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1.
Environmental Effects of Aquifer Overexploitation: A Case Study in the Highlands of Mexico 总被引:7,自引:0,他引:7
There are several environmental processes occurring under aquifer overexploitation conditions. These processes include groundwater
table decline, subsidence, attenuation and drying of springs, decrease of river flow, and increased pollution vulnerability,
among others processes. Some of these effects have been observed on the Upper Basin of the Lerma River. The Lerma River begins
in the SE of the Valley of Toluca at 2,600 m asl, in the wetland known as Lagoons of Almoloya del Río. This wetland is made
up of a group of lagoons, which are an important aquatic system from an environmental point of view. The water inflow of this
wetland is a discharge of springs, which occur between the fractured volcanic material of the mountain range and granular
volcanic–continental deposits of the Valley of Toluca aquifer. The intensive exploitation of the Valley of Toluca aquifer
to supply urban and industrial water to Mexico City and Toluca began in 1950 and is responsible for a steady decline of piezometric
levels of 1–3.5 m/yr. Other effects of this exploitation—the drying of the wetland, the decrease of river flow and the land
subsidence—caused serious ecological and social impacts. The authorities declared this aquifer as overexploited in order to
reduce the exploitation and preserve the availability of water resources in this important region. 相似文献
2.
The US Army Corps of Engineers often requires wetland creation or restoration as compensation for wetlands damaged during
development. These wetlands are typically monitored postconstruction to determine the level of compliance with respect to
site-specific performance standards. However, defining appropriate goals and measuring success of restorations has proven
difficult. We reviewed monitoring information for 76 wetlands constructed between 1992 and 2002 to summarize the performance
criteria used to measure progress, assess compliance with those criteria, and, finally, to evaluate the appropriateness of
those criteria. Goals were overwhelmingly focused on plant communities. Attributes used to assess the quality of restored
plant communities, including percent native species and the Floristic Quality Index, increased over time but were apparently
unrelated to the number of species planted. Compliance frequencies varied depending on site goals; sites often failed to comply
with criteria related to survival of planted vegetation or requirements that dominant plant species should not be exotic or
weedy, whereas criteria related to the establishment of cover by vegetation or by wetland-dependent plants were often met.
Judgment of a site’s success or failure was largely a function of the goals set for the site. Some performance criteria were
too lenient to be of value in distinguishing failed from successful sites, whereas other criteria were unachievable without
more intensive site management. More appropriate goals could be devised for restored wetlands by basing performance standards
on past performance of similar restorations, identifying consistent temporal trends in attributes of restored sites, and using
natural wetlands as references. 相似文献
3.
Life cycle assessment-based environmental product declarations (EPDs) require the inclusion of biodiversity impacts across
the entire supply chain. The objective of this study is to test the applicability of a Scandinavian biodiversity assessment
tool, developed specifically for use with EPD applications, in an African desert environment, linking the industry types power
generation and mining. For this purpose, a GIS-based spatial analysis tool—the biotope method—was adapted to a framework approach
which allowed the selection of more suitable, site-specific biodiversity indicators. The biotope method provides a step-by-step
process of defining system boundaries, mapping biotopes, categorizing biotopes based on site-specific indicators, and evaluating
change in biotope status “before” and “after” the impact. The development of site-specific indicators was piloted in this
study and determined by the affected ecosystem and the status of knowledge on biodiversity in this geographic area. Thus plants
were used as indicators for biodiversity, and red-list status and endemism constituted the prime criteria for conservation
value of plants. This in turn represented the key criterion for classifying biotopes. The tested biodiversity assessment tool
has potential for application in different environments and operational settings but leaves room for improvement by including
secondary impacts in the assessment and using a wider range of taxa for indicators of biodiversity. 相似文献
4.
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
5.
