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1.
Nineteen species of amphibians inhabit Romania, 9 of which reach their range limit on this territory. Based on published occurrence reports, museum collections and our own data we compiled a national database of amphibian occurrences. We georeferenced 26779 amphibian species occurrences, and performed an analysis of their spatial patterns, checking for hotspots and patterns of species richness. The results of spatial statistic analyses supported the idea of a biased sampling for Romania, with clear hotspots of increased sampling efforts. The sampling effort is biased towards species with high detectability, protected areas, and large cities. Future sampling efforts should be focused mostly on species with a high rarity score in order to accurately map their range. Our results are an important step in achieving the long-term goals of increasing the efficiency of conservation efforts and evaluating the species range shifts under climate change scenarios.  相似文献   

2.
We have updated the list of the lizard species present in Qatar and produced the first distribution maps based on two field surveys in 2012 and 2013. We used the QND95/Qatar National Grid with a grid of 10 × 10 km squares for mapping. Our results show the occurrence of 21 lizard species in Qatar, from the 15 species indicated in the last biodiversity report conducted in 2004. The most abundant family found in Qatar is Gekkonidae with nine species (Bunopus tuberculatus, Cyrtopodion scabrum, Hemidactylus robustus, H. flaviviridis, H. persicus, Stenodactylus arabicus, S. slevini, S. doriae, Pseudoceramodactylus khobarensis), followed by Lacertidae with four species (Acanthodactylus schmidti, A. opheodurus, Mesalina brevirostris, M. adramitana), Agamidae with three species (Trapelus flavimaculatus, Uromastyx aegyptia, Phrynocephalus arabicus), Scincidae with two species (Scincus mitranus, Trachylepis septemtaeniata), and Varanidae (Varanus griseus), Sphaerodactylidae (Pristurus rupestris) and Trogonophiidae (Diplometopon zarudnyi) with one species each. The species richness fluctuated largely across Qatar between one and eleven species per grid square. We believe that the lizard fauna records in Qatar are still incomplete and that additional studies are required. However, our study here fills a gap concerning lizard biodiversity knowledge in the Gulf Region.  相似文献   

3.
中国爬行纲动物分类厘定   总被引:2,自引:0,他引:2  
本文对中国爬行纲动物的分类体系和物种进行了系统的评估, 规范了中文学名, 给出了《中国爬行纲校正名录》, 结果表明: 中国现存爬行纲动物3目30科132属462种, 其中鳄形目(Crocodylia)1科1属1种, 龟鳖目(Testudines)6科18属33种, 有鳞目(Squamata)蜥蜴亚目(Lacertilia)10科41属189种, 有鳞目蛇亚目(Serpentes)13科72属239种。与《中国动物志 爬行纲 第一卷(总论、龟鳖目、鳄形目)》、《中国动物志 爬行纲 第二卷(有鳞目: 蜥蜴亚目)》和《中国蛇类》相比, 目和亚目无变化; 科级水平新增5科, 变更2科; 属级水平新增23属, 合并15属, 变更6属; 种级水平新增81种, 变动2种; 未收录同物异名12种、杂交6种、中国无分布7种。形态和分子系统发育研究结果在爬行动物不同分类阶元均有一定差异, 文章对这些争议进行了讨论, 并对名录的选择做了说明。  相似文献   

4.
Abstract. Amphibians and reptiles represent an important group of vertebrates in Mexico; on a global scale 10% of the biodiversity of these groups is found in the country, attaining extraordinarily high levels of endemism (60.7% and 53.7%, respectively). However, fewer than 20% of the known species of amphibians and reptiles in Mexico have been surveyed for helminths, so the inventory is far from complete. We assembled a data base that includes a total of 1246 records (entries) of which 460 correspond to helminths in amphibians and 786 to helminths in reptiles. In total, only 41 species of amphibians (14% of those occurring in Mexico) and only 118 species of reptiles (17% of those occurring in Mexico) have been studied for helminth parasites. From amphibians, 119 species of helminths belonging to 60 genera have been recorded, while 239 species of helminths representing 113 genera have been described from Mexican reptiles. One feature of the distribution of helminths of Mexican amphibians and reptiles is its asymmetry, as seen in representation of helminth groups, host groups and geographical range. However, such statistical asymmetry might be an artefact of sampling effort. Based on our data, we estimate that if all the herpetofauna of Mexico could be studied in the following years, approximately 827 additional species of helminths from amphibians and approximately 1403 from reptiles would be described.  相似文献   

