 0.61) between the suitability map produced and the historical reference map. The model is flexible and can be rerun to reflect changes in policy relating to agri-environmental targets for habitats and species.

National parks influence habitat use of lowland tapirs in adjacent private lands in the Southern Yungas of Argentina

Abstract Protected areas are cornerstones of conservation efforts worldwide. However, protected areas do not act in isolation because they are connected with surrounding, unprotected lands. Few studies have evaluated the effects of protected areas on wildlife populations inhabiting private lands in the surrounding landscapes. The lowland tapir Tapirus terrestris is the largest terrestrial mammal of the Neotropics and is categorized as Vulnerable on the IUCN Red List. It is necessary to understand the influence of landscape characteristics on the tapir's habitat use to enable effective conservation management for this species. Our objectives were to (1) determine the potential distribution of the lowland tapir's habitat in the Southern Yungas of Argentina, and (2) evaluate the role of protected areas and other covariates on tapir habitat use in adjacent private lands. We used records of lowland tapirs to model the species' potential distribution and determined habitat use with occupancy modelling. Based on the covariates found to be significant in our models, we constructed predictive maps of probability of habitat use and assessed the area of potential habitat remaining for the species. Probability of habitat use was higher in the vicinity of two national parks and small households than further away from them. We found that in 85% of the lowland tapir's potential distribution the probability of habitat use is high (> 0.5). These areas are near the three national parks in the study area. The probability of detecting lowland tapirs increased with distance to roads. We conclude that national parks play a key role in the persistence of lowland tapir populations on adjacent private lands.

Eutetranychus orientalis Klein (oriental spider mite). Phytosanitary risk analysis for Ukraine

Goal. To carry out the analysis of phytosanitary risk for Ukraine of a dangerous quarantine pest Eutetranychus orientalis Klein (oriental spider mite).
 Research Methods. The main method is information-analytical. We conducted analytical research and analysis of reports from the Mediterranean, World Plant Protection Organizations, literary sources of scientific publications and online resources. Phytosanitary risk analysis (PRA) was performed according to the EPPO standards PM 5/3 (5), PM 5/1, PM 5/4 [3, 4, 5]. The possibility of acclimatization of the pest was determined using modern computer programs IDRISI SELVA, MapInfo Pro 15.0 and AgroAtlas.
 Results. Eutetranychus orientalis Klein (oriental spider mite) absent in Ukraine is a polyphage, it can damage 217 species of plants, preferring citrus, and is widespread in the world. Many species of plants that are host plants of the eastern spider mite grow in Ukraine and are important in the production of fruits, vegetables, and oils. The primary pest habitat was the Middle East, but currently E. orientalis is found in many countries in Asia, Africa, Europe, Oceania and is in a wide climatic range. Thus, in European countries which lie in the pest habitat, the climate is subtropical, Mediterranean and temperate, transitional to continental (Greece, Spain, Cyprus, Turkey). In Asia (China, India, Israel, Iraq, Saudi Arabia), the area of the pest occupies territories dominated by tropical, subtropical and temperate climates. In recent years, several species of tetrachnid mites, including E. orientalis, have expanded their geographical range, mainly due to increased trade and travel around the world, posing a threat to agriculture in many countries. Under optimal conditions, 25 generations per year can occur. The spread of E. orientalis is by air masses or anthropic. Distribution of E. orientalis is carried out by air masses or anthropically. The most likely pathway for spreading the pest is through infected planting material. Given the high reproductive potential of E. Orientalis, the rate of expansion of the habitat, the diversity of the plant’s food supply, its adaptability to a wide range of climatic conditions, there is a need to analyze the phytosanitary risk (AFR) of the eastern spider mite for Ukraine. The end result of the research is the determination of the quarantine status of the pest and the proposal for amendments to the «List of regulated pests» that are quarantined in Ukraine.
 Conclusions. There is a high likelihood of acclimatization of Eutetranychus orientalis in Ukraine, which is due to the large number of host plants and compliance with the species requirements to the climatic conditions. Potential habitat area in Ukraine may be the southern coast of Crimea. Phytosanitary risk analysis of Eutetranychus orientalis Klein (Eastern spider mite) for Ukraine identified the need for the pest to be granted the status of a quarantine organism absent in Ukraine (list A1) and to amend the «List of regulated pests of Ukraine».

