Affect Habitat Suitability Research Articles

Leopard activity patterns in a small montane protected area highlight the need for integrated, collaborative landscape conservation

Large protected areas are essential for the long-term conservation of wide-ranging or low-density large carnivore populations. However, small protected areas can also contribute to carnivore conservation if they have sufficient prey density, if wildlife crime is controlled and if they are connected to other protected areas and/or embedded within a larger matrix of at least partially suitable habitat. In the central highlands of Sri Lanka, the 31.6 km2 Horton Plains National Park (HPNP) is a mosaic of tropical montane cloud forest and patana grassland set within a mosaic landscape of forest and agriculture. We conducted a camera trapping study in 2017 and 2018 to estimate leopard densities in HPNP and predict their activity centers. A Bayesian multi-session spatially-explicit capture-recapture analysis of 249 independent captures across two 4-month camera trapping campaigns returned density estimates of 10.6 per 100 km2 (95% HDI = 8.0–16.0) in 2017 and 15.1 per 100 km2 (95% HDI = 13.3–18.7) in 2018. Female capture rates and activity centers remained stable over the two survey periods, indicating fidelity to the grasslands. In contrast, most male activity centers were predicted to fall outside of the park, which implied that a significant proportion of males’ activity occurred outside HPNP, likely with occasional returns to the prey-dense grassland area. As a result, HPNP is unlikely to be sufficient on its own to sustain the estimated leopard densities—particularly for males—without contribution from the surrounding landscape. Thus, although the Department of Wildlife Conservation maintains jurisdiction over wildlife anywhere in the country, interagency collaboration in research, management and conservation should be encouraged owing to multiple jurisdictions over land management that will affect habitat suitability for leopards. Finally, we highlight the potential benefits of maintaining an updated camera trap database for outreach and potential conflict management.

Spatial Analysis of Potential Nesting Habitat for Florida Sandhill Cranes

AbstractThe Florida sandhill crane Antigone canadensis pratensis is designated as threatened by the state of Florida, where there is an urgent need to map and quantify available habitat. First, we used habitat suitability index (HSI) modelling to map and assess potential nesting habitat for sandhill cranes in Florida. Second, we used spatial optimization approaches to calculate the maximum number of breeding pairs that can simultaneously occupy potential nests given that they both must be of some minimum quality and must be spaced some minimal distance apart. Mapping results reveal that nesting habitat is concentrated in the central portion of the state, with adequate brooding habitat appearing to be the most limiting factor affecting habitat suitability. Assuming nesting only occurs in habitat rated as high quality (HSI ≥ 0.7) and spacing between adjacent nests is ≥1,000 m, we conservatively estimate that 5,540 nesting pairs of Florida sandhill cranes can potentially be supported. Additional nesting pairs may be supported in habitats of marginal (HSI ≥ 0.3; 14,530) to moderate (HSI ≥ 0.5; 8,723) quality. The suitability maps and breeding pair estimates can be used to identify important habitat areas to focus crane conservation efforts, determine potentially limiting habitat features across the landscape, and potentially guide future population monitoring efforts. For example, grassland or prairie restoration could be used to potentially increase nesting pairs in the southern portion of the state where emergent wetlands are abundant but brooding habitat is lacking.

Pruning of small fruit crops can affect habitat suitability for Drosophila suzukii

Insect activity, survival, and development are affected by climatic conditions that elicit effects at multiple scales. Pruning small fruit crop canopies alters the microclimate, which in turn may influence insect pest activity. We investigated the effect of three canopy density treatments (high, medium, low) on Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) fruit infestation in blueberries and caneberries using a two-year, multi-state experiment. We quantified the effect of canopy density on canopy microclimate, fruit quality (total soluble solids, fruit firmness), and yield. To better understand heterogeneity in canopy microclimate, parameters were further separated by canopy location (exterior vs. interior) in Maryland. In both crops, meta-analyses reveal small magnitude effects of the plant canopy on microclimate, whereas analysis of variance did not separate these effects, with mean canopy differences of 0.1–0.7 °C and 0.5–1.3 % relative humidity (RH) between caneberry canopy densities and locations. In caneberry multi-state trials, 0.14 fewer D. suzukii larvae (g fruit)−1 occurred on average in the low canopy density treatment, and 0.2 fewer D. suzukii larvae (g fruit)−1 occurred in exterior raspberries in Maryland compared with the canopy interior. Artificially infested blueberry fruit indicated immature D. suzukii survival within fruit can vary across canopy densities and locations. Although lower total yield was produced in low density canopies, canopy density did not influence berry quality or marketable yield. Microhabitats provide important shelter from extreme environmental conditions; the availability of shelter and ability to locate it affects insect pest populations and distributions. Understanding how crop canopy microclimate affects D. suzukii infestation can inform efforts to develop habitat manipulation tactics and improve the efficiency of fruit production.

