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1.
An Empirical Evaluation of Private Landowner Participation in Voluntary Forest Conservation Programs
The use of voluntary programs targeting resource conservation on private land has become increasingly prevalent in environmental
policy. Voluntary programs potentially offer significant benefits over regulatory and market-based approaches. This article
examines the factors affecting landowner participation in voluntary forest conservation programs using a combination of parcel-level
GIS and remotely sensed data and semi-structured interviews of landowners in Monroe County, Indiana. A logistic regression
model is applied to determine the probability of participation based on landowner education, membership in other non-forest
voluntary programs, dominant land use activity, parcel size, distance from urban center, land resource portfolios, and forest
cover. Both land use activity and the spatial configuration of a landholder’s resource portfolio are found to be statistically
significant with important implications for the design and implementation of voluntary programs.
相似文献
Derek KauneckisEmail: |
2.
Mannino I Franco D Piccioni E Favero L Mattiuzzo E Zanetto G 《Environmental management》2008,41(1):118-129
A cost-effectiveness analysis was performed to evaluate the competitiveness of seminatural Free Water Surface (FWS) wetlands
compared to traditional wastewater-treatment plants. Six scenarios of the service costs of three FWS wetlands and three different
wastewater-treatment plants based on active sludge processes were compared. The six scenarios were all equally effective in
their wastewater-treatment capacity. The service costs were estimated using real accounting data from an experimental wetland
and by means of a market survey. Some assumptions had to be made to perform the analysis. A reference wastewater situation
was established to solve the problem of the different levels of dilution that characterize the inflow water of the different
systems; the land purchase cost was excluded from the analysis, considering the use of public land as shared social services,
and an equal life span for both seminatural and traditional wastewater-treatment plants was set. The results suggest that
seminatural systems are competitive with traditional biotechnological systems, with an average service cost improvement of
2.1-fold to 8-fold, according to the specific solution and discount rate. The main improvement factor was the lower maintenance
cost of the seminatural systems, due to the self-regulating, low artificial energy inputs and the absence of waste to be disposed.
In this work, only the waste-treatment capacity of wetlands was considered as a parameter for the economic competitiveness
analysis. Other goods/services and environmental benefits provided by FWS wetlands were not considered.
相似文献
Daniel FrancoEmail: |
3.
Agricultural expansion and deforestation are spatial processes of land transformation that impact on landscape pattern. In
peninsular Malaysia, the conversion of forested areas into two major cash crops—rubber and oil palm plantations—has been identified
as driving significant environmental change. To date, there has been insufficient literature studying the link between changes
in landscape patterns and land-related development policies. Therefore, this paper examines: (i) the links between development
policies and changes in land use/land cover and landscape pattern and (ii) the significance and implications of these links
for future development policies. The objective is to generate insights on the changing process of land use/land cover and
landscape pattern as a functional response to development policies and their consequences for environmental conditions. Over
the last century, the development of cash crops has changed the country from one dominated by natural landscapes to one dominated
by agricultural landscapes. But the last decade of the century saw urbanization beginning to impact significantly. This process
aligned with the establishment of various development policies, from land development for agriculture between the mid 1950s
and the 1970s to an emphasis on manufacturing from the 1980s onward. Based on a case study in Selangor, peninsular Malaysia,
a model of landscape pattern change is presented. It contains three stages according to the relative importance of rubber
(first stage: 1900–1950s), oil palm (second stage: 1960s–1970s), and urban (third stage: 1980s–1990s) development that influenced
landscape fragmentation and heterogeneity. The environmental consequences of this change have been depicted through loss of
biodiversity, geohazard incidences, and the spread of vector-borne diseases. The spatial ecological information can be useful
to development policy formulation, allowing diagnosis of the country’s “health” and sustainability. The final section outlines
the usefulness of landscape analysis in the policy-making process to prevent further fragmentation of the landscape and forest
loss in Malaysia in the face of rapid economic development.
相似文献
Adnan A. HezriEmail: |
4.