Niche Partitioning among Native Ciscoes and Nonnative Rainbow Smelt in Lake Superior

AbstractSeveral species of ciscoesCoregonus, subgenusLeucichthysthat are native to the Laurentian Great Lakes are rare or extirpated. The restoration ofCoregonusfishes is being actively pursued through stocking, and success may depend on the availability of unoccupied niche space. We described the spring–summer habitat occupancy and diets of three native cisco species (BloaterCoregonus hoyi, CiscoC. artedi,and KiyiC. Kiyi) and invasive Rainbow SmeltOsmerus mordaxin Lake Superior and measured niche overlap among these species for both small and large sizes. The potential habitat area was highest for Cisco and Kiyi, followed by Bloater and Rainbow Smelt. The probability of overlap in habitat occupation, as measured by bathymetric depth, fish capture depth, distance from shore, and fish capture water temperature was highest for small Rainbow Smelt and Cisco. Trophic overlap, as measured by stomach contents and stable isotopes, was highest between small Bloater and Cisco and between large Bloater and Kiyi. All of the species showed significant ontogenetic change in both habitat occupation and diet. The overall niche overlap in spring–summer habitat and diet was greatest between small Cisco and Rainbow Smelt and between large Bloater and Kiyi; however, differences in individual niche dimensions likely limit competition for both species pairs. Synthesizing the diet and habitat niche data revealed nuanced niches that allow these seemingly similar planktivorous species to coexist. Kiyi had the least niche overlap with other cisco species and Rainbow Smelt, so from an available niche perspective Kiyi would be a strong candidate for reintroduction into lakes from which they were extirpated.

Natal Dispersal of Aplomado Falcons in Chihuahua, Mexico

The persistence of a species throughout its geographic range requires dispersal among its populations. The study of dispersal is particularly relevant for species whose geographic range has contracted, such as the endangered Northern Aplomado Falcon (Falco femoralis septentrionalis). We used Argos 5-g PTT-100 satellite transmitters to determine the movements of two wild Chihuahuan Desert Aplomado Falcons (one female and one male) from fledging to breeding (male), or transmitter failure (female), at 1062 d and 439 d of age, respectively. Both falcons dispersed from their natal territories 2–3 mo after fledging. These falcons then wandered between activity centers near historic breeding territories and some territories recently converted to farmlands. These two falcons also explored areas outside known breeding areas via some long-distance movements to areas of potential breeding habitat being converted to farmland. In 2 yr, movements of the male covered 7412 km2. This falcon nested unsuccessfully with an unbanded female in a vacant breeding territory 15 km from his natal site. His nesting attempt the following year yielded two fledglings. While a breeding bird, the male falcon had a home range of 200 km2. For 17 mo, the female falcon wandered through an area of 12,136 km2. The farthest distance she traveled from her nest site prior to transmitter failure was 154 km.

POTENTIAL HABITAT MODELING OF WATER HYACINTH IN LAKES OF NEPAL USING MAXENT ALGORITHM

Abstract. Invasive Alien Plant Species are spreading outside of their natural geographic range. Water hyacinth (Eichhornia crassipes) is one of the most widely and rapidly spreading invasive species throughout the tropical and subtropical regions of Nepal. In the last decade, water hyacinth has become a chronic problem in many major lakes of Nepal which have affected the habitat aquatic plants and animals. Our study focuses on potential habitat modeling of Water hyacinth over the major lakes of Nepal using Maxent algorithm. Primary data used for modeling were 19 bioclimatic variables and Shuttle Radar Topography Model (SRTM) Digital Elevation Model (DEM). After preparation of the species distribution model, major lakes of Nepal were overlaid over the model to prepare potential invasive map. The performance and accuracy of potential habitat distribution model was evaluated using parameter Area under the Receiver Operating Characteristic Curve (AUC) which was within the range of 0.9–1. Validation of the model was done for the year 2015 with precision and recall, overall accuracy and F-measure and its values are 93% and 85%, 87% and 89% respectively. The model prepared for 2030 and 2050 shows the most suitable habitat for water hyacinth is in province 2 of Nepal and the moderately suitable habitat for this species is plain area of Province 4, 7 and 5. Similarly, the area of potential habitat has been increasing from current scenario to 2030 and 2050. From the potential invasion map, it can be observed that lakes in the Terai and Churey regions have the high risk of invasion of water hyacinth.

