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131.
ke Berg 《Agriculture, ecosystems & environment》2002,90(3):587
Plantations of short-rotation coppice (SRC) have a potential for being a useful measure to stop the ongoing impoverishment of farmland biodiversity by increasing structural diversity, and decreasing cultivation intensity and use of pesticides in intensively managed farmland landscapes. The aim of this study was to investigate the relative importance of the structure of the plantation and composition of adjacent habitats for breeding birds in 41 SRCs (meansize±S.E.=9.4±1.6 ha). Mean number of species per ha in the SRCs was 2.8±0.3 species and there were more farmland birds (32 species, 808 territories) than forest birds (22 species, 400 territories). A major result of the present study was the strong influence of adjacent habitats on bird community composition (18 of 22 analysed species affected). There were large differences in bird communities between forest-bordered and open-bordered sites, but occurrence of residual habitats (i.e. other habitats than forest, pastures, shrub areas and arable fields) was also associated with occurrence of several species. The second factor of major importance for the bird fauna was the height of the plantations. Most species (14) were associated with tall plantations (>2 m), seven species were associated with plantations of intermediate (1–2 m) height, and six species were associated with plantations of low height (<1 m). A comparison of ecological traits between species classified as preferring SRC and species classified as avoiding SRC suggests that nest height was the only ecological character associated with a preference for Salix habitats, i.e. species with nests on the ground or in shrubs were more abundant in Salix habitats than in farmland landscapes in general. However, a broad spectrum of species was found in the SRCs and many of these seemed to be dependent on habitat features outside the plantations. Planting of Salix in intensively managed farmland plains will have positive effects on bird diversity by increasing the structural diversity of the landscape. In contrast, plantations on infields in forest-dominated landscapes will have negative effects, since the mosaic structure (i.e. mixture of open and forested habitats) positive for most farmland birds will disappear, and Salix plantations favour relatively few forest species. Additionally, Salix could be planted along sharp edges between coniferous plantations and open farmland in order to increase the complexity of the ecotone in intensively managed forest-farmland landscapes. 相似文献
132.
133.
Zbigniew W. Kundzewicz 《Journal of the American Water Resources Association》2011,47(3):550-562
Kundzewicz, Zbigniew W., 2011. Nonstationarity in Water Resources – Central European Perspective. Journal of the American Water Resources Association (JAWRA) 47(3): 550‐562. DOI: 10.1111/j.1752‐1688.2011.00549.x Abstract: Nonstationarity in variables describing water quantity and water quality characteristics is reviewed, and an attempt to interpret nonstationary behavior is made with particular reference to the Central European region. Nonstationarity in water‐related variables results from several nonclimatic and climatic factors. Albeit evidence of climate change in Central Europe is clear, anthropogenic nonclimatic change, such as land‐use or land‐cover changes, water engineering measures, and in‐catchment water management play important roles. Systemic socioeconomic and political changes are the main factors responsible for the observed change in water quality in the region. The observed climate change in the Central European region has not been dramatic enough to persuade the water management community that changes of standards, criteria, and evaluation procedures should be made. Projections for the future largely differ between models and scenarios, hence information obtained from climate models is found too vague to be used. However, the water management community shows interest in climate change observations, projections, and impact assessments. Numerous hydrological research projects to tackle nonstationarity have been undertaken in the region. Also important acts of legislation, such as the European Union’s Water Framework Directive and Floods Directive can be regarded in the context of nonstationarity of water‐related variables. 相似文献
134.
Laura Sims 《Journal of Environmental Planning and Management》2017,60(3):538-557
Community-based approaches to environmental management provide opportunities for public engagement in local decision-making processes. This qualitative case study examines learning as resulted from participation in CIDA's “Community-based pest management in Central American agriculture” project. Outcomes include learning about alternative farming practices, human and natural environments, and safer pesticide use. Many participants learnt how to work more effectively with rural communities. For some, this changed their perspective about life and their role in society. Activities that fostered learning outcomes, including sustainability-related outcomes, were: planning and implementing project activities, experimenting on farm demonstration plots, participating in outreach workshops, and students doing rural practica. The learning process, involving international university collaborators and rural participants, is analyzed particularly as it relates to cultural context, collective action, and sustainability. Findings affirm that how the public participates in environmental management decisions influences the breadth and depth of learning outcomes; practical and policy implications are discussed. 相似文献
135.
ABSTRACT: This paper reports the use of a water negotiation model, the Legal‐Institutional Analysis Model (LIAM), in the bi‐national setting of the U.S. and Mexico in the Paso del Norte region. The following study discusses the results of developing baseline data where interstate, international, and cultural factors, as well as a long history of conflict, impact on negotiations and the extent to which the LIAM is a valuable tool for analyzing behavior among institutional actors in such a setting. The findings suggest that most water policy actors in the region prefer brokered solutions as defined within the LIAM framework. 相似文献
136.