The effects of social desirability on self-reported environmental attitudes and ecological behaviour
Taciano L. Milfont 《The Environmentalist》2009,29(3):263-269
There are several claims in the literature that social desirability concerns affect people’s response to self-reported measures
of environmental attitudes and ecological behaviour. However, only a few empirical studies have indirectly evaluated the impact of social desirability on environmental issues measures, and those who did have found only a low impact.
This article describes two studies that explicitly address whether socially desirable responding has direct and moderating effects on self-reported environmental attitudes
and ecological behaviour. Results from correlational and moderated multiple regression analyses from both studies showed that
social desirability had only a weak direct effect on environmental attitudes (but not ecological behaviour), and had no moderating
effect on the environmental attitudes–ecological behaviour relationship. Implications of these findings for research on environmental
issues are discussed.
相似文献
Taciano L. MilfontEmail: |
5.
As in other mountain regions of Asia, agricultural lands in the Chittagong Hill Tracts (CHT) of Bangladesh are undergoing
degradation due primarily to environmentally incompatible land-use systems such as shifting cultivation (jhum) and annual cash crops. The suitable land-use systems such as agroforestry and timber tree plantation provide benefit to
the society at large, but they might not provide attractive economic benefits to farmers, eventually constraining a wide-scale
adoption of such land-use systems. Therefore, it is essential to evaluate agricultural land-use systems from both societal
and private perspectives in the pursuit of promoting particularly environmentally sustainable systems. This article evaluated
five major land-use systems being practiced in CHT, namely jhum, annual cash crops, horticulture, agroforestry, and timber plantation. The results of the financial analysis revealed the
annual cash crops as the most attractive land use and jhum as the least attractive of the five land-use systems considered under the study. Horticulture, timber plantation, and agroforestry,
considered to be suitable land-use systems particularly for mountainous areas, held the middle ground between these two systems.
Annual cash crops provided the highest financial return at the cost of a very high rate of soil erosion. When the societal
cost of soil erosion is considered, annual cash crops appear to be the most costly land-use system, followed by jhum and horticulture. Although financially less attractive compared to annual cash crops and horticulture, agroforestry and timber
plantation are the socially most beneficial land-use systems. Findings of the alternative policy analyses indicate that there
is a good prospect for making environmentally sustainable land-use systems, such as agroforestry and timber plantation, attractive
for the farmers by eliminating existing legal and institutional barriers, combined with the provision of necessary support
services and facilities.
相似文献
Golam RasulEmail: |
6.
Douglas J. Norton James D. Wickham Timothy G. Wade Kelly Kunert John V. Thomas Paul Zeph 《Environmental management》2009,44(2):356-368
Common decision support tools and a growing body of knowledge about ecological recovery can help inform and guide large state
and federal restoration programs affecting thousands of impaired waters. Under the federal Clean Water Act (CWA), waters not
meeting state Water Quality Standards due to impairment by pollutants are placed on the CWA Section 303(d) list, scheduled
for Total Maximum Daily Load (TMDL) development, and ultimately restored. Tens of thousands of 303(d)-listed waters, many
with completed TMDLs, represent a restoration workload of many years. State TMDL scheduling and implementation decisions influence
the choice of waters and the sequence of restoration. Strategies that compare these waters’ recovery potential could optimize
the gain of ecological resources by restoring promising sites earlier. We explored ways for states to use recovery potential
in restoration priority setting with landscape analysis methods, geographic data, and impaired waters monitoring data. From
the literature and practice we identified measurable, recovery-relevant ecological, stressor, and social context metrics and
developed a restorability screening approach adaptable to widely different environments and program goals. In this paper we
describe the indicators, the methodology, and three statewide, recovery-based targeting and prioritization projects. We also
call for refining the scientific basis for estimating recovery potential.
相似文献
Paul ZephEmail: |
7.