Modeling reservoir management for malaria control in Ethiopia

This study investigated how changes in reservoir water level affect mosquito abundance and malaria transmission in Ethiopia. Digital elevation models of three Ethiopian dams at lowland, midland and highland elevations were used to quantify water surface area and wetted shoreline at different reservoir water levels (70, 75, 80, 85, 90, 95 and 100% full capacity) to estimate surface area of potential mosquito breeding habitat. Reservoir water level drawdown rates of 10, 15 and 20 mm.day−1 were applied as scenarios to model larval abundance, entomological inoculation rate (EIR) and malaria prevalence at each dam. Malaria treatment cost and economic cost in terms of lost working days were calculated for each water level scenario and dam. At the lowland dam, increased larval abundances were associated with increasing reservoir water level and wetted shoreline area. In contrast, both larval abundances and area of wetted shoreline declined with increasing reservoir water level at the midland and highland dams. Estimated EIR, malaria prevalence, malaria treatment cost and economic cost generally decreased when the water level drawdown rate increased from 10 to 15 and 20 mm.day−1 irrespective of reservoir water level. Given the expansion of dam construction in sub-Saharan Africa, incorporating malaria control measures such as manipulating drawdown rates into reservoir management has the potential to reduce the malaria burden and health care costs in communities near reservoirs.

Distribution mapping of specialized amphibian species in rare, ephemeral habitats: Implications for the conservation of threatened “acid” frogs in south‐east Queensland

AbstractThe acid frogs of eastern Australia are a highly specialized group of threatened species endemic to acidic coastal wetlands of southern Queensland and New South Wales. The distribution of these species overlaps with areas of increasing development where land‐use intensification poses a significant threat. Successful conservation of these species requires that areas of high conservation value for acid frogs are properly identified and protected, particularly in south‐east Queensland which supports important populations of all four acid frog species: Litoria olongburensis, Litoria freycineti, Crinia tinnula, and the Queensland‐endemic Litoria cooloolensis. Species distribution modeling using rigorously vetted species occurrence data was used to identify areas of potential acid frog habitat with >89% predictive power for all species. Key predictor variables for acid frog species occurrence included: soil sandiness, vegetation, presence and/or type of wetland, and soil clay content. All species' predicted distributions occurred primarily in coastal regions, overlapping with densely human‐populated areas. Our modeling and analysis of species' distributions highlight local government areas where protection of wallum habitat is most important for the conservation of acid frogs, as well as areas of higher conservation value providing habitat for multiple acid frog species.

Identifying climate refugia and its potential impact on Tibetan brown bear (Ursus arctos pruinosus) in Sanjiangyuan National Park, China.

Climate change has direct impacts on wildlife and future biodiversity protection efforts. Vulnerability assessment and habitat connectivity analyses are necessary for drafting effective conservation strategies for threatened species such as the Tibetan brown bear (Ursus arctos pruinosus). We used the maximum entropy (MaxEnt) model to assess the current (1950–2000) and future (2041–2060) habitat suitability by combining bioclimatic and environmental variables, and identified potential climate refugia for Tibetan brown bears in Sanjiangyuan National Park, China. Next, we selected Circuit model to simulate potential migration paths based on current and future climatically suitable habitat. Results indicate a total area of potential suitable habitat under the current climate scenario of approximately 31,649.46 km2, of which 28,778.29 km2 would be unsuitable by the 2050s. Potentially suitable habitat under the future climate scenario was projected to cover an area of 23,738.6 km2. Climate refugia occupied 2,871.17 km2, primarily in the midwestern and northeastern regions of Yangtze River Zone, as well as the northern region of Yellow River Zone. The altitude of climate refugia ranged from 4,307 to 5,524 m, with 52.93% lying at altitudes between 4,300 and 4,600 m. Refugia were mainly distributed on bare rock, alpine steppe, and alpine meadow. Corridors linking areas of potentially suitable brown bear habitat and a substantial portion of paths with low‐resistance value were distributed in climate refugia. We recommend various actions to ameliorate the impact of climate change on brown bears, such as protecting climatically suitable habitat, establishing habitat corridors, restructuring conservation areas, and strengthening monitoring efforts.

