首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
We analysed a recently completed statewide odonate Atlas using multivariate linear models. Within a phylogenetically explicit framework, we developed a suite of data-derived traits to assess the mechanistic distributional drivers of 59 species of damselflies in New York State (NYS). We found that length of the flight season (adult breeding activity period) mediated by thermal preference drives regional distributions at broad (105 km2) scales. Species that had longer adult flight periods, in conjunction with longer growing seasons, had significantly wider distributions. These intrinsic traits shape species'' responses to changing climates and the mechanisms behind such range shifts are fitness-based metapopulation processes that adjust phenology to the prevailing habitat and climate regime through a photoperiod filter.  相似文献   

3.
4.
    
In recent decades, community groups have transformed habitat restoration, pest control and species translocations in New Zealand. Large areas of wild New Zealand benefit hugely from ongoing management by community‐based restoration groups. Areas near cities and towns have especially good access to pools of keen volunteers. Community groups are involved in monitoring progress with their work, as well as monitoring biodiversity changes in general at their project sites. New tools powered by modern technologies are creating the opportunity for New Zealand's community volunteers to play a transformative role in biodiversity monitoring for either purpose. These tools are reducing the resources and expertise required for species detection and identification. Smartphones with cameras, GPS, audio recorders and data apps make it easier than ever to record species observations. Crowd‐sourced identification of species in photographs and sounds loaded onto NatureWatch NZ allow volunteers to make observations of a much wider range of taxa than just common birds and trees. Realising this potential requires community groups, scientists and their institutions to collaborate in building and maintaining simple, accessible monitoring systems that (i) require and promote standard monitoring methods, (ii) provide efficient data entry in standard formats, (iii) generate automated results of use to community groups and (iv) facilitate public sharing of data to contribute to regional, national and global biodiversity monitoring. Some New Zealand monitoring systems developed recently to assist community‐based restoration groups with monitoring mammalian predator control are good examples of this approach. Making this happen at a large scale across many community groups and taxa requires increased and coordinated long‐term institutional support for monitoring systems and training.  相似文献   

5.
    
Many publications make use of opportunistic data, such as citizen science observation data, to infer large‐scale properties of species’ distributions. However, the few publications that use opportunistic citizen science data to study animal ecology at a habitat level do so without accounting for spatial biases in opportunistic records or using methods that are difficult to generalize. In this study, we explore the biases that exist in opportunistic observations and suggest an approach to correct for them. We first examined the extent of the biases in opportunistic citizen science observations of three wild ungulate species in Norway by comparing them to data from GPS telemetry. We then quantified the extent of the biases by specifying a model of the biases. From the bias model, we sampled available locations within the species’ home range. Along with opportunistic observations, we used the corrected availability locations to estimate a resource selection function (RSF). We tested this method with simulations and empirical datasets for the three species. We compared the results of our correction method to RSFs obtained using opportunistic observations without correction and to RSFs using GPS‐telemetry data. Finally, we compared habitat suitability maps obtained using each of these models. Opportunistic observations are more affected by human access and visibility than locations derived from GPS telemetry. This has consequences for drawing inferences about species’ ecology. Models naïvely using opportunistic observations in habitat‐use studies can result in spurious inferences. However, sampling availability locations based on the spatial biases in opportunistic data improves the estimation of the species’ RSFs and predicted habitat suitability maps in some cases. This study highlights the challenges and opportunities of using opportunistic observations in habitat‐use studies. While our method is not foolproof it is a first step toward unlocking the potential of opportunistic citizen science data for habitat‐use studies.  相似文献   

6.
    
ABSTRACT Road mortality is often spatially aggregated, and there is a need for models that accurately and efficiently predict hot spots within a road network for mitigation. We surveyed 145 points throughout a 353-km highway network in New York State, USA, for roadkill of reptiles and amphibians. We used land cover, wetland configuration, and traffic volume data to identify features that best predicted hot spots of herpetofauna road mortality. We resampled 40 points an additional 4 times over 4 years to evaluate temporal repeatability. Both amphibian and reptile road mortality were spatially clustered, and road-kill hot spots of the 2 taxa overlapped. One survey provided a valid snapshot of spatial patterns of road mortality, and spatial patterns remained stable across time. Road-kill hot spots were located where wetlands approached within 100 m of the road, and the best predictor was a causeway configuration of wetlands (wetlands on both sides of the road). We validated causeways as predictors of road mortality by surveying 180 causeways and 180 random points across 5 regions (17,823 km2) of northeastern New York. Causeways were 3 times more likely than random locations to have amphibian and 12 times more likely to have reptile mortality present, and causeways had a 4 times higher total number of amphibian roadkill and 9 times higher reptile roadkill than did random points. We conclude it is possible to identify valid predictors of hot spots of amphibian and reptile road mortality for use when planning roads or when conducting surveys on existing roads to locate priority areas for mitigation.  相似文献   

7.
    
