Environmental Correlates for Species Richness among Amphibians and Reptiles in a Climate Transition Area

Correlations between environmental factors and the distribution of amphibian and reptile species richness were investigated in a climate transition area, Peneda-Gerês National Park (PNPG), in North-Western Portugal. Using presence-data at a local-scale (1 × 1 km), Ecological-Niche Factor Analysis (ENFA) identified a mixture of climatic (precipitation and number of days with fog), topographical (altitude and relief) and habitat factors (number of watercourses and water surfaces, the type of the largest water surface and tree diversity cover), as accurate predictors of species occurrence. Three factors were common for both taxonomic groups, and consistently presented a positive relation with species occurrence: precipitation, number of water surfaces, and tree diversity cover; suggesting a strong coincidence in the environmental correlates that influence amphibian and reptile species richness. Distribution patterns of observed and predicted species richness were compared using a Geographical Information System. Overall, three high species richness areas were predicted in common for both taxonomic groups and two additional areas for amphibians only. These areas matched with the observed species richness but suggested larger areas of high species richness. The location of the PNPG in a biogeographic crossroad, between Euro-Siberian and Mediterranean provinces, emphasised species richness of amphibians and reptiles and suggests a high priority conservation status for this protected area. Most of Central-Northern Portugal is located in a climatic transition area; therefore, increased species richness should be expected for other areas. Local scale studies for other protected areas should be planned as a framework for the development of multi-scale conservation planning by Portuguese authorities.     

Land use and biodiversity patterns of the herpetofauna: The role of olive groves

The intensification of agriculture has significant environmental consequences. This intensification entails the simplification and homogenisation of the landscape, which leads to strong negative impacts at ecosystem level, including declines in animal biodiversity. The purpose of this study was to assess the effect of different land uses on reptilian and amphibian biodiversity patterns at a regional scale by analysing a large database on the presence of amphibians and reptiles in Andalusia (southern Spain). GIS techniques and the Ecological-Niche Factor Analysis (ENFA) were applied in order to assess whether the habitat was suitable for each reptilian and amphibian species, when the land use variables were excluded. The incongruence between the potential and the observed species richness was then correlated with the main types of land use in Andalusia. Our results showed that irrigated and unirrigated olive groves were associated with a biodiversity deficit of amphibians and reptiles respectively, whereas natural forests and pastures, along with more heterogeneous crops areas, were more suitable. A clustering analysis showed that generalist species were related to olive groves whereas rare and specialist species were related to land uses related to natural vegetation. In summary, our results indicate that large areas covered by olives groves harbour less amphibian and reptilian diversity, thus suggesting that agro-environmental schemes should be carried to promote the species richness in these crops.     

Land use and biodiversity congruences at local scale: applications to conservation strategies

The establishment of protected areas is traditionally considered indispensable to preserve biodiversity hotspots or areas inhabited by threatened species. The analysis of correlations between composition or richness of several taxonomic groups in a specific area has emerged as a useful mechanism to quickly identify areas of biological and conservation interest, and is currently used to select and design protected areas. The effect of habitat fragmentation on these correlations at a regional scale has been studied, but the effect of land use on the correlations obtained at local scale is poorly understood. We evaluated the relationships among different taxonomic groups frequently used in biological assessments for reserve design (vascular flora, amphibians, reptiles, birds and mammals), taking into account the effects of land use on these correlations. We compared richness and species composition of these groups in 1 km² quadrants within a total area of 75 km² in a low mountain Mediterranean area. Richness and composition were significantly correlated between several groups, both using the complete data set and also analyzing natural and disturbed areas separately. Species composition and species richness correlations were not congruent at the full landscape approach, nor natural and disturbed quadrants. Factors extrinsic to the communities also varied their influence in the assemblage of the community and species richness or not land uses were taken into account. According to our results, natural and human-disturbed areas should not be combined in cross-taxon congruences analysis at local scale.     

