Ecological Characteristics Of Species Research Articles

Taylor's power law for freshwater fishes: Functional traits beyond statistical inevitability.

Taylor's power law (TPL) describes the expected range of parameters of the mean-variance scaling relationship and has been extensively used in studies examining temporal variations in abundance. Few studies though have focused on biological and ecological covariates of TPL, while its statistical inherences have been extensively debated. In the present study, we focused on species-specific features (i.e. functional traits) that could be influential to temporal TPL. We combined field surveys of 180 fish species from 972 sites varying from small streams to large rivers with data on 31 ecological traits describing species-specific characteristics related to three main niche dimensions (trophic ecology, life history, and habitat use). For each species, the parameters of temporal TPL (intercept and slope) were estimated from the log-log mean-variance relationships while controlling for spatial dependencies and biological covariates (species richness and evenness). Then, we investigated whether functional traits explained variations in TPL parameters. Differences in TPL parameters among species were explained mostly by life history and environmental determinants, especially TPL slope. Life history was the main determinant of differences in TPL parameters and thereby aggregation patterns, with traits related to body size being the most influential, thus showing a high contrast between small-sized species with short lifespans and large-bodied migratory fishes, even after controlling for phylogenetic resemblances. We found that life history traits, especially those related to body size, mostly affect TPL and, as such, can be determinants of temporal variability of fish populations. We also found that statistical effects and phylogenetic resemblances are embedded in mean-variance relationships for fish, and that environmental drivers can interact with ecological characteristics of species in determining temporal fluctuations in abundance.

FUN Azores: a FUNctional trait database for the meio-, macro-, and megafauna from the Azores Marine Park (Mid-Atlantic Ridge)

Trait-based approaches that complement taxonomy-based studies have increased in popularity among the scientific community over the last decades. The collection of biological and ecological characteristics of species (i.e., traits) provides insight into species and ecosystem vulnerability to environmental and anthropogenic changes, as well as ecosystem functioning. Here, we present the FUN Azores trait database, describe our approach, evaluate its scope, compare it to other marine trait databases, and explore the spatial distribution of its traits with “functional maps.” While most of the available trait databases to date contain essential information to understand the functional diversity of a taxonomic or functional group, our ecosystem-based approach provides a comprehensive assessment of diverse fauna (i.e., meio-, macro-, and megafauna) from benthic and pelagic environments in the Azores Marine Park; including ridges, seamounts, hydrothermal vents, and the overlying water column. We used a collaborative approach involving 30 researchers with different expertise to develop the FUN Azores database, which contains compiled data on 14 traits representing morphological, behavioral, and life history characteristics for 1,210 species across 10 phyla. The “functional maps” show a distinct distribution of the two most common size classes, suggesting different communities with different functionalities. The following traits had the best scoring coverage (i.e., >95% of the species scored): maximum body size, body form, skeleton material, feeding structure, motility, environmental position, substratum affinity, distribution, and depth range; while traits related to species behavior (e.g., sociability or aggregation tendencies) and life history (e.g., developmental mechanism) had lower scoring coverage, highlighting the need for further research to fill these knowledge gaps. We found a larger number of species in the benthic compared to the pelagic environment and differing species composition between areas within the Azores Marine Park resulting from varying biodiversity, ecosystem types, sampling effort, and methodologies used. The FUN Azores database will foster and facilitate trait-based approaches in the area, develop a framework for expansion of cross-ecosystem and cross-taxa trait databases elsewhere, and improve our ecological understanding of the Azores Marine Park and its conservation requirements.

Diversity of lithophytic moss species in karst regions in response to elevation gradients.

The distribution pattern of species diversity along various elevation gradients reflects the biological and ecological characteristics of species, distribution status and adaptability to the environment. Altitude, a comprehensive ecological factor, affects the spatial distribution of species diversity in plant communities by causing integrated changes in light, temperature, water and soil factors. In Guiyang City, we studied the species diversity of lithophytic mosses and the relationships between species and environmental factors. The results showed that: (1) There were 52 species of bryophytes in 26 genera and 13 families within the study area. The dominant families were Brachytheciaceae, Hypnaceae and Thuidiaceae. The dominant genera were Brachythecium, Hypnum, Eurhynchium, Thuidium, Anomodon and Plagiomnium; The dominant species were Eurohypnum leptothallum, Brachythecium salebrosum, Brachythecium pendulum etc. The number of family species and dominant family genera increased first and then decreased with the increase of altitude, and their distribution in elevation gradient III (1334-1515m) was the largest, with 8 families, 13 genera and 21 species. The elevation gradient I (970-1151m) was the least species distributed, with 5 families, 10 genera and 14 species. The dominant species with the largest number in each elevational gradient were Eurohypnum leptothallum, Brachythecium pendulum, Brachythecium salebrosum and Entodon prorepens; (2) There were five kinds of life forms in different elevation gradients, including Wefts, Turfs, Mat, Pendants and Tail. Among them, wefts and turfs appeared in all elevations, while a small amount of Pendants appeared in the area of elevational gradient I (970-1151m), and the most abundant life form was found in the range of elevational gradient III (1334-1515m); (3) Patrick richness index and Shannon-Wiener diversity index were highly significantly (p<0.01) positively correlated, both of which increased and then decreased with elevation, reaching a maximum at elevation gradient III (1334-1515m); The Simpson dominance index had a highly significant (p<0.01) negative correlation with the Patrick richness index and the Shannon-Wiener diversity index, which showed a decreasing and then increasing trend with increasing altitude; Pielou evenness index showed no discernible trend; (4) β diversity study revealed that while the similarity coefficient tended to decrease with increasing altitude, the species composition of bryophytes increased. The elevation gradient II (1151-1332m) and elevation gradient I (970-1151m) shared the most similarities, whereas elevation gradient III (1515-1694m) and elevation gradient I shared the least similarities (970-1151m). The findings can enrich the theory of the distribution pattern of lithophytic moss species diversity at distinct elevation gradients in karst regions, and serve a scientific and reasonable reference for restoring rocky desertification and protecting biodiversity there.