5.
Abstract We examined 11 non‐linear regression models to determine which of them best fitted curvilinear species accumulation curves based on pit‐trapping data for reptiles in a range of heterogeneous and homogenous sites in mesic, semi‐arid and arid regions of Western Australia. A well‐defined plateau in a species accumulation curve is required for any of the models accurately to estimate species richness. Two different measures of effort (pit‐trapping days and number of individuals caught) were used to determine if the measure of effort influenced the choice of the best model(s). We used species accumulation curves to predict species richness, determined the trapping effort required to catch a nominated percentage (e.g. 95%) of the predicted number of species in an area, and examined the relationship between species accumulation curves with diversity and rarity. Species richness, diversity and the proportion of rare species in a community influenced the shape of species accumulation curves. The Beta‐P model provided the best overall fit (highest r2) for heterogeneous and homogeneous sites. For heterogeneous sites, Hill, Rational, Clench, Exponential and Weibull models were the next best. For homogeneous habitats, Hill, Weibull and Chapman–Richards were the next best models. There was very little difference between Beta‐P and Hill models in fitting the data to accumulation curves, although the Hill model generally over‐estimated species richness. Most models worked equally well for both measures of trapping effort. Because the number of individuals caught was influenced by both pit‐trapping effort and the abundance of individuals, both measures of effort must be considered if species accumulation curves are to be used as a planning tool. Trapping effort to catch a nominated percentage of the total predicted species in homogeneous and heterogeneous habitats varied among sites, but even for only 75% of the predicted number of species it was generally much higher than the typical effort currently being used for terrestrial vertebrate fauna surveys in Australia. It was not possible to provide a general indication of the effort required to predict species richness for a site, or to capture a nominated proportion of species at a site, because species accumulation curves are heavily influenced by the characteristics of particular sites.  相似文献   

6.
为了解大型底栖动物沿河流分布的物种丰富度变化及环境因子对其种群的影响,于2016年12月对高岚河的大型底栖动物进行了调查,并对理化指标进行了测定。研究结果发现,物种丰富度沿河流纵向梯度变化差异性不显著,生物多样性指数沿河流变化差异不显著,说明高岚河大型底栖动物群落结构稳定。高岚河上游的生态指示种为高翔蜉和四节蜉,中游的生态指示种为四节蜉和萝卜螺,下游的指示种为萝卜螺。模糊聚类分析发现高岚河大型底栖动物类群可划分为3个生境类群,且在梯度分布下群落生境较相似,大型底栖动物群落间关系接近,分布均匀。典范对应分析发现影响大型底栖动物群落结构沿梯度分布的主要因子是海拔、pH、浊度和深度。  相似文献   

7.
Tree species distribution in forests of the Albertine Rift, western Uganda   总被引:1,自引:0,他引:1  
The distribution of trees of diameter ≥ 10 cm was assessed in twelve 1‐ha (20 × 500 m) plots of Bwindi Impenetrable National Park (BINP), Kasyoha‐Kitomi Forest Reserve (KKFR), Kibale National Park (KNP) and Budongo Forest Reserve (BFR) in the Albertine Rift, western Uganda. Distribution was analysed at three spatial scales: local (1 ha plots), within individual forests (>300 km2 each) and regional (>56,000 km2). The aim was to classify tree species into Rabinowitz's seven forms of rarity. We recorded 5747 trees in 53 families, 159 genera, and 212 species. Twenty‐two families had one species each while the rest had between two and 25 species. Number of species was highest in the family Euphorbiaceae (25 species) followed by Meliaceae and Rubiaceae with sixteen species each. Based on Rabinowitz's forms of rarity, 93% of the species were geographically widespread, 47% were restricted to a single forest type, while 41% occurred at densities of <1 individual ha?1. Ubiquitous common species with high frequency and high local abundance occurred in the Meliaceae, Flacourtiaceae, Moraceae and Apocynaceae families. Conservation of geographically widespread species should focus on landscape rather than site specific approaches. The rarest species would benefit from species‐specific strategies.  相似文献   