Hit or miss? Evaluating the effectiveness of Natura 2000 for conservation of forest bird habitat in Sweden

Biodiversity conservation often requires a landscape perspective. When establishing the Natura 2000 (N2k) network, the effectiveness of the sites and the influence of the surrounding landscapes for species of interest was often disregarded. We analyzed the effectiveness of N2k sites in Sweden for three forest bird species of conservation interest in the European boreal landscapes: lesser spotted woodpecker (LSW), Siberian jay (SJ) and hazel grouse (HG). Our objectives were to: 1) quantify effective suitable habitat area in N2k sites with and without consideration of the adjoining landscapes; 2) examine effective habitat area within N2k sites along the north-south vegetation gradient 3) analyze functionality of N2k sites and assess how forests outside the sites affect habitat suitability inside N2k. GIS-based habitat suitability index models were applied to calculate the amount of effective habitat within and outside N2k sites. N2k sites contributed with 10% (HG), 13% (SJ) and 51% (LSW) suitable habitat identified in Sweden. Functionality of forest environments as habitat was higher inside N2k sites for LSW within all vegetation zones, and for SJ in the Alpine and Middle Boreal zones; for HG habitat outside the sites was more functional in all zones accept Alpine and Middle Boreal. The majority of N2k sites were of quite small size (<500 ha) and the size influenced their functionality for LSW and HG, with larger N2k sites being more functional. For SJ, however, average functionality of N2k sites was not influenced by their size. The largest average habitat increase linked to considering the contribution of areas outside N2k sites for their functionality as habitat was for the N2k sites of smaller size (1-500 ha). Therefore, the presence and quality of forests outside of N2k sites are of a greater importance for smaller sites, and as such these should be carefully managed. To improve conservation efficiency of the N2k sites in Sweden, we call for incorporating them into the development and implementation of the regional Green Infrastructure plans.

Impact assessment of climate change on environmental flow component and water temperature—Kikuchi River

The Japanese archipelago extends over a large distance from north to south exposed to the effects of climate change. The aim of this study was to assess the impacts of climate change on environmental components by using hydrological indicators. The future climate change in the region was initially projected using HadGEM2-ES and MICRO5 models in three 20-year periods (2021–2040, 2041–2060 and 2061–2080), considering two representative concentration pathways (RCP4.5 & RCP8.5). The Kikuchi streamflow was then simulated using Soil and Water Assessment Tool modelling for the baseline (1986–2016) and future periods. Finally, the magnitude, duration, timing, and frequency of extreme flows were analysed using Indicators of Hydrologic Alteration software. The results showed a decrease in discharge under both models; however, a 2 m3/s increase was predicted under HadGEM2-ES (RCP4.5) in 2041–2060. Changes in river flow affect habitat suitability in aquatic ecosystems, and might have further impacts if the effects of water temperature are also considered. In our case study, water temperature was predicted to increase by up to 4 °C by 2080. This phenomenon will change habitat suitability, because important environmental flow components, such as the peaks of high flows and large flood frequency, will also increase.

Physicochemical Controls on Spatiotemporal Distribution and Benthic Mat Severity of Didymosphenia geminata in Pine Creek, an Unregulated Watershed in Northern Pennsylvania

Didymosphenia geminata (Didymo) is a benthic freshwater diatom that has been globally expanding its range and extracellular stalk production in freshwater ecosystems. Didymo has been observed in reaches downstream of hypolimnetic reservoir releases in the northeastern US since 2007. This study focused on a newly observed (2013) Didymo occurrence in Pine Creek, a highly forested and unregulated watershed in north-central Pennsylvania. Study objectives included comparing contemporary distribution with historical data to provide insight on historical occurrence, quantifying physicochemical controls on Didymo distribution and benthic mat severity, and examining historical changes in water chemistry that might affect habitat suitability. At present, Didymo cellular distribution is limited to upper reaches of Pine Creek where median soluble reactive phosphorus (SRP) is 2.7 µg/L; median SRP was 4.8 µg/L at sites where Didymo was absent. At the epicenter of distribution in Pine Creek where SRP was consistently <2 µg/L, increased streamflow flashiness and water temperature were associated with decreased benthic mat severity. My results suggest SRP thresholds for Didymo proliferation may vary depending on whether streams are regulated by reservoirs with hypolimnetic releases. Mann–Kendall trends tests of a ∼20-y water chemistry dataset show that orthophosphate and sulfate concentrations decreased while pH increased within Pine Creek, which may have implications for Didymo habitat suitability. Further research is warranted to determine whether improving water quality following the industrial era may facilitate Didymo colonization.

