Diatom Indicators of Stream and Wetland Stressors in a Risk Management Framework

Ecological risk assessment and risk management call for "state-of-the-science" methods and sound scientific assessments of ecosystem health and stressor effects. In this paper recent developments of periphyton indicators of biotic integrity and ecosystem stressors of streams and wetlands are related in a framework of ecological metrics that can be used to quantify risk assessment and risk management options. Many periphyton metrics have been employed in past assessments of water quality and a periphyton indices of biotic integrity has been applied by the state of Kentucky. In addition, the sensitivity of species composition of periphytic diatom assemblages has been shown to respond predictably to ecological stressors so that specific pH, conductivity, and total phosphorus in wetlands and streams can be inferred with weighted average indices. Inference of nutrient conditions by diatom indicators of total phosphorus is shown to have sufficient precision to be a valuable complement to one-time measurement of highly variable total phosphorus in streams. Quantitative indices of sustainability and restorability of ecosystem integrity are proposed, respectively, as the changes in ecological conditions that can occur without significant change in ecological integrity or changes that are necessary to restore ecological integrity.     

Assessing the zooplankton community and environmental factors in a Mediterranean wetland

Mediterranean wetlands represent unique repositories of biodiversity, but these ecosystems are increasingly threatened by human-induced habitat loss. Seventy percent of Greek wetlands (ponds, mires, marshes, etc.) have been lost in the past 80 years due to human intervention. In Greece habitat types of mires, listed in Directive 92/43/EEC, have been recorded in a few locations, one of the most important is Kalodiki wetland. Eutrophication key elements were determined at four sampling stations throughout 1 year in order to monitor the trophic conditions. Moreover, the zooplankton community was described as biological element relevant in the assessment of the ecological status of Kalodiki wetland. Kalodiki wetland exhibits nutrient concentrations corresponding to eutrophic conditions while according to chlorophyll-a values it is classified between mesotrophic and eutrophic status depending mostly on the sampling period. As concerning zooplankton community, it appears poor in species and dominated by small-sized organisms, which is generally typical of eutrophic, disturbed systems. Differences among zooplankton assemblages over seasons as well as among sampling sites highlight the role of both abiotic and biotic factors.     

Application of thresholds of potential concern and limits of acceptable change in the condition assessment of a significant wetland

We propose a framework in which thresholds of potential concern (TPCs) and limits of acceptable change (LACs) are used in concert in the assessment of wetland condition and vulnerability and apply the framework in a case study. The lower Murrumbidgee River floodplain (the ‘Lowbidgee’) is one of the most ecologically important wetlands in Australia and the focus of intense management intervention by State and Federal government agencies. We used a targeted management stakeholder workshop to identify key values that contribute to the ecological significance of the Lowbidgee floodplain, and identified LACs that, if crossed, would signify the loss of significance. We then used conceptual models linking the condition of these values (wetland vegetation communities, waterbirds, fish species and the endangered southern bell frog) to measurable threat indicators, for which we defined a management goal and a TPC. We applied this framework to data collected across 70 wetland storages’, or eco-hydrological units, at the peak of a prolonged drought (2008) and following extensive re-flooding (2010). At the suggestion of water and wetland mangers, we neither aggregated nor integrated indices but reported separately in a series of chloropleth maps. The resulting assessment clearly identified the effect of rewetting in restoring indicators within TPC in most cases, for most storages. The scale of assessment was useful in informing the targeted and timely management intervention and provided a context for retaining and utilising monitoring information in an adaptive management context.     

Using species spectra to evaluate plant community conservation value along a gradient of anthropogenic disturbance