8.
周韩洁  杨入瑄  李嵘 《广西植物》2022,42(10):1694-1702
全球气候变化与人为活动等因素导致的生物多样性丧失,引起了全球各界对生物多样性保护的高度关注。传统生物多样性保护主要对物种、特有种、受威胁物种的种类组成及其分布模式开展研究,忽视了进化历史在生物多样性保护中的作用。云南是全球生物多样性热点地区的交汇区,生物多样性的保护历来受到广泛关注,为了更好地探讨云南生物多样性的保护措施,该研究以云南被子植物菊类分支物种为研究对象,基于物种间的演化关系,结合其地理分布,从进化历史的角度探讨物种、特有种、受威胁物种的种类组成及系统发育组成的分布格局,并整合自然保护地的空间分布,识别生物多样性的重点保护区域。结果表明:云南被子植物菊类分支的物种、特有种及受威胁物种的物种密度与系统发育多样性均显著正相关;通过零模型分析发现,由南向北标准化系统发育多样性逐渐降低;云南南部、东南部、西北部是云南被子植物菊类分支的重点保护区域,加强这些区域的保护,将最大化地保护生物多样性的进化历史和进化潜能。由此可见,融合进化历史信息的植物多样性格局分析不仅有助于更加深入地理解植物多样性的形成与演变,也为生物多样性保护策略的制定提供更多的思路。  相似文献   

9.
10.
1. Blackfly species richness and community structure were analysed at fifty-six sites in northern Sweden in two seasons. The sites were situated in a wide range of streams and rivers from small springbrooks, bog streams and lake-outlet streams to medium-sized forest rivers and large rivers draining montane regions.
2. Thirty-nine blackfly species were found, with between two and thirteen species per site. Neither species richness nor abundance could be related to the environmental variables measured.
3. An analysis of labral fan size of blackflies indicated a clear trend for the prevalence of larvae with small fans in large rivers and larvae with larger fan size in small streams. Similarly, fan size related to current velocities so that large fans were associated with slow current velocities and small fans with high velocities.
4. A strong relationship existed between species composition and habitat, as seen in ordination by non-metric multidimensional scaling. The relationship found between fan size and habitat size-related variables, such as channel width, depth, velocity and substratum particle size, along with longitude and altitude, in partial least squares regression analysis offered an explanation of the species composition–habitat relationship.
5. In addition to testing that distributions of blackfly larvae reflect morphological traits, we tested two general hypotheses pertaining to distribution patterns: (a) that blackfly communities show bimodal distributions; and (b) that their distributions are nested. Neither of these two hypotheses was supported by our observations. However, widespread blackfly species were locally more abundant than those found at relatively few sites, thus showing a positive abundance–occupancy relationship.  相似文献   

11.
对濒危物种在大尺度上地理分布的研究,有助于制定合理的保护规划和保护策略.兰科植物作为一大类急需保护的濒危物种,研究其在中国境内的地理分布格局具有重要的理论和实践意义.通过文献查阅、自然保护区数据整理收集兰科植物在全国范围内的调查数据,利用ArcGIS10.0和SPASS18.0软件对其地理分布进行了分析,结果表明:中国西南地区是兰科植物的分布中心和分化中心;兰科植物丰富度表现出显著的经度和纬度相关性,与经度之间呈单峰关系,在100°E附近出现峰值,但随纬度升高丰富度不断下降.  相似文献   