Section 404 wetland mitigation and permit success criteria in Pennsylvania,USA, 1986-1999 总被引:2,自引:1,他引:1
Twenty-three Section 404 permits in central Pennsylvania (covering a wetland age range of 1–14 years) were examined to determine
the type of mitigation wetland permitted, how the sites were built, and what success criteria were used for evaluation. Most
permits allowed for mitigation out-of-kind, either vegetatively or through hydrogeomorphic class. The mitigation process has
resulted in a shift from impacted wetlands dominated by woody species to less vegetated mitigation wetlands, a trend that
appears to be occurring nationwide. An estimate of the percent cover of emergent vegetation was the only success criterion
specified in the majority of permits. About 60% of the mitigation wetlands were judged as meeting their originally defined
success criteria, some after more than 10 years. The permit process appears to have resulted in a net gain of almost 0.05
ha of wetlands per mitigation project. However, due to the replacement of emergent, scrub–shrub, and forested wetlands with
open water ponds or uplands, mitigation practices probably led to a net loss of vegetated wetlands. 相似文献
6.
Carbon Storage in Soil Size Fractions Under Two Cacao Agroforestry Systems in Bahia, Brazil 总被引:1,自引:0,他引:1
Emanuela F. Gama-Rodrigues P. K. Ramachandran Nair Vimala D. Nair Antonio C. Gama-Rodrigues Virupax C. Baligar Regina C. R. Machado 《Environmental management》2010,45(2):274-283
Shaded perennial agroforestry systems contain relatively high quantities of soil carbon (C) resulting from continuous deposition
of plant residues; however, the extent to which the C is sequestered in soil will depend on the extent of physical protection
of soil organic C (SOC). The main objective of this study was to characterize SOC storage in relation to soil fraction-size
classes in cacao (Theobroma cacao L.) agroforestry systems (AFSs). Two shaded cacao systems and an adjacent natural forest in reddish-yellow Oxisols in Bahia,
Brazil were selected. Soil samples were collected from four depth classes to 1 m depth and separated by wet-sieving into three
fraction-size classes (>250 μm, 250–53 μm, and <53 μm)—corresponding to macroaggregate, microaggregate, and silt-and-clay
size fractions—and analyzed for C content. The total SOC stock did not vary among systems (mean: 302 Mg/ha). On average, 72%
of SOC was in macroaggregate-size, 20% in microaggregate-size, and 8% in silt-and-clay size fractions in soil. Sonication
of aggregates showed that occlusion of C in soil aggregates could be a major mechanism of C protection in these soils. Considering
the low level of soil disturbances in cacao AFSs, the C contained in the macroaggregate fraction might become stabilized in
the soil. The study shows the role of cacao AFSs in mitigating greenhouse gas (GHG) emission through accumulation and retention
of high amounts of organic C in the soils and suggests the potential benefit of this environmental service to the nearly 6
million cacao farmers worldwide. 相似文献
7.
Rapid Assessment of Urban Wetlands: Do Hydrogeomorphic Classification and Reference Criteria Work? 总被引:1,自引:0,他引:1
The Hydrogeomorphic (HGM) functional assessment method is predicated on the ability of hydrogeomorphic wetland classification
and visual assessment of alteration to provide reference standards against which functions in individual wetlands can be evaluated.
The effectiveness of this approach was tested by measuring nitrogen cycling functions in forested wetlands in an urbanized
region in New Jersey, USA. Fourteen sites represented three HGM classes and were characterized as “least disturbed reference”
or “non-reference” based on initial visual assessment. Water table levels and in situ rates of net nitrogen mineralization,
net nitrification, and denitrification were measured over one year in each site. Hydrological alterations, resulting in consistently
low or flashy water table levels, were not correlated with a priori designations as reference and non-reference. Although
the flat-riverine wetland class had lower net nitrification and higher denitrification rates than riverine or mineral flat
wetland classes, this difference was attributable to the lack of hydrologically-altered wetlands in the flat-riverine class,
and thus more consistently wet conditions. Within all HGM classes, a classification based on the long-term hydrological record
that separated sites with “normal,” saturated hydrology from those with “altered,” drier hydrology, clearly distinguished
sites with different nitrogen cycling function. Based on these findings, current practices for designating reference standard
sites to judge wetland functions, at least in urbanized regions, are ineffective and potentially misleading. At least one
year of hydrological monitoring data is suggested to classify wetlands into groups that have different nutrient cycling functions,
particularly in urban landscapes. 相似文献
8.
