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1.
The relatively low population size and long adult lifespan of dragonflies (Odonata, Anisoptera) makes them one of the few non-vertebrate groups likely to be impacted by direct roadway mortality. We studied adult dragonfly mortality and behavior associated with roadways for a number of species. Daily mortality rates for dragonflies were estimated from standardized surveys along predetermined lengths of roads. Relative abundance and flight behavior around and across roadways, a potentially important mortality factor, was determined from timed roadside observations. Observed flight behavior provided no evidence that roads act as significant barriers to dispersal for adult dragonflies. Estimated mean number killed ranged from 2 to 35 dragonflies/km/day. Species varied greatly in their susceptibility to motor vehicles. Two species (Plathemis lydia and Libellula luctuosa) made up more than 70% of the dead dragonflies collected, but only represented 14% and 31% of live dragonflies observed, respectively. The relatively low flight heights of these two species over roads (typically under 2 m) may explain their susceptibility; however, another common species (Tramea lacerata) also exhibited low flight height but did not experience high mortality, possibly because of its increased flight agility. Large numbers of adult dragonflies were killed over the entire flight season by motor vehicle collisions, exhibiting the need for assessing the long-term impact of roadway mortality on dragonfly population dynamics.  相似文献   

2.
Conservation education (CE) is an important component of environmental education. Its goal is to teach the theory and practice of preservation and restoration of biodiversity affected by human activities so that people can increase their awareness of conservation issues and change their attitudes and behavior to promote environmental conservation.This paper describes two successful case studies to highlight trends in CE in Japan. One case is a project implemented to create “agricultural wetlands” that resulted in the establishment of a Ramsar Convention site comprised of a restored wetland and its adjacent rice paddy in a rural area near Sendai City in northern Japan. Rice paddy fields are a major component of Satoyama, which are traditional agricultural ecosystems in Japan and occupy 40% of the undeveloped landscape in Japan (Ministry of the Environment Government of Japan, 2007. Third National Biodiversity Strategy of Japan. Ministry of the Environment Government of Japan, Tokyo). Restoration of Satoyama and wetlands by local citizens is a key component of CE practices in Japan, where practical, hands-on, community-based learning is important. The second CE project, geared toward university students and citizens in Yokohama, restored degraded dragonfly ponds and created butterfly biotope in the second largest city in Japan. Restoration of habitat that is centered around highly visible, popular species such as dragonflies and butterflies also benefits other, less prominent species that share these habitats, yet allows residents to easily monitor the benefits of the project.  相似文献   

3.
A comparative analysis of quantitative parameters of the complexes of large soil invertebrates (mesofauna) in slightly disturbed biotopes of the Kuz’minki–Lyublino natural forest park of Moscow and in natural biotopes of the Prioksko-Terrasnyi Biospheric Reserve as a representative territory of the zone of mixed forests. It is shown that soil mesofauna in forest cenoses of the urban park preserves its natural features, though significant changes take place in the dominant complex. An increase in the biomass (up to 43 g/m2) of invertebrates has been observed in the forest-park soils at the expense of a greater population density of earthworms; the portion of saprophages in them increases, whereas the portion of predators is smaller than that in the native soils of the reserve.  相似文献   

4.
Within species habitat use may depend on age, season or sex of an individual. The distribution of males and females may vary both temporally and spatially due to differences in the costs of reproduction and the distribution of critical resources. Conservation of a species requires knowledge of the habitat use of both sexes in order to predict the population size and protect all habitats that a species requires. Adult dragonfly populations often have highly male-biased sex ratios at the breeding habitat. This bias has been attributed to females using alternative habitats to avoid male harassment, or to high female mortality. We monitored adult Hine’s emerald dragonfly (Somatochlora hineana Williamson) populations, in breeding and non-breeding habitats in Door County, Wisconsin and found significant differences in habitat use between males and females. Males primarily used wetland habitats, while females primarily used dry meadows and marginal breeding habitats, only coming into wetlands to lay-eggs or find mates. We assessed food resources in the different habitats and found that high quality insect prey (primarily adult Diptera) were more available in the wetland habitat, indicating that these areas were likely a more productive foraging area for adult dragonflies. The fact that females appear to avoid the wetland habitat is consistent with the hypothesis that male harassment alters female distribution patterns. Consideration of the patterns of habitat use by S. hineana indicates the need to develop a broader understanding of the importance of non-wetland areas in the conservation of wetland species.  相似文献   

