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1.
Riverine wetlands, which provide numerous valuable functions, are disappearing in floodplains of a channelized European river. A restoration project has been proposed by scientists to restore a former braided channel of the Rhône River by the removal of fine organic sediments in order to enhance groundwater supply. A precise and intensive prerestoration monitoring program during one year (including comparison with a reference channel) has taken into account several variables and ecological performance indicators measured at various spatial and temporal scales. Three restoration techniques were then suggested, taking into account two characteristics of ecosystem functions for increasing restoration success and self-sustainability: (1) the riparian forest as well as the shores must be preserved or disturbed as little as possible; and (2) the upstream alluvial plug must be preserved to prevent direct supply of nutrientrich water from the Rhône River. Among the three restoration options proposed, it was not possible to carry out the less ecologically disturbing one as it was considered too expensive, time consuming, and difficult to realize. A precise and intensive postrestoration monitoring program, conducted over two years, demonstrated restoration success but also unpredicted problems, such as a locally thick layer of fine organic sediment. As long as a self-sustainable state is not achieved, this monitoring should be continued. Afterwards, a less precise and less intensive long-term monitoring should enable the detection of future events that may influence ecosystem changes. 相似文献
2.
/ The management of riverine wetlands, recognized as a major component of biodiversity in fluvial hydrosystems, is problematic. Preservation or restoration of such ecosystems requires a method to assess the major ecological processes operating in the wetlands, the sustainability of the aquatic stage, and the restoration potential of each riverine wetland. We propose a method of diagnosis based on aquatic macrophytes and helophytes. Plant communities are used because they are easy to survey and provide information about (1) the origin of a water supply (i.e., groundwater, seepage, or surface river water) and its nutrient content, (2) effects of flood disturbances, and (3) terrestrialization processes. The novelty of the method is that, in contrast to available typologies, it is based on the interference of gradients resulting from several processes, which makes it possible to predict wetland sustainability and restoration potential. These predictions result from knowledge of the processes involved in terrestrialization, i.e., the influence of flood disturbances, occurrence of groundwater supplies, trophic degree, and water permanency of the habitat during a yearly cycle. The method is demonstrated on five different river systems. 相似文献
3.
Critique of present wetlands mitigation policies in the united states based on an analysis of past restoration projects in San Francisco Bay 总被引:1,自引:1,他引:1
Margaret Seluk Race 《Environmental management》1985,9(1):71-81
A detailed evaluation of past wetland restoration projects in San Francisco Bay was undertaken to determine their present status and degree of success. Many of the projects never reached the level of success purported and others have been plagued by serious problems. On the basis of these findings, it is debatable whether any sites in San Francisco Bay can be described as completed, active, or successful restoration projects at present. In spite of these limited accomplishments, wetland creation and restoration have been adopted in the coastal permit process as mitigation to offset environmental damage or loss of habitat. However, because the technology is still largely experimental, there is no guarantee that man-made wetlands will persist as permanent substitutes for sacrificed natural habitats. Existing permit policies should be reanalyzed to insure that they actually succeed in safeguarding diminishing wetlands resources rather than bartering them away for questionable habitat substitutes. Coastal managers must be more specific about project requirements and goals before approval is granted. Continued research on a regional basis is needed to advance marsh establishment techniques into a proven technology. In the meantime, policies encouraging or allowing quid pro quo exchanges of natural wetlands with man-made replacements should proceed with caution. The technology and management policies used at present are many steps ahead of the needed supporting documentation. 相似文献
4.
Ecosystems, though impacted by global environmental change, can also contribute to the adaptation and mitigation of such large
scale changes. Therefore, sustainable ecosystem management is crucial in reaching a sustainable future for the biosphere.
Based on the published literature and publicly accessible data, this paper discussed the status and trends of forest, grassland,
and wetland ecosystems in China that play important roles in the ecological integrity and human welfare of the nation. Ecological
degradation has been observed in these ecosystems at various levels and geographic locations. Biophysical (e.g., climate change)
and socioeconomic factors (e.g., intensive human use) are the main reasons for ecosystem degradation with the latter factors
serving as the dominant driving forces. The three broad categories of ecosystems in China have partially recovered from degradation
thanks to large scale ecological restoration projects implemented in the last few decades. China, as the largest and most
populated developing nation, still faces huge challenges regarding ecosystem management in a changing and globalizing world.
