Areas Of Potential Habitat Research Articles

Habitat availability is not limiting the distribution of the Bohemian–Bavarian lynxLynx lynxpopulation

AbstractA population of Eurasian lynxLynx lynxwas established by reintroductions in the Bohemian Forest Ecosystem in the 1970s and 1980s. The most recent information on the population status indicates that the distribution has stagnated since the late 1990s, for unknown reasons. We assessed the availability of suitable habitat along the Austrian–German–Czech border, and hypothesized that the Bohemian–Bavarian lynx population is not in equilibrium with habitat suitability. Based on global positioning system data from 10 radio-collared lynx, we used a maximum entropy approach to model suitable habitat. Variables reflecting anthropogenic influence contributed most to the model and were negatively associated with the occurrence of lynx. We evaluated the model prediction using independent records of lynx from monitoring in Bavaria, Germany. Using our habitat approach we estimated the area of potential habitat, based on a mean annual home range of 445 km2for males and 122 km2for females. Our results indicated there were 12,415 km2of suitable habitat, distributed among 13 patches, for a potential population of c. 142 (93–160) resident lynx. We assessed connectivity via least-cost paths and found that all suitable patches could be reached by the lynx. A comparison with the current distribution of lynx, however, confirms that a significant proportion of suitable habitat is not occupied, which indicates that the distribution is limited by factors other than habitat, with illegal killing being the most likely cause. Our study provides crucial information for the development of a conservation strategy and regional planning for the Bohemian–Bavarian lynx population.

Measuring the effectiveness of conservation programs for shrubland birds

Disturbance-dependent habitats such as grasslands and shrublands are declining in many regions. To mitigate these declines, government agencies are using anthropogenic disturbances like logging and mowing to mimic natural ones. Because these programs can be costly or controversial, measuring their effectiveness is important. Here, we evaluate the conservation effectiveness of shrubland management for 15 bird species in Massachusetts, USA. Because shrublands are constantly changing in extent and location, we suggest that the key measure of conservation effectiveness should be how managed areas contribute to habitat availability. We used remotely-sensed data to assess the total area of shrublands in Massachusetts and consulted managers and a timber-harvest database to determine contributions of management by government agencies and non-governmental conservation organizations. We calculated species-specific habitat availability based on the habitat relationships of individual bird species. The area of potential habitat for shrubland birds in Massachusetts averaged 35,000 ± SD of 11,300 ha. Of this total, an average of 20% ± 15% exists because of management by government and NGOs. Management was most important for birds that nest primarily in uplands and avoid wetlands. We conclude that active management by government agencies and NGOs provides a substantial proportion of shrubland habitat in Massachusetts. With habitat on private property being lost to development or succession, active management will be even more important in the future.

Suitable environmental ranges for potential coral reef habitats in the tropical ocean.

Coral reefs are found within a limited range of environmental conditions or tolerance limits. Estimating these limits is a critical prerequisite for understanding the impacts of climate change on the biogeography of coral reefs. Here we used the diagnostic model ReefHab to determine the current environmental tolerance limits for coral reefs and the global distribution of potential coral reef habitats as a function of six factors: temperature, salinity, nitrate, phosphate, aragonite saturation state, and light. To determine these tolerance limits, we extracted maximum and minimum values of all environmental variables in corresponding locations where coral reefs are present. We found that the global, annually averaged tolerance limits for coral reefs are 21.7—29.6 °C for temperature, 28.7—40.4 psu for salinity, 4.51 μmol L-1 for nitrate, 0.63 μmol L-1 for phosphate, and 2.82 for aragonite saturation state. The averaged minimum light intensity in coral reefs is 450 μmol photons m-2 s-1. The global area of potential reef habitats calculated by the model is 330.5 × 103 km2. Compared with previous studies, the tolerance limits for temperature, salinity, and nutrients have not changed much, whereas the minimum value of aragonite saturation in coral reef waters has decreased from 3.28 to 2.82. The potential reef habitat area calculated with ReefHab is about 121×103 km2 larger than the area estimated from the charted reefs, suggesting that the growth potential of coral reefs is higher than currently observed.

