Factors Affecting Predator-Prey Distribution in a Protected Area,Tehran, Iran (a Case with Wolves and Wild Sheep)

We tried to model habitat suitability of two prey and predator species including wild sheep (Ovis orientalis) and wolf (Canis lupus) in Varjin protected area located in northern east of Tehran using a presence only method, maximum entropy (MaxEnt). Totally 11 environmental variables were measured in the species presence points which can be classified in three groups including topographical, vegetation and distal variables. Resulted maps indicated that habitat variables such as slope (ranging from 35 to 40 percent) and elevation (lower than 1700 meters above sea level) are both institute those factors which mostly affect studied prey and predator habitat use. Our results regarding prey and predator geographical range of used habitat indicated that wolves cover most area than wild sheep which show more dispersed habitat resources for the prey species. ENMTools test revealed that wolf’s niche breadth is more than twice as much as wild sheep’s. Wild sheep in Varjin protected area has a relatively narrow geographical extent and shows a tendency to marginal habitats while wolves cover obviously more areas which denotes its high mobility and low dependency to specific habitats.     

Siberian musk deer in the diets of tiger and bears in the Sikhote-Alin

The role of the Siberian musk deer in the diets of the Amur tiger, brown bear, and Asian black bear has been studied in the Sikhote-Alin State Biosphere Reserve in 1992 to 2016. Information has been collected from 763 tiger feeding sites, and the contents of tiger feces have been analyzed. Radiotelemetry has been used to evaluate tiger–musk deer relationships. The musk deer accounted for 0.26% of all animal species found to be eaten by the tiger. Musk deer remains in feces of the tiger, brown bear, and Asian black bear occurred with frequencies of 1.3, 0.2, and 0.3%, respectively. A case of musk deer avoiding the presence of brown bear is described.     

Effects of urbanization on avian community in southwestern China

Surveys at southwestern China were conducted from November 2004 to July 2005 in three habitat types. A total 3319 individual of 69 bird species were recorded. Although urbanization was presumed to be responsible for decreasing species richness and diversity, our results showed bird species richness, diversity and density in urban habitats were not different in rural habitats. Whereas, the wasteland with low human disturbances, was the lowest bird species richness, diversity and density than others habitats. We inferred habitats structural complexity, large forest patches, native trees and human litter sustain many bird species in campus and park. However, human disturbances, habitats substrate and predation from domestic animals may reduce species richness and diversity. Therefore, we suggested that high vegetative cover should be in urban areas, because it may increase the number of bird species, support larger populations of insectivores, and perhaps create suitable habitat for some ground nesters. Moreover, by recreating or preserving natural islands decreased human disturbance and predation from domestic animals.     

Habitat suitability and potential distribution of <Emphasis Type="Italic">Laudakia nupta</Emphasis> (De Filippi, 1843) (Sauria: Agamidae) in Iran

In the present study, Laudakia nupta were selected as a case study and were examined using the Maxent method to evaluate the potential distribution and most suitable areas. All occurrence records of the species have been gathered from literature and recent updated checklists of lizards of Iran. The final model of L. nupta showed a good performance (AUC = 0.962; SD = 0.011) indicating that the most suitable areas are situated in the western Zagros Mountains in Iran. The situation of the suitable areas in the western Zagros, while the remaining southeastern areas are of low suitability, is controversial and needs more investigation with different criteria such as molecular and other systematic methods. Precipitation of the wettest quarter is the most effective factor for the species presence and I can assume this importance is directly related to the growth of plant in the habitat as main source of food.     

Male Alborz Red Sheep (<Emphasis Type="Italic">Ovis gmelini</Emphasis> × <Emphasis Type="Italic">O. vignei</Emphasis>) migration corridors selection from summer to fall habitats in Jajroud Protected Area Complex,Iran

Jajroud Protected Area Complex is one of the main habitats of Alborz Red Sheep (Ovis gmelini × O. vignei) in Iran. Being close to Tehran, this habitat has been reduced and fragmented due to the human constructions. This study was designed with the aim of identifying the summer and fall habitat patches and the suitability of the matrix by means of Ecological Niche Factor Analysis (ENFA). Cost-distance function was then used to calculate the cost of moving among the patches and the corridors with the least cost was identified using Least-cost path analysis. Results showed that, in both seasons, the species inhabits a narrow niche and is very sensitive to habitat changes. Overall, a suitable habitat for this species is at an elevation of more than 1535 m, with a lower average temperature than average of the habitat, with suitable escape terrain, and away from villages. Military areas, based on their specific use, can have different effects on the habitat suitability. This species selects corridors which are close to escape terrain, with a slope of about 15 percent and low slope fluctuation.     