To further improve ecosystem management in China, four recommendations were proposed, including: (1) advance ecosystem management
towards an application-oriented, multidisciplinary science; (2) establish a well-functioning national ecological monitoring
and data sharing mechanism; (3) develop impact and effectiveness assessment approaches for policies, plans, and ecological
restoration projects; and (4) promote legal and institutional innovations to balance the intrinsic needs of ecological and
socioeconomic systems. Any change in China’s ecosystem management approach towards a more sustainable one will benefit the
whole world. Therefore, international collaborations on ecological and environmental issues need to be expanded. 相似文献
5.
Martin W. Doyle F. Douglas Shields 《Journal of the American Water Resources Association》2012,48(3):494-509
Doyle, Martin W. and F. Douglas Shields, 2012. Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy. Journal of the American Water Resources Association (JAWRA) 48(3): 494-509. DOI: 10.1111/j.1752-1688.2011.00631.x Abstract: Current stream restoration science is not adequate to assume high rates of success in recovering ecosystem functional integrity. The physical scale of most stream restoration projects is insufficient because watershed land use controls ambient water quality and hydrology, and land use surrounding many restoration projects at the time of their construction, or in the future, do not provide sufficient conditions for functional integrity recovery. Reach scale channel restoration or modification has limited benefits within the broader landscape context. Physical habitat variables are often the basis for indicating success, but are now increasingly seen as poor surrogates for actual biological function; the assumption “if you build it they will come” lacks support of empirical studies. If stream restoration is to play a continued role in compensatory mitigation under the United States Clean Water Act, then significant policy changes are needed to adapt to the limitations of restoration science and the social environment under which most projects are constructed. When used for compensatory mitigation, stream restoration should be held to effectiveness standards for actual and measurable physical, chemical, or biological functional improvement. To achieve improved mitigation results, greater flexibility may be required for the location and funding of restoration projects, the size of projects, and the restoration process itself. 相似文献
6.
生态保护的基础是生态监测与生态调查,生态保护的关键则是生态系统健康评价,生态系统健康评价因素有组织、结构、活力、恢复力、系统对相邻系统的影响、投入、对人类健康的影响等,其类型有健康、较健康、亚健康、不健康、患病五级;其相应的生态恢复为生态预防、自然恢复、生态修复、生态重建;其相应的生态工程有建立自然保护区、封育、补播与放流、人工林、人工草场、人工湿地等。 相似文献
7.
The coastal landscapes in southwestern Korea include a diverse array of tidal wetlands and salt marshes. These coastal zones
link the ecological functions of marine tidal wetlands and freshwater ecosystems with terrestrial ecosystems. They are rich
in biological diversity and play important roles in sustaining ecological health and processing environmental pollutants.
Korean tidal wetlands are particularly important as nurseries for economically important fishes and habitats for migratory
birds. Diking, draining, tourism, and conversion to agricultural and urban uses have adversely affected Korean tidal wetlands.
Recent large development projects have contributed to further losses. Environmental impact assessments conducted for projects
affecting tidal wetlands and their surrounding landscapes should be customized for application to these special settings.
Adequate environmental impact assessments will include classification of hydrogeomorphic units and consideration of their
responses to biological and environmental stressors. As is true worldwide, Korean laws and regulations are changing to be
more favorable to the conservation and protection of tidal wetlands. More public education needs to be done at the local level
to build support for tidal wetland conservation. Some key public education points include the role of tidal wetlands in maintaining
healthy fish populations and reducing impacts of nonpoint source pollution. There is also a need to develop procedures for
integrating economic and environmental objectives within the overall context of sustainable management and land uses. 相似文献
8.