Correction to: Effects of ecoregional vulnerability on habitat suitability of invasive alien plants: an assessment using 13 species on a global scale

The development of new hypotheses can promote the explanation of mechanisms on plant invasion across different scales. We tested the hypothesis that ecoregional vulnerability can affect habitat suitability of invasive alien plants (IAPs) in non-native ranges. We used 13 IAPs, distributed around the world, and identified vulnerable ecoregions belonging to different biomes and biogeographical realms. Then, Maxent modeling was used to assess the habitat suitability of IAPs. We quantified the effects of ecoregional vulnerability on habitat suitability of IAPs as effect sizes using the log response ratio of habitat suitability. Ecoregional vulnerability had significant effects on habitat suitability for IAPs in invasive ranges across different biomes and biogeographical realms. Such effects may depend on the biomes and biogeographical realms of interest. Ecoregional vulnerability had positive effects on the habitat suitability of Chromolaena odorata, Clidemia hirta, Imperata cylindrica, Melaleuca quinquenervia, Mikania micrantha, Prosopis glandulosa, Rubus ellipticus, and Tamarix ramosissima. Vulnerable ecoregions of tropical and subtropical moist broadleaf forests and temperate broadleaf and mixed forests could result in large distributions and the highest habitat suitability of IAPs. The vulnerable ecoregions were mainly distributed in the biogeographical realms of Australasia, Nearctic, Neotropics, and Oceania. We tested a new hypothesis on disturbances and biological diversity based on ecoregional vulnerability over large scales. Our findings support the hypothesis that ecoregional vulnerability can increase habitat suitability of IAPs, promoting IAPs to expand in invasive ranges. Our study provides insight into the development of new hypotheses on the mechanisms of plant invasion over large scales.

Past role and future outlook of the Conservation Reserve Program for supporting honey bees in the Great Plains

Human dependence on insect pollinators continues to grow even as pollinators face global declines. The Northern Great Plains (NGP), a region often referred to as America's last honey bee (Apis mellifera) refuge, has undergone rapid land-cover change due to cropland expansion and weakened land conservation programs. We conducted a trend analysis and estimated conversion rates of Conservation Reserve Program (CRP) enrollments around bee apiaries from 2006 to 2016 and developed models to identify areas of habitat loss. Our analysis revealed that NGP apiaries lost over 53% of lands enrolled in the CRP, and the rate of loss was highest in areas of high apiary density. We estimated over 163,000 ha of CRP lands in 2006 within 1.6 km of apiaries was converted to row crops by 2012. We also evaluated how alternative scenarios of future CRP acreage caps may affect habitat suitability for supporting honey bee colonies. Our scenario revealed that a further reduction in CRP lands to 7.7 million ha nationally would reduce the number of apiaries in the NGP that meet defined forage criteria by 28% on average. Alternatively, increasing the national cap to 15 million ha would increase the number of NGP apiaries that meet defined forage criteria by 155%. Our scenarios also show that strategic placement of CRP lands near existing apiaries increased the number of apiaries that meet forage criteria by 182%. Our research will be useful for informing the potential consequences of future US farm bill policy and land management in the epicenter of the US beekeeping industry.

Impacts of Changing Forest Management Areas on Forest Landscapes and Habitat Patterns in Northeastern China

The management of multi-use forests often drives forest fragmentation, which leads to decreased habitat areas and quality. We explored suitable habitat distributions of cervids to evaluate the conflict between small-scale human management and large-scale habitat conservation in human-disturbed forest landscapes. We estimated the potential habitat of roe deer (Capreolus pygargus) and determined the contribution of multiple environmental factors to habitat distribution using the presence of roe deer (N = 106) in a maximum entropy (MaxEnt) model. We simulated changes in the suitable habitat and characteristics of landscape patterns based on three forest management area scenarios. The results showed that the potential suitable habitat for roe deer was located mainly in the east. The variables affecting habitat suitability were similar in different scenarios, and included distance to farmland, settlements, rivers and management areas, and elevation. Distance to the management area was found to affect habitat suitability with a contribution probability from 4% to 6%. With an increase in the management area, the suitable habitat decreased. Landscape indexes showed that habitat quality decreased with management area expansion, but patch fragmentation was not aggravated. The expansion of the management area increased the range of human disturbance and had a negative impact on habitat area and quality, which adversely affected the environmental suitability for roe deer.