Relict communities and populations of petrophilous plant species in northern regions of Sverdlovsk oblast and problems in their conservation

An inventory of rock vegetation has been taken in river valleys on the eastern slope of the southern part of the Northern Urals and the northern part of the Middle Urals. New habitats of some rare plant species, relict communities of forest-steppe species at the northern limit of their distribution, and ultrasmall populations of petrophilous species growing in isolation for a long time have been revealed. In studies on a group of similar specially protected areas (e.g., within river valleys), it is proposed to identify key sites distinguished by the highest species richness of vegetation     

大渡河流域川陕哲罗鲑分布与栖息地特征研究

在实地调查和资料分析基础上,对大渡河流域川陕哲罗鲑栖息地及分布进行了量化分析,并对其适宜栖息地保护河段进行了评估与划分。研究表明:(1)1950~2012年,大渡河流域川陕哲罗鲑分布范围持续减少,损失率高达91.4%,强烈的人类活动(如水电开发)成其主要影响因素;(2)川陕哲罗鲑对栖息地生境质量需求较高,适应水温范围较窄(4℃~14℃)。在不同生活史阶段川陕哲罗鲑对于生境的需求存在差异;(3)大渡河上游干流及众多支流对保护川陕哲罗鲑极为重要。在上游适宜划分为川陕哲罗鲑栖息地保护的河段总长度共计2 222.9 km。根据研究结果,我们建议:(1)川陕哲罗鲑栖息地有效保护,不仅应保护其现有分布区域,而且还应涵盖具有较高保护和恢复价值的历史分布和潜在分布空间;(2)尽快开展大渡河河源区川陕哲罗鲑栖息地保护相关规划和研究工作;(3)为协调流域保护和发展,建议建立完善生态补偿机制。     

1990~2013年来洞庭湖区鸟类生物多样性热点区时空动态及变动机理

评估与确定生物多样性分布格局与热点区是建立保护区、制定生物保护决策的基础。洞庭湖地区位处长江中游，是我国重要的淡水湖泊湿地生态系统，为中国乃至亚洲较大的鸟类越冬地之一。以洞庭湖地区14种Ⅰ、Ⅱ级重点保护鸟类为指示物种，基于1990~2013年间的多期遥感影像，运用物种生境分布MAXENT模型，选取地形、水系、植被、气候及人类干扰等共35个影响因子，对其进行生境适宜性评价及生物多样性热点区的筛选与制图，并对热点区时空动态特征进行分析。结果表明：（1）鸟类生物多样性热点区的分布范围呈现出组团状特征，1990~2013年来，热点区面积呈下降趋势；（2）鸟类栖息生境景观格局总体上趋于破碎，生境形状向简单且扁平化形态转变，生境格局呈复杂化；（3）经济与社会发展因素对研究区的鸟类生物多样性热点区变化影响显著，而自然因素产生的影响不明显。研究结果在制定区域生物多样性保护规划方案中可体现较好应用价值。     

Effects of climate change on the distribution of endemic <Emphasis Type="Italic">Ferula xylorhachis</Emphasis> Rech.f. (Apiaceae: Scandiceae) in Iran: Predictions from ecological niche models

Ferula xylorhachis Rech.f. is an endemic plant species belonging to the Apiaceae family and distributed in northeastern Iran. In the present study, we attempted to determine the factors with the greatest effects on the distribution of this species and to determine suitable regions for it based on current and future conditions. The Maximum Entropy method was used in the present study and the results indicated that the Mean Temperature of Wettest Quarter (48.2%), Precipitation of Wettest Quarter (49.1%), and Precipitation of Wettest Month (61.4%) are the most important factors in the current and in two future periods (2040 and 2070). The models suggest that suitable regions for the presence of this species will change over time and that the species will encounter limitations through changes such as moisture reduction. According to the A1B scenario, increases in greenhouse gases such as CO₂ and CH₄ will have direct effects on future precipitation and temperature and these factors will be important in determining species dispersion. Evaluation of important habitat factors using normal ecological methods will help in developing the best conservation programs in the future. Introducing species to new regions will help to protect them from the extinction risk caused by climate change.     

