Determining threatened species distributions in the face of limited data: Spatial conservation prioritization for the Chinese giant salamander (Andrias davidianus)

The purpose of this study was to determine whether limited occurrence data for highly threatened species can provide useful spatial information to inform conservation. The study was conducted across central and southern China. We developed a habitat suitability model for the Critically Endangered Chinese giant salamander (Andrias davidianus) based on one biotic and three abiotic parameters from single‐site locality records, which represent the only relevant environmental data available for this species. We then validated model quality by testing whether increased percentage of predicted suitable habitat at the county level correlated with independent data on giant salamander presence. We randomly selected 48 counties containing historical records which were distinct from, and independent of, the single‐site records used to develop the model, and 47 additional counties containing >50% predicted suitable habitat. We interviewed 2,812 respondents near potential giant salamander habitat across these counties and tested for differences in respondent giant salamander reports between counties selected using each method. Our model predicts that suitable giant salamander habitat is found widely across central and southern China, with counties containing ≥50% predicted suitable habitat distributed in 13 provinces. Counties with historical records contain significantly more predicted suitable habitat than counties without historical records. There are no statistical differences in any patterns of respondent giant salamander reports in surveyed counties selected from our model compared with the areas of known historical giant salamander distribution. A Chinese giant salamander habitat suitability model with strong predictive power can be derived from the restricted range of environmental variables associated with limited available presence‐only occurrence records, constituting a cost‐effective strategy to guide spatial allocation of conservation planning. Few reported sightings were recent, however, with most being over 20 years old, so that identification of areas of suitable habitat does not necessarily indicate continued survival of the species at these locations.     

A census of a community of small terrestrial vertebrates

A small vertebrate community of eighteen terrestrial species was revealed by removal trapping in 1 ha of Western Australian Banksia woodland in autumn. Nine of these species were lizards, three were mammals, three were snakes and three were frogs. The use of pitfall and mammal traps on an 8 × 8 m grid was shown to be sufficient to census the majority of terrestrial species in the study site. A biomass of 2063 g/ha of terrestrial species was estimated from trapping records. Frogs (three species) had the greatest biomass (41% of total), but the introduced mouse Musmusculus contributed the greatest biomass (36%) of any single specie.     

The Biodiversity and Conservation of Saproxylic Diptera In Scotland

Over a ten year period, 1988–1998, over 300 woodlands were visited throughout Scotland and 2061 records of saproxylic Diptera obtained. Of these 1574 were records of early stages; 258 species in 32 families were encountered; 206 species were reared of which 53 were red-listed, 9 were new to Britain and 10 were new to science. Most records came from native boreal trees such as Betula pubescens, Pinus sylvestris and Populus tremula. However, few saproxylic Diptera were specific to tree species, exceptions were 6 red-listed species associated with P. tremula and 5 red-listed species with P. sylvestris. In contrast, most saproxylic Diptera were specific to microhabitat or breeding site. The most important microhabitats were decaying sap under bark and decaying sapwood. Most red-listed species are restricted to Strathspey and north-east Scotland where relatively large stands of native boreal trees exist.     

Historic log structures as ecological archives: A case study from eastern North America

Forests of eastern North America have undergone abrupt transformations over the last several centuries due to changing land use and climate. Researchers look to pre-settlement forests as a guide for forest restoration, though much of our understanding of composition and dynamics in pre-settlement forests is based on spatially restricted sediment records, few and fragmented old-growth stands in a narrow range of site types, and potentially biased historical documentation. Logs from historic structures hold information that may be useful to forest ecology in eastern North America, but before these records can be used, we must first establish where the logs originated, why they were selected over other trees, and what they can and cannot tell us about past forest ecology. Using a case study approach, I collected data from fifteen log structures in the central Appalachian region to compare construction site locations, species used, and mean diameter of logs through time to determine the ecological biases associated with human behavior in log structure construction. Construction site locations changed from valleys to mountains through time and the species used in construction shifted from Quercus alba to a mix of Quercus alba, Liriodendron tulipifera, Pinus strobus, and Castanea dentata over time. The diameter of logs used in construction were generally consistent through time, with an average basal diameter of 31.3 cm (±4.7). Mean age of logs increased through time for Quercus species, regardless of log diameter. These results suggest the species used for structural logs were selected by their abundance at the location of construction but that as construction site locations and resource availability changed through time, the species used in construction changed as well. While there are biases and limitations of dendroecological data from historic structures, the results presented here demonstrate that structural log data provide greater replication during the early European immigration period, representation of upland (valley) forest sites, and establishment of chronologies for species that are not well represented in current tree-ring chronologies (e.g. Castanea dentata, Liriodendron tulipifera). These results suggest structural logs can benefit ecological research by filling the temporal, spatial, and species gaps in tree-ring chronologies not only for the central Appalachian region, but also for other areas in eastern North America.     