The Relationship Between Shoreline Armoring and Adjacent Submerged Aquatic Vegetation in Chesapeake Bay and Nearby Atlantic Coastal Bays

Shoreline armoring is an ancient and globally used engineering strategy to prevent shoreline erosion along marine, estuarine, and freshwater coastlines. Armoring alters the land water interface and has the potential to affect nearshore submerged aquatic vegetation (SAV) by changing nearshore hydrology, morphology, water clarity, and sediment composition. We quantified the relationships between the condition (bulkhead, riprap, or natural) of individual shoreline segments and three measures of directly adjacent SAV (the area of potential SAV habitat, the area occupied by SAV, and the proportion of potential habitat area that was occupied) in the Chesapeake Bay and nearby Atlantic coastal bays. Bulkhead had negative relationships with SAV in the polyhaline and mesohaline zones. Salinity and watershed land cover significantly modified the effect of shoreline armoring on nearshore SAV beds, and the effects of armoring were strongest in polyhaline subestuaries with forested watersheds. In high salinity systems, distance from shore modified the relationship between shoreline and SAV. The negative relationship between bulkhead and SAV was greater further off shore. By using individual shoreline segments as the study units, our analysis separated the effects of armoring and land cover, which were confounded in previous analyses that quantified average armoring and SAV abundance for much larger study units (subestuaries). Our findings suggest that redesigning or removing shoreline armoring structures may benefit nearshore SAV in some settings. Because armoring is ubiquitous, such information can inform efforts to reverse the global decline in SAV and the loss of the ecosystem services that SAV provides.

Current Status of Western Yellow-Billed Cuckoo along the Sacramento and Feather Rivers, California.

To evaluate the current status of the western population of the Yellow-billed Cuckoo (Coccyzus americanus) along the Sacramento and Feather rivers in California’s Sacramento Valley, we conducted extensive call playback surveys in 2012 and 2013. We also quantified the amount and distribution of potential habitat. Our survey transects were randomly located and spatially balanced to sample representative areas of the potential habitat. We estimated that the total area of potential habitat was 8,134 ha along the Sacramento River and 2,052 ha along the Feather River, for a total of 10,186 ha. Large-scale restoration efforts have created potential habitat along both of these rivers. Despite this increase in the amount of habitat, the number of cuckoos we detected was extremely low. There were 8 detection occasions in 2012 and 10 occasions in 2013 on the Sacramento River, in both restored and remnant habitat. We had no detections on the Feather River in either year. We compared our results to 10 historic studies from as far back as 1972 and found that the Yellow-billed Cuckoo had unprecedentedly low numbers in 2010, 2012, and 2013. The current limiting factor for the Yellow-billed Cuckoo in the Sacramento Valley is likely not the amount of appropriate vegetation, as restoration has created more habitat over the last 30 years. Reasons for the cuckoo decline on the Sacramento and Feather rivers are unclear.

Vulnerability of Siberian crane habitat to water level in Poyang Lake wetland, China

Assessment of habitat quality for wetland-obligate wildlife and endangered species of waterfowl is essential particularly in the changing environment. In this study, the areas of potential suitable habitat for Siberian cranes in Poyang Lake natural wetland were evaluated using 11 scenes of Landsat TM/ETM+ images. Habitat quality was assessed against six landscape indices. Results indicate that the optimum water level for habitats of Siberian cranes in Poyang Lake wetland would be about 12 m. Potential suitable habitat areas would be reduced from about 2300 km2 at 5 m lake level to 530 km2 at 15.6 m lake level. Landscape indices revealed that a higher water level would not be suitable for conservation of Siberian cranes. The proposed Poyang Lake Dam should be operated to control water levels for providing a favorable habitat condition for wintering migratory birds. It would create an unfavorable condition to the wintering habitats for Siberian cranes in Poyang Lake wetland if the dam would maintain the lake level higher than 12 m in autumn and winter.