Species‐specific responses to landscape configuration and landscape composition have been studied extensively. However, little work has been done to compare intraspecific differences in habitat preferences. Bats have potential as good bioindicator taxa in woodland habitats. Therefore, studying sex differences in responses to woodland and the wider landscape can allow us to gain insight into the relative importance of these habitats for both bats and other taxa. In this study, we aimed to test the predictions that (i) habitat type and connectivity will influence the probability of recording female bats in woodlands and (ii) sex differences in response to habitat type and connectivity will be species‐specific. Bat capture data was collected in 206 woodlands over 3 years in England. The probability of detecting females relative to males was modeled in response to a range of woodland characteristics and landscape metrics for six bat species. We recorded sex differences in responses to landscape features in three species. We found a higher probability of capturing female Myotis nattereri in woodlands that were surrounded by a higher proportion of improved grasslands, whereas female Myotis mystacinus were less likely to be recorded in woodlands surrounded by semi‐natural vegetation. Female Plecotus auritus were more likely to be recorded in isolated woodlands with less connectivity to other woodlands and where agriculture dominated the surrounding landscape. Our findings indicate that sexual segregation occurs across several UK bat species in response to landscape connectivity and composition. Sexual segregation in response to landscape characteristics in bats should therefore be an important consideration in the management of fragmented agricultural landscapes.  相似文献   

8.
    
  1. We assessed the origins and historical biogeography of a rich regional odonate fauna in New York State (NYS), Northeastern United States.
  2. We computed North American (NA) range centres and NYS range margins and reviewed the taxonomic literature to provide a useful phylogenetic framework for the fauna. We analysed results from a newly completed Odonata atlas using generalised linear anova models to assess the effects of species' origins and zoogeographic affinities on relative frequency and extinction risk metrics.
  3. Phylogenetic reconstruction based on taxonomic nomenclature revealed different patterns of diversification. Zygoptera in NYS is mainly of neotropical origin ˜ 60 Ma displaying a pattern of tropical conservatism, but with a burst recent of Plio–Pleistocene speciation in certain groups. Alternatively, Anisoptera contains crown group endemic taxa and other very old lineages from the Mesozoic era before the breakup of Pangaea, highlighting the evolutionary significance of the Appalachian Mountains as an important global centre of temperate forest freshwater diversity.
  4. These high regional levels of odonate diversity have been brought about by at least three different mechanisms: dependence on forests, predominance of non‐ecological speciation mechanisms, and niche conservatism across hundreds of millions of generations.
  5. NYS lies at a crossroads of both ancient and more recent Odonata evolution comprising separate boreal, temperate, and tropical faunas. Those species encountered less frequently and having higher overall extinction risk metrics generally tended to be the boreal species on the rear edge of their range, a widespread phenomenon for the insects of many regions generally attributed to ongoing climate change.
  相似文献   

9.
    
Aim Early assessment of the impact of invasive alien species is crucial to set up timely management, but often the impact is evident when it is too late for action. We evaluated relationships between the alien crayfish, Procambarus clarkii, the distribution of native amphibians, and the abundance of their larvae. We assessed whether considering measures of reproductive success provide a more prompt measure of impact than considering just species distribution. Location One hundred and twenty‐five wetlands in Northern Italy, in an area recently invaded by P. clarkii. Methods We surveyed wetlands to assess the presence of breeding activity of amphibians and the distribution of P. clarkii. We measured the abundance of amphibian larvae before metamorphosis through pipe sampling. We built models analysing the relationships between amphibian and crayfish distribution, while taking into account spatial autocorrelation and environmental features. Analyses were performed at both the species level (generalized linear models and spatial eigenvector mapping) and community level (constrained redundancy analysis). Results In terms of breeding site distribution, only two amphibians (Lissotriton vulgaris and Hyla intermedia) were negatively associated with P. clarkii, while the relationships between other the species and P. clarkii were positive or not significant. However, larval abundance for all amphibian species was negatively associated with the alien crayfish. Analyses performed at community and single species levels yielded consistent results. Main conclusions Procambarus clarkii impacts amphibians through different processes. Newts probably avoid invaded wetlands for breeding. Other species attempt breeding in wetlands with crayfish, but suffer very low success. Considering distribution data alone would not provide a correct picture of the impact of this alien species; measures of reproductive success may allow a more accurate assessment of the impact.  相似文献   