The aim of this study was to assess the impact of anthropogenic disturbance on the partitioning of plant communities (species spectra) across a landcover gradient of community types, categorizing species on the basis of their biogeographic, ecological, and conservation status. We tested a multinomial model to generate species spectra and monitor changes in plant assemblages as anthropogenic disturbance rise, as well as the usefulness of this method to assess the conservation value of a given community. Herbaceous and arborescent communities were sampled in five Azorean islands. Margins were also sampled to account for edge effects. Different multinomial models were applied to a data set of 348 plant species accounting for differences in parameter estimates among communities and/or islands. Different levels of anthropogenic disturbance produced measurable changes on species spectra. Introduced species proliferated and indigenous species declined, as anthropogenic disturbance and management intensity increased. Species assemblages of relevance other than economic (i.e., native, endemic, threatened species) were enclosed not only in natural habitats, but also in human managed arborescent habitats, which can positively contribute for the preservation of indigenous species outside remnants of natural areas, depending on management strategies. A significant presence of invasive species in margin transects of most community types will contribute to an increase in edge effect that might facilitate invasion. The multinomial model developed in this study was found to be a novel and expedient tool to characterize the species spectra at a given community and its use could be extrapolated for other assemblages or organisms, in order to evaluate and forecast the conservation value of a site.     

Spatial Economic–Hydroecological Modelling and Evaluation of Land Use Impacts in the Vecht Wetlands Area

Wetlands provide many important goods and services to human societies, and generate nonuse values as well. Wetlands are also very sensitive ecosystems that are subject to much stress from human activities. Reducing the stress on wetlands requires a spatial matching between physical planning, hydrological and ecological processes, and economic activities. Spatially integrated modelling and evaluation can support this. The present study has developed a triple layer model that integrates information and concepts from social and natural sciences to address the analysis and evaluation of land-use scenarios for a wetlands area in the Netherlands, the Vecht area. This is the floodplain of river Vecht, located in the centre of the Netherlands. The study has resulted in a set of linked spatial hydrological, ecological and economic models, formulated at the level of grids and polders. The main activities incorporated in the system of models are housing, infrastructure, agriculture, recreation and nature conservation. The formulation of alternative development scenarios is dominated by land use and land cover options that are consistent with the stimulation of agriculture, nature or recreation. Two aggregate performance indicators have been constructed from model output, namely net present value of changes and environmental quality. The spatial characteristics of these indicators are retained in a spatial evaluation that ranks scenarios.     

Contemplating the Assessment of Great River Ecosystems

The science and practice of assessing the status and trends of ecological conditions in great rivers have not kept pace with perturbation wrought on these systems. Participants at a symposium sponsored by the U.S. Environmental Protection Agency (USEPA) and the Council of State Governments concluded that useful and efficient assessments of great river ecosystems require thoughtful alignment of sampling designs, spatial and temporal scales, indicators, management needs, and ecosystem characteristics. Site-specific physical, chemical, and biological data long accumulated by monitoring programs have value but fail to provide the integrated system-wide perspective required for adaptive management and the Clean Water Act. Use of existing data may be limited by methodological incompatibilities, access difficulties, and the exclusive applicability of data to specific habitats or sites. The transition from site-specific to system-wide assessments benefits from research being done by USEPA's Environmental Monitoring and Assessment Program (EMAP) and other programs that use probability surveys and biological indicators. Indicators of various taxa (in particular fish, algae, and benthic invertebrates) have been successfully developed for great rivers. However, optimizing the information these ecological indicators convey to managers and the public is the subject of ongoing research.     

Development and validation of a macroinvertebrate index of biotic integrity (IBI) for assessing urban impacts to Northern California freshwater wetlands

Despite California policies requiring assessment of ambient wetland condition and compensatory wetland mitigations, no intensive monitoring tools have been developed to evaluate freshwater wetlands within the state. Therefore, we developed standardized, wadeable field methods to sample macroinvertebrate communities and evaluated 40 wetlands across Northern California to develop a macroinvertebrate index of biotic integrity (IBI). A priori reference sites were selected with minimal urban impacts, representing a best-attainable condition. We screened 56 macroinvertebrate metrics for inclusion in the IBI based on responsiveness to percent urbanization. Eight final metrics were selected for inclusion in the IBI: percent three dominant taxa; scraper richness; percent Ephemeroptera, Odonata, and Trichoptera (EOT); EOT richness; percent Tanypodinae/Chironomidae; Oligochaeta richness; percent Coleoptera; and predator richness. The IBI (potential range 0–100) demonstrated significant discriminatory power between the reference (mean = 69) and impacted wetlands (mean = 28). It also declined with increasing percent urbanization (R ² = 0.53, p < 0.005) among wetlands in an independent validation dataset (n = 14). The IBI was robust in showing no significant bias with environmental gradients. This IBI is a functional tool to determine the ecological condition at urban (stormwater and flood control ponds), as well as rural freshwater wetlands (stockponds, seasonal wetlands, and natural ponds). Biological differences between perennial and non-perennial wetlands suggest that developing separate indicators for these wetland types may improve applicability, although the existing data set was not sufficient for exploring this option.     