Genetic Diversity, Habitat Relevance and Conservation Strategies of the Silver Carp in the Yangtze River by Simple Sequence Repeat

The spatial distribution of fish individuals is affected by habitat conditions and species ecological characteristics, and it also reflects the longtime adaptation to habitat at the phenotypic and genotypic level. As a typical river-lake migratory fish species, the silver carp habitat selection was determined by its migration preference and genetic features. In this study, 15 microsatellite fluorescent markers combined with capillary electrophoresis were used to analyze the genetic diversity, genetic differentiation, and structure of nature silver carp populations in the Sanzhou (SZ), Hukou (HK), Anqing (AQ), Zhenjiang (ZJ), and Rugao (RG) sections of the Yangtze River. The results showed that 15 microsatellite loci exhibited medium to high polymorphisms. The overall genetic diversity in the Yangtze River was high, with the average value of Shannon’s information index ranging from 1.559 to 1.668. The numbers of alleles (Ne) ranged from 1.630 to 10.100. The expected heterozygosity (He, 0.690–0.721) was higher than observed heterozygosity (Ho, 0.598–0.646), and the genetic variation mainly originated from within the population (94.69%). However, the entire population was in the state of heterozygous deletion, and HK, RG populations encountered the risk of inbreeding risk (F &amp;gt; 1). Interestingly, there was a distinct genetic structure for the population in the HK section, which indicated that local population has occurred to the silver carp in this river section, and they may also possess aggregation characteristics specific to the river-lake-connected (RLC) habitat. The results mostly support the conclusion that the RLC habitat is essential for geographic population formation. The potential impact of special habitats on natural populations should be considered, and continuous surveys on population dynamics should be performed.

洮河自然保护区大峪沟林区紫果云杉群落木本植物种群生态位特征

PDF HTML阅读 XML下载 导出引用 引用提醒 洮河自然保护区大峪沟林区紫果云杉群落木本植物种群生态位特征 DOI: 10.5846/stxb202102070395 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 甘肃省林业科技创新项目（KJCX201909，KJCX202001）；甘肃省林业科技项目（2015KJ051）；林业科技推广项目（2020ZYTG16） Niche of woody plant populations of Picea purpurea community in Dayugou forest area, Taohe Nature Reserve, Gansu Province Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:基于群落调查数据，以样地代表多种资源的综合状态，物种重要值作为生态位的计测指标，利用Levins和Shannon生态位宽度，Schoener生态位相似和Pianka生态位重叠对洮河自然保护区大峪沟林区的紫果云杉群落木本植物种群生态位进行定量研究。结果表明：紫果云杉群落乔木层共有树种8种，隶属于4科6属，紫果云杉占绝对优势，岷江冷杉为次优势种；灌木层共有植物50种，隶属于16科25属，忍冬科的蓝靛果、葱皮忍冬和唐古特忍冬等以及蔷薇科的峨眉蔷薇和银露梅等构成了灌木层的主体，紫果云杉幼苗优势不明显，但生态位宽度最大。本研究表明，生态位宽度受物种生态特性及其分布和生境共同影响，重要值大的物种生态位宽度一般较大，生态位宽度大的物种之间生态位相似性和重叠性一般较大，并与其它物种重叠的概率高、重叠程度大，生态位宽度小的物种集中出现时也会出现较大的生态位重叠，同科或同属的物种间常有较大生态位相似和重叠。生态位宽度反映着种群的扩散潜力，生态位相似反映着群落的稳定性，生态位重叠反映着物种间存在或潜在的竞争程度。紫果云杉在乔、灌木层均有最大的生态位宽度，生态适应性最强，群落结构稳定，具有进一步扩散的可能。 Abstract:Based on the plant community investigation data, and with plots representing the comprehensive status of multiple resources, and species importance values as measurement indicators of niche, the niche characteristics of woody plant species in the Picea Purpurea Community in Dayugou forest area of the Taohe Nature Reserve were quantified with the indices of Levins niche breadth, Shannon niche breadth, Schoener niche similarities and Pianka niche overlap. The results showed that there were 8 tree species in the tree layer of the picea purpurea community, belonging to 4 families and 6 genera, among which the picea purpurea was the absolute dominant species, and the Abies faxoniana was the subdominant species; the shrub layer had a total of 50 species of plants belonging to 16 families and 25 genera, among which Lonicera caerulea, Lonicera ferdinandii and Lonicera tangutica of the Caprifoliaceae and Rosa omeiensis and Potentilla glabra of the Rosaceae are the dominant species of the shrub layer, and the picea purpurea seedlings did not have obvious advantages but they had the widest niche breadth. This study indicated that the niche breadth was affected by the ecological characteristics of species as well as their distribution and habitat. The species with large important values generally had larger niche breadth, and the species with large niche breadth generally had the larger niche similarity and overlap, and had higher probability and degree of overlap with other species; there were also large niche overlaps when species with small niche breadth were concentrated, and the species of the same family or genus often had larger niche similarities and overlaps. Niche breadth reflected the population dispersal potential, the niche similarity reflected the stability of a community, and the niche overlap reflected the degree of the existing or potential competition among species. Picea Purpurea had the widest niche breadth in both the tree layers and shrub layers, the strongest ecological adaptability, the stable community structure, and thus the possibility of further dispersal. 参考文献 相似文献 引证文献