Mae A. Davenport Christopher A. Bridges Jean C. Mangun Andrew D. Carver Karl W. J. Williard Elizabeth O. Jones 《Environmental management》2010,45(4):711-722
Natural resource professionals are increasingly faced with the challenges of cultivating community-based support for wetland
ecosystem restoration. While extensive research efforts have been directed toward understanding the biophysical dimensions
of wetland conservation, the literature provides less guidance on how to successfully integrate community stakeholders into
restoration planning. Therefore, this study explores the social construction of wetlands locally, and community members’ perceptions
of the wetland restoration project in the Cache River Watershed of southern Illinois, where public and private agencies have
partnered together to implement a large-scale wetlands restoration project. Findings illustrate that the wetlands hold diverse
and significant meanings to community members and that community members’ criteria for project success may vary from those
identified by project managers. The case study provides managers with strategies for building community commitment such as
engaging local citizens in project planning, minimizing local burdens, maximizing local benefits, and reducing uncertainty. 相似文献
9.
Golet GH Roberts MD Larsen EW Luster RA Unger R Werner G White GG 《Environmental management》2006,37(6):862-879
Studies have shown that ecological restoration projects are more likely to gain public support if they simultaneously increase important human services that natural resources provide to people. River restoration projects have the potential to influence many of the societal functions (e.g., flood control, water quality) that rivers provide, yet most projects fail to consider this in a comprehensive manner. Most river restoration projects also fail to take into account opportunities for revitalization of large-scale river processes, focusing instead on opportunities presented at individual parcels. In an effort to avoid these pitfalls while planning restoration of the Sacramento River, we conducted a set of coordinated studies to evaluate societal impacts of alternative restoration actions over a large geographic area. Our studies were designed to identify restoration actions that offer benefits to both society and the ecosystem and to meet the information needs of agency planning teams focusing on the area. We worked with local partners and public stakeholders to design and implement studies that assessed the effects of alternative restoration actions on flooding and erosion patterns, socioeconomics, cultural resources, and public access and recreation. We found that by explicitly and scientifically melding societal and ecosystem perspectives, it was possible to identify restoration actions that simultaneously improve both ecosystem health and the services (e.g., flood protection and recreation) that the Sacramento River and its floodplain provide to people. Further, we found that by directly engaging with local stakeholders to formulate, implement, and interpret the studies, we were able to develop a high level of trust that ultimately translated into widespread support for the project. 相似文献
10.
For the first time, the methane emissions from diverse coastal wetlands of South India have been measured. Annual emission
rates varied widely, ranging from 3.10 mg/m2/hr (Bay of Bengal) to 21.56 mg/m2/hr (Adyar River), based on nature of the perturbance to each of the ecosystems studied. Distinct seasonality in methane emission
was noticed in an unpolluted ecosystem (mangrove: 7.38 mg/m2/hr) and over a twofold increase was evident in the ecosystem that was disturbed by human activities (21.56 mg/m2/hr). The wide ranges in estimate suggest that methanogenesis occurs by both natural and anthropogenic activities in these
coastal wetlands. Several physical and chemical factors such as salinity, sulfate, oxygen, and organic matter content influenced
methanogenesis to a large degree in each of these ecosystems in addition to individual responses to human-induced stress.
For example, there was a clear negative correlation between oxygen availability (0.99), sulfate (0.98), and salinity (0.98)
with CH4 emission in the Adyar river ecosystem. Although similar results were obtained for the other wetland ecosystems, CH4 emission was largely influenced by tidal fluctuations, resulting in a concomitant increase in methanogenesis with high sulfate
concentrations. This study demonstrates that coastal wetlands are potentially significant sources of atmospheric methane and
could be a greater source if anthropogenic perturbations continue at the current rate. RID=" ID=" *Author to whom correspondence
should be addressed. 相似文献
11.
The restoration of degraded systems is essential for maintaining the provision of valuable ecosystem services, including the
maintenance of aesthetic values. However, restoration projects often fail to reach desired goals for a variety of ecologic,
financial, and social reasons. Feasibility studies that evaluate whether a restoration effort should even be attempted can
enhance restoration success by highlighting potential pitfalls and gaps in knowledge before the design phase of a restoration.
Feasibility studies also can bring stakeholders together before a restoration project is designed to discuss potential disagreements.
For these reasons, a feasibility study was conducted to evaluate the efficacy of restoring a tidal freshwater marsh in the
Potomac River near Alexandria, Virginia. The study focused on science rather than engineering questions, and thus differed
in approach from other feasibility studies that are mostly engineering driven. The authors report the framework they used
to conduct a feasibility study to inform other potential restoration projects with similar goals. The seven steps of the framework
encompass (1) initiation of a feasibility study, (2) compilation of existing data, (3) collection of current site information,
(4) examination of case studies, (5) synthesis of information in a handbook, (6) meeting with selected stakeholders, and (7)
evaluation of meeting outcomes. By conducting a feasibility study using the seven-step framework, the authors set the stage
for conducting future compliance studies and enhancing the chance of a successful restoration. 相似文献
12.