Parasites of marine sticklebacks

A total of three specimens of Spinachia spinachia and 11 Gasterosteus aculeatus were caught in Loch Etive, Scotland. The salinity of the water at the capture site was 23%. Nine species of parasites were collected from individuals of the mixed population of sticklebacks, which included seven new parasite records for the British Isles.     

Deriving site-specific species pools from large databases

Defining the species pool of a community is crucial for many types of ecological analyses, providing a foundation to metacommunity, null modelling or dark diversity frameworks. It is a challenge to derive the species pool empirically from large and heterogeneous databases. Here, we propose a method to define a site-specific species pool (SSSP), i.e. the probabilistic set of species that may co-occur with the species of a target community. Using large databases with geo-referenced records that comprise full plant community surveys, our approach characterizes each site by its own species pool without requiring a pre-defined habitat classification. We calculate the probabilities of each species in the database to occur in the target community using Beals’ index of sociological favourability, and then build sample-based rarefaction curves from neighbouring records with similar species composition to estimate the asymptotic species pool size. A corresponding number of species is then selected among the species having the highest occurrence probability, thus defining both size and composition of the species pool. We tested the robustness of this approach by comparing SSSPs obtained with different spatial extents and dissimilarity thresholds, fitting different models to the rarefaction curves, and comparing the results obtained when using Beals co-occurrence probabilities or presence/absence data. As an example application, we calculated the SSSPs for all calcareous grassland records in the German Vegetation Reference Database, and show how our method could be used to 1) produce grain-dependent estimations of species richness across plots, 2) derive scalable maps of species richness and 3) define the full list of species composing the SSSP of each target site. By deriving the species pool exclusively from community characteristics, the SSSP framework presented here provides a robust approach to bridge biodiversity estimations across spatial scales.     

The Marchioness of Huntly: the written record and the herbarium

By collating the evidence provided by written records and herbaria, and with a knowledge of the present-day habits of individual species, it is sometimes possible to reconstruct the vegetation pattern and, thereby, changes in the natural environment of a site or region during the last few centuries. This paper takes the form of a case study of the records left by the Marchioness of Huntly (1821–1893) and the information they provide, for example, on changes in the Huntingdonshire fenland.     

Identifying hotspots of molluscan species richness on rocky intertidal reefs

A significant question faced by environmental managers is how muchsurvey effort is required in order to obtain an accurate representation of thespecies richness in an area. The appropriateness of rapid survey techniques foridentifying biodiverse hotspots has not been previously tested for molluscs onintertidal rocky reefs. We used species inventories from standardized 4-h searchsurveys to rank 13 intertidal reefs in terms of their species richness and thesewere then compared to cumulative species records following repeated surveys fromthe same sites. A total of 172 surveys were conducted during low water springtides over a 3 year period, with up to 20 surveys at a single site.Species richness in the inventories varied from 20 to 94 on the different reefs.There was a strong correlation between the number of species recorded in thestandardized inventory and the total species richness from cumulative surveyrecords (r = 0.969; P < 0.001).Importantly, the total species diversity recorded at each site was not relatedto the number of surveys that were conducted at that site(r = 0.110; P = 0.784). This confirmsthat a single standardized timed search produces a useful representation ofmolluscan species richness. The majority of molluscs recorded in this study wereendemic to Australia (59%) and, significantly, the number of endemics waspositively correlated to the total species richness found at each site(r = 0.992; P < 0.0001). Our dataprovide clear evidence for a local hotspot of molluscan species richness andendemism on the northern side of Bass Point, Shellharbour. We suggest that on alocal scale biodiversity hotspots should only be identified as those sites thatcontain significantly more species than the local average. Two standarddeviations above the mean appears to be an appropriate cut-off for identifyinglocal biodiversity hotspots.     