江苏生物多样性保护进展、问题及对策建议

总结了江苏生物多样性保护管理工作取得的主要进展、典型做法及有益经验,分析了生物多样性现状特点,针对法规制度亟需加强、典型生境连通较差、基础能力尚显薄弱、物种入侵不容忽视、开发矛盾仍未根治等问题,提出,完善生物多样性管理政策制度、优化保护空间格局、加大自然生态系统保护修复、深化生物多样性本底调查评估、构建多级生物多样性观测网络、加强入侵物种监督管理、探索生物多样性可持续利用机制、提升生物多样性保护宣贯力度等对策建议,以期为新时期江苏生物多样性保护策略的制定提供参考和借鉴。     

Comparing the natural variation of oribatid mite communities with their changes associated with anthropogenic disturbance

Several organism communities serve as ecological and environmental indicators to detect changes in human-impacted habitats. However, the composition of indicator communities may vary because of natural variation in addition to the changes associated with human disturbances. This meta-analysis compared the natural variation of oribatid mite assemblages, a good indicator model group in soil ecosystems, with their deviations associated with disturbance using diversity and dissimilarity indices and three human disturbance types. Literature data were collected about oribatid mite assemblages from natural and disturbed habitats. Human disturbances consisted of agriculture, heavy metal pollution and forest management. Biodiversity indices (Shannon and Berger-Parker) and dissimilarity indices (Jaccard and Bray-Curtis) were calculated among natural habitats and between disturbed and control habitats at the species and genus level. We considered oribatid mite assemblages as effective community-level indicators when the methods separated the differences of assemblages between disturbed and control habitats from their varieties among natural habitats. In addition, the study analysed the correlation between these indices and environmental variables of the study sites. Oribatid mite assemblages performed high indication strength with Bray-Curtis index for agricultural disturbances since dissimilarity values between disturbed and control habitats were as high as between different natural habitats and higher than among the same types of natural habitats. Genus-level values showed similar results to the species level. This approach may be useful to test the effectiveness of other indicator groups and methods.     

Monitoring the Conservation of Grassland Habitats, Prairie Ecozone, Canada

The Prairie Ecozone contains 5% of Canada's land area and represents 16% of the Great Plains of North America. Current estimates indicate that 25–30% of original Canadian grassland habitats remain, largely concentrated in southeastern Alberta and southwestern Saskatchewan with fragments distributed throughout southern Manitoba. The size, distribution and condition of native grasslands serve as valuable indicators of the ecological integrity and the sustainability of those landscape types. With so little native grasslands remaining, areas that conserve grasslands serve as core sites for indicators such as gaps in ecosystem and wildlife habitat protection, i.e. which ecosystems are well-represented, poorly represented or have no representation. Such gap analyses helps to determine where protection efforts need to be placed in the future. Overall, about 3.5% of the Prairie Ecozone of Canada is under some form of conservation area status. This paper reports, relative to the ecoregions and political jurisdictions of the Prairie Ecozone, on the amount and distribution of various types of conservation areas and native grasslands. Relationships between the occurrence of conservation areas and grasslands are presented. Implications for conservation area planning and management are discussed within regional, national and international contexts. The issue of which characteristics of conservation areas should be assessed and monitored to address conservation objectives for sustainability is also discussed.     