Population dynamics of Great Bittern (Botaurus stellaris) in the Netherlands: interaction effects of winter weather and habitat fragmentation

The increased variability in weather as a manifestation of climate change is expected to have negative impacts on population survival in wildlife species, because it will likely lead to increased variation in vital demographic rates (mortality and reproduction) in these populations. For the effective protection of biodiversity, adaptation measures are needed to compensate for the expected increase in weather variability and the negative interaction with habitat fragmentation. As a case study, we studied the fluctuations in Great Bittern numbers (Botaurus stellaris) from 28 monitoring plots scattered over the Netherlands to explore the interaction between the effect of weather and possible remediating effects of the landscape structure. Great Bittern habitat surrounding these plots differs with respect to area, quality, and degree of isolation of this habitat. In western Europe, Great Bitterns are found to be susceptible to continuous loss of suitable habitat due to vegetation succession and fragmentation. Moreover, year-to-year fluctuations in local Great Bittern populations can be caused by severe winter weather or other weather extremes. Our results show that severe winter weather has indeed a significant negative impact on Great Bittern population growth rates. Furthermore, we found that an increased carrying capacity and spatial cohesion (i.e. inverse of habitat fragmentation) contribute to an increase in mean growth rates over the years. As growth rates are higher in large, well-connected habitats, we argue that recovery from negative effects of, e.g. severe winters on Great Bittern population numbers is enhanced in these less-fragmented habitats. We derived generic adaptation measures for enhancing the recovery rate of populations of species in general: one should invest in more large, well-connected nature areas, not only to diminish the negative effects of habitat fragmentation on wildlife populations, but additionally to reduce the impacts of climatic variability.     

Specific ecological features of the brown bear (<Emphasis Type="Italic">Ursus arctos</Emphasis> L. 1758) in Yakutia

In Yakutia, the brown bear inhabits the forest and forest-tundra zones. Compared to bears from other regions of Russia, Yakutian bears have slightly smaller body and skull sizes and are mainly herbivorous, with their wood spectrum being relatively narrow. Their fecundity averages 1.68 cubs per parous female. The bears make their dens at a depth reaching 2.5–3 m. The denning period begins early and is 195–210 days long. An electroencephalographic analysis of the effect of a 1–10 kDa peptide fraction from the bear brain on Wistar rats has shown that wintering bears are in the state of sleep, or “superficial hibernation.”     

Association of sympatric small mammal species under contrasting environmental conditions

The transformation of microenvironmental conditions in habitats of small mammals and related changes in their spatial structure, manifested in changing levels of interspecific contacts, have been studied in microhabitats of plots affected by anemogenic (windfall) and pyrogenic influence in a protected area of the Middle Urals. The association of the dominant species (the bank vole) and other species of the community (grey red-backed vole, northern red-backed vole, and common shrew) increases in environments disturbed by disastrous natural factors. Association of species is less pronounced in the pyrogenic area, compared to the anemogenic area. The type of association between species differs between stages of progressive succession depending on conditions in particular microhabitats and specific features of functional organization in populations of small mammal species.     

Projecting current and potential future distribution of the Fire-bellied toad Bombina bombina under climate change in north-eastern Germany

Environmental change is likely to have a strong impact on biodiversity, and many species may shift their distribution in response. In this study, we aimed at projecting the availability of suitable habitat for an endangered amphibian species, the Fire-bellied toad Bombina bombina, in Brandenburg (north-eastern Germany). We modelled a potential habitat distribution map based on (1) a database with 10,581 presence records for Bombina from the years 1990 to 2009, (2) current estimates for ecogeographical variables (EGVs) and (3) the future projection of these EGVs according to the statistical regional model, respectively, the soil and water integrated model, applying the maximum entropy approach (Maxent). By comparing current and potential future distributions, we evaluated the projected change in distribution of suitable habitats and identified the environmental variables most associated with habitat suitability that turned out to be climatic variables related to the hydrological cycle. Under the applied scenario, our results indicate increasing habitat suitability in many areas and an extended range of suitable habitats. However, even if the environmental conditions in Brandenburg may change as predicted, it is questionable whether the Fire-bellied toad will truly benefit, as dispersal abilities of amphibian species are limited and strongly influenced by anthropogenic disturbances, that is, intensive agriculture, habitat destruction and fragmentation. Furthermore, agronomic pressure is likely to increase on productive areas with fertile soils and high water retention capacities, indeed those areas suitable for B. bombina. All these changes may affect temporary pond hydrology as well as the reproductive success and breeding phenology of toads.     