Marco Beccali Maurizio Cellura Maria Iudicello Marina Mistretta 《Environmental management》2009,43(4):707-724
Food production and consumption cause significant environmental burdens during the product life cycles. As a result of intensive
development and the changing social attitudes and behaviors in the last century, the agrofood sector is the highest resource
consumer after housing in the EU. This paper is part of an effort to estimate environmental impacts associated with life cycles
of the agrofood chain, such as primary energy consumption, water exploitation, and global warming. Life cycle assessment is
used to investigate the production of the following citrus-based products in Italy: essential oil, natural juice, and concentrated
juice from oranges and lemons. The related process flowcharts, the relevant mass and energy flows, and the key environmental
issues are identified for each product. This paper represents one of the first studies on the environmental impacts from cradle
to gate for citrus products in order to suggest feasible strategies and actions to improve their environmental performance.
相似文献
Marina Mistretta (Corresponding author)Email: |
8.
Willingness to Pay for Improving the Residential Waste Disposal System in Korea: A Choice Experiment Study 总被引:1,自引:0,他引:1
This study attempts to apply choice experiments with regard to the residential waste disposal system (RWDS) in Korea by considering
various attributes that are related to RWDS. Using data from a survey conducted on 492 households, the empirical analysis
yields estimates of the willingness to pay for a clean food-waste collection facility, the collection of small items (such
as obsolete mobile phones and add-ons for personal computers), and a more convenient large waste disposal system. The estimation
results of multinomial logit models are quite similar to those of nested logit models. The results reveal that residents have
preferences for the cleanliness of facilities and the collection of small items. In Korea, residents are required to purchase
and attach stickers for the disposal of large items; they want to be able to obtain stickers at not only village offices but
also supermarkets. On the other hand, the frequency of waste collection is not a significant factor in the choice of the improved
waste management program.
相似文献
Seung-Hoon YooEmail: |
9.
In the United States, the common interest often is conceived as a by-product of the pluralist, interest-group-driven democratic
process. Special interests dominate in many political arenas. Consequently, we have lost the language, vocabulary, and ability
to talk about the common interest. The way to reverse this trend is to develop and practice with new tools that allow us to
articulate what we mean by the common interest in specific contexts. In this article, we leveraged the literature on procedural,
substantive, and pragmatic decision making to illustrate how they work together to demonstrate whether and how the common
interest was served in three case studies of Healthy Forests Restoration Act implementation on the Apache-Sitgreaves National
Forest in Arizona. In two of the cases we found that the common interest was mostly served, while in the third case it was
not. Our results raise questions about the ability of procedural criteria or substantive criteria alone to determine effectiveness
in decision making. When evaluated together they provide a more complete understanding of how the common interest is or is
not served.
相似文献
Toddi A. SteelmanEmail: |
10.
Sustainability assessment (SA) is a holistic and long-range strategic instrument capable of assisting policy-making in electing,
and deciding upon, future development priorities. The outcomes of an SA process become more relevant and strengthened when
conducted with multi-stakeholder engagement, which provides for multiple dialogues and perspectives. This was the object of
research of the SA team in the context of BioScene (Scenarios for Reconciling Biodiversity Conservation with Declining Agriculture Use in Mountain Areas in Europe), a three-year project (2002–2005) funded by the European Union 5th Framework Program, which aimed to investigate the implications
of agricultural restructuring and decline for biodiversity conservation in the mountain areas of Europe, using three distinct
methodological streams: the ecological, the socio-economic, and the SA approaches. The SA approach drew on the previous two
to assess the importance for biodiversity management of different scenarios of agri-environmental change and rural policy
in six countries (France, Greece, Norway, Slovakia, Switzerland, and the United Kingdom), develop causal chains, include stakeholder
views, and identify potential contributions for, or conflicts with, sustainability. This article tells how SA was used, what
sustainability meant in each study area through different objectives of sustainability considered, discusses the methods used
in SA, and the benefits arising. The SA was conducted by a team independent of any study area, who developed and oversaw the
application of the SA methodology, assisting national teams, and developing a cross-country understanding of the sustainability
of proposed scenarios in the different geographical and social contexts, and their implications for policy-making. Finally,
it reflects on the persistent challenges of interdisciplinary research, compounded by multi-cultural teams, and concludes
on the BioScene’s lessons for the further development and application of SA.