Recent wetland area trends were estimated from the National Resources Inventory (NRI) for nonfederal rural lands for the period
1982–1987. NRI-based estimates of wetland area for states comprising the conterminous United States were highly correlated
with estimates made by the US Fish and Wildlife Service and with estimates of coastal salt marsh wetlands made by the National
Oceanic and Atmospheric Administration. Net wetland area declined by 1.1% (≈363,200 ha) during the five-year study period.
Conversion to open water, primarily caused by natural flooding in western inland basins, was responsible for altering extensive
wetland areas (≈171,400 ha). Of the human-induced wetland conversions, urban and built-up land was responsible for 48% of
the wetland loss, while agricultural development was indicated in 37% of the converted wetland area. A decrease in rural land,
and increases in both population, and urban and built-up land were associated with wetland loss among states. Potential reasons
for wetland loss were different in 20 coastal states than in 28 inland states. Proportionately, wetland loss due to development
was three times greater in coastal states than inland states, while agriculturally induced wetland losses were similar in
both groups. The proportionate declines of forested vs nonforested wetlands were not significantly different among states. 相似文献
9.
Hydrological classification constitutes the first step of a new holistic framework for developing regional environmental flow
criteria: the “Ecological Limits of Hydrologic Alteration (ELOHA)”. The aim of this study was to develop a classification
for 390 stream sections of the Segura River Basin based on 73 hydrological indices that characterize their natural flow regimes.
The hydrological indices were calculated with 25 years of natural monthly flows (1980/81–2005/06) derived from a rainfall-runoff
model developed by the Spanish Ministry of Environment and Public Works. These indices included, at a monthly or annual basis,
measures of duration of droughts and central tendency and dispersion of flow magnitude (average, low and high flow conditions).
Principal Component Analysis (PCA) indicated high redundancy among most hydrological indices, as well as two gradients: flow
magnitude for mainstream rivers and temporal variability for tributary streams. A classification with eight flow-regime classes
was chosen as the most easily interpretable in the Segura River Basin, which was supported by ANOSIM analyses. These classes
can be simplified in 4 broader groups, with different seasonal discharge pattern: large rivers, perennial stable streams,
perennial seasonal streams and intermittent and ephemeral streams. They showed a high degree of spatial cohesion, following a gradient associated with climatic aridity from NW to SE, and were
well defined in terms of the fundamental variables in Mediterranean streams: magnitude and temporal variability of flows.
Therefore, this classification is a fundamental tool to support water management and planning in the Segura River Basin. Future
research will allow us to study the flow alteration-ecological response relationship for each river type, and set the basis
to design scientifically credible environmental flows following the ELOHA framework. 相似文献
10.
Addressing the need for reference sites that permit wetland managers to evaluate the relative success of wetland restoration
efforts, this project examines the early successional properties of a chronosequence of 17 forested wetlands that have been
clear-cut and allowed to naturally revegetate. Ordinations performed on the data using CANOCO software indicated three general
types of communities—one dominated by bald cypress (Taxodium distichum) and water tupelo (Nyssa aquatica), one dominated by black willow (Salix nigra), and one with a species composition similar to that of a mature stand of bottomland hardwoods. These divisions were correlated
with the percentage of stems originating as coppice on stumps leftover from the clear-cut. In particular, the bottomland hardwood
stands were regenerating predominantly as coppice, while the cypress/tupelo and black willow stands were regenerating primarily
as seedlings. As indicated by the earlier development of overstory basal area, coppice sites were also regenerating much faster.
The hydrology of a site also exhibited a strong impact on the rate of regeneration, with the semipermanently to permanently
flooded portions of sites often exhibiting little or no regeneration. The results indicate that, because of the overwhelming
reliance on coppice sprouts as the main source of stems and the concomitant enhanced rates of regeneration, certain vegetative
parameters of clear-cut bottomland hardwood stands would not be effective benchmarks by which to judge the relative success
of creation and restoration efforts. 相似文献
11.