Exploring a new biodiversity frontier: subterranean ants in northern Australia

Although it is common for ant surveys to uncover previously uncollected species, a recent study of subterranean ants in Amazonian Ecuador has indicated that an entire ant fauna may remain largely undiscovered. Here we report on the first systematic investigation of subterranean ants in northern Australia, in order to assess the extent to which the high abundance and diversity of subterranean ants in Amazonia is apparent in tropical Australia. We use a novel sampling technique that combines elements of an attractant bait and a pitfall trap, and allows many traps to be deployed simultaneously. Our main study was conducted at three closely approximated sites in Darwin, where the local ant fauna has been intensively surveyed using conventional (above-ground) sampling techniques. The 720 traps deployed resulted in 421 species records, representing 29 species from 17 genera. Sixteen of these species have cryptobiotic morphology, with four recorded here for the first time. Remarkably, one of these four (a blind species of Solenopsis) was the second most frequently caught species in subterranean traps, with 70 records. Ant abundance, species richness and composition varied markedly between sites, despite site similarity in soils and vegetation. Total ant records were greater in the middle compared with start of the wet season, declined with depth, and were greater after 4 days than one. Sampling at six sites in the Mitchell Falls area of the northern Kimberley region, 1,200 km southwest of Darwin, also revealed several cryptobiotic species new to science, including a new genus record (Pseudolasius) for Western Australia. Our underground sampling has therefore revealed an abundant and diverse subterranean ant fauna in northern Australia, containing many cryptobiotic species not previously collected. We use our results to provide methodological guidelines for most effectively sampling this fauna. Combined with the Amazonian study, our findings indicate that a specialist subterranean ant fauna, including numerous species remaining to be discovered, might be a feature of tropical landscapes throughout the world.     

Spatial patterns and vegetation–site relationships of the presettlement forests in western New York, USA

Aim The purposes of this study were to develop a Geographic Information System and spatial analytical methodology to reconstruct and represent the presettlement vegetation in a spatially continuous manner over large areas and to investigate vegetation–site relationships before widespread changes of the vegetation had taken place. Location The study area was the Holland Land Company Purchase in western New York, a 14,400 km² area extending across the physiographic provinces of the Erie–Ontario Lowlands and the Appalachian Uplands. Methods Bearing‐tree records from the Holland Land Company township surveys of western New York in c. 1800 were collected and analysed. The geostatistical method of indicator kriging was used to map spatially continuous representations of individual tree species. Rule‐based and statistically clustered approaches were used to analyse and classify the reconstructed tree species distributions in order to obtain the vegetation association distribution. Contingency table analysis was conducted to quantify species relationships with soil conditions. Results The presettlement vegetation at both the tree species and the vegetation association levels were easier to interpret and visually more effective as a spatially continuous representation than as a discontinuous distribution of symbols. The results for tree species were probability occurrences of species distribution, showing spatial patterns that were not apparent in discrete maps of points or in summary tables of species frequencies. Analysis of the 8792 bearing trees suggested the dominance of American beech (Fagus grandifolia) and sugar maple (Acer saccharum) in the forest composition 200 years ago. Both soil drainage and texture were important site determinants of the vegetation in western New York. The rule‐based and statistically clustered approaches had the advantage of summarizing vegetation compositional patterns in a single image, thus avoiding the need to delineate manually and subjectively the location of boundaries between adjacent vegetation associations. Main conclusions The study offers more insights into the spatial pattern of presettlement forests in western New York than do prior studies. The spatially continuous representation could also enable the comparison of vegetation distribution from data sources that have different sampling schemes, for example the comparison of presettlement vegetation from the presettlement land survey records with current vegetation from modern forest inventories. The results are of value, providing a useful benchmark against which to examine vegetation change and the impacts of human land use.     

Tardigrades of Louisiana and Arkansas, United States of America

The distribution of tardigrades in the states of the southern United States is poorly known. There are no published records from the state of Louisiana, while in Arkansas only one species has been reported. Samples of mosses and lichens from trees and rocks were collected from three sites in central and southern Louisiana and six sites in western Arkansas. Leaf litter samples were collected from one site in Louisiana. Nine species of tardigrade were found in Louisiana and 22 in Arkansas. The number of species per sample ranged from one to six.     