Integrating Multiple Distribution Models to Guide Conservation Efforts of an Endangered Toad

Species distribution models are used for numerous purposes such as predicting changes in species’ ranges and identifying biodiversity hotspots. Although implications of distribution models for conservation are often implicit, few studies use these tools explicitly to inform conservation efforts. Herein, we illustrate how multiple distribution models developed using distinct sets of environmental variables can be integrated to aid in identification sites for use in conservation. We focus on the endangered arroyo toad (Anaxyrus californicus), which relies on open, sandy streams and surrounding floodplains in southern California, USA, and northern Baja California, Mexico. Declines of the species are largely attributed to habitat degradation associated with vegetation encroachment, invasive predators, and altered hydrologic regimes. We had three main goals: 1) develop a model of potential habitat for arroyo toads, based on long-term environmental variables and all available locality data; 2) develop a model of the species’ current habitat by incorporating recent remotely-sensed variables and only using recent locality data; and 3) integrate results of both models to identify sites that may be employed in conservation efforts. We used a machine learning technique, Random Forests, to develop the models, focused on riparian zones in southern California. We identified 14.37% and 10.50% of our study area as potential and current habitat for the arroyo toad, respectively. Generally, inclusion of remotely-sensed variables reduced modeled suitability of sites, thus many areas modeled as potential habitat were not modeled as current habitat. We propose such sites could be made suitable for arroyo toads through active management, increasing current habitat by up to 67.02%. Our general approach can be employed to guide conservation efforts of virtually any species with sufficient data necessary to develop appropriate distribution models.     

Modeling Spatial Trends in Estimated Species Richness using Breeding Bird Survey Data: A Valuable Tool in Biodiversity Assessment

We used data from the French breeding bird survey to estimate local bird species richness within sampled sites, using capture–recapture models. We investigated the possible effects of habitat structure and composition (landscape fragmentation, habitat cover and diversity) on estimated species richness at a local scale, and used the identified trends to help with modeling species richness at a large spatial scale. We performed geostatistical analyses based on spatial autocorrelation – cokriging models – to interpolate estimated species richness over the entire country, providing an opportunity to predict species-rich areas. We further compared species richness obtained with this method to species and rarity richness obtained using a national atlas of breeding birds. Estimated species richness was higher in species richness hotspots identified by the atlas. Combining informations on rare species from Atlas and species richness estimates from sound sampling based schemes should help with identifying species-rich areas for various taxa and locating biodiversity hotspots to be protected as high conservation value areas, especially in temperate zones where diversity hotspots are likely to match centers of high species richness because of very few centers of true endemicity.     

The distribution of amphibian species richness in protected areas of Chiapas,Mexico

Due to the current environmental crisis, many animal species face extinction problems. Amphibian populations have been affected by this crisis. Our goal is to study amphibian species diversity in Chiapas, which has 7.6% of the endemic amphibians in Mexico and 53 protected areas. Only 58% of the protected areas have management plans or information on their resident amphibians. We aim to determine the extent of protection provided by the network of natural areas for the conservation of amphibian species in the state and to discuss the effectiveness of this protection. Therefore, we compiled a georeferenced database of 112 amphibian species in Chiapas to create each distribution model. In addition, we carried out representativeness, beta diversity, and species richness analyses. As a result, we obtained a high degree of representativeness for the records and species distribution models. However, we found a decrease in the richness of amphibians involving 20% of total species, 13% of endemics, 18% threatened according to NOM-059, and 31% threatened according to IUCN between 1800 and 2020 and 1980–2020. We also identified two biodiversity hotspots in the Sierra Madre de Chiapas and the Northern Highlands physiographic regions. Finally, based on potential distributions, we found more endemic and threatened species outside protected natural areas than inside them. Our results give a broader picture of how amphibian richness is distributed in Chiapas. This information can help to prioritize conservation efforts toward those areas rich in threatened or endemic species, such as the Northern Mountains Hotspot we identified in northern Chiapas.     

Do hotspots fall within protected areas? A Geographic Approach to Planning analysis of regional freshwater biodiversity

相似文献   

Patterns of species richness hotspots and estimates of their protection are sensitive to spatial resolution

Aim

Species richness is a measure of biodiversity often used in spatial conservation assessments and mapped by summing species distribution maps. Commission errors inherent those maps influence richness patterns and conservation assessments. We sought to further the understanding of the sensitivity of hotspot delineation methods and conservation assessments to commission errors, and choice of threshold for hotspot delineation.

Location

United States.

Methods

We created range maps and 30‐m and 1‐km resolution habitat maps for terrestrial vertebrates in the United States and generated species richness maps with each dataset. With the richness maps and the GAP Protected Areas Dataset, we created species richness hotspot maps and calculated the proportion of hotspots within protected areas; calculating protection under a range of thresholds for defining hotspots. Our method allowed us to identify the influence of commission errors by comparing hotspot maps.