Using Scenario Modeling for Red Spruce Restoration Planning in West Virginia

Active restoration of threatened or endangered species habitat may seem in conflict with the provisions of the Endangered Species Act because of the prohibition of “take,” which can include habitat modification as well as death or harm to individuals. Risk-averse managers may choose to forego active management in known or presumed endangered species habitat to avoid killing an individual or harming critical habitat. We used the landscape-scale model LANDIS-II to simulate red spruce (Picea rubens Sarg.)-dominated forest response to restoration actions for 100 years. Restoration strategies differed in management of the potential habitat for the recently delisted Virginia northern flying squirrel (Glaucomys sabrinus fuscus). Model simulations show that active management with protections for existing red spruce stands resulted in a greater area dominated by red spruce than did larger, areawide protections. However, protecting larger areas of potential habitat resulted in an increase in red spruce in areas of low to moderate probability of occurrence for the flying squirrel, potentially increasing the area’s suitability for this species.

Environmental requirements for three sea pen species: relevance to distribution and conservation

Abstract The aim is to determine the environmental requirements, estimate the extent of suitable habitat for three sea pen species, and assess the implications for marine protected areas (MPAs). The sea pen Funiculina quadrangularis and the habitat associated with two further sea pen species, Virgularia mirabilis and Pennatula phosphorea, are of key conservation importance and are recommended for protection within MPAs. This study models their potential distributions using the MAXimum ENTropy algorithm and assesses these in relation to five possible marine protected areas (pMPAs) proposed for Scottish waters. Metrics relevant to assessing the efficacy of MPAs are also presented. Four environmental variables of prime importance for predicting the presence of all three species of sea pen were identified: mud, minimum salinity, depth, and gravel. The habitat suitability index increased with mud content. The modelled distribution of F. quadrangularis indicated a deeper distribution than V. mirabilis or P. phosphorea and was not present in sediment with gravel content above 30%. Pennatula phosphorea had the smallest area of suitable habitat, while V. mirabilis had the largest. The percentage predicted suitable area for each species that was encompassed by the five pMPAs ranged from 11% for F. quadrangularis to 15% for P. phosphorea. Some of the largest areas predicted as suitable for F. quadrangularis lay outside the pMPAs. The model results indicated differences in the environmental requirements of the three species of sea pen that can be linked to the autecology of each species. Patch sizes, calculated from a binary output of the model, were used to estimate the degree of habitat fragmentation, thereby giving a partial assessment of the adequacy criterion for these pMPAs. The results suggest that potential MPAs within the study area cover sizeable areas of potential sea pen habitat. However, further areas suitable for F. quadrangularis could be considered.