An evaluation of multi-species empirical tree mortality algorithms for dynamic vegetation modelling

Tree mortality is key for projecting forest dynamics, but difficult to portray in dynamic vegetation models (DVMs). Empirical mortality algorithms (MAs) are often considered promising, but little is known about DVM robustness when employing MAs of various structures and origins for multiple species. We analysed empirical MAs for a suite of European tree species within a consistent DVM framework under present and future climates in two climatically different study areas in Switzerland and evaluated their performance using empirical data from old-growth forests across Europe. DVM projections under present climate showed substantial variations when using alternative empirical MAs for the same species. Under climate change, DVM projections showed partly contrasting mortality responses for the same species. These opposing patterns were associated with MA structures (i.e. explanatory variables) and occurred independent of species ecological characteristics. When comparing simulated forest structure with data from old-growth forests, we found frequent overestimations of basal area, which can lead to flawed projections of carbon sequestration and other ecosystem services. While using empirical MAs in DVMs may appear promising, our results emphasize the importance of selecting them cautiously. We therefore synthesize our insights into a guideline for the appropriate use of empirical MAs in DVM applications.

Genetic differentiation among populations of the blackfin goodea Goodea atripinnis (Cyprinodontiformes: Goodeidae): implications for its evolutionary history.

Central Mexico is characterized by a complex topography that is the result of historic and contemporary tectonic and climatic factors. These events have influenced the evolutionary history of numerous freshwater fishes in the region. Nonetheless, recent studies have shown that life-history traits and ecological characteristics of species may influence dispersal capabilities and the degree of genetic connectivity. Goodea (Cyprinodontiformes: Goodeidae) is one of the most widely distributed and environmentally tolerant genera of goodeids. In this study, the authors analysed variation in the mitochondrial cytochrome b gene to evaluate the phylogeographic relationships, genetic structure, genetic diversity and demographic history of Goodea from across its distribution range. They found low genetic differentiation and identified shared haplotypes among several regions. Geographic segregation was found in samples southwest and northeast of the Lower Lerma region, with some internal isolated groups showing phylogeographic differentiation and unique haplotypes. The AMOVA best explained genetic structure when grouped by haplogroups rather than when grouped by recognized biogeographic regions. Several regions showed null genetic diversity, raising the possibility of dispersal mediated by humans. Finally, Bayesian Skyline Plot analysis showed a population expansion for the Southwest haplogroup, except for the Armería population and sub-group II of the Northeast haplogroup. All this suggests a recent colonization of Goodea atripinnis throughout some of the biogeographic regions currently inhabited by this species.

Diffusion of Social Information in Non-grouping Animals

Recent findings indicate that the utilization of social information, produced inadvertently by other individuals through their spatial location and/or interaction with the environment, may be ubiquitous in the animal kingdom. If so, social information-mediated effects on population growth and interspecies interactions may be more prevalent than previously thought. However, little is known about how social information may spread among non-grouping individuals, i.e., in animals that do not form cohesive groups and therefore social attraction among group-mates does not facilitate information diffusion. Are there any perception-related, temporal, and/or spatial parameters that may facilitate or limit the spread of social information in temporary aggregations or among dispersed individuals in a population? We argue that living in cohesive groups is not necessarily required for the diffusion of social information and for social information-mediated effects to emerge in a population. We propose that while learning complex problem-solving techniques socially is less likely to occur in non-grouping animals, the spread of adaptive responses to social stimuli, especially to non-visual cues, can be common and may affect population, and/or community dynamics in a wide range of taxa. We also argue that network-based diffusion analysis could be a suitable analytical method for studying information diffusion in future investigations, providing comparable estimations of social effects on information spread to previous studies on group-living animals. We conclude that more studies are warranted to verify what intrinsic and extrinsic factors influence information propagation among incidentally and/or indirectly interacting individuals if we are to better understand the role of social information in animal populations and how the social and ecological characteristics of species are related to information spread in natural communities.