10.
Abstract Integration of habitat heterogeneity into spatially realistic metapopulation approaches reveals the potential for key cross-scale interactions. Broad-scale environmental gradients and land-use practices can create autocorrelation of habitat quality of suitable patches at intermediate spatial scales. Patch occupancy then depends not only on habitat quality at the patch scale but also on feedbacks from surrounding neighborhoods of autocorrelated patches. Metapopulation dynamics emerge from how demographic and dispersal processes interact with relevant habitat heterogeneity. We provide an empirical example from a metapopulation of round-tailed muskrats (Neofiber alleni) in which habitat quality of suitable patches was spatially autocorrelated most strongly within 1,000 m, which was within the expected dispersal range of the species. After controlling for factors typically considered in metapopulation studies—patch size, local patch quality, patch connectivity—we use a cross-variogram analysis to demonstrate that patch occupancy by muskrats was correlated with habitat quality across scales ≤1,171 m. We also discuss general consequences of spatial heterogeneity of habitat quality for metapopulations related to potential cross-scale interactions. We focus on spatially correlated extinctions and metapopulation persistence, hierarchical scaling of source–sink dynamics, and dispersal decisions by individuals in relation to information constraints.  相似文献   

11.
    
Field investigations of phenotypic variation in free‐living organisms are often limited in scope owing to time and funding constraints. By collaborating with online communities of amateur naturalists, investigators can greatly increase the amount and diversity of phenotypic data in their analyses while simultaneously engaging with a public audience. Here, we present a method for quantifying phenotypes of individual organisms in citizen scientists’ photographs. We then show that our protocol for measuring wing phenotypes from photographs yields accurate measurements in two species of Calopterygid damselflies. Next, we show that, while most observations of our target species were made by members of the large and established community of amateur naturalists at iNaturalist.org , our efforts to increase recruitment through various outreach initiatives were successful. Finally, we present results from two case studies: 1) an analysis of wing pigmentation in male smoky rubyspots Hetaerina titia showing previously undocumented geographical variation in a seasonal polyphenism, and 2) an analysis of variation in the relative size of the wing spots of male banded demoiselles Calopteryx splendens in Great Britain questioning previously documented evidence for character displacement. Our results demonstrate that our protocol can be used to create high quality phenotypic datasets using citizen scientists’ photographs, and, when combined with metadata (e.g. date and location), can greatly broaden the scope of studies of geographical and temporal variation in phenotypes. Our analyses of the recruitment and engagement process also demonstrate that collaborating with an online community of amateur naturalists can be a powerful way to conduct hypothesis‐driven research aiming to elucidate the processes that impact trait evolution at landscape scales.  相似文献   

12.
京沪穗三地近十年夜间热力景观格局演变对比研究   总被引:3,自引:2,他引:3       下载免费PDF全文
孟丹  王明玉  李小娟  宫辉力 《生态学报》2013,33(5):1545-1558
城市热环境是城市生态环境的重要方面,它与城市气候、城市生态、城市灾害有着重要的联系.以北京、上海、广州三地为研究区,选取近10年MODIS的夜晚地表温度(LST)产品MOD11A2,分别采用质心迁移、景观格局指数、空间自相关方法研究京沪穗三地近10年的不同等级热力景观质心迁移演变、格局变迁和空间集聚特征.主要结论为:三地热力景观随郊区向市中心趋近,体现了由低温区、次中温区向中温区、次高温区、高温区过渡的趋势;三地的中温区所占比例最大,城市热力景观破碎度三地中上海市最高,5种热力景观比较,次中温区和高温区的破碎度最高;城市热力景观离散度三地中北京市最高,低温区和高温区的离散度较高.热环境空间自相关分析表明三地均以高温-高温区,低温-低温区集聚为主,北京、广州高温-高温区分布于南部,且集中成片分布,而上海市高温-高温区分布比较离散,相对较为复杂.从分布面积来说,10a中北京、上海表现为先减少后增加,而广州则持续减少.总体而言北京热环境恶化,而广州、上海热环境有所好转.  相似文献   