A Systems Approach to Biodiversity Conservation Planning

With a recent media-fueled transition from a scientific to a political perspective, biodiversity has become an issue of ethics and ensuing values, beyond its traditional ecological roots. More fundamentally, the traditional perspective of biodiversity is being challenged by the emergence of a post-normal or systems-based approach to science. A systems-based perspective of living systems rests on the central tenets of complexity and uncertainty, and necessitates flexibility, anticipation and adaptation rather than prediction and control in conservation planning and management. What are the implications of this new perspective? This paper examines these challenges in the context of biodiversity conservation planning. The new perspectives of biodiversity are identified and explored, and the emergence of a new ecological context for biodiversity conservation is discussed. From the analysis, the challenges and implications for conservation planning are considered, and a systems-based or post-normal approach to conservation planning and management is proposed. In light of the new perspectives for biodiversity, conservation planning and management approaches should ultimately reflect the essence of living systems: they should be diverse, adaptive, and self-organizing, accepting the ecological realities of change.     

A Bird Community Index of Biotic Integrity for the Mid-Atlantic Highlands

We report on the development and preliminary application of a songbird community-based index of biotic integrity. The bird community index (BCI) sorts bird species found at sample sites into a series of values representing the proportional species richness of 20 behavioral and physiological response guilds. Relative proportions of specialist and generalist guilds are used to assign a composite score to each site. Scores from multiple sites indicate the overall biotic integrity of the study area. The BCI is intended to function as a landscape-scale indicator of biotic integrity, integrating conditions across large sample sites containing diverse ecological resources and intensities of human use. We developed the BCI with data from a 1994 pilot study in central Pennsylvania, then applied our preliminary index in 1995 and 1996 to independent samples of sites across the Mid-Atlantic Highlands Assessment area (MAHA). The 1995 and 1996 sample sites were selected using the probability-based sampling design of the Environmental Monitoring and Assessment Program (EMAP), and therefore represent the total land area in MAHA. Our preliminary assessment indicates that MAHA exhibits six categories of biotic integrity, and that more than 40% of the land area supports the two highest biotic integrity categories. Pending BCI refinement and incorporation of landscape and vegetation explanatory variables, the BCI will be included in a suite of indicators designed to provide an assessment of overall ecological condition in MAHA.     

Mapping and quantifying habitat fragmentation in small coastal areas: a case study of three protected wetlands in Apulia (Italy)

In the Mediterranean Region, habitat loss and fragmentation severely affect coastal wetlands, due to the rapid expansion of anthropogenic activities that has occurred in the last decades. Landscape metrics are commonly used to define landscape patterns and to evaluate fragmentation processes. This investigation focuses on the performance of a set of landscape pattern indices within landscapes characterized by coastal environments and extent below 1,000 ha. The aim is to assess the degree of habitat fragmentation for the monitoring of protected areas and to learn whether values of landscape metrics can characterize fine-resolution landscape patterns. The study areas are three coastal wetlands belonging to the Natura 2000 network and sited on the Adriatic side of Apulia (Southern Italy). The Habitat Maps were derived from the Vegetation Maps generated integrating phytosociological relevés and Earth Observation data. In the three sites, a total of 16 habitat types were detected. A selected set of landscape metrics was applied in order to investigate their performance in assessing fragmentation and spatial patterns of habitats. The final results showed that the most significant landscape patterns are related to highly specialized habitat types closely linked to coastal environments. In interpreting the landscape patterns of these highly specialized habitats, some specific ecological factors were taken into account. The shape indices were the most useful in assessing the degree of fragmentation of habitat types that usually have elongated morphology along the shoreline or the coastal lagoons. In all the cases, to be meaningful, data obtained from the application of the selected indices were jointly assessed, especially at the class level.     

Assessing dam implementation impact on threatened carnivores: the case of Alqueva in SE Portugal