Weed invasive

Biological invasions are increasingly attracting the attention of ecologists, so it seems that this phenomenon is relatively new. However, the beginning of the study of biological invasions is publication of the book "The Ecology of Invasions by Animals and Plants" (1958), which is classified as classic works of invasions. Research of biological invasion is focused on the study of crucial biological and ecological characteristics which enable species invasiveness, as well as the characteristics of the recipient community. Despite the intensive study of this phenomenon, there are still differing views whether only introduced alien species or even native species can be considered as invasive species. While some researchers consider that native species cannot belong to the invasive category, others thought that a species that is native, when expend to adjacent habitats, may also be considered as invasive. Understanding biological invasions as if there no difference between native and introduced allochthonous species eliminates the dilemma that arises in the case of cryptogenic species (species that cannot be clearly classified into one of these two groups), whether it is native or introduced species, the success of the spreading depends on ecological adaptations. In addition, there is also disagreement about the stages of biological invasions. One point of view is, invasion processes take place through three phases (introduction, colonization and naturalization), while to other, the introduction is an elementary requirement for invasion, colonization is an integral part of the concept of naturalization, and naturalization which is referred in to previous point of view, is the phase that corresponds to the term "invasiveness". The time and route of introduction, as well as the mode and pathways of spreading for a large number of adventitious weed species have not been precisely established. Depending on whether weed species are introduce accidentally or intentionally, they are divided into boyletophytes (intentionally introduce) and aboyletophytes (accidentally introduce), while according to period of introduction they are divided into archeophytes (introduced in the Paleozoic to Neolithic period), paleophytes (introduced during the Old and Middle Ages until the discovery of America), neophytes (introduced after the discovery of America until to World War II), and neotophytes (introduced from the World War II until nowadays). Invasive processes are very complex, and it is not easy to predict and evaluate the behavior of introduced species in a new environment. Depending on the shape, structure and size of the reproductive organs, invasive weeds can be spread in several ways: autochthonous (selfpropagating), anemohoric (spreading through the wind), hydrohorn (spreading through water), zohornous (spreading by animals) and anthroporous (spreading by human). The success of invasive processes depends on the ecological characteristics of species, environmental resources and degree of ecosystem damage into which species has reached. According to success of survival in the new environment, allochthonous species can have status of the ephemeral (species which temporarily retained in the new environment and do not form stable populations), naturalized (species that are maintained in the new habitat but do not have an expansive character) and invasive (species that are adapted to the new habitat, spreading, forming indigenous part of flora and leave fertile offspring). The ecological-genetic potential of these species is the result of genetic diversity and their capacity for ecological adaptation; mutations, recombination, hybridization and introgression are the main processes responsible for genetic diversity. In the area of introduction, allochthonous species manifest numerous negative impacts on agriculture, ecosystems, human and domestic animal health, socioeconomic relationships and can jeopardize the survival of native species. Invasions are generally classified as negative occurrences, although in some circumstances they may also have a positive effect on the environment. For example, introduction of allochthonous species can enrich biodiversity, in case when number of introduced species far exceeds the number of extinct species. Despite the great scientific and technological progress, the problem of biological invasions cannot be completely resolved, but it is possible to limit these processes and reduce their negative consequences. The European and Mediterranean Plant Protection Organization (EPPO) dedicate special attention to the risks of invasive plant species and recommends measures to prevent their introduction and spread, with special reference to organisms that cause damage in agriculture. Control of these species implies application of all available preventive and direct measures, integrated into a system of integral measures.

Phytodiversity of the "Samara plavni" regional landscape park

Рresented the results of floroecological, hydrobotanical and geobotanical researches of the Regional Landscape Park "Samara Plavni". Regional Landscape Park (RLP) "Samara Plavni" is located in the waters of the Samara Bay, which was formed as a result of flooding of the floodplain of the Samara River during the creation of the Zaporozhye (Dnieper) Reservoir and the surrounding area. Conducted a systematic and bioecological analysis of the flora of vascular plants. Studied the composition of the rare fraction of flora and associated flora element. The research was carried out according to the generally accepted methods of floristic, geobotanical and hydrobotanical research. Bioecomorphic characteristics of species (selection of ecomorphs) are compiled according by A. L. Belgard ecomorph system using the following ecomorphs: biomorphs (one-, two-, perennials); heliomorphs (relation to light); hygromorphs (relation to the aquatic environment); tropomorphs (relation to nutrition); cenomorphs (growth in certain phytocenoses). Ecological characteristics of species were given from literature sources and according to the results of many years of own research. The analysis of the adventitious fraction was carried out at the time of drift – archaeophytes, neophytes. Advent status was determined on the basis of literature data. Vegetation of the regional landscape park "Samara Plavni" is represented by natural and semi-natural groups. The main area of shallow water is occupied by massifs of Phragmites australis (Cav.) Trin. ex Steud and groups of submerged vegetation. The tree and shrub vegetation of the park is represented by natural forest complexes, semi-natural groups and artificial plantations. Meadow and meadow-swamp vegetation of the landscape park is represented by complexes of associations of mesophytes and hygrophytes. The floristic list of vascular plant flora is 617 species. Hemicryptophytes, perennials, sciogeliophytes and heliophytes, mesotrophs, mesophytes, hygrophytes predominate here. Among cenomorphs, most species are represented by meadow (139) and forest (108) species. The rare fraction of flora is 73 species. There are 128 species of ruderal flora and 140 species of adventive flora, including 6 invasive species. At the time of entry into the study area allochthonous element of flora is divided into two groups: archaeophytes – 63 species (45%) and neophytes – 77 species (55%).