Long-term habitat changes in a protected area: Implications for herpetofauna habitat management and restoration.

Point Pelee National Park, located at the southern-most tip of Canada’s mainland, historically supported a large number of herpetofauna species; however, despite nearly a century of protection, six snake and five amphibian species have disappeared, and remaining species-at-risk populations are thought to be in decline. We hypothesized that long-term changes in availability and distribution of critical habitat types may have contributed to the disappearance of herpetofauna. To track habitat changes we used aerial image data spanning 85 years (1931–2015) and manually digitized and classified image data using a standardized framework. Change-detection analyses were used to evaluate the relative importance of proportionate loss and fragmentation of 17 habitat types. Marsh habitat diversity and aquatic connectivity has declined since 1931. The marsh matrix transitioned from a graminoid and forb shallow marsh interspersed with water to a cattail dominated marsh, altering critical breeding, foraging, and overwintering habitat. Reduced diversity of marsh habitats appears to be linked to the expansion of invasive Phragmites australis, which invaded prior to 2000. Loss of open habitats such as savanna and meadow has reduced availability of high quality thermoregulation habitat for reptiles. Restoration of the northwestern region and tip of Point Pelee National Park to a mixed landscape of shallow wetlands (cattail, graminoid, forb, open water) and eradication of dense Phragmites stands should improve habitat diversity. Our results suggest that long-term landscape changes resulting from habitat succession and invasive species can negatively affect habitat suitability for herpetofauna and protection of land alone does not necessarily equate to protection of sensitive herpetofauna.

A RETROSPECTIVE SUMMARY OF RAPTOR MORTALITY IN ONTARIO, CANADA (1991-2014), INCLUDING THE EFFECTS OF WEST NILE VIRUS.

The causes of mortality of free-ranging raptors range from anthropogenic (e.g., trauma) to dynamic environmental conditions that may affect habitat suitability and prey availability. The province of Ontario, Canada, is vulnerable to anthropogenic and environmental changes because of its northern latitudes and expanding human populations, both of which may impact wildlife. We retrospectively evaluated diagnostic data from raptors submitted to the Ontario/Nunavut node of the Canadian Wildlife Health Cooperative (CWHC) from 1991 to 2014 ( n=1,448). Submissions encompassed 29 species, most commonly the Red-tailed Hawk ( Buteo jamaicensis; n=308) and Great Horned Owl ( Bubo virginianus; n=237). Trauma ( n=716) accounted for the majority of deaths among all species, followed by emaciation ( n=241). Traumatic deaths were most commonly attributed to collisions with stationary objects, and the odds of a diagnosis of trauma were significantly higher in adult versus immature raptors. The odds of being diagnosed with emaciation were significantly higher in males than in females but not in any age class or season. Mortality was less commonly attributed to infectious diseases ( n=214), for which West Nile virus (WNV) was the most common etiology, making up 53.1% of infectious diagnoses after its 2001 arrival in Ontario. The odds of a raptor being diagnosed with an infectious disease were significantly greater in summer and fall versus spring. Immature Red-tailed Hawks had significantly greater odds of being diagnosed with WNV compared to adults. These results reveal that human- and potentially environmentally-associated deaths (e.g., trauma and emaciation, respectively) are commonly diagnosed among Ontario raptors submitted to the CWHC. Infectious diseases are less commonly diagnosed, but WNV may have underlying, ongoing impacts on the health of some raptor species.

Climate and air pollution impacts on habitat suitability of Austrian forest ecosystems.