Predicting growth and habitat responses of Ginkgo biloba L. to climate change

Key messageWe developed a climatic response function using 20-year tree height observed from 45Ginkgo bilobaplantations in China and used it to predict the growth and habitat responses to anticipated climate change. We projected northward and upward shifts in the species habitat and productive areas, but a dramatic contraction of the species distribution is unlikely to occur at least during the present century.ContextGinkgo biloba is the only living species in the division Ginkgophyta. The species exists in small natural populations in southeastern China but is cultivated across China and the world. The species’ future under climate change is of concern.AimsThis study was initiated to model the species’ growth response to climate change and to predict its range of suitable habitat under future climates.MethodsUsing height data from 45 20 years old plantations growing under a wide range of climatic conditions across China, we developed univariate and bivariate climatic response functions to identify the climate requirements of the species.ResultsAccording to the amount of variance explained (> 70%) and the high level of agreement (> 99%) with independent species occurrence coordinates, the developed climate response function was highly accurate and credible. Projections for future periods (2011–2040, 2041–2070, and 2071–2100) under the Representative Concentration Pathway 4.5 (RCP4.5) scenario indicated that the areas of potential suitable habitat would increase (25–67 million hectares). It would also be associated with northward (0.21–0.62° in latitude) and elevational (24–75 m) shifts.ConclusionGlobal climate change is projected to increase the area of potential suitable habitats for Ginkgo and shift its spatial distributions northward and upward.

Potential habitat and priority protection area of cranes with climate change in the Great Xing'an Mountains, China

To clarify the impacts of climate change on the potential distribution of six crane species in the Great Xing'an Mountains region, and promote the effective protection of these species, we selected key environmental variables such as climate, topography, and vegetation type based on Pearson correlation and Jackknife analysis, and modeled the potential distribution of six crane species in the Great Xing'an Mountains using MaxEnt with the current and the future climate change scenarios (RCP4.5 and RCP8.5). We identified the priority protection areas (PPAs) and the target PPAs by zonation and ArcGIS. The results showed that with the current climate condition, the sui-table habitats of these species were mainly distributed in the central and the northwest part of the Great Xing'an Mountains. With RCP4.5 and RCP8.5 scenarios, the suitable habitats of Grus monacha, Grus japonensis, Grus vipio, Grus grus and Anthropoides virgo would decrease, while that of Grus leucogeranus would expand by 5.4%-6.3%. With current and the future climate change scenarios, the PPAs of these species were mainly distributed in the northwest, southeast and west-central parts of the Great Xing'an Mountains. The protect rate could reach about 20.1%-23.8% of the target PPAs conserved by protected areas (PAs). The protection gaps were mainly distributed in the west of Mohe County, the north-central of Ergun, the central and east of Genhe, the northeast of Yakeshi, and the south of Oroqen Autonomous Banner. We proposed to expand PAs to provide a strong guarantee for the effective protection of cranes species.

Modelling the environmental niche space and distributions of cold-water corals and sponges in the Canadian northeast Pacific Ocean