Large dam construction in water deficient areas is a management decision often controversial. Besides providing water storage, economical benefits, and a source of renewable energy, the construction and flooding caused by large dams cause disruptions in natural systems. We monitored the pre- and post-Alqueva dam impacts on the threatened carnivore species (polecat, otter, wildcat and Iberian lynx) populations in SE Portugal, and assessed which factors mostly contribute to post-dam distribution. Major short term impacts of large dams are: (1) increase in accessibility and human presence; (2) movement of heavy machinery and dam-workers; (3) deforestation with habitat loss and fragmentation; (4) change from lotic to lentic system; (5) lower prey availability and harsher capture; and (6) changes in land use adjacent to the reservoir. Thus, the response to those impacts can be predicted as a decline of polecat, wildcat and lynx distribution ranges, and a recovery of the otter from the severe short term impacts. Our results corroborate this hypothesis for all the species, especially during deforestation/early flooding. Otter's distribution range increased in the phase of greater impact, with a subsequent decrease with flooding. Our results suggest carnivores used "escape" areas with favourable habitat and prey conditions, however, the areas with higher probability of species presence decreased by two fold showing a drastic range reduction. To ensure populations' survival of these charismatic threatened carnivore populations of Mediterranean landscapes of south-east Portugal, we propose continuing the monitoring program and the development of a conservation program for the subsisting areas of optimal and suboptimal habitats.     

Knowing, Mapping and Understanding st. Lawrence Biodiversity, with Special Emphasis on Bird Assemblages

Environment Canada and the Québec Department of the Environment, partners in the St Lawrence Vision 2000 Action Plan, set out to prepare a compendium of knowledge of the flora and fauna of the St Lawrence and to identify potential conservation sites. The resulting Portrait is an Internet site that presents the current knowledge base of the river's ecological and biological diversity (http://lavoieverte.qc.ec.gc.ca/faune/biodiv/index.html). The Portrait provides information on over 5,000 species of flora and fauna. On the website, you will find a detailed ecological analysis of the richness, rarity and vulnerability of several broad groups of plant and animal species. Furthermore, you will find a list of species for each of the 700 survey units and a distribution map for 2,500 species recorded along the St Lawrence., in atlas form, along with a detailed conservation plan. The plan encompasses the most unique and heterogeneous landscapes of the St Lawrence, some of which have no protection at present. The Portrait provides an overview of the sites that are currently protected by public agencies and private-sector organisations and identifies new sites of interest for conserving biodiversity and protecting species at risk. This paper exposes the content of this extensive compendium on the biodiversity of the St. Lawrence. For conciseness, it presents some of the analyses conducted on birds to illustrate a few of the analytical approaches that were used. Then, the information on species richness and concentration areas for priority species of vascular plants, breeding birds and herpetofauna will serve to identify the terrestrial sites of significance for biodiversity. Finally, a similar approach having been applied to the aquatic environnement, we will conclude with a conservation plan that identifies the terrestrial and aquatic ecosystems, and the geographic sites where the most important elements of St. Lawrence biodiversity are concentrated. Our analysis of the biodiversity of the most thoroughly studied taxa of the St. Lawrence clearly shows the importance of wetlands, particularly those located at the mouths of rivers or within archipelagos or delta complexes, such as the groups of islands and channels found at both ends of the Montréal Archipelago. These aquatic landscapes are sites of intense biological production, combining in a small geographical area spawning, nursery and feeding grounds for a large number of fish species and breeding, rearing and foraging areas for aquatic birds. Variable flooding conditions, associated with seasonal flooding or daily tidal fluctuations, create a complex mosaic of wetland and aquatic habitats. Although wetlands occupy only a small area in comparison with terrestrial habitats, they support a large number of rare plant and animal species in relation to their size. At present, 10% of the vascular flora and 27% of the herpetofauna of the St. Lawrence are at risk. In the case of reptiles and amphibians, the situation is especially worrisome because nearly all of the most threatened species live in a narrow band along the river corridor. Not only is this the sector that is under the greatest pressure from human development, very little public land remains here, making it difficult to create protected areas. Increased participation by non-governmental organisations and individuals, through private stewardship arrangements, is an essential precondition for completing the network of conservation areas in this part of the St. Lawrence. Along the estuary and the Gulf, habitat integrity has not been affected as much by the expansion of Québec's human population. This is a vast territory, and sites have been identified with a view to making up for the deficiencies in the present network of protected sites in terms of representing biodiversity.     