5.
The status and trends of global biodiversity are often measured with a bias towards datasets limited to terrestrial vertebrates. The first global assessment of an insect order (Odonata) provides new context to the ongoing discussion of current biodiversity loss. A randomly selected sample of 1500 (26.4%) of the 5680 described dragonflies and damselflies was assessed using IUCN’s Red List criteria. Distribution maps for each species were created and species were assigned to habitat types. These data were analysed in respect to threat level for regions and habitat types. We have found that one in 10 species of dragonflies and damselflies is threatened with extinction. This threat level is among the lowest of groups that have been assessed to date, suggesting that previous estimates of extinction risk for insects might be misleading. However, Odonata only comprise a small invertebrate order, with above-average dispersal ability and relatively wide distribution ranges. For conservation science and policy to be truly representative of global biodiversity a representative cross-section of invertebrates needs to be included.  相似文献   

6.
Reserves are frequently constrained in design and size by various financial, social or political factors. Maintenance of existing reserves must therefore rely on strategic management practices, and prioritization of conservation activities within them. Identification of global and regional hotspots have been effective for prioritizing conservation activities. Yet, identification of micro-hotspots, or overlapping areas of endemic and rare species that are under threat at the landscape scale, have largely been ignored. From a reserve management point of view, knowledge of critical micro-hotspots within a reserve, are focal points for directing cost effective, conservation initiatives, especially removal of invasive alien plants which are a major threat to biodiversity.Using diversity patterns of dragonfly assemblages, many endemic and threatened, within a biosphere reserve located in the core of a global biodiversity hotspot, we investigated the concept of micro-hotspots. As biosphere reserves contain zones with varying degrees of anthropogenic impact, we also investigated the value of buffer and transition zones for complementing the dragonfly fauna of the reserve core. We found a distinct micro-hotspot within the protected core zone which shows concordance for both endemism and species richness. We conclude that focused conservation actions to remove invasive alien plants within this micro-hotspot would help insure its continued integrity. Furthermore, while there is greater habitat degradation within the buffer and transition zones, they support many additional species, but not those necessarily endemic or threatened. The complementary value of buffer and transition zones therefore lies in increasing habitat heterogeneity and species richness of the whole reserve.  相似文献   

7.
蜻蜓飞行能力高超,其膜翅具有超强抵御负载能力,为了理解和向生物系统学习进而进行技术创新,该文以蜻蜓膜翅为研究对象,以研究蜻蜓膜翅仿生模型的静力学特性为目标,采用ANSYS有限元模拟软件对蜻蜓膜翅有限元模型进行分析,在模型中采用二节点管单元Pipe20模拟翅脉,四节点壳单元Shell43模拟翅膜。对蜻蜓膜翅有限元模型进行结构静力学分析,考察了模型在均布载荷、弯矩、扭矩作用下的变形和应力、应变情况。结果显示,蜻蜓膜翅模型在均布载荷、弯矩、扭矩作用下只发生了整体变形,且变形较小,说明蜻蜓膜翅在主翅脉与支翅脉的交界处变形一致,具有优越的整体性能。通过仿蜻蜓膜翅结构模型的建立以及对蜻蜓膜翅结构和功能相关性的分析,为设计具有较好承载能力的薄膜材料提供了新的思路。  相似文献   

8.
This study examines factors affecting the rate and extent of biomass build-up among commercially important groupers, snappers, grunts, parrotfish and surgeonfish in a network of four marine reserves in southwest St. Lucia, Caribbean. Reserves constituted 35% of the total reef area originally available for fishing. Protection was instigated in 1995 after a baseline survey with annual or biennial censuses performed until 2002. Each survey consisted of 114 fifteen minute fish counts in reserves and 83 in fishing grounds, at depths of 5 m and 15 m in a 10 m diameter counting area. Estimates of number and size (cm) of target species were used to calculate fish family biomass. Data were analysed using three-way ANOVA in a before-after-control-impact pairs (BACIP) design. All families increased significantly in biomass over time at nearly all sites. Increases were greater in reserves than fishing grounds, except for grunts, and responses were strongest in parrotfish and surgeonfish. The combined biomass of families more than quadrupled in reserves and tripled in fishing grounds between 1995 and 2002. During this period coral cover declined by 46% in reserves and 35% in fishing grounds. Multiple regression showed that neither habitat characteristics nor habitat deterioration significantly affected rates of biomass build-up. The key factor was protection from fishing, which explained 44% of the variance in biomass growth. A further 28% of the variance was explained by sedimentation, a process known to stress reef invertebrates, significantly reducing the rate of biomass build-up. St. Lucia’s reserves succeeded in producing significant gains to fish stocks despite coral cover and structural complexity falling steeply over the period of the study.  相似文献   

