Spatiotemporal dynamics of Lutzomyia longipalpis and macro‐habitat characterization using satellite images in a leishmaniasis‐endemic city in Argentina

The spatiotemporal population dynamics of Lutzomyia longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae) were evaluated in a city in Argentina in which visceral leishmaniasis is endemic. Over 14 sampling sessions, 5244 specimens of five species of Phlebotominae (Diptera: Psychodidae) were captured, of which 2458 (46.87%) specimens were L. longipalpis. Generalized linear models were constructed to evaluate the associations between L. longipalpis abundance and explanatory variables derived from satellite images. The spatial variable ‘stratum’ and the temporal variable ‘season’ were also included in the models. Three variables were found to have significant associations: the normalized difference vegetation index; land surface temperature, and low urban coverage. The last two of these were associated with L. longipalpis abundance only during summer and winter, respectively. This variation between seasons supports the development of models that include temporal variables because models of distributions of the abundance of a species may show different critical variables according to the climatic period of the year. Abundance decreased gradually towards the downtown area, which suggests that L. longipalpis responds to a meta‐population structure, in which rural–periurban source populations that persist over time may colonize adjacent areas. This information allows for a spatiotemporal stratification of risk, which provides public health authorities with a valuable tool to help optimize prevention measures against visceral leishmaniasis.     

Assessing extinction-risk of endangered plants using species distribution models: a case study of habitat depletion caused by the spread of greenhouses

The species distribution models (SDMs) are useful tools for investigating rare and endangered species as well as the environmental variables affecting them. In this paper, we propose the application of SDMs to assess the extinction-risk of plant species in relation to the spread of greenhouses in a Mediterranean landscape, where habitat depletion is one of the main causes of biodiversity loss. For this purpose, presence records of the model species (Linaria nigricans, a endemic and threatened species) and the greenhouses, a dataset of environmental variables, and different only presence-based modelling algorithms (Bioclim, Domain, GARP, MaxEnt and ENFA) were used to build SDMs for L. nigricans as well as for greenhouses. To evaluate the models a modified approach of the area-under-curve ROC was applied. Combining the most accurate models, we generated an extinction-risk model of L. nigricans populations, which enabled us to assess the sustainability of the most threatened populations. Our results show that is possible to model greenhouses spreading as a “biological invasion”. The procedure explained and used in this work is quite novel, and offers an objective spatial criterion intended for the management of natural resources and for the conservation of the biodiversity in areas threatened by habitat depletion processes as particular as greenhouses expansion.     

Assessment of instream structures for habitat improvement for two critically endangered fish species

The number of fish habitat improvement schemes has greatly increased in response to the widespread degradation of aquatic ecosystems. However, many of these enhancement projects often fail to create expected habitat conditions, because they are rarely planned and executed with inputs from the species’ habitat requirements throughout their life histories, and it is frequently assumed that the implementation of a specific instream structure for habitat improvement will always benefit all species present. Using a 2D hydraulic model, the present study evaluates the potential habitat improvement for two critically endangered fish species—the Southwestern arched-mouth nase Iberochondrostoma almacai and the Arade chub Squalius aradensis—resulting from simulating the introduction of different instream structures (islands, lateral bays, and deflectors) in a modified Mediterranean river reach. The introduction of islands in the river channel was found to be the best improvement measure for YOY and juvenile nase and chub, as shown by increases in the mean annual Weighted Usable Area (WUA) of more than 100 and 50%, respectively, compared to the present conditions. On the other hand, the simulation with current deflectors proved to be the worst scenario, particularly for nase, with mean annual WUA decreasing by 3.6, 17.8 and 22.7% for YOY, juveniles and adults, respectively. The findings of this study point to the need to account for different species life-history stages when modelling the implementation of instream structures for habitat improvement and also provide a sound basis for future conservation-related studies conducted in Mediterranean rivers that harbour other threatened “sister” species.     