Climate change and excess deposition of airborne nitrogen (N) are among the main stressors to floristic biodiversity. One particular concern is the deterioration of valuable habitats such as those protected under the European Habitat Directive. In future, climate-driven shifts (and losses) in the species potential distribution, but also N driven nutrient enrichment may threaten these habitats. We applied a dynamic geochemical soil model (VSD+) together with a novel niche-based plant response model (PROPS) to 5 forest habitat types (18 forest sites) protected under the EU Directive in Austria. We assessed how future climate change and N deposition might affect habitat suitability, defined as the capacity of a site to host its typical plant species. Our evaluation indicates that climate change will be the main driver of a decrease in habitat suitability in the future in Austria. The expected climate change will increase the occurrence of thermophilic plant species while decreasing cold-tolerant species. In addition to these direct impacts, climate change scenarios caused an increase of the occurrence probability of oligotrophic species due to a higher N immobilisation in woody biomass leading to soil N depletion. As a consequence, climate change did offset eutrophication from N deposition, even when no further reduction in N emissions was assumed. Our results show that climate change may have positive side-effects in forest habitats when multiple drivers of change are considered.

Seasonal evaluation habitat of Asian Houbara in the Central and East Iran

The Asian Houbara is vulnerable species, the population of which is dwindling. Its protection must be prioritized in conservation programs. In this study, maximum entropy models were developed in four seasons to evaluate habitat suitability and factors affecting Asian Houbara in the Center and East Iran. Environmental variables used in modeling and evaluating the niche consisted of 24 environmental and climate variables for Gharetapeh hunting prohibited region and 36 environmental and climate variables for Petregan protected area. Also, seasonal overlap area was obtained using the ENM TOOLS software. The results showed that the most important factors affecting habitat suitability of the Asian Houbara in all seasons included the ratio of distance to the type of Artemisia sieberi–Zygophyllum eurypterum, distance to the slope 2–5%, distance to the type of Seidlitzia rosmarinus in the Gharetapeh hunting prohibited region, distance to the type of Artemisia aucheri, distance to the land passion, and distance to the dry land farming in the Petregan region. In summer and fall–winter, the most suitable habitat is Gharetapeh but is Petergan during fall–winter. There is maximum overlap in fall and winter, and the least overlap in the spring in these areas.

Bat species vulnerability in Cerrado: integrating climatic suitability with sensitivity to land-use changes

SUMMARYClimate variables are commonly used to predict suitability for species occurrence, but local processes, such as landscape changes, may affect habitat suitability. We identified levels of exposure to deforestation of suitable climatic areas for eight bat species in the Brazilian Cerrado and explored how sensitivity to land-use changes could reduce their persistence. We created scenarios of sensitivity to land-use changes using theoretical species persistence thresholds to natural vegetation loss in landscapes (70%, 50% and 30% of loss). We also assessed sensitivity to land-use changes using empirical data. Species are under higher exposure to land-use changes in the southern Cerrado, a region more affected by humans due to its proximity to major urban areas. Changes in land use in the Cerrado mostly affect Myotis nigricans, Artibeus cinereus and Platyrrhinus lineatus. Empirically derived scenarios encountered significant thresholds at 50% of natural vegetation loss in landscapes for Artibeus lituratus and P. lineatus. Deforestation has already affected a half of the Cerrado area, but in terms of possibly vulnerable suitable areas, a larger proportion has been lost, amounting to up to 80% of the suitable area. We propose that information on species-specific sensitivity thresholds to habitat loss and on the exposure of suitable landscapes to land-use changes can be useful to assessing species vulnerability.