9.
Risk analysis has been employed, amongst other things, both to estimate the probability of future water demand emergencies in reservoir systems (using simulation modelling), and to estimate environmental and public health risks (using empirical data). We assert that this framework, when coupled with simulation modelling, can be applied to examine and compare the impacts of resource exploitation, land use and production strategies which may cause land degradation. Our representation of risk analysis relies on the assumption that each land use strategy is associated with a risk of the system (i.e., social system, production system, ecosystem) attaining a subjectively unacceptable environmental condition (e.g. poor human nutrition, crop failure, degradation of a natural resource) sometime during a management planning period. The research methodology entails: (1) the identification of critical variables in the social and biological environment that are affected by exploitation and management of resources; (2) the identification through interviews, surveys, and research of regions of unacceptability in these variables that determine the dynamics of local environmental degradation; (3) the translation of resource policy and practice into a computer model of impact on the resource system; (4) many iterations of simulation of the system to determine the ‘risk of failing’ in each of the critical variables. The presentation of risk probabilities to decision-makers represents a reduction of many simulations into an understandable estimate of environmental impact. More importantly, risk analysis is potentially a learning tool for human system studies, and an interface for applied social science and ecological research.  相似文献   

10.
The early preoccupation of public health agencies with epidemics led to a dominance of the public health movement by medical concepts. Included were a narrow focussing on disease control, and an authoritarian approach. When a broadening public concern with environmental quality became manifest, in the early 1940's, new agencies were created to control ‘pollution’, and efforts were made to involve the citizenry in the decision making process. In the late 1960's, with the ushering in of the age of ecological awareness, it became evident that even these two programs were not enough, and that he who undertakes to control man's health must so manage the total system that man enjoys an optimum habitat, and must do this within the limits of the total biospheric life support system. This new effort is appropriately termed environmental health. The paper sets forth habitat requirements of man in the form of five separate goals and describes the limitations of the biosphere in terms of four modes of failure, and then proceeds to show the general direction that these two sets of constraints will give to future programs of solid waste management.  相似文献   

11.
Wood ants (Formica rufa group) normally feed on secretions of aphids to obtain carbohydrates, and on free-living invertebrates to obtain proteins. The availability of protein resources is usually unpredictable, and the demand for proteins is high during the period when ant larvae are developing. Thus, ants should select high quality food patches, i.e. patches with plenty of prey, when these are available. Foraging on the forest floor is seldom observed, but should be an alternative behaviour during periods of scarce food supply in the trees. To study the hunting behaviour of wood ants on soil invertebrates, ants were offered fly larvae (maggots) in two different quantities (six or two per pah) at two distances from an ant trail. Maggots exposed on the forest floor were found by randomly patrolling ant scouts regardless of bait quality. However, scouts that found the baits with six larvae recruited workers faster and, on average, four times as many workers were recruited to the six-larvae bait than to the bait with only two larvae. This indicates that ants can distinguish between poor and rich patches and that they are able to use this information to recruit more workers. Also, more workers were recruited and more maggots were carried away from patches nearby trails than from those far away. The results indicate that, during the warm season, ants explore and exhibit adaptive ‘foraging behaviour’ on the forest floor in the whole territory, not only close to trails. Consequently, wood ant feeding on soil invertebrates may be a common way for obtaining a large amounts of protein.  相似文献   

12.
Invertebrate control of soil organic matter stability   总被引:17,自引:0,他引:17  
 The control of soil organic matter (SOM) stability by soil invertebrates is evaluated in terms of their impact on the inherent recalcitrance, accessibility to microorganisms, and interaction with stabilizing substances of organic compounds. Present knowledge on internal (ingestion and associated transformations) and external (defecation, constructions) control mechanisms of soil invertebrates is also reviewed. Soil animals contribute to the stabilization and destabilization of SOM by simultaneously affecting chemical, physical, and microbial processes over several orders of magnitude. A very important aspect of this is that invertebrates at higher trophic levels create feedback mechanisms that modify the spatio-temporal framework in which the micro-food web affects SOM stability. Quantification of non-trophic and indirect effects is thus essential in order to understand the long-term effects of soil biota on SOM turnover. It is hypothesized that the activities of invertebrates which lead to an increase in SOM stability partly evolved as an adaptation to the need for increasing the suitability of their soil habitat. Several gaps in knowledge are identified: food selection and associated changes in C pools, differential effects on SOM turnover, specific associations with microorganisms, effects on dissolution and desorption reactions, humus-forming and humus-degrading processes in gut and faeces, and the modification of invertebrate effects by environmental variables. Future studies must not be confined merely to a mechanistic analysis of invertebrate control of SOM stability, but also pay considerable attention to the functional and evolutionary aspects of animal diversity in soil. This alone will allow an integration of biological expertise in order to develop new strategies of soil management which can be applied under a variety of environmental conditions. Received: 6 April 1999  相似文献   