John Cairns Jr. 《Environmental management》1990,14(5):517-526
An inadequate basis for precisely predicting the outcome of lotic ecosystem recovery, whether due to unaided natural processes
or management techniques or both, exists because: (1) the field of ecology has not yet matured as a rigorous predictive science;
(2) the precise sequence of events, including climatic occurrences, affecting the recovery process may be unique events and
thus rarely or never repeated; and (3) even when attempts are made to control the recolonization process through introduction
of species, etc., the interaction of these species may not follow deterministic models. Although this symposium focuses on
lotic ecosystems, such systems are influenced strongly by exports from the surrounding land mass and, under certain circumstances,
this may be the overriding influence on the recovery process; therefore, unless the boundary conditions are determined realistically,
the recovery process may not follow desirable pathways. Despite the lack of a robust theoretical support base for lotic ecosystem
recovery, some remarkable and rapid recoveries have occurred to either a close approximation of the original condition or
to a condition ecologically superior to the damaged condition. In some cases, the recovery was due entirely to natural processes
and, in others, often followed relatively straightforward management practices. There is evidence indicating that lotic ecosystem
restoration is both cost effective and likely to produce satisfying results relatively rapidly. It is both fortunate that
this is the case, since society is likely to support such efforts when the results have been extraordinarily successful, and
unfortunate since restoration ecology needs a predictive capability. 相似文献
13.
Judy L. Meyer Michael J. Sale Patrick J. Mulholland N. LeRoy Poff 《Journal of the American Water Resources Association》1999,35(6):1373-1386
ABSTRACT: We review published analyses of the effects of climate change on goods and services provided by freshwater ecosystems in the United States. Climate-induced changes must be assessed in the context of massive anthropogenic changes in water quantity and quality resulting from altered patterns of land use, water withdrawal, and species invasions; these may dwarf or exacerbate climate-induced changes. Water to meet instream needs is competing with other uses of water, and that competition is likely to be increased by climate change. We review recent predictions of the impacts of climate change on aquatic ecosystems in eight regions of North America. Impacts include warmer temperatures that alter lake mixing regimes and availability of fish habitat; changed magnitude and seasonality of runoff regimes that alter nutrient loading and limit habitat availability at low flow; and loss of prairie pothole wetlands that reduces waterfowl populations. Many of the predicted changes in aquatic ecosystems are a consequence of climatic effects on terrestrial ecosystems; shifts in riparian vegetation and hydrology are particularly critical. We review models that could be used to explore potential effects of climate change on freshwater ecosystems; these include models of instream flow, bioenergetics models, nutrient spiraling models, and models relating riverine food webs to hydrologic regime. We discuss potential ecological risks, benefits, and costs of climate change and identify information needs and model improvements that are required to improve our ability to predict and identify climate change impacts and to evaluate management options. 相似文献
14.
The Concept of Habitat Diversity Between and Within Ecosystems Applied to River Side-Arm Restoration 总被引:3,自引:0,他引:3
Amoros C 《Environmental management》2001,28(6):805-817
Since returning an ecosystem to its pristine state may not be realistic in every situation, the concept of habitat diversity is proposed to help decision-makers in defining realistic restoration objectives. In order to maintain habitat diversity and enhance the long-term success of restoration, process-oriented projects should be preferred to species-oriented ones. Because the hydrogeomorphological processes that influence biodiversity operate at different spatiotemporal scales, three scales are considered: river sectors, floodplain waterbodies, and mesohabitats within each waterbody. Based on a bibliographical review, three major driving forces are proposed for incorporation into the design of restoration projects: (1) flow velocity and flood disturbances, (2) hydrological connectivity, and (3) water supply. On the sector scale, increased habitat diversity between waterbodies can be achieved by combining various intensities of these driving forces. On the waterbody scale, increased habitat diversity within the ecosystem can be achieved by varying water depth, velocity, and substrate. The concept is applied to a Rhône River sector (France) where three terrestrialized side arms will be restored. Two were designed to be flood scoured, one having an additional supply of groundwater, the other being connected to the river at both ends. The third cannot be scoured by floods because of upstream construction and would be supplied by river backflow through a downstream connection. Habitat diversity within the ecosystem is exemplified on one side arm through the design of a sinuous pathway combined with variation of water depth, wetted width, and substrate grain size. Self-colonization of the side arms is expected owing to the restoration of connectivity to upstream sources of potential colonizers. 相似文献
15.