Quantified ecology and co-occurrence of Mediterranean woody species in a landscape context

Understanding co-occurrence and ecological affinities of plant species is essential in vegetation and landscape ecology. In a case study, we analysed distribution records with high data density of all commonly occurring tree and shrub species of Crete (Greece) with offshore islands. We present the ecological range of widespread and more range-restricted species in the Mediterranean area, visualising their affinities for macroclimate, topoclimate and geology by means of an ecological heatmap. Complete linkage classification of combined ecological spectra revealed groups of generalist species with broad ecological amplitude, groups related to zonal vegetation and chiefly dependent on elevation, and species of azonal vegetation grouped mainly by topography and substrates. Species and ecological groups with high affinity may be indicative of (a combination of) site features. Our re-evaluation of plant distribution records links plant geographical and ecological information, and thereby complements expert habitat and species assessments. Our case study provides deeper understanding of ecological patterns, and at the same time allows for comparison and extrapolation to other biomes.     

Gerarda prevostiana(Eydoux and Gervais,1837)(Squamata:Serpentes:Homalopsidae),a New Snake for Borneo

A new record of the homalopsid snake, Gerarda prevostiana is presented from a mangrove-dominated patch in the vicinity of Kampung Bako, Sarawak, East Malaysia, and this comprises the first published record from the Sundaic Island of Borneo. A possible second locality for the species is a ca. 6.68 km site to its northeast, Kampung Buntal, based on an unlocated museum specimen. The species is widespread in mainland Southeast Asia, with additional records to the west(the Indian Subcontinent) and east(the Philippines Archipelago), but was previously unrecorded from the islands of the Sundas. The secretive habits of the species, including the occupancy of mud lobster(Thalassinia spp.) mounds in mostly inaccessible, swampy habitats may be a reason for its perceived rarity and few published records.     

Spatiotemporal distribution and dynamic changes of myxomycetes in subtropical forests of China

The spatiotemporal distribution and dynamic changes of species composition of myxomycetes in humid subtropical forests of Houhe National Nature Reserve in southern China were studied by collecting samples of bark and ground litter within four seasons for isolation of myxomycetes in moist chamber cultures and by collecting fruiting bodies in the field from June to October. A total of 725 specimens of myxomycete fruiting bodies representing 77 species of 25 genera were registered, among them 302 records/51 species from field collections and 423 records obtained from 600 moist chamber cultures of ground litter and bark of living trees, which resulted in 35 and 39 species, respectively. Cornuvia serpula and Perichaena microspora were recorded for the first time in China. Both myxomycete species richness and diversity were significantly different in ground litter among sites and field collections among months. NMDS combined with Permanova indicated that the site had a greater impact on the myxomycete community of bark and litter than the season, while the month of field collections had a greater impact than the sampling sites. CCA and VPA analysis showed that the bark-inhabiting myxomycete species were mainly affected by spatial variables, while the litter-inhabiting and field collected species were more affected by climatic factors.     

中国桂林岩溶洞穴苔藓植物研究

对采自中国广西桂林17个岩溶洞穴的192份苔藓植物标本进行研究,报道了洞穴苔藓13科19属28 种,其中含广西苔藓植物新记录16种。野外观察表明,桂林岩溶洞穴苔藓植物主要分布于洞穴洞口0～32m 弱光带范围内。三种丛集型藓类植物:净口藓、钩喙净口藓和东亚泽藓参与岩溶洞穴洞口带钙华沉积。     

Distribution and ecology of myxomycetes in the high-elevation oak forests of Cerro Bellavista, Costa Rica

Myxomycetes associated with a high-elevation (>3000 m) oak forest in the Talamanca Range of Costa Rica were studied for 7 mo. Field collections were supplemented with collections obtained from moist chamber cultures prepared with samples of bark and ground litter of Quercus costaricensis. Various microenvironmental parameters including pH, substrate moisture and diameter, height above the ground and canopy openness were recorded for each field collection, whereas macroenvironmental data for temperature and precipitation were obtained from a meteorological station near the study area. Niche breadth and niche overlap indices were calculated to assess possible resource partitioning by myxomycetes. Thirty-seven species were recorded, including 11 new records for Costa Rica, eight for Central America and one for the neotropics. Both PCA and NMS multivariate analyses indicated that pH and height above the ground explained most of the observed variation, although substrate diameter also seemed to be an important factor. Precipitation showed an inverse correlation with the number of fruitings, confirming its importance as a macroenvironmental factor. Niche overlap values were not higher for closely related species and values for niche breadths were similar for most of the more common species, suggesting that most members of the assemblage of myxomycetes present in the study site are ecological generalists.     