12.
13.
National key protected wild plants (NKPWPs) are species with important conservation value based on genetics, ecology, culture, and/or scientific research, which are also confronted with serious threats. However, their geographical distribution patterns and conservation status remain unclear. In this study, we compiled 1032 species of NKPWPs. We measured the diversity to identify hotspots of NKPWPs based on species richness, weighted range size rarity and a complementarity-based analysis. Comparing the distribution and hotspots of NKPWPs with the coverage of Chinese nature reserves (NRs), we assessed conservation effectiveness and identified conservation gaps. The results identified 13 diversity hotspots; only 9.5% of them were covered by NRs with >30% of the grid cell area, and even 19.5% were not covered at all by NRs. Overall, 44.7% of NKPWPs were effectively protected by national NRs. Despite this success, 571 species in Yunnan, Guizhou, Sichuan, Chongqing, Guangxi, Guangdong, southern Hainan, Taiwan, and northern Xinjiang remain unprotected by NRs. The protected proportion of plants with first-level protection was lower than that of plants with second-level protection. The low overall proportion of protected hotspots indicates that the conservation outlook for NKPWPs is not optimistic. This study identifies priority conservation areas and conservation gaps and provides a scientific reference for the conservation of wild plants in China.  相似文献   

14.
Parasitic plants are an important component of vegetation worldwide, but their diversity and distribution in China have not been systematically reported. This study aimed to (1) explore floral characteristics of China's parasitic plants, (2) map spatial distribution of diversity of these species, and (3) explore factors influencing the distribution pattern. We compiled a nationwide species list of parasitic plants in China, and for each species, we recorded its phylogeny, endemism, and life form (e.g., herb vs. shrub; hemiparasite vs. holoparasite). Species richness and area‐corrected species richness were calculated for 28 provinces, covering 98.89% of China's terrestrial area. Regression analyses were performed to determine relationships between provincial area‐corrected species richness of parasitic plants and provincial total species richness (including nonparasitic plants) and physical settings (altitude, midlongitude, and midlatitude). A total of 678 species of parasitic angiosperms are recorded in China, 63.13% of which are endemic. Of the total, 59.73% (405 species) are perennials, followed by shrubs/subshrubs (14.75%) and vines (1.47%). About 76.11% (516 species) are of root hemiparasites, higher than that of stem parasites (100, 14.75%), root holoparasites (9.00%), and endophytic parasites (0.15%). A significant positive relationship is found between the area‐corrected species richness and the total species richness, which has been previously demonstrated to increase with decreasing longitude and latitude. Moreover, more parasitic species are found in the southwest high‐altitude areas than low areas. Consistently, the area‐corrected species richness increases with increasing altitude, decreasing latitude, and decreasing longitude, as indicated by regression analyses. China is rich in parasitic flora with a high proportion of endemic species. Perennials and root hemiparasites are the dominant types. The spatial distribution of parasitic plants is largely heterogeneous, with more species living in southwest China, similar to the distribution pattern of Chinese angiosperms. The positive relationship between parasitic and nonparasitic plant species richness should be addressed in the future.  相似文献   

15.
Aim The assumption that ecological patterns at large spatial scales originate exclusively from non‐anthropogenic processes is growing more questionable with the increasing domination of the biosphere by humans. Because common and rare species are known to respond differently to anthropogenic activities at local scales these differential responses could, over time, be reflected in distributional patterns of species richness at larger spatial scales. This work tests the hypothesis that modern processes have played a role in shaping these patterns, by examining recent changes in the structure and composition of assemblages of breeding avifauna over a large geographical extent. Location The portion of North America containing the contiguous United States and southern Canada. Methods Changes in the geographical range structure of breeding avifauna in North America from 1968 to 2003 were analysed in regions containing historically moderate levels of anthropogenic activities. Two geographical measures, extent of occurrence and area of occupancy, were used to identify the level of rarity or commonality of individual species and to estimate, based on a vector analysis, patterns of change in geographical range structure for individual species and avian assemblages. Results More species experienced patterns of geographical range expansion (51%) than contraction (28%). The majority of avian assemblages (43%) displayed patterns of geographical range expansion: common species increased in number and proportion (6%) in association with reciprocal losses in rare and moderately rare species, resulting in a constant level of species richness. The minority of avian assemblages (21%) displayed patterns of geographical range contraction: gains occurred for common species as well as for rare and moderately rare species, resulting in substantial increases in species richness and a decline in the proportion of common species (4%). The remaining avian assemblages presented equivocal patterns characterized by gains in the number and proportion (2%) of common species and gains in species richness. Main conclusions Modern processes have played a role in shaping the distribution patterns of species richness at large spatial scales based on the composition of common and rare species. This suggests that anthropogenic activities cannot be ignored as a possible causal factor when considering ecological patterns at large spatial scales.  相似文献   