Cold-water coral and sponge (CWCS) communities are important indicators of vulnerable marine ecosystems (VMEs) and are used to delineate areas for marine conservation and fisheries management. Although the northeast Pacific region of Canada (NEPC) is notable for having unique CWCS assemblages and is the location of >80% of Canadian seamounts, the extent of potential CWCS-defined VMEs in this region is unknown. Here, we used a diverse set of environmental data layers (n=30) representing a range of bathymetric derivatives, physicochemical variables, and water column properties to assess the primary factors influencing the niche separation and potential distributions of six habitat-forming groups of CWCS in the NEPC (sponge classes: Hexactinellida, Demospongiae; coral orders: Alcyonacea, Scleractinia, Antipatharia, Pennatulacea). The primary environmental gradients that influence niche separation among CWCS are driven by total alkalinity, dissolved inorganic carbon, and dissolved oxygen. Significant niche separation among groups indicates CWCS to be primarily specialists occurring in rare habitat conditions in the NEPC. Species distribution models (SDMs) developed for each CWCS group shared severely low dissolved oxygen levels ([O2] < 0.5 ml L−1) as a top predictor for habitat suitability in the NEPC. Niche separation is further emphasized by differences in the model-predicted areas of suitable habitat among CWCS groups. Although niches varied among taxa, the general areas of high habitat suitability for multiple CWCS groups in the NEPC occurred within the 500–1400 m bottom depth range which is strongly associated with the extensive oxygen minimum zone (OMZ) characterizing this region. As a result, the largest continuous area of potential CWCS habitat occurred along the continental slope with smaller, isolated patches also occurring at several offshore seamounts that have summits that extend into OMZ depths. Our results provide insight into the factors that influence the distributions of some of the most important habitat-forming taxa in the deep ocean and create an empirical foundation for supporting cold-water coral and sponge conservation in the NEPC.

SUPPORT VECTOR MACHINE AND DECISION TREE BASED CLASSIFICATION OF SIDE-SCAN SONAR MOSAICS USING TEXTURAL FEATURES

Abstract. The diversity and heterogeneity of coastal, estuarine and stream habitats has led to them becoming a prevalent topic for study. Woody ruins are areas of potential riverbed habitat, particularly for fish. Therefore, the mapping of those areas is of interest. However, due to the limited visibility in some river systems, satellites, airborne or other camera-based systems (passive systems) cannot be used. By contrast, sidescan sonar is a popular underwater acoustic imaging system that is capable of providing high- resolution monochromatic images of the seafloor and riverbeds. Although the study of sidescan sonar imaging using supervised classification has become a prominent research subject, the use of composite texture features in machine learning classification is still limited. This study describes an investigation of the use of texture analysis and feature extraction on side-scan sonar imagery in two supervised machine learning classifications: Support Vector Machine (SVM) and Decision Tree (DT). A combination of first- order texture and second-order texture is investigated to obtain the most appropriate texture features for the image classification. SVM, using linear and Gaussian kernels along with Decision Tree classifiers, was examined using selected texture features. The results of overall accuracy and kappa coefficient revealed that SVM using a linear kernel leads to a more promising result, with 77% overall accuracy and 0.62 kappa, than SVM using either a Gaussian kernel or Decision Tree (60% and 73% overall accuracy, and 0.39 and 0.59 kappa, respectively). However, this study has demonstrated that SVM using linear and Gaussian kernels as well as a Decision Tree makes it capable of being used in side-scan sonar image classification and riverbed habitat mapping.

Current and future potential distributions of three Dracaena Vand. ex L. species under two contrasting climate change scenarios in Africa.

Forest undergrowth plants are tightly connected with the shady and humid conditions that occur under the canopy of tropical forests. However, projected climatic changes, such as decreasing precipitation and increasing temperature, negatively affect understory environments by promoting light‐demanding and drought‐tolerant species. Therefore, we aimed to quantify the influence of climate change on the spatial distribution of three selected forest undergrowth plants, Dracaena Vand. ex L. species, D. afromontana Mildbr., D. camerooniana Baker, and D. surculosa Lindl., simultaneously creating the most comprehensive location database for these species to date.A total of 1,223 herbarium records originating from tropical Africa and derived from 93 herbarium collections worldwide have been gathered, validated, and entered into a database. Species‐specific Maxent species distribution models (SDMs) based on 11 bioclimatic variables from the WorldClim database were developed for the species. HadGEM2‐ES projections of bioclimatic variables in two contrasting representative concentration pathways (RCPs), RCP2.6 and RCP8.5, were used to quantify the changes in future potential species distribution. D. afromontana is mostly sensitive to temperature in the wettest month, and its potential geographical range is predicted to decrease (up to −63.7% at RCP8.5). Optimum conditions for D. camerooniana are low diurnal temperature range (6–8°C) and precipitation in the wettest season exceeding 750 mm. The extent of this species will also decrease, but not as drastically as that of D. afromontana. D. surculosa prefers high precipitation in the coldest months. Its potential habitat area is predicted to increase in the future and to expand toward the east.This study developed SDMs and estimated current and future (year 2050) potential distributions of the forest undergrowth Dracaena species. D. afromontana, naturally associated with mountainous plant communities, was the most sensitive to predicted climate warming. In contrast, D. surculosa was predicted to extend its geographical range, regardless of the climate change scenario.