川东平行岭谷区野生春剑伴生植物群落特征研究

为了对春剑野生种群生物多样性保护和再引入生态重建提供理论和技术基础，采用典型样地调查法，对川东平行岭谷区野生春剑伴生植物群落特征进行了研究。结果表明：野生春剑主要分布在松科与壳斗科针阔混交林、壳斗科常绿 落叶阔叶混交林和松树林植物群落，伴生植物有40科58属70种，优势种主要是乔木层的马尾松、青冈、巴山松、油松等，灌木层的杜鹃花、马桑、山茶花等，草本层的蕨类和地被层的苔藓。其中，马尾松、杜鹃花、蕨类、苔藓具有较高的重要值，可作为野生春剑栖息地的指示植物。春剑伴生植物种类具有相对的特异性和选择性，与其它群落相比，群落3、群落4和群落6物种多样性指数H′和均匀度指数E都相对较低，松科和壳斗科植物个体数量较多并占有突出地位，春剑种群的生态密度也相对较高。虽然川东平行岭谷区野生春剑的适生生境条件依然存在，但春剑种群数量总体较小，种群的生态密度在11～60株/hm2，人为破坏性的滥采，是其濒危的直接原因。加强野生春剑资源的就地保护和生境保护，突破春剑种子野生环境共生萌发技术瓶颈，积极开展春剑的“再引入”工作，是春剑保育策略的重要方向     

Effects of climate change on species distribution, community structure, and conservation of birds in protected areas in Colombia

Climate change is expected to cause shifts in species distributions worldwide, threatening their viability due to range reductions and altering their representation in protected areas. Biodiversity hotspots might be particularly vulnerable to climate change because they hold large numbers of species with small ranges which could contract even further as species track their optimal habitat. In this study, we assessed the extent to which climate change could cause distribution shifts in threatened and range-restricted birds in Colombia, a megadiverse region that includes the Tropical Andes and Tumbes-Choco-Magdalena hotspots. To evaluate how climate change might influence species in this region, we developed species distribution models using MAXENT. Species are projected to lose on average between 33 and 43 % of their total range under future climate, and up to 18 species may lose their climatically suitable range completely. Species whose suitable climate is projected to disappear occur in mountainous regions, particularly isolated ranges such as the Sierra Nevada de Santa Marta. Depending on the representation target considered, between 46 and 96 % of the species evaluated may be adequately represented in protected areas. In the future, the fraction of species potentially adequately represented is projected to decline to 30–95 %. Additional protected areas may help to retain representativeness of protected areas, but monitoring of species projected to have the largest potential declines in range size will be necessary to assess the need of implementing active management strategies to counteract the effects of climate change.     

Habitat suitability for the Caucasian frog <Emphasis Type="Italic">Rana macrocnemis</Emphasis> Boulenger, 1885 (Amphibia:Anura: Ranidae)

Modeling the distribution patterns of species is a generally efficient tool to assess their ecological characteristics. In this study, we compared ecological niche factor analysis (ENFA) and maximum entropy (Maxent) techniques to predict the most suitable distribution range of Rana macrocnemis. The Maxent model predicted potential suitable habitats for R. macrocnemis with high success rates (AUC Training data = 0.877 ± 0.039). According to the map constructed, three important variables had high contribution to species presence: temperature (50.4%), land cover (24.6%) and elevation (14.4%) variables. The ENFA results were relatively similar to Maxent jackknife analysis. The results implied that R. macrocnemis prefers grassland and needle leaf deciduous forest with high elevations, and low temperature.     

