Global hotspots of species richness are not congruent with endemism or threat

Biodiversity hotspots have a prominent role in conservation biology, but it remains controversial to what extent different types of hotspot are congruent. Previous studies were unable to provide a general answer because they used a single biodiversity index, were geographically restricted, compared areas of unequal size or did not quantitatively compare hotspot types. Here we use a new global database on the breeding distribution of all known extant bird species to test for congruence across three types of hotspot. We demonstrate that hotspots of species richness, threat and endemism do not show the same geographical distribution. Only 2.5% of hotspot areas are common to all three aspects of diversity, with over 80% of hotspots being idiosyncratic. More generally, there is a surprisingly low overall congruence of biodiversity indices, with any one index explaining less than 24% of variation in the other indices. These results suggest that, even within a single taxonomic class, different mechanisms are responsible for the origin and maintenance of different aspects of diversity. Consequently, the different types of hotspots also vary greatly in their utility as conservation tools.     

Dynamic biogeography and conservation of endangered species

As one moves from the core to the periphery of a species' geographical range, populations occupy less favourable habitats and exhibit lower and more variable densities. Populations along the periphery of the range tend to be more fragmented and, as a result, are less likely to receive immigrants from other populations. A population's probability of extinction is directly correlated with its variability and inversely correlated with density and immigration rate. This has led to the prediction that, when a species becomes endangered, its geographical range should contract inwards, with the core populations persisting until the final stages of decline. Convinced by these logical but untested deductions, conservation biologists and wildlife managers have been instructed to avoid the range periphery when planning conservation strategies or allocating resources for endangered species. We have analysed range contraction in 245 species from a broad range of taxonomic groups and geographical regions. Here we report that observed patterns of range contraction do not support the above predictions and that most species examined persist in the periphery of their historical geographical ranges.     

Global tests of biodiversity concordance and the importance of endemism

Understanding patterns of biodiversity distribution is essential to conservation strategies, but severe data constraints make surrogate measures necessary. For this reason, many studies have tested the performance of terrestrial vertebrates as surrogates for overall species diversity, but these tests have typically been limited to a single taxon or region. Here we show that global patterns of richness are highly correlated among amphibians, reptiles, birds and mammals, as are endemism patterns. Furthermore, we demonstrate that although the correlation between global richness and endemism is low, aggregate regions selected for high levels of endemism capture significantly more species than expected by chance. Although areas high in endemism have long been targeted for the protection of narrow-ranging species, our findings provide evidence that endemism is also a useful surrogate for the conservation of all terrestrial vertebrates.     

云南桫椤科植物的分类和地理分布

通过野外调查、查阅有关资料及标本,对云南境内桫椤科植物的分类、地理分布、丰富程度和生态习性进行了系统研究。云南省境内桫椤科植物共3属11 种,占我国(3 属约 20 种)总种数的 55%,其地理分布可划分为5个区,其中,滇东南区种类最为丰富,共有9种,占全省总种数的 81.8%;其次是滇南、滇西南区和滇西、滇西北区;中部高原区和滇东北区最少。     

Floristic Characteristics of the Rare and Endangered Plants and the Conservation Countermeasures in Tibet, China

The floristic elements and the geographical distribution are analyzed in this paper based on statistics of elements of rare and endangered plants in Tibet. The results have been gained as following:① According to ““““the National Important Wild Conservative Plants List (List 1)““““ and ““““the National Important Wild Conservative Plants List (List 1)““““, there are a total of 54 plant species (48 genera and 33 families); ② The geographical elements are very complicated in Tibet with 12 of 15 distribution patterns of genera classified byacademician Wu; ③ There are obvious temperate genera with 28 genera accounting for 60.40% of the total genera; ④ There are abundant endemic speciesaccounting for 18.52% of total species but poor endemic genera; ⑤ The geographical distribution is uneven and a great of species distribute in the areas be-tween 1 000 m and 3 500 m above sea level; ⑥ To protect the rare and endangered plants efficiently, six conservation measures are proposed, and 35 species are suggested for the conservative plants of the autonomous conservation level.     