不同尺度下停歇点湿地对迁徙水鸟的影响研究综述

PDF HTML阅读 XML下载 导出引用 引用提醒 不同尺度下停歇点湿地对迁徙水鸟的影响研究综述 DOI: 10.5846/stxb201510262158 作者: 作者单位: 中国科学院生态环境研究中心,中国科学院生态环境研究中心,中国科学院生态环境研究中心,中国科学院生态环境研究中心 作者简介: 通讯作者: 中图分类号: 基金项目: 国家"十二五"科技支撑计划项目课题（2012BAC07B04） The effect of stopover wetlands on migratory waterbirds at different scales: a review Author: Affiliation: State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:停歇点湿地是迁徙水鸟重要的能量补给地，在水鸟每年的往返迁徙过程中具有十分重要的生态意义。近年来随着全球变化和人类活动增加，迁飞路线上的停歇点湿地正发生剧烈变化。各个停歇点湿地的生境变化及周围环境不仅是影响水鸟栖息地适宜性的重要因素，还改变了各路线上迁徙水鸟的种群大小和群落多样性。分析不同尺度下停歇点湿地影响迁徙水鸟种群变化的主要生态因子和环境因素，不仅有助于理解各停歇点景观变化的生态效应，也可为迁徙水鸟种群保护提供理论支持。首先分析了在栖息地斑块尺度上停歇点湿地内的水、食物、栖息地格局和人类干扰等生态要素对水鸟觅食和栖息活动的影响；其次，分析了景观尺度上湿地周围的气候变化、土地利用和外来生物等环境条件在各停歇点对水鸟栖息地质量的改变；最后，基于多尺度条件下湿地影响因素的耦合效应，分析了当前湿地生境与水鸟种群关系研究中存在的主要问题，并总结了对湿地和水鸟保护的启示。 Abstract:Stopover wetlands are important refueling stations for numerous migratory waterbird species, and are ecologically significant in the annual cycle of birds. Recently, stopover wetlands located on flyways were faced with dramatic changes owing to global warming and increasing human activities. Previous studies have suggested that both habitat and environmental factors of these wetlands contributed to the habitat suitability of various species, and the key factors affecting the abundance and diversity of waterbird communities. Therefore, it would be helpful to understand the ecological effects of landscape changes at each stopover by analyzing the diverse habitats and environmental factors that affect various waterbird populations during migration. Furthermore, it would provide theoretical support necessary to formulate effective conservation strategies. In this review, we systematically analyzed how habitat factors such as water body, food resources, habitat configuration, and human disturbance affect the foraging and resting of waterbirds at a local scale. Then, we discussed various environmental contexts, including global warming, land use, and exotic species, that indirectly affect habitat suitability and bird migration at the landscape scale. Finally, on the basis of the coupling effects of various influencing factors that were related to stopover wetlands at different scales, we summarized some shortages based on the research of the present relationships between wetlands and waterbirds, and suggested some priorities for future studies and environmental conservation. 参考文献 相似文献 引证文献

Seasonal habitat suitability modeling and factors affecting the distribution of Asian Houbara in East Iran.

In this study, maximum entropy models were developed in four seasons to evaluate habitat suitability and factors affecting Asian Houbara in Iran. Environmental variables used in modeling consisted of 42 environmental and climate variables for Nayband wildlife refuge and 36 environmental and climate variables for Petregan protected area. Also, seasonal overlap area were obtained using the ENM TOOLS software. The results showed that the most important factors affecting habitat suitability of the Asian Houbara in all seasons included the ratio of distance to hill, the type of Artemisia−Gymnocarpus, distance to the slope (8–12%) in the Nayband wildlife refuge, distance to the type of Artemisia aucheri, distance to the Land Passion, and distance to the dry land farming in the Petregan region. In summer, the most suitable habitat is Nayband but is Petergan during fall-winter. there is maximum overlap in summer, and the least overlap in the spring these areas. The results of this study can be used as a valuable tool in implementing conservation and management strategies, in order to increase desirable habitats in the eastern part of Iran.

Habitats climaticamente adequados para uma espécie de serpente potencialmente ameaçada em cenários atuais e futuros

Climate change may cause several biodiversity impacts in the near future, including shifts in the range of species, as well as local population declines. Distribution modeling tools have proven to be useful to predict areas with environmentally suitable conditions for numerous taxa, and predicting these changes in distribution are critically important for conservation. We assessed environmentally suitable areas for the snake Drymoluber brazili under current climate conditions and evaluated how future scenarios of climate change may affect habitat suitability for this species. Currently, there are suitable areas for the occurrence of this snake along the southeastern Cerrado and portions of the Atlantic Forest. Under future climate scenarios, predicted areas of occurrence tend to become more fragmented, but increase northeast and west from the areas of current distribution. Despite these predictions, the difficulties that D. brazili has to face in order to survive in human altered landscapes may cause a decrease in suitable areas as habitat destruction increases throughout this region. Our results suggest that D. brazili may be threatened in the Brazilian state of Sao Paulo, highlighting the urgency in reassessing the conservation status of this species. Keywords: Cerrado, climate change, habitat conservation, species distribution modeling, Squamata.