Community Structure and Quality After 10 Years in Two Central Ohio Mitigation Bank Wetlands 总被引:1,自引:1,他引:0
We evaluate two 10-year-old mitigation bank wetlands in central Ohio, one created and one with restored and enhanced components,
by analysis of vegetation characteristics and by comparison of the year-10 vegetation and macroinvertebrate communities with
reference wetlands. To assess different measures of wetland development, we compare the prevalence of native hydrophytes with
an index of floristic quality and we evaluate the predictability of these parameters in year 10, given 5 years of data. Results
show that the mitigation wetlands in this study meet vegetation performance criteria of native hydrophyte establishment by
year 5 and maintain these characteristics through year 10. Species richness and floristic quality, as well as vegetative similarity
with reference wetlands, differ among mitigation wetlands in year 1 and also in their rate of change during the first 10 years.
The prevalence of native hydrophytes is reasonably predictable by year 10, but 5 years of monitoring is not sufficient to
predict future trends of floristic quality in either the created or restored wetland. By year 10, macroinvertebrate taxa richness
does not statistically differ among these wetlands, but mitigation wetlands differ from reference sites by tolerance index
and by trophic guild dominance. The created wetland herbivore biomass is significantly smaller than its reference, whereas
detritivore biomass is significantly greater in the created wetland and smaller in the restored wetland as compared with respective
reference wetlands. These analyses illustrate differences in measures of wetland performance and contrast the monitoring duration
necessary for legal compliance with the duration required for development of more complex indicators of ecosystem integrity. 相似文献
12.
P. H. Anderson M. W. Lefor W. C. Kennard 《Journal of the American Water Resources Association》1980,16(2):248-255
ABSTRACT: The delineation of inland wetlands requires close field examination of the biological and physical gradients (transition zones) between wetlands and bordering uplands. As part of a study on the detection and delineation of inland wetlands in eastern Connecticut by remote sensing techniques, this effort was designed to investigate vegetation distribution and composition and selected physical and chemical properties of the soils of wetland to upland transition zones in deciduous wetland forests. Field research was conducted during the growing season of 1975 within a test area consisting of the 45 mi2 Town of Mansfield, Connecticut. Changes in vegetation composition and structure, soil pH, and soil water content were determined along line transects extended over wetland to upland transition zones. Differences in soil pH occurred along the transects but were of such magnitude that they probably have little impact on plant distribution. There were significant changes in soil water content along the wetland to upland gradients. Discriminant analysis applied to statistical “index of abundance” data describing vegetation distribution among the various zones (wetland, transition, upland) showed which plant species best distinguish wetlands from uplands. Of the criteria studied, vegetation composition and distribution, soil water content, and relief are the most useful criteria for delineating deciduous wetland forests. 相似文献
13.
Francisco Seijo Maria Marcela Godoy Dante Guglielmin Cecilia Ciampoli Samuel Ebright Omar Picco Guillermo Defoss 《Environmental management》2020,65(4):448-462
The creation of protected conservation areas may result in protracted conflicts between stakeholders. In this study we examine the drivers of anthropogenic wildfire ignitions in the National Park of “los Alerces” (NPA) in Patagonia, Argentina. The NPA was established in 1937 to protect the native “andino-patagónico” forests from wildfires as well as preserving its scenic beauty and native flora and fauna. At the time of its creation state authorities prohibited all extractive human activities in the “intangible”—fully protected—“National Park” section, while other regulated extractive and ecotourism activities were allowed to continue in the “Natural Reserve” section in an effort to accommodate the historical entitlements of the displaced populations of “pobladores” (settlers) that had been living in the NPA for over a century. Here we interviewed the main stakeholder groups—“pobladores”, forest rangers and administrators, ecolodge owners and angler club members—to identify the drivers of wildfire ignitions in the park. Wildfires have been singled out by state authorities as the main threat to the NPA though considerable scientific uncertainty exists regarding their complex ecological effects. This study argues, based on the human and biophysical system data collected, that two conflicting cultural frames exist within the NPA that provide the necessary backdrop for understanding the drivers of wildfire ignitions. In turn, these findings raise puzzling dilemmas for the main theoretical approaches that have been used to inform and design conflict management strategies in protected conservation areas. 相似文献
14.