Jos de Anda Sergio E. Quinones-Cisneros Richard H. French Manuel Guzmn 《Journal of the American Water Resources Association》1998,34(6):1319-1331
ABSTRACT: Lake Chapala, whose primary tributary is the Río Lerma, is the largest freshwater lake in Mexico and for the past 95 years has maintained an average storage capacity close to 6,700 Mm3. Starting hi the early 1970s, the Lerma-Chapala basin rapidly industrialized. In response to these upstream anthropogenic activities, the fisheries, aesthetics, and water quality of Lake Chapala have decreased as a consequence of the increasing chemical and biologic pollutants mainly from the Río Lerma. Additionally, the growth of Guadalajara has resulted in increasing potable water demands on the lake to satisfy a population currently greater than 4.5 million. During the 1980s, the outflow and water losses from the lake substantially exceeded the inflow and other water contributions. In this paper, the recent behavior of the hydrologic and bathymetric parameters of Lake Chapala are summarized and some important physical stresses on the system are identified. The focus of this work is the 1934–1989 period, and it is shown that starting around 1980 some of the main contributors to the lake water balance were severely perturbed and the lake reached its second lowest recorded level. The disturbances of the system are so severe that the entire regional ecosystem could be irreversibly affected in the near future. 相似文献
137.
ABSTRACT Mexico faces multiple water quality challenges, both in terms of the water supplied to the population as well as surface and underground water sources. Problems with drinking water supply affect the population in diverse ways, from associated health risks to high levels of intermittency in service to the poor perception of the quality of piped water – leading to high levels of bottled water consumption. In this text we explore the issue of drinking water quality in three contexts in the state of Jalisco: in Guadalajara, the state’s main urban area, in the peri-urban municipality of El Salto, and in the mid-sized city of San Juan de los Lagos. Our analysis explores drinking water regulations, the water quality monitoring undertaken by state and local authorities, access to information, as well as the actions and perceptions of water service providers. Looking at cases of indirect reuse of wastewater as well as groundwater sources with high levels of fluoride and arsenic, we argue that the foregrounding of water quality is key to illuminating social inequalities in access to water and in teasing out power relations prevailing in current hydrosocial regimes. We conclude that this hydrosocial cycle of drinking water is characterised by prioritising access to water for economic actors, facilitated by lax regulations and minimal enforcement, as well as by the systematic neglect by government authorities at all levels of the protection of watersheds and aquifers, and of water quality issues generally. 相似文献
138.
According to the environmental justice (EJ) literature, one important factor in the movement's success is the development of a frame linking inequality to the disproportionate presence of environmental toxins in low-income communities of colour. This article highlights the resonance of this frame among grassroots activists and professional advocates in California's Central Valley. However, through interviews and focus groups with activists and advocates in six Central Valley communities, we found that only the latter identified their work as EJ. Grassroots activists instead identified their work as about health, community development and environmentalism. Moreover, some were unfamiliar with EJ as a concept while others denied its applicability to their work. Theoretically, our findings suggest that frame resonance needs to be delinked conceptually from movement identification; it is possible for a movement's analysis of social problems and solutions to resonate among those who do not identify with the movement itself. Pragmatically speaking, this can prevent some grassroots activists who are directly affected by environmental racism from accessing the resources and networks that the EJ movement has painstakingly built, and suggests that movement leaders may need to increase their outreach to community groups. 相似文献
139.
Tijuana Childhood Lead Risk Assessment Revisited: Validating a GIS Model with Environmental Data 总被引:3,自引:0,他引:3
The objective of this research was to determine the spatial distributions of childhood lead poisoning and soil lead contamination
in urban Tijuana. The Bocco–Sanchez model of point-source emissions was evaluated in terms of validity and reliability. We
compared the model's predicted vulnerable populations with observed cases of childhood lead poisoning in Tijuana, identified
fixed point sources in the field, and analyzed 76 soil samples from 14 sites. The soil lead results were compared to the blood
lead analyses performed on Tijuana children whose blood lead levels were ≥10 μg/dL, who reported that they did not use lead-glazed
ceramics for cooking or storing food (n = 63). Using GIS, predicted vs observed risk areas were assessed by examining spatial patterns, including the distribution of cases
per designated risk area. Chi-square analysis of expected vs observed values did not differ significantly at the p = 0.02 level, showing that the model was strikingly accurate in predicting the distribution of subjects with elevated blood lead.
Results reveal that while point sources are significant, other sources of lead exposure are also important. The relative public
health risk from exposure to lead in an urban setting may be assessed by distinguishing among sources of exposure and associating
concentrations to blood lead levels. The results represent an iterative approach in environmental health research by linking
environmental and human biomarker lead concentrations and using these results to validate an environmental model of risk to
lead exposure. 相似文献
140.
Penov I 《Environmental management》2004,34(2):304-313
The amount of water Bulgaria uses for irrigation sharply declined during the transition. Large sections of the existing irrigation systems were abandoned, and those still in use are hardly maintained. Crops such as wheat and barley have replaced more water-intensive crops, such as vegetables, rice, and maize. This problem has an impact on the future development of agriculture and the allocation of the countrys water resources. The central argument is that land fragmentation in the wake of decollectivization and restitution contributes to the irrigation systems abandonment. This article focuses on the institutional factors involved, but also considers additional factors that might have influenced the process. Further, it examines the causes driving these changes and analyzes their effect on irrigation. It is based on a review of the relevant legislation as well as fieldwork in 17 villages located in the Plovdiv region of Bulgaria. The article concludes that institutional settings, in addition to changes in large-scale market forces and the state enforcement mechanism, have contributed to the irrigation decline in Bulgaria.Published online
Note: This version was published online in June 2005 with the cover date of August 2004. 相似文献