相似文献
William R. SheateEmail: |
11.
Andrew McKinley 《The Environmentalist》2008,28(3):319-326
In this short essay it is argued that recent criticisms portraying the activist environmental movement as overly pessimistic
are valid and that the communication of this pessimism to the public at large has been largely counterproductive to the objectives
of environmentalists. It is argued that, in contrast to historic assumptions of a ‘progress paradigm’ that epitomized the
widely held optimism of the past, the shock tactics and pessimistic media campaigns employed by the activist environmental
movement, and the media that capitalizes upon those campaigns, have contributed to the creation of a figurative hopeless age. The key characterization of the hopeless age is the widely held assumption that the future will be worse than the present
and that the lives of future generations will be diminished relative to our own. It is argued that the creation of this social-psychological
phenomenon is counterproductive to the aims of the environmental movement and that the restoration of a collective vision
and message of hope would be far more productive. Lastly, some reasons for a hopeful outlook are suggested.
相似文献
Andrew McKinleyEmail: Email: |
12.
Cross-Boundary Coordination on Forested Landscapes: Investigating Alternatives for Implementation 总被引:2,自引:0,他引:2
Cross-boundary coordination is a tool for ecosystem management whereby landowners voluntarily coordinate management practices
toward economic and/or ecological landscape-scale outcomes (e.g., fiber, invasive species control, habitat). Past research
indicates that it may be particularly applicable on landscapes that include small forest landholdings. To explore alternatives
by which coordination might occur, we conducted seven focus groups with landowners (n = 51) who actively manage their forests in southwest Wisconsin and northeast Iowa. Focus group participants were presented
with three hypothetical alternatives to coordinate with their neighbors; landowners could self-organize, work with a natural
resource professional (i.e., forester), or work with an organization to complete a cross-boundary practice. In this article,
we focus on the latter two alternatives and the role of two social theories—principal-agent and cooperation—in explaining
landowners’ evaluations of these alternatives. Key findings are that (1) cross-boundary coordination has the potential to
alleviate problems between landowners and resource professionals inherent to their typical working relationship, and (2) social
relationships are a major factor contributing to landowners’ willingness to participate. We posit that cross-boundary coordination
offers a non-economic incentive for landowners to work together as it may reduce the uncertainty associated with hiring a
resource professional. At the same time, professionals can provide a bridging function among landowners who are unacquainted.
To achieve these outcomes and expand the adoption of cross-boundary coordination, we suggest four guidelines. First, foster
dialogue among landowners toward shared cognition and oversight. Second, match landowners’ practices and objectives such that
there are clear benefits to all. Third, develop relationships through low risk activities where possible. Fourth, do not expect
on-going commitments.
相似文献
Mark RickenbachEmail: |
13.
Public rangelands in North America are typically managed under a multiple use policy that includes livestock grazing and wildlife
management. In this article we report on the landscape level extent of grassland loss to shrub encroachment in a portion of
the Rocky Mountain Forest Reserve in southwestern Alberta, Canada, and review the associated implications for simultaneously
supporting livestock and wildlife populations while maintaining range health on this diminishing vegetation type. Digitized
aerial photographs of 12 km of valley bottom from 1958 and 1974 were co-registered to ortho-rectified digital imagery taken
in 1998, and an un-supervised classification used to determine areas associated with grassland and shrubland in each year.
Field data from 2002 were over-layed using GPS coordinates to refine the classification using a calibration-validation procedure.
Over the 40-year study period, open grasslands declined from 1,111 ha in 1958 to 465 ha in 1998, representing a 58% decrease.