Sanjiang National Nature Reserve (NNR) is a state-owned natural wetland in China that has suffered severe degradation due
to cultivation and wetland reclamation by farmers. As a consequence, the conversion of cultivated land to wetlands (CCW) was
proposed by the government of Heilongjiang province and the United Nations Development Programme/Global Environment Facility
(UNDP/GEF) project team in 2007. We suggest that voluntary participation in the CCW could be an important tool for accomplishing
the integrated objectives of wetland conservation and local development. The purpose of this study was to examine the main
factors that influence farmers’ willingness to participate in the CCW through a field investigation and a questionnaire. Based
on the data from our questionnaire, which provided an effective sample of 310 households in 11 villages, the influencing factors
of farmers’ willingness to participate were analyzed through binary logistic regression analyses. It was concluded that age,
education, the amount of cultivated land, geographical location, and the perceived benefits and risks were important factors
for participation. Furthermore, suggestions for improving the wetland compensation system and providing alternative livelihoods
are proposed to strengthen participation. 相似文献
15.
Pasqualini V Oberti P Vigetta S Riffard O Panaïotis C Cannac M Ferrat L 《Environmental management》2011,48(1):38-56
Forest management can benefit from decision support tools, including GIS-based multicriteria decision-aiding approach. In
the Mediterranean region, Pinus pinaster forests play a very important role in biodiversity conservation and offer many socioeconomic benefits. However, the conservation
of this species is affected by the increase in forest fires and the expansion of Matsucoccus feytaudi. This paper proposes a methodology based on commonly available data for assessing the values and risks of P. pinaster forests and to generating maps to aid in decisions pertaining to fire and phytosanitary risk management. The criteria for
assessing the values (land cover type, legislative tools for biodiversity conservation, environmental tourist sites and access
routes, and timber yield) and the risks (fire and phytosanitation) of P. pinaster forests were obtained directly or by considering specific indicators, and they were subsequently aggregated by means of GIS-based
multicriteria analysis. This approach was tested on the island of Corsica (France), and maps to aid in decisions pertaining
to fire risk and phytosanitary risk (M. feytaudi) were obtained for P. pinaster forest management. Study results are used by the technical offices of the local administration—Corsican Agricultural and Rural Development Agency (ODARC)—for planning the conservation of P. pinaster forests with regard to fire prevention and safety and phytosanitary risks. The decision maker took part in the evaluation
criteria study (weight, normalization, and classification of the values). Most suitable locations are given to target the
public intervention. The methodology presented in this paper could be applied to other species and in other Mediterranean
regions. 相似文献
16.
Ellen-Marie Forsberg 《Journal of Agricultural and Environmental Ethics》2011,24(4):351-366
Over the last years, Norway has revised its animal welfare legislation. As of January 1, 2010, the Animal Protection Act of
1974 was replaced by a new Animal Welfare Act. This paper describes the developments in the normative structures from the
old to the new act, as well as the main traits of the corresponding implementation and governance system. In the Animal Protection
Act, the basic animal ethics principles were to avoid suffering, treat animals well, and consider their natural needs and
instincts. In addition, a principle for balancing our duties towards animals with the needs and interests of humans was expressed
by the formulation “unnecessary suffering.” These principles (only with slightly different formulations) are retained in the new act. The novelty of the
new act is shown by its explicit intention to promote respect for animals and its recognition of animals’ intrinsic value.
Whereas intrinsic value is only given a symbolic function, the notion of respect is intended to have practical consequences.
One interpretation of respect for animals is taking the animal’s integrity—and not only welfare—into account. Another is to
see the introduction of respect as a call to animal keepers to provide animals with welfare exceeding the minimum requirements.