13.
闽南三市绿地景观格局与地表温度的空间关系   总被引:2,自引:0,他引:2  
沈中健  曾坚  梁晨 《生态学杂志》2020,(4):1309-1317
深入探索绿地景观格局对热环境的影响机制,对于改善城市生态环境具有重要意义。基于厦门、漳州、泉州三市的Landsat遥感数据,应用景观生态学与空间自相关理论,探讨了绿地景观与地表温度的空间分布特征,并用双变量空间自相关与空间自回归模型分析两者之间的空间关系。结果表明:闽南三市绿地与地表温度均具有显著的空间自相关性;内陆的高海拔地区,绿地分布密集,地表温度较低,而城区、乡镇及大片的耕地,绿地分布较少,地表温度较高;漳州、泉州绿地景观格局对地表温度的影响更显著,厦门最弱;绿地的景观类型比例、最大斑块指数、聚集度指数、平均斑块面积与地表温度呈负相关,斑块密度与地表温度呈正相关;边缘密度、平均形状指数与地表温度的关系存在不确定性;空间滞后模型与空间误差模型能更好地解释绿地景观格局与地表温度的空间关系。  相似文献   

14.
    
We tested four major hypotheses on the ecological aspects of body mass variation in extant Malagasy strepsirrhines: thermoregulation, resource seasonality/scarcity, resource quality, and primary productivity. These biogeographic hypotheses focus on the ecological aspects of body mass variation, largely ignoring the role of phylogeny for explaining body mass variation within lineages. We tested the independent effects of climate and resource-related variables on variation in body mass among Malagasy primates using recently developed comparative methods that account for phylogenetic history and spatial autocorrelation. We extracted data on lemur body mass and climate variables for a total of 43 species from 39 sites. Climatic data were obtained from the WorldClim database, which is based on climate data from weather stations compiled around the world. Using generalized linear models that incorporate parameters to account for phylogenetic and spatial autocorrelation, we found that diet and climate variables were weak predictors of lemur body mass. Moreover, there was a strong phylogenetic effect relative to the effects of space on lemur body mass in all models. Thus, we failed to find support for any of the four hypotheses on patterns of geography and body mass in extant strepsirrhines. Our results indicate that body mass has been conserved since early in the evolutionary history of each genus, while species diversified into different environmental niches. Our findings are in contrast to some previous studies that have suggested resource and climate related effects on body mass, though these studies have examined this question at different taxonomic and/or geographic scales.  相似文献   

15.
    
Landscape ecology plays a vital role in understanding the impacts of land‐use change on biodiversity, but it is not a predictive discipline, lacking theoretical models that quantitatively predict biodiversity patterns from first principles. Here, we draw heavily on ideas from phylogenetics to fill this gap, basing our approach on the insight that habitat fragments have a shared history. We develop a landscape ‘terrageny’, which represents the historical spatial separation of habitat fragments in the same way that a phylogeny represents evolutionary divergence among species. Combining a random sampling model with a terrageny generates numerical predictions about the expected proportion of species shared between any two fragments, the locations of locally endemic species, and the number of species that have been driven locally extinct. The model predicts that community similarity declines with terragenetic distance, and that local endemics are more likely to be found in terragenetically distinctive fragments than in large fragments. We derive equations to quantify the variance around predictions, and show that ignoring the spatial structure of fragmented landscapes leads to over‐estimates of local extinction rates at the landscape scale. We argue that ignoring the shared history of habitat fragments limits our ability to understand biodiversity changes in human‐modified landscapes.  相似文献   