稀有濒危植物坡垒的迁地保护

国家二级保护树种坡垒（ＨｏｐｅａｈａｉｎａｎｅｎｓｉｓＭｅｒｒ．ｅｔＣｈｕｎ）原产海南岛。在西双版纳勐仑热带植物园迁地栽培,年平均增高０．４４～０．９ｍ,胸径加粗０．５４～１．３１ｃｍ,比原产地野生或其他迁地保护地区的植株生长快。花期８～１０月,果熟期翌年３～５月。种子发芽率达９６．７％。经多年观察,未见寒害和严重的病虫害。已繁衍了３代并扩大种植２８４株,说明坡垒在西双版纳热带植物园迁地保护获得成功。     

濒危植物秦岭冷杉种群数量动态

为了对濒危植物秦岭冷杉种群数量动态评价和预测,通过样地调查和数据统计,研究了秦岭冷杉种群的年龄结构、静态生命表及其与环境因子关系,运用时间序列模型预测了种群数量动态.结果表明,多数秦岭冷杉种群幼龄级个体数较少,中老龄个体数量较大,呈衰退趋势.仅处于低海拔地区的秦岭冷杉-木蓝-苔草群丛中的种群(D种群)由于立地条件较好,幼龄级个体数量相对丰富,种群稳定.不同秦岭冷杉种群生命表和存活曲线的分析表明,尽管生境条件差异,但存活曲线基本接近DeeveyⅢ型;不同种群偏离典型存活曲线的程度与幼苗缺乏程度有关,一般Ⅲ～Ⅴ龄级死亡率较高.时间序列分析表明,在未来20、40和80年中,不同秦岭冷杉种群均会呈现老龄级株数先增后减的趋势,种群稳定性长期维持困难.对影响秦岭冷杉种群增长的10个环境因子通过主成分分析(PCA)发现,乔木层盖度、土壤有机质含量和空气湿度对种群发挥有利影响,而人为干扰和光照强度对秦岭冷杉种群增长发挥不利影响.应充分利用秦岭冷杉性喜荫、耐寒、种子活力较强的特点,加强现有林分就地保护,重点是具有结实能力的中老龄个体;在阴坡地带,对林下灌木比较密集的群丛,通过砍灌、清理林下活地被物等抚育措施,为幼苗发育创造良好的环境条件;就地采种育苗,扩大人工种群.     

Projections of suitable habitat for rare species under global warming scenarios

? Premise of the study: Modeling the contemporary and future climate niche for rare plants is a major hurdle in conservation, yet such projections are necessary to prevent extinctions that may result from climate change. ? Methods: We used recently developed spline climatic models and modified Random Forests statistical procedures to predict suitable habitats of three rare, endangered spruces of Mexico and a spruce of the southwestern USA. We used three general circulation models and two sets of carbon emission scenarios (optimistic and pessimistic) for future climates. ? Key results: Our procedures predicted present occurrence perfectly. For the decades 2030, 2060, and 2090, the ranges of all taxa progressively decreased, to the point of transient disappearance for one species in the decade 2060 but reappearance in 2090. Contrary to intuition, habitat did not develop to the north for any of the Mexican taxa; rather, climate niches for two taxa re-materialized several hundred kilometers southward in the Trans-Mexican Volcanic Belt. The climate niche for a third Mexican taxon shrank drastically, and its two mitotypes responded differently, one of the first demonstrations of the importance of intraspecific genetic variation in climate niches. The climate niche of the U.S. species shrank northward and upward in elevation. ? Conclusion: The results are important for conservation of these species and are of general significance for conservation by assisted colonization. We conclude that our procedures for producing models and projecting the climate niches of Mexican spruces provide a way for handling other rare plants, which constitute the great bulk of the world's endangered and most vulnerable flora.     

Advances in the reintroduction of rare and endangered wild plant species

Human disturbance and climate change have increased the risk of extinction for rare and endangered wild plant species.One effective way to conserve these rare and endangered species is through reintroduction.In this review,we summarize the advances in wild plant reintroduction from five perspectives:the establishment of reintroduction biology as an important tool for biodiversity conservation;the importance of genetic diversity in reintroduction;reintroduction under global climate change;recruitment limitation in reintroduction;and reintroduction and ecological restoration.In addition,we consider the future of plant reintroduction strategies.     