Resource-use efficiency and plant invasion in low-resource systems

No species can maximize growth, reproduction and competitive ability across all environments, so the success of invasive species is habitat-dependent. Nutrient-rich habitats often experience more invasion than resource-poor habitats, a pattern consistent with traits generally associated with successful invaders (high growth rates, early reproduction and many offspring). However, invaders do colonize resource-poor environments, and the mechanisms that allow their success in these systems are poorly understood. Traits associated with resource conservation are widespread among species adapted to resource-poor environments, and invasive species may succeed in low-resource environments by employing resource conservation traits such as high resource-use efficiency (RUE; carbon assimilation per unit of resource). We investigated RUE in invasive and native species from three habitats in Hawaii where light, water or nutrient availability was limiting to plant growth. Here we show that across multiple growth forms and broad taxonomic diversity invasive species were generally more efficient than native species at using limiting resources on short timescales and were similarly efficient when RUE measures were integrated over leaf lifespans. Our data challenge the idea that native species generally outperform invasive species under conditions of low resource availability, and suggest that managing resource levels is not always an effective strategy for invasive species control.     

胶东海岸野生玫瑰(Rosa rugosa)的濒危现状与保护策略

玫瑰是具有重要种质和生态价值的濒危植物,胶东海岸是玫瑰在我国的主要分布区之一．通过野外调查和种群特征分析,基本查清了该区域内现存的玫瑰野生分布区(点)及主要分布区的生境特征、玫瑰种群的数量、空间格局,揭示了人为导致的生境破坏、玫瑰种子传播受阻是导致野生玫瑰种群数量持续减少、有性繁殖成功率低的主要原因．在此基础上,提出应对该区域的野生玫瑰种群采取就地保护、迁地保护和利用性保护相结合的多途径保护策略．     

闽西常绿阔叶林的分类和地理分布研究

常绿阔叶林是我国亚热带温暖湿润地区特有的地带性植被类型.通过全面的实地考察和调查,结果表明:闽西常绿阔叶林植物种类丰富,群落类型多种多样,可划分为2个植被亚型、11个群系组、22个群系、64个群丛,建群种的重要值为45.6-184.0.扼要地阐述了它们的地理分布和生境特点;并根据其现状提出了科学、合理的保护和管理措施.     

Patterns and processes in reef fish diversity

A central aim of ecology is to explain the heterogeneous distribution of biodiversity on earth. As expectations of diversity loss grow, this understanding is also critical for effective management and conservation. Although explanations for biodiversity patterns are still a matter for intense debate, they have often been considered to be scale-dependent. At large geographical scales, biogeographers have suggested that variation in species richness results from factors such as area, temperature, environmental stability, and geological processes, among many others. From the species pools generated by these large-scale processes, community ecologists have suggested that local-scale assembly of communities is achieved through processes such as competition, predation, recruitment, disturbances and immigration. Here we analyse hypotheses on speciation and dispersal for reef fish from the Indian and Pacific oceans and show how dispersal from a major centre of origination can simultaneously account for both large-scale gradients in species richness and the structure of local communities.     

特有濒危植物长柄双花木濒危原因及其保护对策

长柄双花木为我国特有二级重点保护濒危植物,主要分布于江西、湖南、浙江和广东等省的部分区域。本研究综合分析了长柄双花木的自然地理分布特征、群落学特征、生物学特性、繁殖生态学特征及其濒危的可能原因。导致长柄双花木濒危的原因主要有：（1）在有性生殖过程中,由于花粉和资源限制、花粉竞争、传粉昆虫缺乏以及有机养分积累不足等,导致其有性繁殖能力差,结实率和结籽率低。（2）自然条件下种子萌发困难,萌发率、成苗率。（3）克隆繁殖能力有限,自然种群中克隆个体稀少。（4）生境片段化导致种群缩小,更新困难。（5）严重人为干扰直接导致种群锐减。此外,本研究还从强化科学研究和和保护途径等方面探讨了其保护对策。     