草原区矿产开发对景观格局和初级生产力的影响—以黑岱沟露天煤矿为例

煤炭是我国的主要能源，大型露天煤矿的开发推动了地区经济与社会的发展，但同时也引发了区域生态环境问题。因此，探讨矿产开发对区域景观格局的影响，并阐明景观格局动态与生态系统初级生产力的关系，对生态环境的保护具有重要意义。以内蒙古草原区的黑岱沟露天煤矿为例，利用3S（RS、GIS和GPS）技术，在野外实地调查的基础上，分析了1987年以来矿产开发导致的土地利用/覆盖变化、景观格局动态及其与生态系统初级生产力之间的关系，主要结果如下：（1） 提出了界定最适研究区范围的方法，认为沿矿区边界向外建立10 km的缓冲区是该研究最适研究区域的大小；（2） 草地和耕地是研究区主要的土地利用/覆盖类型，但是在过去20多年间其面积在逐渐减少，而工矿仓储用地及住宅用地面积在急剧增加；（3） 矿产开发导致景观格局发生变化，并且在两种不同的空间尺度（研究区和矿区）上表现出总体变化趋势的一致性，但在后期有较大差异；（4）初级生产力变化呈现下降趋势，并且矿区的降低更为突出；（5）以生长季降水量为控制因子的偏相关分析表明，景观配置（平均斑块周长面积比、景观形状指数）与初级生产力呈正相关关系，在研究区尺度上尤其显著，但在矿区尺度上，景观结构组成（斑块密度、均匀度指数和多样性指数）更为重要，与初级生产力呈显著负相关；（6）受复垦规模和演替进程的影响，局限在矿区排土场上的植被重建尚不能改变研究区尺度景观-生态系统初级生产力之间的关系。可见，景观格局的变化以及景观格局与生态系统初级生产力之间的关系均存在尺度依赖性。;Coal has been the primary energy resource that made rapid economic and social development in China possible. Yet, its extraction in the form of open-field mining operations changed landscape patterns considerably and created a suite of environmental and ecological problems. Therefore, it is very important to understand these landscape pattern dynamics and their effects on ecosystem processes. While open pit coal mining is one of the fast growing human modifications of the Earth's surface which transforms landscapes and ecological functioning, studies in applied ecology and restoration ecology examining the effects of this human activities have been lacking. We conducted a field study in the 10 km buffer around the landscape of Zhungger Heidaigou in Inner Mongolia where large open mine operations are presently underway. Within this landscape land use/land cover changed substantially between 1987 and 2010. We related these human transformed landscape patterns to primary productivity and found the relationship to be highly scale dependent. Our results are summarized as follows. First, the 10 km buffer was found to be the optimum size of this study area, although we seek expanding the scale domain of our study because the size of the mining area is expected to increase. Second, grassland and agricultural areas, the two main land uses that preceded coal mining, have both decreased in the past 20 years. Grassland area decreased from 71.18% (45 199.73 hm²) in 1987 to 60.71% (38 550.76 hm²) in 2010,while agricultural area decreased from 25.76% (16 360.24 hm²) in 1987 to 20.48% (13 002.40 hm²) in 2010. On the other hand, industrial and residentia lareas increased between 1987 and 2010. Particularly, mining operations occupied only 0.01% (3.12 hm²) in 1987, but increased to 3.16% (2 007.04 hm²) in 2000, which corresponds to 10.05% (6 385.04 hm²) in 2010, respectively. Third, although landscape structure in the area has experienced overall consistent trend of change dynamics of landscape pattern at later stages were very different at two spatial scales-the scale of the mining area and the whole landscape. The number of introduced and disturbance patches increased at the expense of dominant resource patches, which resulted in severe landscape fragmentation. At the fine scale, previously dominant grassland patches characterized by higher pattern complexity and irregular shapes were replaced by simpler and more regular patches of coal mining operations and accompanying infrastructures.Fourth, primary productivity in the landscape as a whole and mining area in particular decreased with time since mining operations started. Areas affected by mining experienced more significant decrease of primary productivity. Partial correlation analysis of landscape patterns and primary productivity, with growing season precipitation as the controlling factor, showed that primary productivity was positively correlated with landscape configuration landscape pattern indices(perimeter-area ratio average, PARA; landscape shape index, LSI),especially at the whole landscape level. Primary productivity was negatively correlated with landscape composition indices (patch density, PD; shannon-weaver diversity index, SHDI; and shannon evenness index, SHEI) in the mining area. We conclude that vegetation restoration cannot change the relationship between landscape patterns and primary productivity at the large scale because of current limitations of available potential habitat areas and long term successions.We believe the success of restoration of damaged ecosystems in the study area is heavily dependent upon the realization of the importance of natural ecosystems.