珍稀濒危植物单性木兰传粉生态学研究

野外定位观测了单性木兰的花期物候、访花昆虫种类、访花频率、访花行为和同花期植物种类,并对其花粉散播距离和繁育系统进行了检测,旨在探讨制约单性木兰传粉过程的某些因素,为单性木兰的保护生物学提供科学依据。结果表明,单性木兰雄株和雌株在花期物候上存在差异,雌株在结实上存在明显的大小年现象。单性木兰以虫媒传粉为主,雄株访花昆虫30种,雌株访花昆虫仅14种,雌株和雄株共有的访花昆虫仅6种。单性木兰同花期植物共17种,其访花昆虫种类大部分与单性木兰的访花昆虫种类相同。蜂类和蝶类均非单性木兰的传粉者,其结实率低的原因不仅与访花昆虫种类少和访花频率少有关,更与其缺乏有效的传粉昆虫有关。     

Modelling habitat distributions for multiple species using phylogenetics

In this paper, we describe an empirical approach to model community structure using phylogenetic signals. That approach combines information about the species (i.e. traits and phylogeny) with information about the habitat (i.e. environmental conditions and spatial distribution of sampling sites) and their interactions to predict the species responses (e.g. the local densities). As an application, we use the approach to model fish densities in rivers. In the model, the different species and size classes were described using a functional trait, body length, and phylogenetic eigenvectors maps whereas the sites were described using water velocity, depth, substrate composition, macrophyte cover, degree‐days, total phosphorus, and spatial eigenvector maps. The model (estimated using a regularised Poisson‐family generalised linear modelling approach) fitted the data well (likelihood‐based R²_adj = 0.512) and showed fair predictive power (likelihood‐based cross‐validation R² = 0.283) to predict the density of fish pertaining to 48 species totalling 143 combinations of species and size classes in 15 unregulated Canadian rivers. Using the model as a baseline to estimate the effect of flow regulation on community composition, we found that, with few exceptions, the densities of most fish species were lower in regulated than in unregulated rivers. Phylogenetics have been proposed to study community structure, but this is, to our knowledge, the first time phylogenetic information is used explicitly for numerical habitat modelling. We expect that models of that type will be in increasing demand now that development projects are routinely assessed through impact studies.     

珍稀濒危植物桫椤种群结构与动态研究

采用空间序列代替时间变化的方法,对7个地段中的桫椤种群大小结构进行分析,运用C、K、m^*、m^*/m和Iδ5种聚集度指标测定不同地段内桫椤种群的空间分布格局及其动态,并根据植株个体点位图,考察桫椤种群在不同取样尺度上的空间分布格局.结果表明,不同地段中的桫椤种群结构存在增长型、稳定型、成熟型和衰退型4种类型;不同地段中的桫椤种群空间分布格局有所差异,表现为集群分布或随机分布;在桫椤种群生长过程中,分布格局从集群型向随机型转变;种群扩散型指数Iδ随取样尺度的增大而减小.     

内蒙古珍稀濒危植物濒危现状及优先保护评估

以《中国珍稀濒危保护植物名录》、《中国植物红皮书》、《国家重点保护野生植物名录(第一批)》、《中国物种红色名录》、《中国生物多样性红色名录(高等植物卷)》、《内蒙古珍稀濒危保护植物名录》和《内蒙古珍稀濒危植物图谱》中127种内蒙古珍稀濒危植物为研究对象,通过资料收集及专家咨询,构建了内蒙古珍稀濒危植物受威胁等级、优先保护评估体系.建立了濒危系数、遗传价值系数、利用价值系数、生境系数、繁殖系数5项准则,准则下共设17个指标;运用层次分析法确定指标体系权重,计算出珍稀濒危植物濒危等级及优先保护级别.结果表明: 极危种2种、濒危种13种、易危种37种、近危种44种、无危种31种,分别占总数的1.6%、10.2%、29.1%、34.7%、24.4%.其中,受威胁种(极危、濒危和易危种)共52种,占总种数的40.9%.一级保护植物35种、二级保护植物72种、三级保护植物20种,分别占总数的27.6%、56.7%、15.8%.本评估结果与《中国生物多样性红色名录(高等植物卷)》、《内蒙古珍稀濒危保护植物名录》相比,有75种植物的濒危等级和62种植物的保护级别发生了变化.其中新增了9种植物的濒危等级评估和32种植物的保护级别.     