中国鸡形目鸟类分布数据库及其应用

中国鸡形目鸟类分布数据库(The Site Record Database for Chinese Galliformes,SRDG)是以中国鸡形目鸟类分布点的有关信息为数据源的综合性资源数据库,于1996年初步建立,2005～2006年进行了更新维护和完善,由中国鸡形目鸟类物种代码库(WZDM)、中国鸡形目鸟类分布状况库(FBZK)和信息来源库(XXLY)三部分构成,包括中国鸡形目全部63个种的5859条分布信息和1027条相关文献记录。本数据库操作简单,各库之间通过共有字段相链接,具有信息查询、修改和维护等功能。本数据库的物种信息有助于加深对我国鸡形目鸟类资源的了解,可为中国鸡形目鸟类的研究和保护提供翔实的基础数据。在数据库基础上,可以进行有关我国鸡形目鸟类分布状况的分析,如鸡形目鸟类地理区划研究、分布区与占有面积的比较、物种濒危状况评估以及热点地区分析和GAP分析等。     

Assessing the accuracy of species distribution models to predict amphibian species richness patterns

1. Evaluating the distribution of species richness where biodiversity is high but has been insufficiently sampled is not an easy task. Species distribution modelling has become a useful approach for predicting their ranges, based on the relationships between species records and environmental variables. Overlapping predictions of individual distributions could be a useful strategy for obtaining estimates of species richness and composition in a region, but these estimates should be evaluated using a proper validation process, which compares the predicted richness values and composition with accurate data from independent sources. 2. In this study, we propose a simple approach to estimate model performance for several distributional predictions generated simultaneously. This approach is particularly suitable when species distribution modelling techniques that require only presence data are used. 3. The individual distributions for the 370 known amphibian species of Mexico were predicted using maxent to model data on their known presence (66,113 presence-only records). Distributions were subsequently overlapped to obtain a prediction of species richness. Accuracy was assessed by comparing the overall species richness values predicted for the region with observed and predicted values from 118 well-surveyed sites, each with an area of c. 100 km(2), which were identified using species accumulation curves and nonparametric estimators. 4. The derived models revealed a remarkable heterogeneity of species richness across the country, provided information about species composition per site and allowed us to obtain a measure of the spatial distribution of prediction errors. Examining the magnitude and location of model inaccuracies, as well as separately assessing errors of both commission and omission, highlights the inaccuracy of the predictions of species distribution models and the need to provide measures of uncertainty along with the model results. 5. The combination of a species distribution modelling method like maxent and species richness estimators offers a useful tool for identifying when the overall pattern provided by all model predictions might be representing the geographical patterns of species richness and composition, regardless of the particular quality or accuracy of the predictions for each individual species.     

Feeding Ecology of Black-headed Uacaris (Cacajao melanocephalus melanocephalus) in Pico da Neblina National Park,Brazil

From June 1994 to October 1995, I conducted a study of the feeding ecology of one group of black-headed uacaris (Cacajao melanocephalus melanocephalus) in Pico da Neblina National Park, Brazil, near the Venezuelan border (01°10N to 00°26S, 65°03W to 66°52W). Of a total of 429 feeding records, 89% corresponded to fruits from which black-headed uacaris ate ripe and unripe seeds, mesocarps and arils. Seeds were the single most important food item year-around, corresponding to 81% of the feeding records for fruits. Black-headed uacaris used 120 different plant species in 32 families as food. The 3 most important plant species in their diet, Micrandra spruceana, Eperua leucantha, and Hevea braziliensis (all trees), accounted for 38% of the feeding records for fruits. These species produced fruits that were protected by very hard green husks, were barochorous, did not have fleshy mesocarps, and were slow to mature, thus being available as unripe fruits for long periods. The second and third most important species in the diet of black uacaris, Eperua leucantha and Hevea braziliensis, were dominant in the forest: approximately 30% of trees 10 cm dbh sampled in a 2-ha botanical transect at the study site. I discuss the formation of large social groups of black-headed uacaris in Pico da Neblina National Park in light of the peculiar floristic composition of the study site.     

贵州黏菌初报

通过对作者2005年采自贵州的119份黏菌标本和从湿室培养10份树皮基物获得的19份黏菌标本进行的鉴定分类研究,以及对保存在中国科学院微生物研究所真菌标本馆和中国科学院昆明植物研究所隐花植物标本馆的共21份黏菌标本的鉴定复核,报告了目前已明确了的贵州黏菌51种,分隶属于6目9科21属,其中44种为贵州新记录种,白鳞钙丝菌和红柄发菌为中国新记录种。