Control of Tamarix in the Western United States: Implications for Water Salvage, Wildlife Use, and Riparian Restoration 总被引:1,自引:0,他引:1
Shafroth PB Cleverly JR Dudley TL Taylor JP van Riper C Weeks EP Stuart JN 《Environmental management》2005,35(3):231-246
Non-native shrub species in the genus Tamarix (saltcedar, tamarisk) have colonized hundreds of thousands of hectares of floodplains, reservoir margins, and other wetlands in western North America. Many resource managers seek to reduce saltcedar abundance and control its spread to increase the flow of water in streams that might otherwise be lost to evapotranspiration, to restore native riparian (streamside) vegetation, and to improve wildlife habitat. However, increased water yield might not always occur and has been substantially lower than expected in water salvage experiments, the potential for successful revegetation is variable, and not all wildlife taxa clearly prefer native plant habitats over saltcedar. As a result, there is considerable debate surrounding saltcedar control efforts. We review the literature on saltcedar control, water use, wildlife use, and riparian restoration to provide resource managers, researchers, and policy-makers with a balanced summary of the state of the science. To best ensure that the desired outcomes of removal programs are met, scientists and resource managers should use existing information and methodologies to carefully select and prioritize sites for removal, apply the most appropriate and cost-effective control methods, and then rigorously monitor control efficacy, revegetation success, water yield changes, and wildlife use. 相似文献
16.
Traditionally, wetland management strategies have focused on single familiar objectives, such as improving water quality, strengthening biodiversity, and providing flood control. Despite the relevant amount of studies focused on wetland creation or restoration with these and other objectives, still little is known on how to integrate objectives of wetland creation or restoration at different landscape scales. We have reviewed the literature to this aim, and based on the existing current knowledge, we propose a four step approach to take decisions in wetland creation or restoration planning. First, based on local needs and limitations we should elucidate what the wetland is needed for. Second, the scale at which wetland should be created or restored must be defined. Third, conflicts and compatibilities between creation or restoration objectives must then be carefully studied. Fourth, a creation or restoration strategy must be defined. The strategy can be either creating different unipurpose wetlands or multipurpose wetlands, or combinations of them at different landscape scales. In any case, in unipurpose wetland projects we recommend to pursue additional secondary objectives. Following these guidelines, restored and created wetlands would have more ecological functions, similar to natural wetlands, especially if spatial distribution in the landscape is considered. Restored and created wetlands could then provide an array of integrated environmental services adapted to local ecological and social needs. 相似文献
17.
PROFILE: Risk Assessment as an Environmental Management Tool: Considerations for Freshwater Wetlands
A. Dennis Lemly 《Environmental management》1997,21(3):343-358
/ This paper presents a foundation for improving the risk assessmentprocess for freshwater wetlands. Integrating wetland science, i.e., use of anecosystem-based approach, is the key concept. Each biotic and abiotic wetlandcomponent should be identified and its contribution to ecosystem functionsand societal values determined when deciding whether a stressor poses anunreasonable risk to the sustainability of a particular wetland.Understanding the major external and internal factors that regulate theoperational conditions of wetlands is critical to risk characterization.Determining the linkages between these factors, and how they influence theway stressors affect wetlands, is the basis for an ecosystem approach.Adequate consideration of wetland ecology, hydrology, geomorphology, andsoils can greatly reduce the level of uncertainty associated with riskassessment and lead to more effective risk management. In order to formulateeffective solutions, wetland problems must be considered at watershed,landscape, and ecosystem scales. Application of an ecosystem approach can begreatly facilitated if wetland scientists and risk assessors work together todevelop a common understanding of the principles of both disciplines.KEY WORDS: Ecological risk assessment; Freshwater wetlands;Environmental pollution; Chemical stressors; Physical stressors; Biologicalstressors 相似文献
18.