Using mean production data for grass and shrub dominated areas we then quantified aggregate changes in grazing capacity of
both primary (grassland) and secondary (shrubland) habitats for livestock and wildlife. Total declines in grazing capacity
from 1958 to 1998 totaled 2,744 Animal Unit Months (AUMs) of forage (−39%), including a 58% decrease in primary (i.e., open
grassland) range, which was only partly offset by the availability of 1,357 AUMs within less productive and less accessible
shrubland habitats. Our results indicate shrub encroachment has been extensive and significantly reduced forage availability
to domestic livestock and wildlife, and will increase the difficulty of conserving remaining grasslands. Although current
grazing capacities remain marginally above those specified by regulated grazing policies, it is clear that continued habitat
change and decreases in forage availability are likely to threaten the condition of remaining grasslands. Unless shrub encroachment
is arrested or grassland restoration initiated, reductions in aggregate ungulate numbers may be necessary.
相似文献
Edward W. BorkEmail: |
14.
Farmers attempting to subsist in tropical uplands often rely upon unsustainable resource use practices that lead to soil erosion, declining crop yields, and a loss of soil productivity capacity. Other uses of tropical uplands, including logging and conversion of forest to rangelands, have similar results. The undesirable effects of these actions are felt on-site, at the watershed level, and even nationally. Ecological cause-effect relationships are poorly understood, and few examples exist of the successful integration of ecological knowledge with upland development. It is hypothesized that recent results of ecological research could be applied to uplands management so that stable sustainable systems of human use may be established. A second hypothesis is that statistically reliable data can be obtained from experiments in upland situations, although natural variations of soils, weather, and vegetation are great. To test these hypotheses, research involving multinational collaboration among American and Southeast Asian scientists has begun. The objective of the work is to provide credible quantitative information to help policy and decision makers and resident farmers to plan and implement improved practices based on ecological principles.Some findings to date include:
相似文献
1. | Ecological principles are difficult to relate to the practical context of upland agroecosystems. Indeed, the null hypothesis is necessary for planning experiments and demonstrations. |
2. | The signal-to-noise ratio in these field experiments is low, and the detection of changes due to human intervention in soil erosion, nutrient movement, and plant productivity is difficult. |
3. | Obstacles to field research in developing countries include logistic, cultural, political, and institutional factors. It is essential that local land managers participate from the start with scientific researchers in designing experiments. |
4. | Planned collaboration among academic and government scientists facilitates design of relevant research and the implementation of results. |
5. | The idea of ecologically based management has been well received by researchers and government officials in Asia. There is little argument with the logic of the approach. |
6. | Pressures for quick responses to urgent problems in the uplands conflict with the need for careful, long-term, statistically valid scientific research. |
7. | Ecological principles are vaguely understood and poorly articulated in the scientific literature. The transfer and application of ecological science to the developing world would be enhanced by clearer statements of principles. |
15.
Robins L 《Environmental management》2008,42(5):833-846
This paper aims to give practical meaning to ‘capacity building’ through (a) identifying a suite of practical measures, such
as mentoring or best practice guidelines, that have been shown to or are considered to build human, social, institutional,
and economic capital; (b) placing these measures within a broader systems framework; and (c) exploring stakeholder feedback
on specific measures to inform framework implementation. The 29 measures described provide actors, whether government or nongovernment,
with a suite of practical investment choices for building capacity. These measures are then clustered into eight groups according
to their primary purpose and placed within a systems framework. The framework provides a tool for actors with responsibilities
for or an interest in capacity building to inform more holistic and strategic targeting of effort and investment. Stakeholder
feedback gathered through surveys and workshops is subsequently reported to further inform implementation of specific measures
within the framework’s eight groupings. The framework presented may be built upon through the identification and inclusion
of further capacity building measures. The research is conducted within the context of decentralized governance arrangements
for natural resource management (NRM), with specific focus on Australia’s recently formalized 56 NRM regions and their community-based
governing boards as an informative arena of learning. Application of the framework is explored in the Australian setting through
the identification and comparison of measures supported and most preferred by four major stakeholder groups, namely board
members, regional NRM organization staff, policy/research interests, and Indigenous interests. The research also examines
stakeholder perceptions of capacity issues, and whether these issues are likely to be addressed through implementing their
preferred measures.