Modeling impacts of climate change on the potential habitat of an endangered Brazilian endemic coral: Discussion about deep sea refugia.

Climate and environmental conditions are determinant for coral distribution and their very existence. When changes in such conditions occur, their effects on distribution can be predicted through species distribution models, anticipating suitable habitats for the subsistence of species. Mussismilia harttii is one of the most endangered Brazilian endemic reef-building corals, and in increasing risk of extinction. Herein, species distribution models were used to determine the present and future potential habitats for M. harttii. Estimations were made through the maximum entropy approach, predicting suitable habitat losses and gains by the end of the 21st century. For this purpose, species records published in the last 20 years and current and future environmental variables were correlated. The best models were chosen according to the Akaike information criterion (AIC) and evaluated through the partial ROC (AUCratio), a new approach which uses independent occurrence data. Both approaches showed that the models performed satisfactorily in predicting potential habitat areas for the species. Future projections were made using the International Panel on Climate Change (IPCC) scenarios for 2100, with different levels of greenhouse gas emission. Representative Concentration Pathways (RCPs) were used to model the Future Potential Habitat (FPH) of M. harttii in two different scenarios: stabilization of emissions (RCP 4.5) and increase of emissions (RCP 8.5). According to the results, shallow waters to the south of the study area concentrate most of the current potential habitats for the species. However, in future scenarios, there was a loss of suitable areas in relation to the Current Potential Habitat (RCP 4.5 46% and RCP 8.5 59%), whereas there is a southward shift of the suitable areas. In all scenarios of FPH, the temperature was the variable with the greatest contribution to the models (> 35%), followed by the current velocity (> 33%) and bathymetry (>29%). In contrast, there is an increase of deep (50–75 m) suitable areas FPH scenarios, mainly in the southern portion of its distribution, at Abrolhos Bank (off Espirito Santo State). These deeper sites might serve as refugia for the species in global warming scenarios. Coral communities at such depths would be less susceptible to impacts of climate change on temperature and salinity. However, the deep sea is not free from human impacts and measures to protect deeper ecosystems should be prioritized in environmental policies for Brazilian marine conservation, especially the Abrolhos Bank, due to its importance for M. harttii.

Genomic evidence of survival near ice sheet margins for some, but not all, North American trees

Temperate species experienced dramatic range reductions during the Last Glacial Maximum, yet refugial populations from which modern populations are descended have never been precisely located. Climate-based models identify only broad areas of potential habitat, traditional phylogeographic studies provide poor spatial resolution, and pollen records for temperate forest communities are difficult to interpret and do not provide species-level taxonomic resolution. Here we harness signals of range expansion from large genomic datasets, using a simulation-based framework to infer the precise latitude and longitude of glacial refugia in two widespread, codistributed hickories (Carya spp.) and to quantify uncertainty in these estimates. We show that one species likely expanded from close to ice sheet margins near the site of a previously described macrofossil for the genus, highlighting support for the controversial notion of northern microrefugia. In contrast, the expansion origin inferred for the second species is compatible with classic hypotheses of distant displacement into southern refugia. Our statistically rigorous, powerful approach demonstrates how refugia can be located from genomic data with high precision and accuracy, addressing fundamental questions about long-term responses to changing climates and providing statistical insight into longstanding questions that have previously been addressed primarily qualitatively.