In several respects, the legal system now seems to leave more responsibility to the individual animal keeper—and to citizens
in general. I argue that if the authorities really do want to promote respect for animals, they must at the same time initiate
activities to achieve this. In my perspective the challenge is to provide adequate measures to achieve in practice the intended
respect for animals expressed in the new act. 相似文献
17.
This article critically reviews the evolution of urban environmental management in Shanghai since 1978. Established in a transitional
postsocialist economy and shaped by a spectacular urban redevelopment process, the current environmental management framework
of Shanghai has succeeded in mitigating major industrial pollution and improving urban amenities with unprecedented pace and
magnitude. However, it generally failed to take social equity and environmental justice issues into consideration. Based on
Haughton’s models of sustainable urban development, this article proposes four priorities and five principles within the framework
of a fair shares cities model for the future environmental management of Shanghai and briefly discusses their policy implications
and implementation issues. The authors argue that Haughton’s approach is relevant to Shanghai’s case because the essence of
his argument—the multidimensional equity principles—is the core of the concept of sustainable development. 相似文献
18.
The importance of riparian vegetation to support stream function and provide riparian bird habitat in semiarid landscapes
suggests that standardized assessment tools that include vegetation criteria to evaluate stream health could also be used
to assess habitat conditions for riparian-dependent birds. We first evaluated the ability of two visual assessments of woody
vegetation in the riparian zone (corridor width and height) to describe variation in the obligate riparian bird ensemble along
19 streams in eastern Oregon. Overall species richness and the abundances of three species all correlated significantly with
both, but width was more important than height. We then examined the utility of the riparian zone criteria in three standardized
and commonly used rapid visual riparian assessment protocols—the USDI BLM Proper Functioning Condition (PFC) assessment, the
USDA NRCS Stream Visual Assessment Protocol (SVAP), and the U.S. EPA Habitat Assessment Field Data Sheet (HAFDS)—to assess
potential riparian bird habitat. Based on the degree of correlation of bird species richness with assessment ratings, we found
that PFC does not assess obligate riparian bird habitat condition, SVAP provides a coarse estimate, and HAFDS provides the
best assessment. We recommend quantitative measures of woody vegetation for all assessments and that all protocols incorporate
woody vegetation height. Given that rapid assessments may be the only source of information for thousands of kilometers of
streams in the western United States, incorporating simple vegetation measurements is a critical step in evaluating the status
of riparian bird habitat and provides a tool for tracking changes in vegetation condition resulting from management decisions. 相似文献
19.
Shrimp exports are one of Sri Lanka's major foreign exchange earners and account for 40%–50% of total aquaculture exports.
There has been a recent and rapid expansion of the industry in the Northwestern Province (NWP) of Sri Lanka but the industry
has suffered from disease outbreaks and environmental problems. Currently, shrimp farms cover nearly 3000 ha of the coastal
area of the NWP.
The environmental impacts of shrimp cultivation in general are well known and numerous research studies have been done. However,
little work has been carried out in Sri Lanka. This study provides some necessary background to brackish water shrimp aquaculture
in Sri Lanka. It focuses briefly on the development of shrimp aquaculture and the current status of the industry. Emphasis
is placed on two broader aspects—impacts on the existing wetland ecosystem and on the environment. These impacts are presumed
to be the main causes hindering the growth of the industry and raising widespread public protest. Current ecosystem and environmental
management practices are discussed. Finally, strategic issues for management and sustainable growth are discussed. 相似文献
20.
Chemical Characteristics of Urban Stormwater Sediments and Implications for Environmental Management, Maricopa County, Arizona 总被引:2,自引:0,他引:2
On the basis of published guidelines, urban stormwater sediments do not appear to constitute a major regional environmental
problem with respect to the chemical characteristics investigated here. At individual sites, high concentrations of organic
compounds—chlordane, dieldrin, PCBs, and toxaphene—may require some attention. The possible environmental hazard presented
by low-level organochlorine contamination is not addressed in this paper; however, high levels of toxicity in urban sediments
are difficult to explain. Sediment toxicity varied significantly with time, which indicates that these tests should be evaluated
carefully before they are used for management decisions. 相似文献