江西桃红岭国家级自然保护区梅花鹿生境适宜性评价

The South China subspecies of sika deer(Cervus nippon) has been listed as an endangered species in the IUCN Red Data List,and is also assigned to Protection Class I in the List of Wildlife under Special State Protection as designated by the Chinese State Council.In recent years,sika deer have formed several relatively isolated populations and are distributed in parts of Jiangxi,Zhejiang and Anhui provinces.Taohongling National Nature Reserve is located in Pengze County,Jiangxi Province of China,which has been designated for the protection of wild southern sika deer.The reserve is12 500 hm in area,of which the Core Protected Zone is 2 670 hm,the Buffer Zone is 1 830 hm and the Experimental Zone is 8 000 hm.In the Experimental Zone,there is a considerable area of agricultural land with a high human population density.Highways surround the eastern,northern,and western boundaries of the nature reserve,while the southern border of the reserve is marked by valleys and creeks.The last estimated population of sika deer in the nature reserve was 365,which was thought to be the largest population of this sika deer subspecies.However,after strict protection for 30 years,the vegetation in the nature reserve has changed into evergreen broadleaf forests which is the local climax vegetation.Meanwhile,human activities have led to further habitat fragmentation and habitat loss.Therefore,it is necessary to carry out further studies on the population of sika deer in Taolongling National Nature Reserve for proper population conservation.Based on the data on habitat used by sika deer in the Taohongling National Nature Reserve between March 2011 and March 2013,we used the habitat evaluation model and a Geographic Information System(GIS) to assess the suitability of the habitat for sika deer.Vegetation type,slope,aspect,elevation and human activities were selected as factors for habitat suitability assessment.The results showed that forests,including deciduous forests,coniferous forests,mixed broadleafconiferous forests,broad-leaved evergreen forests and bush fallow were the dominant land cover in the Taohongling area.The area of forest was 9 488.15 hm,accounting for 75.90%of the total area.In the absence of human disturbance,the areas of suitable and marginally suitable habitat were 2 233.99 hm and 2 980.24 hm,respectively,accounting for 18.61%and 24.83%of the total area.In the presence of human activity,suitable and marginally suitable habitats decreased to about1 224.04 hm2 and 2 164.70 hm2,respectively,representing 10.20%and 18.04%of the total area.Because residential areas,main roads,farming activity and timber harvesting have a strong impact on the habitat of sika deer,suitable and marginally suitable habitats have been intensively lost and isolated with the landscape fragmentation index increasing from0.4345 to 0.5898.Using the potential available habitat area,the carrying capacity of sika deer is calculated as 568±160individuals,but using the actual available habitat area,the carrying capacity is only 368 ±105.Habitat loss and fragmentation have been the main limiting factors for population recovery of sika deer in the Taohongling National Nature Reserve.We suggest that it is very important to take reasonable measures to manage forest harvesting,eliminate poaching,control the number of wild boar,and to establish habitat corridors.

Limbless geckoes hanging on? Lessons in exploiting arid-zone unpredictability from an elusive habitat-specialist pygopod

Context The study of threatened species is often challenged by their rarity and secretive life-history traits. Species adapted to extreme environments prone to stochastic conditions present further challenges because of fluctuating populations and patchy distributions. We employed a variety of methods to gather records and habitat information on the bronzeback legless lizard (Ophidiocephalus taeniatus), an endemic, nationally vulnerable monotypic pygopod reptile that is poorly understood because of fossorial, cryptic behaviour and remote distribution in the stony deserts of inland Australia. Aims Our aim was to determine foundational information on the distribution and landscape parameters relevant to this species and its disturbance-prone habitat and to formulate conceptual models to guide understanding, future research and management of threats. Methods We used multiple data sources, including targeted field surveys with Antakarintja traditional land owners across ~5000 km2 of previously unsurveyed habitat, sampled the catch of uncapped mine shafts with community volunteers, trialled artificial refuge substrates and elicited public opportunistic sightings. Key results We gathered 30 new records of the species from leaf litter mats of six shrub species, across four land systems. Examination of these records in the context of land system boundaries demonstrated a continuous distributional link between previously known areas of habitat and suggested large tracts of potential habitat that remain unsurveyed for the species. This information in combination with other published data was used to create conceptual models of habitat preference, population and disturbance, in which we suggest that O. taeniatus favours microhabitats that are prone to severe and long-lasting disturbance in some parts of the landscape, exacerbated by human land use practices. Conclusions Our study suggests that O. taeniatus distribution is unlikely to be severely fragmented, as had previously been suggested. Its total extent of occurrence may be greater than previously thought, despite a very low area of occupancy within this. Implications This study emphasises the value of using multiple, innovative data sources when studying rare and cryptic species. Further distributional surveys in identified areas of potential habitat in combination with testing and refinement of our conceptual model of habitat and population drivers are needed to fully assess the distribution, conservation status and ecological drivers of O. taeniatus.