13.
毕节喀斯特山区饮用水源地水环境污染分析及保护   总被引:1,自引:0,他引:1  
在对毕节地区倒天河水库等13个饮用水源地水质进行评价的基础上,选择生活污水排放量等9个水环境因素作为分析变量,通过采用主成分分析,把水源地水环境影响因素概括为流域人口数量、流域农业土地利用强度、流域农业化学污染、流域自然条件4个主因素,其方差累积贡献率达86.093%。根据各主因素影响水体污染的强度差异和水体污染现状,将饮用水源地水环境划分为生活废水污染、水土流失污染和农药化肥污染3种类型,提出了相应的水环境保护措施。  相似文献   

14.
Despite their high diversity and importance for humankind, invertebrates are often neglected in biodiversity conservation policies. We identify seven impediments to their effective protection: (1) invertebrates and their ecological services are mostly unknown to the general public (the public dilemma); (2) policymakers and stakeholders are mostly unaware of invertebrate conservation problems (the political dilemma); (3) basic science on invertebrates is scarce and underfunded (the scientific dilemma); (4) most species are undescribed (the Linnean shortfall); (5) the distribution of described species is mostly unknown (the Wallacean shortfall); (6) the abundance of species and their changes in space and time are unknown (the Prestonian shortfall); (7) species ways of life and sensitivities to habitat change are largely unknown (the Hutchinsonian shortfall).Numerous recent developments in taxonomy, inventorying, monitoring, data compilation, statistical analysis and science communication facilitate overcoming these impediments in both policy and practice. We suggest as possible solutions for the public dilemma: better public information and marketing. For the political dilemma: red-listing, legal priority listing and inclusion in environmental impact assessment studies. For the scientific dilemma: parataxonomy, citizen science programs and biodiversity informatics. For the Linnean shortfall: biodiversity surrogacy, increased support for taxonomy and advances in taxonomic publications. For the Wallacean shortfall: funding of inventories, compilation of data in public repositories and species distribution modeling. For the Prestonian shortfall: standardized protocols for inventorying and monitoring, widespread use of analogous protocols and increased support for natural history collections. For the Hutchinsonian shortfall: identifying good indicator taxa and studying extinction rates by indirect evidence.  相似文献   

15.
Twenty-three reserves in the Western Australian wheatbelt were examined in an attempt to assess their conservation value for native mammals, excluding bats. Multiple regression analysis on log transformed data showed that 72% of the observed variation in mammal species richness between reserves was accounted for by reserve size. The addition of the other reserve variables examined did not increase significantly this explained variation, although significant correlations existed with most variables. Estimates suggest that a minimum reserve area of about 40,000 ha is required to conserve that part of the regional assemblage of mammals in southern and western Australia likely to persist in the face of moderate disturbances by man and his agencies. Reserves should have large areas of major vegetation formations and maximise the number of regional vegetation associations. Nature reserves as small as 30 ha are valuable sanctuaries for certain species of native mammals.Comparison with mammal faunas isolated on islands by Quaternary glacioeustatic sea-level rise shows that in relation to area, wheatbelt reserves are richer in species, but the slopes of the regressions are similar, particularly for those islands that are little disturbed by man and introduced predators. We suggest that most of the species of mammals surviving in the wheatbelt are suited to existing within patches of vegetation, such as nature reserves, because they are adapted to surviving within the natural archipelago of soil and vegetation types which characterise the wheatbelt and southwestern Western Australia. We suggest that the species of mammals that have become extinct in the wheatbelt are those that are unable to cope with alteration in environmental patchiness caused by changes in the pattern of fires resulting from European occupation.  相似文献   