Increasingly government agencies are seeking to quantify the outcomes of proposed policy options in terms of ecosystem service
benefits, yet conflicting definitions and ad hoc approaches to measuring ecosystem services have created confusion regarding
how to rigorously link ecological change to changes in human well-being. Here, we describe a step-by-step framework for producing
ecological models and metrics that can effectively serve an economic-benefits assessment of a proposed change in policy or
management. A focus of the framework is developing comparable units of ecosystem goods and services to support decision-making,
even if outcomes cannot be monetized. Because the challenges to translating ecological changes to outcomes appropriate for
economic analyses are many, we discuss examples that demonstrate practical methods and approaches to overcoming data limitations.
The numerous difficult decisions that government agencies must make to fairly use and allocate natural resources provides
ample opportunity for interdisciplinary teams of natural and social scientists to improve methods for quantifying changes
in ecosystem services and their effects on human well-being. This framework is offered with the intent of promoting the success
of such teams as they support managers in evaluating the equivalency of ecosystem service offsets and trades, establishing
restoration and preservation priorities, and more generally, in developing environmental policy that effectively balances
multiple perspectives. 相似文献
19.
Basic Principles and Ecological Consequences of Altered Flow Regimes for Aquatic Biodiversity 总被引:42,自引:2,他引:42
The flow regime is regarded by many aquatic ecologists to be the key driver of river and floodplain wetland ecosystems. We
have focused this literature review around four key principles to highlight the important mechanisms that link hydrology and
aquatic biodiversity and to illustrate the consequent impacts of altered flow regimes: Firstly, flow is a major determinant
of physical habitat in streams, which in turn is a major determinant of biotic composition; Secondly, aquatic species have
evolved life history strategies primarily in direct response to the natural flow regimes; Thirdly, maintenance of natural
patterns of longitudinal and lateral connectivity is essential to the viability of populations of many riverine species; Finally,
the invasion and success of exotic and introduced species in rivers is facilitated by the alteration of flow regimes. The
impacts of flow change are manifest across broad taxonomic groups including riverine plants, invertebrates, and fish. Despite
growing recognition of these relationships, ecologists still struggle to predict and quantify biotic responses to altered
flow regimes. One obvious difficulty is the ability to distinguish the direct effects of modified flow regimes from impacts
associated with land-use change that often accompanies water resource development. Currently, evidence about how rivers function
in relation to flow regime and the flows that aquatic organisms need exists largely as a series of untested hypotheses. To
overcome these problems, aquatic science needs to move quickly into a manipulative or experimental phase, preferably with
the aims of restoration and measuring ecosystem response. 相似文献
20.
Project River Recovery: Restoration of Braided Gravel-Bed River Habitat in New Zealand’s High Country 总被引:1,自引:1,他引:0
Caruso BS 《Environmental management》2006,37(6):840-861
Ecological restoration is increasingly becoming a primary component of broader environmental and water resources management
programs throughout the world. The New Zealand Department of Conservation implemented Project River Recovery (PRR) in 1991
to restore unique braided gravel-bed river and wetland habitat in the Upper Waitaki Basin in New Zealand’s high country of
the South Island, which has been severely impacted by hydroelectric power development. These braided rivers are highly dynamic,
diverse, and globally important ecosystems and provide critical habitat to numerous native wading and shore bird species,
including several threatened species such as the black stilt. The objective of this study was to review and summarize PRR
after more than 10 years of implementation to provide information and transfer knowledge to other nations and restoration
programs. Site visits were conducted, discussions were held with key project staff, and project reports and related literature
were reviewed. Primary components of the program include pest plant and animal control, wetland construction and enhancement,
a significant research and monitoring component, and public awareness. The study found that PRR is an excellent example of
an ecological restoration program focusing on conserving and restoring unique habitat for threatened native bird species,
but that also includes several secondary objectives. Transfer of knowledge from PRR could benefit ecological restoration programs
in other parts of the world, particularly riverine floodplain and braided river restoration. PRR could achieve even greater
success with expanded goals, additional resources, and increased integration of science with management, especially broader
consideration of hydrologic and geomorphologic effects and restoration opportunities. 相似文献