Theory predicts the uneven distribution of genetic diversity within species

Global efforts to conserve species have been strongly influenced by the heterogeneous distribution of species diversity across the Earth. This is manifest in conservation efforts focused on diversity hotspots. The conservation of genetic diversity within an individual species is an important factor in its survival in the face of environmental changes and disease. Here we show that diversity within species is also distributed unevenly. Using simple genealogical models, we show that genetic distinctiveness has a scale-free power law distribution. This property implies that a disproportionate fraction of the diversity is concentrated in small sub-populations, even when the population is well-mixed. Small groups are of such importance to overall population diversity that even without extrinsic perturbations, there are large fluctuations in diversity owing to extinctions of these small groups. We also show that diversity can be geographically non-uniform--potentially including sharp boundaries between distantly related organisms--without extrinsic causes such as barriers to gene flow or past migration events. We obtained these results by studying the fundamental scaling properties of genealogical trees. Our theoretical results agree with field data from global samples of Pseudomonas bacteria. Contrary to previous studies, our results imply that diversity loss owing to severe extinction events is high, and focusing conservation efforts on highly distinctive groups can save much of the diversity.     

滇西山地城市水源涵养功能研究——以保山市为例

以云南省保山市为例, 利用CHELSA全球月降水量和月平均气温数据(900 m分辨率)以及MOD17A3 NPP数据和HWSD-V1.2土壤数据, 基于Budyko水平衡模型, 定量地评估区域水源涵养功能的空间分布状况。研究结果表明, 研究区的水源涵养量空间分布主要受降水空间分布不均影响, 其中高黎贡山的阻隔对水汽分布起重要作用; 不同地类的单位水源涵养量和总水源涵养量排序均为森林>灌草地>耕地>水域>建设用地。森林的保护和维持对区域水源涵养能力的提升至关重要。研究区水源涵养极重要区占市域面积的14%, 且集中于高黎贡山西侧, 东侧大部分区域水源涵养能力较弱, 水资源涵养功能维持的压力较大。     

武夷山和九龙山崇安髭蟾的同工酶分析

本文采用聚丙烯酰胺凝胶垂直平板电泳的方法,对产于福建武夷山和浙江九龙山的崇安髭蟾(Vibrissaphora Liui Pope)作了四种器官组织(肝、心、脑、肾)乳酸脱氢酶(LDH)和酯酶(EST)同工酶的分析比较,结果表明,两个产地髭蟾的同工酶谱无差别,我们认为,武夷山和九龙山崇安髭蟾的形态差异只能是地理种群分化(geographical population differentiation),把这两个不同产地的髭蟾作为同一个种处理是恰当的。     

青海杜鹃花种质资源及分布

对青海省杜鹃花种质资源及分布作了研究,其产地及生态地理分布各异,许多种类具有较高的园林观赏价值和药用价值,并对杜鹃花资源的保护和利用提出了建议。     

浙江新昌县野生珍稀植物资源调查

统计得出新昌县有野生珍稀植物34种,隶属于31属25科.简要论述了几种主要的新昌县野生珍稀植物的生物学特性、自然条件和分布现状.并且将新昌县野生珍稀植物属划分成10个分布区类型,发现新昌珍稀植物的分布具有明显的热带、亚热带向暖温带过渡的特征.研究结果为新昌县野生珍稀植物的保护和可持续利用提供科学依据.     

海坛岛灌丛群落的地理分布特点

据对海坛岛南部,中部和东北部选取的６个地区２４处样地,３８４ｍ＾２灌丛群落的调查,以地区间灌木种多频度相似性指数作地区聚类和排序分析,得出海坛岛东北部和西部南两个地区组合,它们依海拔和降水量作略有规律的分布。     

The nature of plant species

Many botanists doubt the existence of plant species, viewing them as arbitrary constructs of the human mind, as opposed to discrete, objective entities that represent reproductively independent lineages or 'units of evolution'. However, the discreteness of plant species and their correspondence with reproductive communities have not been tested quantitatively, allowing zoologists to argue that botanists have been overly influenced by a few 'botanical horror stories', such as dandelions, blackberries and oaks. Here we analyse phenetic and/or crossing relationships in over 400 genera of plants and animals. We show that although discrete phenotypic clusters exist in most genera (> 80%), the correspondence of taxonomic species to these clusters is poor (< 60%) and no different between plants and animals. Lack of congruence is caused by polyploidy, asexual reproduction and over-differentiation by taxonomists, but not by contemporary hybridization. Nonetheless, crossability data indicate that 70% of taxonomic species and 75% of phenotypic clusters in plants correspond to reproductively independent lineages (as measured by postmating isolation), and thus represent biologically real entities. Contrary to conventional wisdom, plant species are more likely than animal species to represent reproductively independent lineages.     