16.
This paper investigates the distribution of species richness, rarity and endemicity of European land mammals (bats and introduced species excluded). The highest level of species richness was in Central Europe, while Southern areas had the highest rarity and endemicity scores. The distribution of richness was affected by the location of sampling points in islands and peninsulas. After excluding these sampling points, richness continued to decrease Westward suggesting the existence of a large-scale peninsular effect on mammal distribution. These patterns of continental distribution of richness, rarity and endemicity could be the result of the distribution of refuge areas in the southern Mediterranean peninsulas, and the Pleistocene advances and retreats of mammals throughout the Western Palearctic. Thus, European mammal distribution can be interpreted on the basis of two different patterns of abundance distribution in which Palearctic species reduce their abundance from central-Europe outwards, while endemic, rare species show a similar depletion in the North. It should be useful to evaluate the role of the different regions in Europe in conserving the demographic interactions between central and peripheral populations of mammal species. Given the restricted distribution and potential small size of population, these endemic species are most likely to be susceptible to anthropogenic environmental degradation.  相似文献   

17.
为了评估中国爬行动物红色名录, 我们按照爬行动物生物学特性, 适当修改了IUCN濒危物种红色名录标准Version 3.1。在此基础上, 评估了中国爬行动物生存现状, 参与编制了《中国生物多样性红色名录——脊椎动物卷》。此次评估的中国爬行动物有3目32科133属461种, 结果为: 区域灭绝(RE) 2种、极危(CR) 34种、濒危(EN) 37种、易危(VU) 66种、近危(NT) 78种、无危(LC) 175种以及数据缺乏(DD) 69种。中国受威胁(包括极危、濒危、易危)的爬行动物共计137种, 约占总数的29.72%, 包括龟鳖目31种、有鳞目蛇亚目67种、蜥蜴亚目38种和鳄形目1种, 高于2014年《IUCN濒危物种红色名录》评估的世界爬行动物受威胁比例(13.61%)。在所有受威胁物种中, 受威胁比例最高的类群是鳄形目(100%)和龟鳖目(91.18%), 其次是有鳞目蛇亚目(28.39%), 第三是有鳞目蜥蜴亚目(20.21%)。中国爬行动物特有种受威胁物种有39种, 占特有种总数(143种)的27.27%, 占受威胁物种总数(137)的28.47%。长江以南的华南和西南地区受威胁的物种最多。爬行动物受人类干扰严重, 主要表现为: 栖息地质量退化及生境破碎化、过度利用及污染和气候变化等。尽管自1989年《中华人民共和国野生动物保护法》实施以来, 一些中国濒危爬行动物的生存状况得到改善。但鉴于中国爬行动物区系的独特性和多样性、地形地貌的复杂性及社会经济发展的不均衡性, 为了维持区域生态安全和资源可持续利用, 拯救中国濒危爬行动物, 尤其是中国特有爬行动物中的极危物种, 是中国动物保护工作最迫切的任务之一。  相似文献   