16.
李灿  张凤荣  朱泰峰  曲衍波 《生态学报》2013,33(17):5363-5374
探索大城市边缘区景观破碎化格局及其空间异质性特征,有助于把握景观动态的变化机制及其生态问题.以北京市顺义区这一典型大城市边缘区为例,基于土地利用分类数据,采用有效粒度尺寸方法,对1992年、1999年和2009年景观破碎化空间变异进行了地统计学分析,主要包括尺度依赖性、空间异质性、空间格局及其生态过程的分析.研究结果表明:1)景观破碎化空间变异具有明显的尺度依赖性特征,由空间自相关部分引起的空间异质性较高;1992年和1999年景观破碎化空间总变异相对缓和,2009年空间总变异强烈;通过不同尺度上的异质性对比,选取1000m幅度作为研究区景观破碎化的空间异质性分析较为适宜.2)景观破碎化空间异质性表现出明显的上升趋势,土地利用斑块破碎化不断加剧,其中1999-2009年间的表现尤为强烈.3)景观破碎化高值区呈现出由东部向西部转移的态势,并且其空间布局具有集聚性与分散性的显著特征,空间上相似属性聚集与相异属性聚集的空间格局十分突出.4)景观破碎化空间自相关作用主要来自高强度社会经济活动的影响,并表现出明显的区位特征.该研究结果可为土地、城镇规划以及景观生态建设提供参考.  相似文献   

17.
云南省红河流域景观生态风险及驱动力分析   总被引:5,自引:0,他引:5       下载免费PDF全文
刘世梁  刘琦  张兆苓  邓丽  董世魁 《生态学报》2014,34(13):3728-3734
以云南省红河流域为研究区域,利用GIS和RS技术,建立基于景观格局和土壤侵蚀过程的景观生态风险指数,分析研究区域内景观生态风险分布规律。研究结果表明:重度和极重度格局风险区域、土壤侵蚀区域及综合景观生态风险区域主要沿红河主干道分布;综合景观生态风险指数在空间上呈现正的自相关性,高风险聚集区主要沿河流分布;不同景观类型中,建设用地、未利用地和水域的景观格局风险大于耕地、草地和林地,未利用地的土壤侵蚀风险最高,综合景观生态风险度依次为建设用地水域未利用土地耕地林地草地;坡度在一定程度上影响着景观格局、土壤侵蚀以及综合景观生态风险。  相似文献   

18.
19.
Port Stephens, a large natural harbour on the central New South Wales (NSW) coast, provides ideal oceanographic and benthic conditions for the growth of marine algae and seagrasses, and this promotes a suite of herbivorous heterobranch sea slugs such as sea hares and sap-sucking sea slugs. In this article we document both historic and recent observations of sea hares (family Aplysiidae) from Port Stephens with the intention of recording species diversity. The western South Pacific region has the richest aplysiid fauna in the world, with 16 species now recorded in Port Stephens. This location is the most taxonomically diverse for this family in Australia. Despite this hotspot of aplysiid diversity, the taxonomy and nomenclature of 12 species is uncertain, a fact highlighted by a series of nomenclatural notes included in this article. We herein report the first observation of Petalifera sp. in Australian waters. Dolabrifera jacksoniensis Pilsbry, 1896 Pilsbry, H. (1896) Genus III. Dolabrifera Gray, 1847. Manual of Conchology series 1, volume 16, part 63, 113–160, pls 32–43. [Google Scholar] is newly synonymised with D. brazieri G.B. Sowerby II, 1870. Recent reports of southern range extensions for other heterobranch sea slugs, both in Port Stephens and elsewhere in NSW, highlight the importance of recording the existing aplysiid diversity in the port. Thus, any future alteration to species composition and range shifts driven by climate change may be detected.  相似文献   

20.
    
1. Spatial patterns of beta-diversity, an important property of species communities, are less well-studied than those of local species richness, particularly in insects from tropical rainforests. 2. We use geometrid moth samples from northern Borneo to quantify ensemble turnover across distances of > 700 km, consider habitat- and sampling-related impacts on their composition, and evaluate remaining spatial patterns in the data. 3. Geometrid moth ensembles from Borneo are shaped by environmental parameters such as elevation and habitat disturbance, by temporal factors acting at small (mediated by weather) and large scales (i.e. changes over decades), and by methodological differences of sampling (related to the nightly flight times of species). 4. These parameters explain a large portion of the spatial structure of ensemble composition, but residual variation still contains a pattern that is tentatively best explained by geographical distance, particularly at distances < 20 km. 5. Patterns of species turnover indicate no evidence for biotic homogenization due to human-caused degradation of habitats. Beta-diversity plays a crucial part in mediating the regional diversity of geometrids on Borneo.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号