Monitoring endangered freshwater biodiversity using environmental DNA

Freshwater ecosystems are among the most endangered habitats on Earth, with thousands of animal species known to be threatened or already extinct. Reliable monitoring of threatened organisms is crucial for data‐driven conservation actions but remains a challenge owing to nonstandardized methods that depend on practical and taxonomic expertise, which is rapidly declining. Here, we show that a diversity of rare and threatened freshwater animals—representing amphibians, fish, mammals, insects and crustaceans—can be detected and quantified based on DNA obtained directly from small water samples of lakes, ponds and streams. We successfully validate our findings in a controlled mesocosm experiment and show that DNA becomes undetectable within 2 weeks after removal of animals, indicating that DNA traces are near contemporary with presence of the species. We further demonstrate that entire faunas of amphibians and fish can be detected by high‐throughput sequencing of DNA extracted from pond water. Our findings underpin the ubiquitous nature of DNA traces in the environment and establish environmental DNA as a tool for monitoring rare and threatened species across a wide range of taxonomic groups.     

重庆市珍稀濒危植物适生环境及濒危原因初探

重庆市有各类珍稀濒危植物93种,其中国家一、二级保护植物50种,受气候和人为等多种因素的影响,很多物种已经面临灭绝的危险。本文主要对造成它们濒危的各种原因作了初步分析,并据此提出了相应的保护对策。     

Structural diversity as a habitat indicator for endangered lakeshore flora using an assemblage of common plant species in Atlantic Canada

Vegetation structure, defined by the height, cover, and types of plants, is an important component of habitat suitability for plant species or communities. The identification of potential habitat is a crucial knowledge gap for endangered Atlantic Coastal Plain Flora (ACPF), a group of taxonomically unrelated plants that share common habitat types and are mostly found on lakeshores and wetlands in the Atlantic coastal region of North America. Our objectives were to assess spatial patterns and relationships of ACPF richness and structural diversity indices at different scales and positions along the lakeshore-to-forest gradient. We sampled 16 sites at 7 lakes in southwestern Nova Scotia using contiguous 20 × 20 cm quadrats along 20 m transects, perpendicular to the waterline, and in 5 × 5 m grids, between the lake and the forest edge. We measured the cover of 19 ACPF species and structural elements at different heights and calculated structural diversity indices using the Shannon index. Spatial patterns were assessed using one- and two-dimensional wavelet variance and covariance. The edge of the zone of high ACPF richness coincided with greater structural diversity at the lakeshore edge. Herbaceous ACPF richness was positively associated with structural diversity at finer scales and on lakeshores, but negatively associated at coarser scales and farther from the waterline. A strong association of structural diversity with ACPF richness suggests it could be used as a habitat indicator for ACPF on lakeshores, which could help the identification and conservation of potential suitable shorelines for ACPF populations in Nova Scotia.     

Conservation of rare and endangered plants using in vitro methods

Summary Many botanic gardens now have tissue culture laboratories for the micropropagation of plants that are difficult to propagate by conventional horticultural techniques. In many cases the work centers on rare and endangered species. Examples of the use of different techniques including micropropagation, in vitro seed germination, dual culture with symbiotic fungi, and regeneration from callus are discussed with reference to their application to plant germplasm conservation. Presented in the Session-in-Depth Cell Culture of Endangered Species at the 1991 World Congress on Cell and Tissue Culture, Anaheim, California, June 16–20, 1991.     

浙江省珍稀濒危植物物种多样性保护的关键区域

浙江省植物资源丰富,有野生维管植物215科1196属3283种,其中包含了我国特有属49个,浙江省特有植物约200余种,许多物种十分稀少,并受到严重威胁,亟待保护。但浙江省需优先保护的植物物种的分布并不是均匀的,有些地区的重要保护对象比较集中,对这些地区我们应该给予更多的保护。本文根据维管植物物种多样性、珍稀濒危植物的物种数量及个体数量特征、受威胁状况以及浙江省特有植物的分布情况,提出了浙江省珍稀濒危植物保护的7个关键区域：以西天目山为中心的浙西北山区,以古田山为中心的浙西山区,以九龙山为中心的浙西南山区,以凤阳山－百山祖为中心的浙南山区,以括苍山为中心的浙东山区,以天台山为中心的浙东丘陵,以普陀山为中心的舟山群岛。最后提出了浙江省植物物种多样性保护的几点建议。