相似文献
Lisa RobinsEmail: |
16.
Qiu Z 《Environmental management》2003,32(3):299-311
Conservation buffers have the potential to reduce agricultural nonpoint source pollution and improve terrestrial wildlife habitat, landscape biodiversity, flood control, recreation, and aesthetics. Conservation buffers, streamside areas and riparian wetlands are being used or have been proposed to control agricultural nonpoint source pollution. This paper proposes an innovative strategy for placing conservation buffers based on the variable source area (VSA) hydrology. VSAs are small, variable but predictable portion of a watershed that regularly contributes to runoff generation. The VSA-based strategy involves the following three steps: first, identifying VSAs in landscapes based on natural characteristics such as hydrology, land use/cover, topography and soils; second, targeting areas within VSAs for conservation buffers; third, refining the size and location of conservation buffers based on other factors such as weather, environmental objectives, available funding and other best management practices. Building conservation buffers in VSAs allows agricultural runoff to more uniformly enter buffers and stay there longer, which increases the buffers capacity to remove sediments and nutrients. A field-scale example is presented to demonstrate the effectiveness and cost-effectiveness of the within-VSA conservation buffer scenario relative to a typical edge-of-field buffer scenario. The results enhance the understanding of hydrological processes and interactions between agricultural lands and conservation buffers in agricultural landscapes, and provide practical guidance for land resource managers and conservationists who use conservation buffers to improve water quality and amenity values of agricultural landscape. 相似文献
17.
Brad Gilmour Ted Huffman Andy Terauds Charles Jefferson 《Journal of Agricultural and Environmental Ethics》1996,9(1):16-41
The specific issue addressed in this paper is urban encroachment on agricultural lands, and the problems it poses for both analysis and the conservation of the land resource. The purpose of our discussion is two-fold: (1) to identify where and why traditional analytical and regulatory approaches fail to resolve land use conflicts, and (2) to explore ways and means of resolving some of the dilemmas which society faces in making land use decisions. This paper's contribution is in the spirit of Getting Incentives Right for the inter-temporal transfer of wealth, as represented in trade-offs between environmental and resource endowments and human and physical capital. Efforts are placed on identifying what the appropriate price, levy, taxes, and grant ratios ought to be in order to encourage individuals in the marketplace to act in society's interest. We have also explored ways of efficiently transmitting those incentives through the market mechanism, without unduly relying on bureaucratic methods or suasion. Emphasis is placed on mechanisms that have little scope for preferential access and are subject to public scrutiny; emphasis on such self-disciplining approaches should result in less effort expended on (unproductive) lobbying activities and bureaucratic administration.Brad Gilmour and Ted Huffman are Policy Analyst and Land Use Specialist respectively with Agriculture and Agri-food Canada. Andy Terauds and Charlie Jefferson are chairman and secretary respectively for the Ontario Institute of Agrologists Ottawa Branch Land Use Committee. This paper is intended to provoke thought and stimulate debate for input into the land use policy process and should not be seen as representing the views and policies of either Agriculture Canada or the Ontario Institute of Agrologists. 相似文献
18.
Management and valuation of an environmentally sensitive area: Norfolk Broadland,England, case study 总被引:1,自引:0,他引:1
Wetlands, like any other environmentally sensitive resource, require very careful evaluation. While it is accepted that all wetlands may be equally valuable in terms of maintaining global life-support systems, individual areas may be ranked according to their uniqueness or the irreplaceability of the resource should the wetland be developed. The various techniques available for evaluating the wetland resource in the development versus conservation conflict situation are critically assessed. Indirect appraisal via the opportunity cost method can generate valuable data which have contributed to the mitigation of such conflict situations.The Broadland, in Norfolk, England, recently designated an environmentally sensitive area (ESA), provides a case study example of wetland management. The search for an acceptable flood alleviation strategy for the ESA is examined in detail. The economic and environmental asset structure of the study area is examined at two levels. A basic screening system is applied to each of the identified flood protection planning units to enable the rank ordering of the units. A more detailed appraisal is then made of the value of selected units so that the cost-effectiveness of any planned expenditure on flood protection works can be assessed. Specific management issues and their likely effect on the environment, in terms of land use for example, are also addressed. The 1986 Agriculture Act marks a potential watershed in British conservation policy. The ESA policy encompasses a dual management strategy that attempts to stimulate compatible agricultural and conservation practices and activities. Other countries that still retain significant unspoiled wetland resources may find that preemptive regulatory government intervention in favor of conservation would help to avoid the worst aspects of the British experience. 相似文献
19.