Distribution models of estuarine fish species: The effect of sampling bias, species ecology and threshold selection on models' accuracy

Species distribution models (SDMs) relate presence/absence data to environmental variables, allowing to predict species environmental requirements and potential distribution. They have been increasingly used in fields such as ecology, biogeography and evolution, and often support conservation priorities and strategies. Thus, it becomes crucial to understand how trustworthy and reliable their predictions are. Different approaches, such as using ensemble methods (combining forecasts of different single models), or applying the most suitable threshold to transform continuous probability maps into species presences or absences, have been used to reduce model-based uncertainty. Taking into account the influence of biased sampling imprecision in species location, small datasets and species ecological characteristics, may also help to detect and compensate for uncertainty in the model building process. To investigate the effect of applying an ensemble approach, several threshold selection criteria and different datasets representing seasonal and spatial sampling bias, on models' accuracy, SDMs were built for four estuarine fish species with distinct use of the estuarine systems. Overall, predictions obtained with the ensemble approach were more accurate. Variability in accuracy metrics obtained with the nine threshold selection criteria applied was more pronounced for species with low prevalence and when sensitivity was calculated. Higher values of accuracy measures were registered with the threshold that maximizes the sum of sensitivity and specificity, and the threshold where the predicted prevalence equals the observed, whereas the 0.5 cut-off was unreliable, originating the lowest values for these metrics. Accuracy of models created from a spatially biased sampling was overall higher than accuracy of models created with a seasonally biased sampling or with the multi-year database created and this pattern was consistently obtained for marine migrant species, which use estuaries as nursery areas, presenting a seasonally and regular use of these ecosystems. The ecological dependence between these fish species and estuaries may add difficulties in the model building process, and needs to be taken into account, to improve their accuracy. The present study highlights the need for a thorough analysis of the critical underlying issues of the complete model building process to predict the distribution of estuarine fish species, due to the particular and dynamic nature of these ecosystems.

Weak evidence for fine-scale genetic spatial structure in three sedentary Amazonian understorey birds

The ecological characteristics of a species, along with small-scale landscape features are known to affect the patterns of genetic structure within populations. Due to dispersal limitation, closely-related individuals tend to be closer spatially, leading to spatial genetic structure. Physical barriers also may prevent individuals from dispersing further, and lead individuals on one side of a barrier to be more related than individuals from different sides. We tested these hypotheses by examining patterns of fine-scale spatial genetic structure within populations of three relatively sedentary Amazonian-forest understorey birds that differ in their ecological requirements. We sampled birds in a 10,000 ha reserve, covered by largely undisturbed old-growth forests and traversed by a central ridge. We found positive spatial genetic structure at short distances only for Percnostola rufifrons, a treefall-gap specialist. Positive genetic structure occurred at 6 km for Glyphorynchus spirurus, a solitary bark-forager; no spatial genetic structure was found for Gymnopithys rufigula, an army-ant follower. Individuals of none of the three species were more related on a given side of the ridgeline than between different sides but, at greater distances, there was a tendency of individuals located on opposite sides of the ridgeline to be less related than individuals located on the same side, for all species analysed. Our study indicates that local topographic features do not prevent, but likely reduce, gene flow within populations in continuous forests, and that the development of fine-scale spatial genetic structure may depend on the dispersal propensity of a species. Thus, studies of species assemblages need to account for the different ecological characteristics of the constituent species.

ECOLOGICAL AND FUNCTIONAL CLUSTERING OF FORESTAL SPECIES IN THE SOUTH WESTERN AMAZONIA

ABSTRACT The aim of this study was to perform ecological and functional clustering of tree species in southwestern Amazon. Developed from data from 95 permanent plots of 1 ha each, all individuals with diameter at breast height (DBH) ≥10 cm were measured. The species grouping was performed in three stages: (1) cluster analysis, using the variables: diameter annual periodic increment -(IPADAP) considering three competition levels (high, medium and low) and the 95th percentile of the diameters (P95) cumulative frequency distribution (Ward hierarchical method); (2) Discriminant analysis, using the variables P95 and IPADAP by Fisher's method and (3) subjective stage, considering the species ecological characteristics. The Ward and Fisher methods used for discriminant and cluster analyses were effective for species grouping resulting on the formation of 10 groups. Variables: IPADAP and and P95 were efficient on the formed groups discrimination.. Variations in the growth rates for the overall mean data were reduced wen calculated for each group of species.

Predicting fish species distribution in estuaries: Influence of species’ ecology in model accuracy