16.
Assessment of the spatial distribution of environmental variables and of the associated uncertainty is a key issue in environmental modelling. The water content of soil plays an important role in many ecological and hydrological processes for land suitability evaluation. In this study we present a flexible procedure to interpolate soil-related variables that uses covariates to estimate the spatial trend of the variables and quantifies the uncertainty dealing with non-linear relationships. The procedure further extends approaches based on generalized additive models. The use of Gaussian simulations of the error allows the assessment of spatial uncertainty. The method was applied to available soil water capacity for three different nested extents: national, regional, and catchment. The models fitted have different significant covariates and different estimated values according to the region considered. The results suggest that the estimates from the model fitted at the appropriate extent are the most accurate. Taking into account the uncertainty of the trend, the results provided a realistic estimation of the variability and they are spatially consistent with the geomorphological patterns. Estimating the variability with the proposed procedure is useful for further environmental and land use modelling and it can be integrated with uncertainty from other variables, such as those derived from climate models.  相似文献   

17.
[目的]探究西安市节水型园林建设中市民社会行为特征及影响因素,为更好地建设节水型园林城市以及普及园林中再生水的使用提供科学依据。[方法]通过SPSS与AMOS工具对西安市13个区县的问卷调查结果进行相关性分析。[结果]西安市民有较高的节水意识,其中女性、年龄较长、受教育程度较高、经历过缺水和认为城市缺水的群体有着较高的节水意识,并且性别、年龄和对城市缺水程度的感知影响显著。对再生水用于园林的接受程度也普遍较为赞同,年龄较长、受教育程度较高、经历过缺水的人群接受度普遍较高,且年龄和受教育程度的影响表现出了一定的显著性。市民节水意识与园林再生水接受程度正向相关。[结论]性别、年龄、感知城市缺水正向影响节水意识;年龄、受教育程度正向影响园林再生水接受程度;节水意识正向影响园林再生水接受程度。  相似文献   

18.
云南省住房和城乡建设厅前庭位于昆明市红塔东路中段,属于临街的公共环境区域。设计中将云南省住房和城乡建设厅前庭分为整体构图,局部的水体、道路铺装、植物种植、景观设施等。改造方案设计完成了"将该前庭改造成一处公共绿地性质的,具有一定景观效果、空间变化丰富、园林组成要素多样的现代景观"的任务。文章对设计手法进行了初步的分析探讨,根据对该项目的设计经验对公共环境的景观设计提出了一些看法。  相似文献   

19.
Knowledge about the ecology of urban water systems is very scarce. We assessed the conservation value of urban drainage systems in lowland areas and compared these with similar watercourses in rural areas. A total of 36 water bodies in urban areas were selected to investigate the macroinvertebrate biodiversity in relation to environmental variables. Multivariate analysis of aquatic macroinvertebrate assemblages was used to distinguish urban water types and to link these types to key environmental variables. Several biodiversity indices for urban water systems were compared with those for other drainage systems in The Netherlands. Four types of macroinvertebrate assemblages were distinguished in the urban water systems, differing in environmental conditions and values of ecological indicators. The variation in macroinvertebrate assemblages was significantly explained by nitrate, pH, grain size (sediment composition), transparency, nymphaeid and submerged vegetation. Urban drainage systems can sustain a macroinvertebrate biodiversity comparable to that of drainage systems in rural areas (ditches and canals) and (semi)natural watercourses (lotic waters such as small streams and rivulets) and can even be a habitat for red list species. To optimize biodiversity values, urban water management should aim at lowering nutrient levels, stimulating vegetation (diversity of habitat structure) and increasing transparency, which are key factors for macroinvertebrate diversity. We show the potential conservation benefits of water systems in urban areas, but further studies are needed to investigate the optimal design of cities to include biodiversity as an integrated part of the urban environment, thereby sustaining a higher biodiversity in an increasingly urbanizing world.  相似文献   

20.
Surface water quality monitoring is one of the responsibilities of a number of provincial and federal environmental departments in Canada. In Saskatchewan, the Ministry of Environment is responsible for the province water quality monitoring network. The sampling effort was initiated 40 years ago and has been ongoing since, with varying degrees of spatial and temporal coverage. The main objective of the Saskatchewan monitoring network is the assessment of ambient water quality status. In addition, one of the main uses of the generated water quality data is the calculation of a Water Quality Index. The adequacy of the monitoring network to perform these tasks needs to be validated. The objective of this study is to provide a statistical assessment of two of the monitoring network main aspects, the water quality variables and their sampling frequency. A new rationalization approach is applied for the assessment and reselection of water quality variables. The proposed approach provides, in a systematic way, the optimal combinations of variables to continue measuring, variables that may be redundant and could be considered for discontinuance, and variables that may need to be added to the list of variables being measured. The confidence interval around the mean is used as the main criterion for the sampling frequency assessment. A design chart is provided for the sampling frequency assessment, which is easy to use, and provides an initial assessment of the number of samples required to provide a mean value with a predefined error percentage.  相似文献   

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