Using remotely sensed data to model suitable habitats for tree species in a desert environment

AbstractQuestionsCan the species–environment relationship be understood using current remote sensing techniques? Can the derived indicators of remotely sensed data serve as a proxy for variables that affect habitat suitability of plant species? Which remote sensing predictors are best associated with woody species occurrence in a desert environment? How well do models with derived indicators of remotely sensed data predict the occurrence of these species? What are the potential distributions of Ramorinoa girolae, Prosopis spp. and Bulnesia retama in the study area?LocationIschigualasto Provincial Park, San Juan province, Argentina.MethodsWe selected random field points from a Landsat 8 OLI to determine presence/absence of trees species. We calculated Brightness index (BI) using the same image and used this index to calculate texture measures on a 3 × 3 moving window size. We used the following subset of texture measures: (1) first‐order: range, (2) second‐order: mean, variance, contrast, entropy, second moment and correlation. We also calculated Topographic Wetness Index (TWI), slope angle and slope aspect from Global Digital Elevation Model.Results and ConclusionSecond‐order mean of BI had an important effect on the occurrence of target trees species. TWI was an important variable for Prosopis spp. and B. retama, whereas slope angle was important for R. girolae and B. retama. In addition, the occurrence of R. girolae was affected by second‐order variance of BI and slope aspect; and the presence of B. retama was affected by second‐order contrast of BI. All the variables that had important effects on the occurrence of tree species provide environmental information about their different habitat requirements; therefore, our findings indicate that the remote sensing data are reliable to derive indicators of tree species presence in our study area.

Conservation of future boreal forest bird communities considering lags in vegetation response to climate change: a modified refugia approach

AbstractAimSpecies and ecosystems may be unable to keep pace with rapid climate change projected for the 21st century. We evaluated an underexplored dimension of the mismatch between climate and biota: limitations to forest growth and succession affecting habitat suitability. Our objective was to inform continental‐scale conservation for boreal songbirds under disequilibria between climate, vegetation and fauna.LocationBoreal and southern arctic ecoregions of North America.MethodsWe used forest inventory and avian survey data to classify 53 species by seral‐stage affinity and applied these to generate alternative projections of changes in species' core habitat distributions based on different vegetation lag‐time assumptions. We used our seral stage‐modified refugia approach and the Zonation algorithm to identify multispecies boreal conservation priorities over the 21st century. We evaluated the sensitivity of land rankings to seral‐stage affinity and species' weights and assessed the conservation value of the existing protected areas network compared to Zonation results.ResultsEnd‐of‐century projected changes in songbird distribution were reduced by up to 169% when vegetation lags were considered. Zonation land rankings based on unconstrained climate projections were concentrated at high latitudes, whereas those based on strict and modified refugia scenarios were concentrated in coastal and high‐elevation areas, as well as biome transition zones, which were fairly consistent over time and species weights. The existing protected areas network covering 14% of the study area was estimated to conserve 12–14% of baseline avian biodiversity across time periods and scenarios, compared to 16–25% for top‐ranked Zonation areas.Main conclusionsFor some boreal songbirds, limits to forest growth and succession may result in dramatic reductions in suitable habitat over the next century. Our seral stage‐adjusted approach provides conservative and efficient boreal conservation priorities anchored around climatic macrorefugia that are robust to century‐long climate change and complement the current protected areas network.

Range-wide analysis of northern spotted owl nesting habitat relations

Recently the US Fish and Wildlife Service, as part of a critical habitat analysis for the northern spotted owl (Strix occidentalis caurina), developed habitat suitability models based on thousands of owl nest sites distributed across 11 regions using the MaxEnt tool. Because these models formed the basis for critical habitat designations on millions of hectares of land, we undertook an independent evaluation of the FWS effort. We evaluated the accuracy of vegetation data used as input to develop the models, conducted out of sample analyses, correlated model output with owl reproductive success in two study areas, and developed alternate models using two different statistical methods. Vegetation data appeared accurate for only a few variables, and accuracy varied among model regions. Out of sample testing gave a high rate of classification errors and owl productivity was not correlated with MaxEnt model output in two study areas. Alternate statistical methods produced reasonable models with fewer variables. Critically, neither the models compared across regions nor the regions analyzed with different tools led to comparable use of variables. Thus biological interpretation of owl habitat selection models seemed ambiguous. In addition, for MaxEnt and one of the other tools, a highly significant trend by regression was found showing decreasing model accuracy as number of training nest sites increased. Together, these two results suggest that the generated models may be spurious to some unknown degree, perhaps because the underlying vegetation data, also derived from a model, are not sufficiently accurate to support the analysis and/or because the owls themselves affect habitat suitability by consuming their prey base. We suggest that the USFWS exercise caution in using MaxEnt models as a basis for regulatory purposes such as consultation, estimating likelihood of occupancy by owls, or evaluation of site-specific recovery actions.