Current threats to biodiversity, combined with limited data availability, have made for species distribution models (SDMs) to be increasingly used due to their ability to predict species’ potential distribution, by relating species occurrence with environmental estimates. Often used in ecology, conservation biology and environmental management, SDMs have been informing conservation strategies, and thus it is becoming crucial to understand how trustworthy their predictions are. Uncertainty in model predictions is expected, but knowing the origin of prediction errors may help reducing it. Indeed, uncertainty may be related not only with data quality and the modelling algorithm used, but also with species ecological characteristics. To investigate whether the performance of SDM’s may vary with species’ ecological characteristics, distribution models for 21 fish species occurring in estuaries from the Portuguese coast were examined. These models were built at two distinct spatial resolutions and seven environmental explanatory variables were used as predictors. SDMs’ accuracy was assessed with the area under the curve (AUC) of receiver operating characteristics (ROC) plots, sensitivity and specificity. Relationships between each measure of accuracy and species ecological characteristics were then examined. SDMs of the fish species presented small differences between the considered scales, and predictors as latitude, temperature and salinity were often selected at both scales. Measures of model accuracy presented differences between species and scales, but generally higher accuracy was obtained at smaller spatial scales. Among the ecological traits tested, species feeding mode and estuarine use functional groups were the most influential on the performance of distribution models. Habitat tolerance (number of habitat types frequented), species abundance, body size and spawning period also showed some effect. This analyses will contribute to distinguish, based on species ecological characteristics, between species whose occurrence is reliably or less reliably predicted by distribution models. Fish species assigned to the benthivores feeding group, and using estuaries opportunistically (either as feeding or nursery grounds) seem to be more accurately predicted by SDM’s.

Effects of urbanization on bird phenology: a continental study of paired urban and rural populations

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 66:185-199 (2015) - DOI: https://doi.org/10.3354/cr01344 Effects of urbanization on bird phenology: a continental study of paired urban and rural populations Anders Pape Møller1,2, Mario Díaz3, Tomáš Grim4, Alena Dvorská4, Einar Flensted-Jensen5, Juan Diego Ibáñez-Álamo6,7, Jukka Jokimäki8, Raivo Mänd9, Gábor Markó10,11,12, Paweł Szymański13,*, Piotr Tryjanowski14 1Laboratoire d’Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, 91405 Orsay Cedex, France 2Center for Advanced Study, Drammensveien 78, 0271 Oslo, Norway 3Department of Biogeography and Global Change (BGC-MNCN-CSIC), National Museum of Natural Sciences, CSIC, c/Serrano 155bis, 28006 Madrid, Spain 4Palacký University, Department of Zoology and Laboratory of Ornithology, 17. listopadu 50, 77146 Olomouc, Czech Republic 5Cypresvej 1, 9700 Brønderslev, Denmark 6Animal Ecology Group, Centre for Ecological and Evolutionary Studies, University of Groningen, PO Box 11103, 9700 CC Groningen, The Netherlands 7Department of Wetland Ecology, Estación Biológica de Doñana, C.S.I.C, Avda. Américo Vespucio s/n, 41092 Sevilla, Spain 8University of Lapland, Arctic Centre, 96101 Rovaniemi, Finland 9University of Tartu, Institute of Ecology & Earth Sciences, Department of Zoology, 51014 Tartu, Estonia 10MTA-ELTE-MTM, Ecology Research Group, 1117 Budapest, Pázmány Péter sétány 1/c, 1117 Budapest, Hungary 11Corvinus University of Budapest, Department of Plant Pathology, Ménesi út 44, 1118 Budapest, Hungary 12Eötvös Loránd University, Behavioral Ecology Group, Department of Systematics, Zoology and Ecology, Pázmány Péter sétány 1/c, 1117 Budapest, Hungary 13Department of Behavioural Ecology, Faculty of Biology of Adam Mickiewicz University, Umultowska 89, 61-114 Poznań, Poland 14Institute of Zoology, Poznań University of Life Sciences, Wojska Polskiego 71C, 60-625 Poznań, Poland *Corresponding author: paweelszymanski@gmail.com ABSTRACT: Urban habitats differ from adjacent natural habitats in terms of disturbance regimes, light, temperature, rainfall, habitat distribution and resource abundance. Meteorological differences advance and prolong the growing season in urban habitats compared to nearby rural areas. In turn, urban bird populations may potentially start singing earlier, and reproduce earlier and more frequently than rural populations. However, this prediction has previously only been tested with data from single species using single spatial replicates from rural and urban sites. Here we provide the first general (paired urban and rural populations of 54 bird species) and large-scale (a 3800 km long latitudinal gradient across Europe) empirical evidence for longer and earlier singing periods in urban compared to rural habitats. Effects of urbanization on start and duration of the singing period (as a proxy for the breeding season) were positively related to size of cities and ecological characteristics of species. Bird species that have been urbanized for a long time started to sing earlier and had a more extended singing period in urban compared to rural habitats. We also found that the singing period started later and was shorter at higher latitudes. Geographical variation in phenology was related to temperature and rainfall, although differences between urban and rural habitats were not. Differences in duration of singing periods between paired urban and rural sites were as large as latitudinal differences between southern and northern Europe (5, 6 and 28 d for 3 common species, as compared to a mean latitudinal variation of 17.1 d). This suggests local adjustment to urban environments, either due to evolution or to plasticity of phenological behaviour. KEY WORDS: Singing periods · Phenology · Population density · Urbanization Full text in pdf format Supplementary material NextCite this article as: Møller AP, Díaz M, Grim T, Dvorská A and others (2015) Effects of urbanization on bird phenology: a continental study of paired urban and rural populations. Clim Res 66:185-199. https://doi.org/10.3354/cr01344 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 66, No. 3. Online publication date: December 03, 2015 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2015 Inter-Research.

Ficus insipida subsp. insipida (Moraceae) reveals the role of ecology in the phylogeography of widespread Neotropical rain forest tree species.