18.
1. Climate change could be one of the main threats faced by aquatic ecosystems and freshwater biodiversity. Improved understanding, monitoring and forecasting of its effects are thus crucial for researchers, policy makers and biodiversity managers. 2. Here, we provide a review and some meta‐analyses of the literature reporting both observed and predicted climate‐induced effects on the distribution of freshwater fish. After reviewing three decades of research, we summarise how methods in assessing the effects of climate change have evolved, and whether current knowledge is geographically or taxonomically biased. We conducted multispecies qualitative and quantitative analyses to find out whether the observed responses of freshwater fish to recent changes in climate are consistent with those predicted under future climate scenarios. 3. We highlight the fact that, in recent years, freshwater fish distributions have already been affected by contemporary climate change in ways consistent with anticipated responses under future climate change scenarios: the range of most cold‐water species could be reduced or shift to higher altitude or latitude, whereas that of cool‐ and warm‐water species could expand or contract. 4. Most evidence about the effects of climate change is underpinned by the large number of studies devoted to cold‐water fish species (mainly salmonids). Our knowledge is still incomplete, however, particularly due to taxonomic and geographic biases. 5. Observed and expected responses are well correlated among families, suggesting that model predictions are supported by empirical evidence. The observed effects are of greater magnitude and show higher variability than the predicted effects, however, indicating that other drivers of changes may be interacting with climate and seriously affecting freshwater fish. 6. Finally, we suggest avenues of research required to address current gaps in what we know about the climate‐induced effects on freshwater fish distribution, including (i) the need for more long‐term data analyses, (ii) the assessment of climate‐induced effects at higher levels of organisation (e.g. assemblages), (iii) methodological improvements (e.g. accounting for uncertainty among projections and species’ dispersal abilities, combining both distributional and empirical approaches and including multiple non‐climatic stressors) and (iv) systematic confrontation of observed versus predicted effects across multi‐species assemblages and at several levels of biological organisation (i.e. populations and assemblages).  相似文献   

19.
1.  We tested the species diversity–energy hypothesis using the British bird fauna. This predicts that temperature patterns should match diversity patterns. We also tested the hypothesis that the mechanism operates directly through effects of temperature on thermoregulatory loads; this further predicts that seasonal changes in temperature cause matching changes in patterns of diversity, and that species' body mass is influential.
2.  We defined four assemblages using migration status (residents or visitors) and season (summer or winter distribution). Records of species' presence/absence in a total of 2362, 10 × 10-km, quadrats covering most of Britain were used, together with a wide selection of habitat, topographic and seasonal climatic data.
3.  We fitted a logistic regression model to each species' distribution using the environmental data. We then combined these individual species models mathematically to form a diversity model. Analysis of this composite model revealed that summer temperature was the factor most strongly associated with diversity.
4.  Although the species–energy hypothesis was supported, the direct mechanism, predicting an important role for body mass and matching seasonal patterns of change between diversity and temperature, was not supported.
5.  However, summer temperature is the best overall explanation for bird diversity patterns in Britain. It is a better predictor of winter diversity than winter temperature. Winter diversity is predicted more precisely from environmental factors than summer diversity.
6.  Climate change is likely to influence the diversity of different areas to different extents; for resident species, low diversity areas may respond more strongly as climate change progresses. For winter visitors, higher diversity areas may respond more strongly, while summer visitors are approximately neutral.  相似文献   

20.
Mitochondrial genomes can be assembled readily from shotgun‐sequenced DNA mixtures of mass‐trapped arthropods (“mitochondrial metagenomics”), speeding up the taxonomic characterization. Bulk sequencing was conducted on some 800 individuals of Diptera obtained by canopy fogging of a single tree in Borneo dominated by small (<1.5 mm) individuals. Specimens were split into five body size classes for DNA extraction, to equalize read numbers across specimens and to study how body size, a key ecological trait, interacts with species and phylogenetic diversity. Genome assembly produced 304 orthologous mitochondrial contigs presumed to each represent a different species. The small‐bodied fraction was the by far most species‐rich (187 contigs). Identification of contigs was through phylogenetic analysis together with 56 reference mitogenomes, which placed most of the Bornean community into seven clades of small‐bodied species, indicating phylogenetic conservation of body size. Mapping of shotgun reads against the mitogenomes showed wide ranges of read abundances within each size class. Ranked read abundance plots were largely log‐linear, indicating a uniformly filled abundance spectrum, especially for small‐bodied species. Small‐bodied species differed greatly from other size classes in neutral metacommunity parameters, exhibiting greater levels of immigration, besides greater total community size. We suggest that the established uses of mitochondrial metagenomics for analysis of species and phylogenetic diversity can be extended to parameterize recent theories of community ecology and biodiversity, and by focusing on the number mitochondria, rather than individuals, a new theoretical framework for analysis of mitochondrial abundance spectra can be developed that incorporates metabolic activity approximated by the count of mitochondria.  相似文献   

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