Results

Commission errors from coarse spatial grain data and lack of porosity in the range data inflated richness estimates and altered their spatial patterns. Coincidence of hotspots from different data types was low. The 30‐m hotspots were spatially dispersed, and some were very long distances from the hotspots mapped with coarser data. Estimates of protection were low for each of the taxa. The relationship between estimates of hotspot protection and threshold choice was nonlinear and inconsistent among data types (habitat and range) and grain size (30‐m and 1‐km).

Main conclusions

Coarse mapping methods and grain sizes can introduce commission errors into species distribution data that could result in misidentifications of the regions where hotspots occur and affect estimates of hotspot protection. Hotspot conservation assessments are also sensitive to choice of threshold for hotspot delineation. There is value in developing species distribution maps with high resolution and low rates of commission error for conservation assessments.     

Using Self-Organizing Maps to Explore Patterns in Species Richness and Protection

The combination of species distributions with abiotic and landscape variables using Geographic Information Systems can prioritize areas for biodiversity protection by identifying areas of high richness, although the number of variables and complexity of the relationships between them can prove difficult for traditional statistical methods. The use of these methods, which commonly assume linearity and low correlation between independent variables, can obscure even strong relationships and patterns. Self-Organizing Maps (SOM) is a heuristic statistical tool based on machine learning methods that can be used to explore patterns in large, complex datasets for linear and nonlinear patterns. Here we use SOM to visualize broad patterns in species richness by taxonomic group (birds, mammals, reptiles, and amphibians) and 78 habitat, landscape and environmental variables using data from the Gap analysis project for West Virginia, USA. Soil and habitat variables demonstrated clear relationships with species richness; areas with high species richness occurred in areas with high soil richness. Landscape metrics were less important, although habitat diversity and evenness indices were positively related to species richness in some taxonomic groups. Current coverage of protected areas (e.g., National Forests and state parks) appeared to be insufficient to cover most of the areas of high species richness, especially for reptiles; many of the polygons with the highest richness were not covered by these areas. The identification of polygons with high richness and low protection can be used to focus conservation efforts in those areas.     

Habitat requirements of Eurasian pine marten <Emphasis Type="Italic">Martes martes</Emphasis> in a Mediterranean environment

Evaluating presence and habitat requirements of small carnivores is essential for their conservation. The Eurasian pine marten Martes martes, often described as a habitat specialist associated primarily with forest habitats, has been recently found to live even in patchily wooded country and in shrublands. We evaluated the environmental factors that determine the distribution of the pine marten in a Mediterranean landscape on the island of Sardinia (central Italy). Camera trapping sessions and scat surveys were carried out to assess the presence of the species, then a potential distribution model was developed using ecological niche factor analysis (ENFA), which requires only presence data. The pine marten selected highest altitudes, shrublands, rocky areas, and woodlands, and avoided urban areas and arable lands. Our results indicate that pine marten distribution in our study area is constrained by these variables. The ENFA analysis provided important clues about the distribution range of M. martes and its preferential environmental conditions, updating knowledge of its ecological requirements in Italy.     

Global species richness of hydrobiid snails determined by climate and evolutionary history

相似文献   

Distribution patterns of biodiversity and the design of a representative reserve network in Portugal

Representativeness is a desirable property of conservation networks. In this paper an attempt is made to assess the efficiency of current conservation networks in Portugal in representing vertebrates (reptiles and amphibians) and plants (gymnosperms, pteridophytes and bryophytes). It was found that whilst the protected areas do not sample all species in the database they provide a better result than choosing areas at random. For the goal of maximizing representation of taxa per unit area hotspots and complementarity performed better. A pattern of over-representation of vertebrates in relation to lower plants was discovered among selected conservation areas in Portugal suggesting that charismatic organisms with large home ranges may not always be the most appropriate surrogates for biodiversity when representativeness is sought. When trying to fill the gaps in current protected areas with additional areas only complementarity performed better than choosing areas at random. Both rarity and richness hotspots gave worse results. Opportunistic administrative criteria such as supplementing the PAS with other conservation areas (CORINE Biotopes) without taking into account their contribution to a representation goal was nearly half as good as choosing areas at random. The results recall for the need of explicit goals and accountable methods in area selection for conservation and reinforce the role of complementarity for finding additional areas to protected areas when limited resources are available for ‘in situ’ conservation.     