AimTo examine the phylogeography of Ficus insipida subsp. insipida in order to investigate patterns of spatial genetic structure across the Neotropics and within Amazonia.LocationNeotropics.MethodsPlastid DNA (trnH–psbA; 410 individuals from 54 populations) and nuclear ribosomal internal transcribed spacer (ITS; 85 individuals from 27 populations) sequences were sampled from Mexico to Bolivia, representing the full extent of the taxon's distribution. Divergence of plastid lineages was dated using a Bayesian coalescent approach. Genetic diversity was assessed with indices of haplotype and nucleotide diversities, and genetic structure was examined using spatial analysis of molecular variance (SAMOVA) and haplotype networks. Population expansion within Amazonia was tested using neutrality and mismatch distribution tests.ResultstrnH–psbA sequences yielded 19 haplotypes restricted to either Mesoamerica or Amazonia; six haplotypes were found among ITS sequences. Diversification of the plastid DNA haplotypes began c. 14.6 Ma. Haplotype diversity for trnH–psbA was higher in Amazonia. Seven genetically differentiated SAMOVA groups were described for trnH–psbA, of which two were also supported by the presence of unique ITS sequences. Population expansion was suggested for both markers for the SAMOVA group that contains most Amazonian populations.Main conclusionsOur results show marked population genetic structure in F. insipida between Mesoamerica and Amazonia, implying that the Andes and seasonally dry areas of northern South America are eco-climatic barriers to its migration. This pattern is shared with other widespread pioneer species affiliated to wet habitats, indicating that the ecological characteristics of species may impact upon large-scale phylogeography. Ficus insipida also shows genetic structure in north-western Amazonia potentially related to pre-Pleistocene historical events. In contrast, evident population expansion elsewhere in Amazonia, in particular the presence of genetically uniform populations across the south-west, indicate recent colonization. Our findings are consistent with palaeoecological data that suggest recent post-glacial expansion of Amazonian forests in the south.

小秦岭森林群落数量分类、排序及多样性垂直格局

PDF HTML阅读 XML下载 导出引用 引用提醒 小秦岭森林群落数量分类、排序及多样性垂直格局 DOI: 10.5846/stxb201308162093 作者: 作者单位: 河南农业大学 生命科学学院,河南小秦岭国家级自然保护区管理局,河南小秦岭国家级自然保护区管理局,河南农业大学 生命科学学院,郑州大学 离子束生物工程省重点实验室,河南农业大学 生命科学学院,河南农业大学 生命科学学院 作者简介: 通讯作者: 中图分类号: 基金项目: 河南省科技攻关（132102110133）；河南省教育厅科学技术研究重点项目（14A180013） Numerical classification, ordination and species diversity along elevation gradients of the forest community in Xiaoqinling Author: Affiliation: College of life sciences, Henan Agricultural University,Administration Bureau of Xiaoqinling National Nature Reserve of Henan,,,Henan Provincial Key Laboratory of Ion Beam Bio-engineering, Zhengzhou University,,college of life sciences, Henan Agricultural University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:采用分层取样的方法，沿小秦岭林区海拔梯度设立56块20 m×20 m样地，用多元回归树（MRT）方法对小秦岭森林群落进行分类，采用除趋势对应分析（DCA）进行排序，用广义可加模型（GAM）研究不同生活型物种多样性沿海拔梯度分布格局。结果表明：（1）56个样地进行MRT分类，经交叉验证并依据植物群落分类和命名原则，本区植物群落可分为5类；（2）样方DCA排序明确地揭示各群落类型生境分布范围，较好地反映小秦岭自然保护区森林群落与环境因子的关系；（3）不同生活型物种多样性指数随海拔梯度变化发生一定的波动，且呈现不同的多样性格局：丰富度指数中，乔木层呈显著的单峰分布格局，灌木层在中海拔段呈明显下降趋势，草本层随着海拔的升高总体呈下降趋势；Shannon-Wiener多样性指数中，不同生活型物种随海拔变化趋势与物种丰富度变化趋势大体相同；不同生活型物种的均匀度指数随海拔变化趋势较平缓。 Abstract:Forest community classification, ordination, and species diversity patterns along altitudinal gradients can reveal relationships between species distribution and environmental factors, providing an important basis for understanding the function of mountain ecosystems. Quantitative analysis is an important approach to research the community classification and sorting. And can reveal profoundly the ecological relationship between plant communities and environmental factors. Species diversity altitude gradient pattern study can further reflect the biological and ecological characteristics of species, distribution and its adaptability to the environment, to reveal the biological diversity environment gradient variation rule, and is important basis to know the mountain ecosystem function and carries on the reasonable operation. But different area and different life forms of species due to the restriction of various factors and present different gradient pattern. Therefore, for a specific mountain to carry out a case study of the species diversity altitude pattern is very necessary to. Xiaoqinling Nature Reserve is located at the intersection of northern, northeastern, central and southwestern plant community types resulting in rich plant resources. The unique geography, climate, and vegetation conditions make Xiaoqinling an ideal location to research forest communities. Few studies exist about the number of forest community types and species diversity along an altitudinal gradient in Xiaoqinling. However, in recent years, due to population pressures and large-scale economic development there have been declines in biodiversity in protected areas. We conducted a field investigation of 56 plots (20 m×20 m) in Xiaoqinling. The main site factors, forest communities were classified through ordination and species diversity patterns along the altitudinal gradient were analyzed using multivariate regression trees (MRT), detrended correspondence analysis (DCA), and generalized additive model (GAM). Results showed that, (1) forest communities were classified into 5 types by MRT. Ⅰ: Euptelea pleiospermum-Acer grosseri-Glechoma longituba + Poa acroleuca Association, Ⅱ: Pinus armandii + Betula utilis-Salix phylicifolia-Carex siderosticta Association, Ⅲ: Quercus mongolica-Rosa bella-Cayerus compressus Association, Ⅳ: Pinus armandii + Quercus baronii var. baronii + Cotinus coggygria-Forsythia suspensa-Cayerus compressus Association, Ⅴ: Pinus armandii + Pinus tabulaeformis-Acer grosseri-Oplismenus undulatifolius Association; (2) the results of DCA clearly reflected the distribution range of various community types and better reflect relationships between species distribution and environmental factors; (3) GAM simulation results show that along an altitudinal gradient woody have clearer distribution patterns than herbs. Richness index in the tree layer showed a significant unimodal distribution pattern, the shrub layer showed a downward trend in mid-elevation and herbceous layer showed a downward trend with increasing altitude. The Shannon-Wiener index showed the same trends as the richness index. The Pielou index of three-layer distribution showed little variation with increasing altitude. Forest community structure and vertical pattern of species diversity vary with altitude gradient have important significance to reveal biodiversity environment gradient variation rule. The results help to deeply understand the space distribution pattern of forest community and ecological characteristics of species and for the future provide the corresponding theoretical basis for management and protection, as well as to elucidate mountain flora distribution and diversity of vertical distribution pattern to accumulate basic data. 参考文献 相似文献 引证文献