Low beta diversity of herbivorous insects in tropical forests

Recent advances in understanding insect communities in tropical forests have contributed little to our knowledge of large-scale patterns of insect diversity, because incomplete taxonomic knowledge of many tropical species hinders the mapping of their distribution records. This impedes an understanding of global biodiversity patterns and explains why tropical insects are under-represented in conservation biology. Our study of approximately 500 species from three herbivorous guilds feeding on foliage (caterpillars, Lepidoptera), wood (ambrosia beetles, Coleoptera) and fruit (fruitflies, Diptera) found a low rate of change in species composition (beta diversity) across 75,000 square kilometres of contiguous lowland rainforest in Papua New Guinea, as most species were widely distributed. For caterpillars feeding on large plant genera, most species fed on multiple host species, so that even locally restricted plant species did not support endemic herbivores. Large plant genera represented a continuously distributed resource easily colonized by moths and butterflies over hundreds of kilometres. Low beta diversity was also documented in groups with differing host specificity (fruitflies and ambrosia beetles), suggesting that dispersal limitation does not have a substantial role in shaping the distribution of insect species in New Guinea lowland rainforests. Similar patterns of low beta diversity can be expected in other tropical lowland rainforests, as they are typically situated in the extensive low basins of major tropical rivers similar to the Sepik-Ramu region of New Guinea studied here.     

典型喀斯特区域植物物种多样性研究——以广西中越边境喀斯特地区种子植物为例

【目的】广西中越边境地区喀斯特地貌广泛发育,是广西生物多样性研究和保护的关键区域,也是全球生物多样性研究和保护的热点地区。鉴于当前该地区植物区系复杂,植物调查薄弱,生物多样性面临严重威胁,特选该区域开展研究。【方法】基于相关文献资料,整合野外调查数据和历史标本信息,完成该地区的种子植物物种多样性编目,并据此开展综合分析。【结果】广西中越边境喀斯特地区共有种子植物3 118种(含种下单位),隶属于187科、1 050属,科属以寡种占优势,但优势科属也较明显。该区野生种子植物184科,可分为10个分布区类型,其中热带性质的共97科,温带性质的共39科,种子植物热带性科和温带性科的比值约为2.5/1,在属级水平上,该区野生的1 028属可划分为14个分布区类型和24个变型,热带性属共736个,温带性属共219个,热带性属和温带性属的比值约为3.4/1。可见不管在科级还是属级水平都表明该地区地理成分复杂,表现出强烈的热带性质。广西中越边境喀斯特地区种子植物特有现象突出,该地区拥有294种广西特有植物;还有351种为石灰岩特有植物,占该地区总种数的11.51%,另外还有423种为石灰岩适宜植物,综合二者,广西中越边境喀斯特地区典型的喜钙植物种类高达774种,占该地区总种数的25.38%,而且这些特有植物集中于少数的几个科属内,科属优势明显。广西中越边境喀斯特地区珍稀濒危植物众多,其中国家重点保护野生植物29种,包括11种Ⅰ级和18种Ⅱ级保护植物;广西重点保护野生植物有292种,兰科植物就多达261种,其余的31种;另外还有12种被列为全国极小种群保护野生植物。【结论】广西中越边境喀斯特地区植物物种多样性丰富,地理成分复杂,表现出明显的热带性质,特有现象突出,珍稀濒危植物众多,该地区具有重要的研究和保护价值,对广西乃至中国的生物多样性研究和保护都有着举足轻重的意义。     

湖北省连香树自然种群分布研究

对天然连香树的地理分布、种群特征等进行了分析讨论，试图揭示其致危机理。连香树星散间隔分布形式、种群规模较小和对生境的特定要求，反映出该物种正处于濒危状态。应借助于人为帮助，将不同种群的连香树引种到合适的生境中，扩大其种群规模，促进不同种群之间的基因交流，以利保护。