Distribution models and species discovery: the story of a new Solanum species from the Peruvian Andes

A new species of Solanum sect. Solanum from Peru is described here. Solanum pseudoamericanum Särkinen, Gonzáles & S.Knapp sp. nov. is a member of the Morelloid clade of Solanum, and is characterized by the combination of mostly forked inflorescences, flowers with small stamens 2.5 mm long including the filament, and strongly exerted styles with capitate stigmas. The species was first thought to be restricted to the seasonally dry tropical forests of southern Peru along the dry valleys of Río Pampas and Río Apurímac. Results from species distribution modelling (SDM) analysis with climatic predictors identified further potential suitable habitat areas in northern and central Peru. These areas were visited during field work in 2013. A total of 17 new populations across the predicted distribution were discovered using the model-based sampling method, and five further collections were identified amongst herbarium loans. Although still endemic to Peru, Solanum pseudoamericanum is now known from across northern, central and southern Peru. Our study demonstrates the usefulness of SDM for predicting new occurrences of rare plants, especially in the Andes where collection densities are still low in many areas and where many new species remain to be discovered.

Assessing the regional impacts of increased energy maize cultivation on farmland birds

The increasing cultivation of energy crops in Germany substantially affects the habitat function of agricultural landscapes. Precise ex ante evaluations regarding the impacts of this cultivation on farmland bird populations are rare. The objective of this paper was to implement a methodology to assess the regional impacts of increasing energy maize cultivation on the habitat quality of agricultural lands for farmland birds. We selected five farmland bird indicator species with varying habitat demands. Using a crop suitability modelling approach, we analysed the availability of potential habitat areas according to different land use scenarios for a real landscape in Northeast Germany. The model was based on crop architecture, cultivation period, and landscape preconditions. Our results showed that the habitat suitability of different crops varied between bird species, and scenario calculations revealed an increase and a decrease in the size of the potential breeding and feeding habitats, respectively. The effects observed in scenario 1 (increased energy maize by 15%) were not reproduced in all cases in scenario 2 (increased energy maize by 30%). Spatial aggregation of energy maize resulted in a negative effect for some species. Changes in the composition of the farmland bird communities, the negative effects on farmland bird species limited in distribution and spread and the relevance of the type of agricultural land use being replaced by energy crops are also discussed. In conclusion, we suggest a trade-off between biodiversity and energy targets by identifying biodiversity-friendly energy cropping systems.

Delineating generalized species boundaries from species distribution data and a species distribution model

Species distribution models (SDM) are commonly used to provide information about species ranges or extents, and often are intended to represent the entire area of potential occupancy or suitable habitat in which individuals occur. While SDMs can provide results over various geographic extents, they normally operate within a grid and cannot delimit distinct, smooth boundaries. Additionally, there are instances where a zone of primary occupancy (i.e., a mostly continuous region where species exists, excluding outliers) is better suited for particular analyses, such as when examining source/sink population dynamics or modeling movement into new habitats. We present a semi-automated method to delineate a generalized species boundary (GSB) from SDM output, which provides a practical alternative to digitizing. This preliminary boundary is then manually updated based on inventory data and historical ranges. We used the method to generate contemporary boundaries for 132 tree species of the eastern United States, which are complementary to the ranges generated by Elbert Little for North America during the 1970s, but are not replacements. The methods we present can broadly be applied to other grid-based SDM to generate GSBs.