Soil moisture from remote sensing to forecast desert locust presence

Abstract Preventive control of desert locusts is based on monitoring recession areas to detect outbreaks. Remote sensing has been increasingly used in the preventive control strategy. Soil moisture is a major ecological driver of desert locust populations but is still missing in the current imagery toolkit for preventive management. By means of statistical analyses, combining field observations of locust presence/absence and soil moisture estimates at 1 km resolution from a disaggregation algorithm, we assess the potential of soil moisture to help preventive management of desert locust. We observe that a soil moisture dynamics increase of above 0.09 cm3/cm3 for 20 days followed by a decrease of soil moisture may increase the chance to observe locusts 70 days later. We estimate the gains in early warning timing compared to using imagery from vegetation to be 3 weeks. We demonstrate that forecasting errors may be reduced by the combination of several types of indicators such as soil moisture and vegetation index in a common statistical model forecasting locust presence. Policy implications. Soil moisture estimates at 1 km resolution should be used to plan desert locust surveys in preventive management. When soil moisture increases in a dry area of potential habitat for the desert locust, field surveys should be conducted two months later to evaluate the need of further preventive actions. Remote sensing estimates of soil moisture could also be used for other applications of integrated pest management.

Conservation planning for species recovery under the Endangered Species Act: A case study with the Northern Spotted Owl.

The northern spotted owl (Strix occidentalis caurina) was listed as threatened under the U.S. Endangered Species Act (ESA) in 1990. We applied modern spatial conservation theory and models to evaluate several candidate critical habitat networks, and sought an efficient conservation solution that encompassed the highest value lands for spotted owl recovery rather than maximizing the total area of potential critical habitat. We created a map of relative habitat suitability, which served as input to the spatial conservation prioritization program Zonation. We used the spatially-explicit individual-based population model HexSim to estimate and compare simulated spotted owl population outcomes among a suite of candidate critical habitat networks that varied in size and spatial arrangement under alternative scenarios of future habitat suitability and barred owl (S. varia) effects. We evaluated simulated spotted owl population outcomes, including total population size, and extinction and quasi-extinction likelihoods for 108 combinations of candidate critical habitat networks by habitat change by barred owl scenarios, both range-wide and within 11 distinct portions of the owl’s range. Barred owl encounter rates and the amount and suitability of habitat had substantial effects on simulated spotted owl populations. When barred owl encounter rates were high, changes in the amount and suitability of habitat had minimal impacts on population performance. Under lowered barred owl encounter rates, candidate critical habitat networks that included most existing high suitability habitat supported a high likelihood of long-term population persistence. Barred owls are currently the primary driving force behind poor population performance of NSOs; however, our models demonstrated that a sufficient area of high suitability habitat remains essential for recovery when effects of barred owls can be reduced. The modeling approach we employed is sufficiently flexible to incorporate new information about spotted owls as it becomes available and could likely be applied to conservation planning for other species.

All the eggs in one basket: Are island refuges securing an endangered passerine?

AbstractRefuges for threatened species are important to prevent species extinction. They provide protection from a range of environmental and biotic stressors, and ideally provide protection against all threatening processes. However, for some species it may not be clear why some areas are refuges and others are not. The forty‐spotted pardalote (Pardalotus quadragintus) is an endangered, sedentary, cryptic and specialised bird endemic to the island of Tasmania, Australia. Having undergone an extreme range contraction over the past century the species is now mostly confined to a few small offshore island refuges. Key threatening processes to the species include habitat loss, wildfire, competition and predation. The ways in which these processes have molded the species’ contemporary range have not been clearly evaluated. Furthermore, the security of the remnant population within refuges is uncertain. To overcome this uncertainty we assessed key threats and established the population status in known refuges by developing a robust survey protocol within an occupancy modelling framework. We discuss our results in the context of planning trial reintroductions of this endangered species in suitable habitat across its former range. We found very high occupancy rates (0.75–0.96) at two refuges and in suitable conditions, the species was highly detectable (p, 0.43–0.77). At a third location our surveys indicated a local extinction, likely due to recent wildfire. We demonstrate that all refuges are at high risk of one or more threatening processes and the current distribution across island refuges is unlikely to secure the species from extinction. We identified large areas of potential habitat across the species’ former mainland range, but these are likely too distant from source populations for natural recolonisation. We propose that establishing new populations of forty‐spotted pardalotes via reintroduction is essential to secure the species and that this is best achieved while robust source populations still exist.