Amphibian Hotspots and Conservation Priorities in Eastern Cuba Identified by Species Distribution Modeling

The high rate of amphibian endemism and the severe habitat modification in the Caribbean islands make them an ideal place to test if the current protected areas network might protect this group. In this study, we model distribution and map species richness of the 40 amphibian species from eastern Cuba with the objectives of identify hotspots, detect gaps in species representation in protected areas, and select additional areas to fill these gaps. We used two modeling methods, Maxent and Habitat Suitability Models, to reach a consensus distribution map for each species, then calculate species richness by combining specific models and finally performed gap analyses for species and hotspots. Our results showed that the models were robust enough to predict species distributions and that most of the amphibian hotspots were represented in reserves, but 50 percent of the species were incompletely covered and Eleutherodactylus rivularis was totally uncovered by the protected areas. We identified 1441 additional km² (9.9% of the study area) that could be added to the current protected areas, allowing the representation of every species and all hotspots. Our results are relevant for the conservation planning in other Caribbean islands, since studies like this could contribute to fill the gaps in the existing protected areas and to design a future network. Both cases would benefit from modeling amphibian species distribution using available data, even if they are incomplete, rather than relying only in the protection of known or suspected hotspots.     

Human population, grasshopper and plant species richness in European countries

Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species–people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population–biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.     

黔西北石漠化地区两栖动物多样性及其生境选择

对两栖动物多样性及其生境选择的调查, 可为两栖动物的保护提供基础性资料。我们于2018年9-10月、2019年3-8月对贵州省毕节市撒拉溪石漠化综合治理示范区30个研究样方的两栖动物进行了调查, 共观察到两栖动物5,688只, 隶属2目6科9属10种。采用Shannon-Wiener多样性指数、Margalef丰富度指数、Pielou均匀度指数等分析了不同等级石漠化区域中的两栖动物物种多样性, 采用Sorenson相似性系数、聚类分析等方法分析了群落的相似性与差异性。结果显示: (1)云南小狭口蛙(Glyphoglossus yunnanensis)为优势种, 贵州疣螈(Tylototriton kweichowensis)、红点齿蟾(Oreolalax rhodostigmatus)、中华蟾蜍(Bufo gargarizans)、华西雨蛙(Hyla annectans)和昭觉林蛙(Rana chaochiaoensis)为常见种, 粗皮姬蛙(Microhyla butleri)、沼水蛙(Hylarana guentheri)、筠连臭蛙(Odorrana junlianensis)和威宁蛙(Rana weiningensis)为稀有种。(2)无石漠化区域与潜在石漠化区域两栖动物物种数、个体数以及生境类型较之其他3个等级石漠化区域更为丰富, 多样性指数、丰富度指数以无石漠化区域为最大。(3)无石漠化区域和潜在石漠化区域之间、无石漠化区域和潜在石漠化区域分别与其他3个等级石漠化区域之间表现出较强的差异性。研究表明, 喀斯特地区石漠化导致的生境差异是两栖动物分布差异的重要原因, 加强石漠化的生态治理是喀斯特地区保护两栖动物的重要途径。     

Habitat suitability,corridors and dispersal barriers for large carnivores in Poland

Carnivores are often particularly sensitive to landscape fragmentation. Ecological corridors may help to connect local populations, ensuring gene flow and retaining viable meta-populations. We aimed to establish habitat suitability models for two large carnivores in Poland, the grey wolf Canis lupus Linnaeus, 1758 and the Eurasian lynx Lynx lynx Linnaeus, 1758, based on ecological niche factor analysis (ENFA). Secondly, we calculated least cost paths (LCPs) based on cost values obtained from ENFA. Thirdly, we determined structures that might act as barriers, thus diminishing the value of the corridor unless appropriate conservation measures are taken. We compared some of the results with actual dispersal data of four lynx in eastern Poland. Results indicate that both species are highly marginalised. Less habitat that is currently available in Poland is suitable for lynx than for wolves. We determined a total of 76 LCPs. Comparison of these theoretical corridors with actual dispersal routes suggests that the traits of calculated LCPs are mostly within the range of those of real routes. We highlight a variety of features that might act as barriers, such as major roads (including planned highways), urbanized areas, and large un-forested areas. We give suggestions where concerted conservation efforts (eg wildlife passages) might be particularly well-directed.     