Range contraction and loss of genetic variation of the Pyrenean endemic newt <Emphasis Type="Italic">Calotriton asper</Emphasis> due to climate change

Many studies have identified climate warming to be among the most important threats to biodiversity. Climate change is expected to have stronger effects on species with low genetic diversity, ectothermic physiology, small ranges, low effective populations sizes, specific habitat requirements and limited dispersal capabilities. Despite an ever-increasing number of studies reporting climate change-induced range shifts, few of these have incorporated species’ specific dispersal constraints into their models. Moreover, the impacts of climate change on genetic variation within populations and species have rarely been assessed, while this is a promising direction for future research. Here we explore the effects of climate change on the potential distribution and genetic variation of the endemic Pyrenean newt Calotriton asper over the period 2020–2080. We use species distribution modelling in combination with high-resolution gridded climate data while subsequently applying four different dispersal scenarios. We furthermore use published data on genetic variation of both mtDNA and AFLP loci to test whether populations with high genetic diversity (nucleotide diversity and expected heterozygosity) or evolutionary history (unique haplotypes and K clusters) have an increased extinction risk from climate change. The present study indicates that climate change drastically reduces the potential distribution range of C. asper and reveals dispersal possibilities to be minimal under the most realistic dispersal scenarios. Despite the major loss in suitable climate, the models highlight relatively large stable areas throughout the species core distribution area indicating persistence of populations over time. The results, however, show a major loss of genetic diversity and evolutionary history. This highlights the importance of accounting for intraspecific genetic variation in climate change impact studies. Likewise, the integration of species’ specific dispersal constraints into projections of species distribution models is an important step to fully explore the effects of climate change on species potential distributions.     

长江口滩涂湿地景观变化对典型水鸟生境适宜性的影响

近年来在海平面上升、长江水沙变化、植被演替等自然因素以及促淤圈围工程、深水航道建设等人为因素的共同作用下，长江口滩涂湿地水鸟适宜生境发生了巨大变化。针对长江口滩涂湿地典型水鸟中的鸻鹬类(Charadriiformes)与雁鸭类(Anseriformes)，采用空间多样性指数、人为干扰度等指标研究1980～2010年长江口滩涂湿地景观变化对两类水鸟生境适宜性的影响。结果表明：两类水鸟的不适宜生境、边缘生境、次级生境面积均呈增长趋势，鸻鹬类共增加682 km2，雁鸭类共增加314 km2。而核心生境面积却呈不同的变化趋势，鸻鹬类减少136 km2，雁鸭类增加232 km2，但鸻鹬类和雁鸭类核心生境面积百分比均分别减少566%和194%。1980～2010年鸻鹬类生境适宜性综合评价指数由092下降到053，雁鸭类由089下降到070，鸻鹬类降幅大于雁鸭类。通过定量分析人为干扰度对水鸟生境的影响，发现鸻鹬类对人类干扰更加敏感，中等强度的人类干扰在一定程度上扩大了雁鸭类的适宜生境面积     

Dynamics of Habitat Distribution in Birds Differing in the Level of Site Tenacity

The dynamics of habitat distribution in two bird species differing in the level of site tenacity—willow warbler (relatively tenacious) and little bunting (more flexible)—were studied at the boundary of the northern taiga and forest–tundra zones over ten years. The distribution pattern proved to be more uniform in the willow warbler than in the little bunting. Both species occupied their habitats according to a well-known scheme: initially, the birds settled in their favorable floodplain habitats and later; when their abundance increased, in less preferable habitats (terraces above the floodplain, moss bogs, and the tundra). In the case of willow warbler, the process of occupying the floodplain was stepwise: bird density increased sharply, remained at the same level in the next year, then increased again, etc. In the case of little bunting, the degree of floodplain occupation by birds remained high, except for the years when high spring floods interfered with bird settling.     

How Prey Density and Distribution Can Affect Predator Habitat Usage Pattern: a Case Study on Sand Cat (<Emphasis Type="Italic">Felis margarita</Emphasis>, Locke 1858) from Iran

Prey-predator relationships can affect habitat selection of the animals greatly. In the recent investigation we tried to test how rodents can affect nocturnal sand cat habitat usage pattern. Microhabitat affinities of sand cat and its den site selection were investigated in Sistan and Baluchistan Province from early 2013 to late 2015 in Semsor area. The data acquired from 29 presence plots of individuals were compared by paired non-used plots; the results indicated that the presence of Haloxylon ammodendron and relative density of rodents mainly affected Sand cat microhabitat selection. We also found that the species den site selection was mainly influenced by the presence of tall shrubs such as Haloxylon ammodendron and Tamarix sp. We concluded that the habitat selection pattern of sand cat in the study area could be significantly influenced by rodents’ microhabitat selection; however, such relationship may not be true in larger spatial scales like species home range.