Hybridization may facilitate in situ survival of endemic species through periods of climate change

Predicting species’ chances of survival under climate change requires an understanding of their adaptive potential. Now research into hybridization—one mechanism that could facilitate adaptation—shows that species of the plant genus Pachycladon that survived the Last Glacial Maximum benefited from the transfer of genetic information through hybridization. Predicting survival and extinction scenarios for climate change requires an understanding of the present day ecological characteristics of species and future available habitats, but also the adaptive potential of species to cope with environmental change. Hybridization is one mechanism that could facilitate this. Here we report statistical evidence that the transfer of genetic information through hybridization is a feature of species from the plant genus Pachycladon that survived the Last Glacial Maximum in geographically separated alpine refugia in New Zealand’s South Island. We show that transferred glucosinolate hydrolysis genes also exhibit evidence of intra-locus recombination. Such gene exchange and recombination has the potential to alter the chemical defence in the offspring of hybridizing species. We use a mathematical model to show that when hybridization increases the adaptive potential of species, future biodiversity will be best protected by preserving closely related species that hybridize rather than by conserving distantly related species that are genetically isolated.

Geographical Distributions of Mitochondrial DNA Lineages Reflect Ancient Directions of River Flow: A Case Study of the Japanese Freshwater ShrimpNeocaridina denticulata denticulata(Decapoda: Atyidae)

The mitochondrial DNA phylogeographical structure of the freshwater atyid shrimp Neocaridina denticulata denticulata was investigated near the Yura and Kako Rivers in western Japan. To assess the biological significance of drainage evolution, fragments of 390 base pairs (bp) extending from the NADH dehydrogenase subunit 2 gene to the tryptophan transfer RNA gene were sequenced for 246 specimens from twenty locations. The phylogenetic tree detected two distinct clades corresponding to the region along the Sea of Japan and Seto Inland Sea, respectively. Geographical mapping of the two clades well reflected the river capture, in which the upper reaches of the Yura River draining into the Sea of Japan had been captured from the Kako River into the Seto Inland Sea. The clear pattern of mitochondrial DNA distribution may be accounted for by the ecological characteristics of species that minimize passive downstream drift, local adaptation, and mountain topography.

Geographical and ecological patterns of range size in North American trees

We analysed the degree to which spatial, ecological and phylogenetic factors influenced geographic gradients in range size for all trees native to North America. We compared observed range sizes, measured in either one (latitudinal or longitudinal extent) or two dimensions (range area), with three null models that respected constraints imposed by the geometry of the continent; we tested whether climatic gradients could account for increasing range size with latitude – a Rapoport effect – in North American trees; and whether variation in range size was associated with phylogeny or ecological characteristics of species. We documented an excess of species with small ranges and a lack of widely distributed species compared with null expectations both with and without environmental constraints. We found evidence for a Rapoport effect in North American trees, at different taxonomic levels and for different groups defined by ecological characteristics. This pattern is not an outcome constrained by continental shape and does not depend on the metric for range size, but it is consistent with the climatic variability hypothesis proposed to explain the Rapoport pattern. Finally we showed that trees east of the Rocky Mountains have larger ranges on average than trees to the west or in Mexico and that the proportion of deciduous compared to evergreen species increases with range size. Variation in range size among North American trees is not spatially random, and has a phylogenetic and ecological signal. Consistent with the climatic variability hypothesis, range size of North American trees increases with increasing variability in annual temperature range at higher latitudes.