Estimating Esox lucius (Esocidae, Esociformes) density and population structure in a large European alluvial river: the Allier (France)

We developed a sampling protocol for pike (Esox lucius L., 1758) in large alluvial rivers in order to estimate adult population density and structure. This species is known as an indicator of lowland river biotic integrity in Europe evidencing the interest to determine population densities to a reliable degree of accuracy. A two occasion mark-recapture experiment based on a combination of net fishing and boat electro-fishing was specifically designed for monitoring of backwaters and channel sectors during the annual high flow level of an alluvial river, the Allier (France). Estimated densities calculated by using Chapman-Petersen and Loglinear models were weak, ranging from 0.68 (±0.16) fish.ha−1 to 0.71 (±0.20) fish.ha−1. However, when the densities are divided by the area of potential riverine habitats, pike abundance was calculated as being 15.3 (±3.7) fish.ha−1 to 15.9 (±3.8) fish.ha−1. Pike growth was high and 8 to 9 year-old females were captured. Age and sex distribution emerged as unbalanced, highlighting the precarious status of pike in the studied stretch of the river due to very limited recruitment. Pike were mainly captured in parapotamic side arms which underlines the importance of lateral habitats in semi regulated large alluvial rivers with wide riffle-pool-run sequences dominating geomorphological units.

Potential Distributional Patterns of Three Wild Ungulate Species in a Fragmented Tropical Region of Northeastern Mexico

In the northernmost American tropical forests of eastern Mexico, we analyzed the potential distribution of three ungulate species, Odocoileus virginianus, Mazama temama and Pecari tajacu, in response to several physical, climatic, biological, and anthropogenic variables, in order to identify environmental factors affecting distribution and potential key areas for ungulate conservation. Current presence records for these species were gathered, and potential distribution models were built using Maximum Entropy niche modeling (MaxEnt). Model suitability surfaces were used to calculate remaining potential habitat areas in the region, as well as the potential sympatric area and representation of these areas in Natural Protected Areas. Biological and anthropogenic variables were the best species distribution predictors. Landscape composition (the proportion of different land-use and land-cover classes: forest, agriculture, and pasture) within approximately 120 ha, was the most important variable for all models, influencing each species differently with respect to their tolerance of altered habitats. The remaining potential area of all three species is fragmented and has apparently been nearly lost in plains (<14% remaining). Distribution models allowed us to detect an important location in the western portion of our study area which may function as a large biological corridor in the Sierra Madre Oriental mastogeographic province, a region heavily transformed by land use change. In the context of habitat transformation, management promoting quality matrix at the landscape level promises to be a viable alternative for ungulate conservation in tropical regions of Mexico.

Climate predictions accelerate decline for threatened macrozamia cycads from queensland, australia.

Changes in the potential habitat of five allopatric species of threatened Macrozamia cycads under scenarios of increased ambient temperature were examined. A lack of seed dispersal, poor recruitment, low seedling survival, obligate pollinator mutualisms and continued habitat loss have led to extant populations being largely restricted to refugia. Models predict that the area of suitable habitat will further contract and move upslope, resulting in a reduced incidence within protected areas with increasing annual mean temperature. Areas of potential habitat for all five species are also predicted to become increasingly isolated from one another, further reducing the exchange between metapopulations and subpopulations, exacerbating existing threatening processes.