国家重点保护野生植物的保护现状及潜在分布区预测分析

野生植物是自然生态系统的重要组成部分,中国是野生植物种类最丰富的国家之一。研究国家重点保护野生植物的分布特征、保护现状以及潜在分布区,对于制定与支持生物多样性保护策略具有重要意义。该研究基于1 032种(隶属于129科315属)国家重点保护野生植物,利用前5%丰富度算法识别其热点地区,并与自然保护区叠加评估其保护成效、确定保护空缺,进而运用MaxEnt模型预测了国家重点保护野生植物的潜在分布区分布与变化趋势。结果表明:(1)中国南部和西南部是国家重点保护野生植物物种丰富度最高的地区,尤其是四川中部、云南南部和东南部、广西北部、广东北部与海南。(2)热点网格的保护成效分析表明,171个(85.50%)热点网格得到了有效保护(含80.50%的物种),29个(14.50%)热点网格未得到自然保护区的保护(含51.20%物种)。(3)通过比较当前与未来气候变化下国家重点保护野生植物的潜在分布区分布,发现未来潜在分布区将向西藏东南部、广西西南部、广东南部以及福建南部等地扩张,而向环四川盆地、云南南部和贵州南部等地缩减。因此,需要加强这些区域生物多样性的动态监测,持续关注气候变化对该区域国家重点保护野生植物的影响。基于该研究所确定的热点网格、保护成效以及潜在分布区的分析结果,可为国家重点保护野生植物多样性优先保护区的确定和保护政策的制定提供有力的数据支持与参考。     

Jumping into the grids: mapping biodiversity hotspots in groundwater habitat types across Europe

Biodiversity hotspots are routinely identified by grid-based analyses, despite grids encompassing different habitats, thus hindering the potential to assess which habitat type accounts for the conservation priority assigned to a grid. In this study, we aimed at identifying the main hotspots for the conservation of the European stygobitic Crustacea Copepoda Harpacticoida at the groundwater habitat scale. A multi-metric approach was used, based on six biodiversity indicators: species richness, endemicity, evolutionary origin, phylogenetic rarity, taxonomic distinctness, habitat specificity. The Hot Spot Analysis, based on the statistics Getis-Ord Gi*, was used to compare the local to the global average values of each indicator to identify hotspots of conservation. The operational units used to perform the analyses were the groundwater habitat types, in order to gather all the possible patterns of spatial occupancy in terms of habitat variability. Eight biodiversity hotspots of stygobitic Crustacea Harpacticoida were highlighted: 1) the Pyrenees (Spain and France), 2) the Jura Massif (France), 3) the Alpine arc (France, Switzerland and Italy) embracing southward the River Po alluvial plain and the Slovenian External Dinarides, 4) the Central Apennines (Italy), 5) the Carpathian and Balkan mountains in Romania and at the boundary between western Bulgaria and north-west Macedonia, 6) the Dinaric Alps (from Croatia to Albania), 7) the Sardinia Island, 8) an area in central-northern Europe embracing Denmark, the Netherlands and Germany. The hotspots showed a clear spatial distribution in southern Europe where they were distributed predominantly south to the 45th parallel, in line to what reiteratively observed in previous studies. Many hotspots embraced more than one habitat type. The adoption of discrete groundwater habitat types as working spatial units rather than grids provided a higher resolution of where the stygobitic harpacticoid species effectively live, with the possibility of intervening more precisely to preserve them and their habitats.     

Global diversity of land planarians (Platyhelminthes, Tricladida, Terricola): a new indicator-taxon in biodiversity and conservation studies

Biodiversity conservation requires prioritization of areas for in situ conservation. In that perspective, the present study documents the global diversity of a component of the soil macrofauna, the land planarians, and concerns an exploratory analysis of their possible role as indicators of biodiversity. Diversity is described by three quantitative methods: (1) hotspots of species richness, selecting areas richest in species, (2) hotspots of range-size rarity, identifying areas richest in narrowly endemic species, and (3) complementarity, prioritizing areas according to their greatest combined species richness. The biodiversity measures of species richness and range-size rarity show a great correspondence in the identification of hotspots of diversity; both measures identify the following seven areas as the most biodiverse for land planarians: Sao Paulo, Florianopolis, western Java, Tasmania, Sri Lanka, North Island/New Zealand, and Sydney. It is discussed to what extent the results for the land planarians correspond with those obtained in other studies that assessed biodiversity hotspots for taxa on a global scale. It is noteworthy that land planarians identify a few global hotspots of diversity that generally do not feature, or only have low rankings, in other studies: New Zealand, southeastern Australia, and Tasmania.