W.L. Hargrove Z. Sheng A. Granados J.M. Heyman S.T. Mubako 《Journal of the American Water Resources Association》2021,57(1):170-185
The objectives were to (1) delineate the complex set of rules governing the fate and transfer of water rights as agricultural land is urbanized in Texas and New Mexico in the United States and Chihuahua in Mexico and (2) estimate the change in water use as a result of such urbanization. Important additional determinants of water use in the region include intensification of agriculture and the hydroschizophrenic policy framework. We conducted interviews with key informants to identify the possible outcomes for changes in water rights as land is urbanized. We constructed decision trees for each of the three jurisdictions, Chihuahua, Texas, and New Mexico, that identified the possible outcomes from urbanization. For each of the possible outcomes in the decision tree, we estimated a range of potential water use outcomes and the most likely water use outcome on a per unit of land area basis. Results show that urbanization of agricultural land has almost no impact on the aggregate demand for or use of surface water. However, the impacts of urbanization on groundwater use vary considerably over the region from Texas to New Mexico to Chihuahua. In New Mexico and Chihuahua where groundwater rights can be leased or sold to other users, the likely impact is a net increase in groundwater use as land is urbanized, ranging from 0 to 3,000 m3/ha in New Mexico and averaging 3,000 m3/ha or more in Chihuahua. In Texas, there is a net benefit in groundwater savings, but those savings are subject to being offset by increased groundwater pumping to meet the needs of expanding pecan production. The net result is continued groundwater depletion, threatening the life of the transboundary aquifers, the Hueco Bolson and the Mesilla Bolson, in the Middle Rio Grande basin (defined as the part of the basin between Elephant Butte Reservoir in New Mexico to the confluence of the river with the Rio Conchos from Mexico). 相似文献
20.
Agricultural Land Use Effects on Sediment Loading and Fish Assemblages in Two Minnesota (USA) Watersheds 总被引:1,自引:1,他引:0
We examined the relationship between water quality and fish communities within two agricultural areas using a computer simulation model. Our analyses focused on a coolwater stream, Wells Creek in southeastern Minnesota, and a warmwater stream, the Chippewa River in western Minnesota. We used the Agricultural Drainage and Pesticide Transport (ADAPT) model in relation to land use to calculate instream suspended sediment concentrations using estimates of sediment delivery, runoff, baseflow and streambank erosion, and quantified the effects of suspended sediment exposure on fish communities. We predicted the effects of agricultural practices on stream fish communities under several possible land use scenarios, with reference to current conditions. Land use changes led to reductions in sediment loading of up to 84% in Wells Creek and 49% in the Chippewa River. The reduction in sediment loading across scenarios may be directly related to a reduction in runoff by about 35% in both study areas. We found a 98% decrease in lethal concentrations of suspended sediment on fish in Wells Creek with an increase in conservation tillage, riparian buffers, and permanent vegetative cover. However, the effects of suspended sediment did not significantly decrease in the Chippewa River. This difference between study areas was likely due to differences in tolerance to suspended sediment between coolwater and warmwater fish communities and differences in topography, runoff and bank erosion between the two streams.
The Minnesota Cooperative Fish and Wildlife Research Unit is jointly sponsored by the US Geological Survey, the University of Minnesota, the Minnesota Department of Natural Resources, and the Wildlife Management Institute. 相似文献