Environmental Monitoring and Assessment of a Great River Ecosystem: The Upper Missouri River Pilot

Most Great River ecosystems (GREs) are extensively modified and are not receiving adequate protection to prevent further habitat degradation and loss of biotic integrity. In the United States, ecological monitoring and assessment of GREs has lagged behind streams and estuaries, and the management of GREs is hampered by the lack of unbiased data at appropriate spatial scales. Properties of GREs that make them challenging to monitor and assess include difficult sample logistics and high habitat diversity. The U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program (EMAP) has developed a comprehensive, regional-scale, survey-based monitoring approach to assessment of streams and estuaries, but has not yet conducted research on applying these tools to GRE monitoring. In this paper we present an overview of an EMAP research project on the Upper Missouri River (UMR). We summarize the assessment objectives for the study, the design for selecting sample locations, the indicators measured at these sites and the tools used to analyze data. We present an example of the type of statements that can be made with EMAP monitoring data. With modification, the set of methodologies developed by EMAP may be well suited for assessment of GREs in general.     

Environmental assessment of trace element bioaccumulation in sipunculan from seagrass and wetland sediments

This study is the first measurement of trace elements in sipunculan and their surrounding sediments. The bioaccumulation characteristics of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), and zinc (Zn) were analyzed and compared in two sipunculan species, Sipuncula nudus and Siphonosoma vastum, which were collected from seagrass beds and wetlands in Taiwan. The sipunculan and sediment samples were analyzed using an inductively coupled plasma mass spectrometer. Both sipunculan in the wetlands and seagrass beds had a high Cu bioaccumulation mechanism. Multivariate analysis, principle component analysis, and partial least squares for discriminant analysis of trace element levels and bioaccumulation factors were used to distinguish the element distributions that corresponded to the two habitats (seagrass beds and wetlands). Different levels of certain trace elements in these two sipunculan species may result not only from the environmental factors of various habitats but also from the accumulation characteristics of various species. The As, Cd, Cr, Cu, Hg, and Zn concentrations were markedly lower in sipunculan than in other invertebrates from the adjacent polluted regions. The public health issues regarding the consumption of sipunculan are also discussed.     

河流生态系统指示生物与生物监测:概念、方法及发展趋势

综述了河流生物监测的概念、常用指示生物与监测指标、国外相对完善的技术体系及发展趋势。大型底栖动物、着生藻类、鱼类是河流生物监测中最常使用的指示生物,可以单独使用,也可结合使用,详述了这些类群在河流生态系统中的重要地位及用于生物监测的优点。常用的监测指标包括生物多样性指数、生物指数、多参数指数、多变量指数及功能性指数。许多国家和地区(如英国、美国、欧盟等)都已经将生物监测纳入水环境管理系统,并开发出自己的技术体系。未来的河流生物监测中,功能性指数的应用会越来越多,分子技术的介入也会为提高分类辨识度和检测遗传多样性提供更为有效的途径。最后,思考并总结了国内河流生物监测的现状及趋势。     

A Hierarchical Approach to Designing Compact Ecological Reserve Systems

A number of mathematical models and solution techniques have been developed to design systems of reserve sites to protect species and their natural habitats. This paper presents two optimization models for obtaining ecological reserve systems that are spatially compact. Compact reserve systems will increase species persistence relative to more fragmented systems and can reduce the costs associated with reserve boundaries. These optimization models employ a hierarchical approach that incorporates both the boundary length of all clusters and the sum of within-cluster distances. Unlike previous approaches, we argue that measuring the distance between sites within clusters (and not between clusters) is more appropriate. Numerical experiments are conducted on synthetic grid systems and on a real-world hexagonal data set. These experiments confirm that the models produce reasonably compact clusters of reserve sites that respect species availability and budget constraints. Simplifications to the models are developed that significantly reduce the computational effort, while still identifying reasonable sets of reserve clusters. Sensitivity of the results to changes in model parameters (number of allowable sites, number of possible clusters, and rarity of species covered) is also explored.     

长江流域水生态评价指标初步研究

通过调研20世纪90年代以来国外主流水生态评价项目中采用的生境指标,统计了14个类型生境指标的使用频率,并针对不同的河流类型,筛选出物理形态特征、河岸带状况、生境组成、生境复杂性、人类干扰和水质状况等6个类型的11项评价指标,推荐作为长江流域河流生境评价指标.随后,利用层次分析法对国外水生生物评价指标进行了统计分析,并...