Multisensor Monitoring System for Assessment of Locust Hazard Risk in the Lake Balkhash Drainage Basin

Satellite and ground-based data were combined in a monitoring system to quantify the link between climate conditions and the risk of locust infestations in the southern part of Lake Balkhash’s drainage basin in the Republic of Kazakhstan. In this monitoring system, the Normalized Difference Vegetation Index (NDVI), derived from the SPOT-VGT satellite, was used for mapping potential locust habitats and monitoring their area throughout 1998 to 2007. TOPEX/Poseidon and Jason 1 altimeter data were used to track the interannual dynamics of water level in Balkhash Lake. Climate conditions were represented by weather records for air temperature and precipitation during the same period. The classification procedure, based on an analysis of multitemporal dynamics of SPOT-VGT NDVI values observed by individual vegetation classes, generated annual areas of ten land-cover types, which were then categorized as areas with low, medium, and high risk for locust infestation. Statistical analyses showed significant influences of the climatic parameters and the Balkhash Lake hydrological regime on the spatial extend of annual areas of potential locust habitats. The results also indicate that the linkages between locust infestation risk and environmental factors are characterized by time lags. The expansion of locust risk areas are usually preceded by dry, hot years and lower water levels in Balkhash Lake when larger areas of reed grass are free from seasonal flooding. Years with such conditions are favourable for locust outbreaks due to expansion of the habitat areas suitable for locust oviposition and nymphal development. In contrast, years with higher water levels in Balkhash Lake and lower temperature decrease the potential locust habitat area.

Range shifts of a relict Himalayan dragonfly in the Hindu Kush Himalayan region under climate change scenarios

Although understanding of geographic range shifts of many species in response to global climate change is expanding steadily, little is known about the Himalayan fauna, which in particular is affected by relatively faster warming rates than other parts of the world. Anticipated increases in temperature and changes in hydrological regimes will have significant adverse impacts on the habitat suitability for many species. This threat will even be higher to endemic and already threatened species due to their restricted distribution and narrow climate tolerance ranges. We investigated the range shifts of a relict Himalayan dragonfly (Epiophlebia laidlawi), a species that is endemic to the Hindu Kush Himalayan region. Currently, the species is only known from few localities in Bhutan, India and Nepal. For conservation of the species, it is necessary to foresee potential suitable habitat areas and range shifts due to global climate change. Here, we first estimated the current potential geographic distribution by...

Spatial polychaeta habitat potential mapping using probabilistic models

The purpose of this study was to apply probabilistic models to the mapping of the potential polychaeta habitat area in the Hwangdo tidal flat, Korea. Remote sensing techniques were used to construct spatial datasets of ecological environments and field observations were carried out to determine the distribution of macrobenthos. Habitat potential mapping was achieved for two polychaeta species, Prionospio japonica and Prionospio pulchra, and eight control factors relating to the tidal macrobenthos distribution were selected. These included the intertidal digital elevation model (DEM), slope, aspect, tidal exposure duration, distance from tidal channels, tidal channel density, spectral reflectance of the near infrared (NIR) bands and surface sedimentary facies from satellite imagery. The spatial relationships between the polychaeta species and each control factor were calculated using a frequency ratio and weights-of-evidence combined with geographic information system (GIS) data. The species were randomly divided into a training set (70%) to analyze habitat potential using frequency ratio and weights-of-evidence, and a test set (30%) to verify the predicted habitat potential map. The relationships were overlaid to produce a habitat potential map with a polychaeta habitat potential (PHP) index value. These maps were verified by comparing them to surveyed habitat locations such as the verification data set. For the verification results, the frequency ratio model showed prediction accuracies of 77.71% and 74.87% for P. japonica and P. pulchra, respectively, while those for the weights-of-evidence model were 64.05% and 62.95%. Thus, the frequency ratio model provided a more accurate prediction than the weights-of-evidence model. Our data demonstrate that the frequency ratio and weights-of-evidence models based upon GIS analysis are effective for generating habitat potential maps of polychaeta species in a tidal flat. The results of this study can be applied towards conservation and management initiatives for the macrofauna of tidal flats.