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1.
Arsenic and fluoride in the groundwater of Mexico   总被引:4,自引:0,他引:4  
Concentrations of arsenic and fluoride above Mexican drinking water standards have been detected in aquifers of various areas of Mexico. This contamination has been found to be mainly caused by natural sources. However, the specific processes releasing these toxic elements into groundwater have been determined in a few zones only. Many studies, focused on arsenic-related health effects, have been performed at Comarca Lagunera in northern México. High concentrations of fluoride in water were also found in this area. The origin of the arsenic there is still controversial. Groundwater in active mining areas has been polluted by both natural and anthropogenic sources. Arsenic-rich minerals contaminate the fractured limestone aquifer at Zimapán, Central México. Tailings and deposits smelter-rich fumes polluted the shallow granular aquifer. Arsenic contamination has also been reported in the San Antonio-El Triunfo mining zone, southern Baja California, and Santa María de la Paz, in San Luis Potosí state. Even in the absence of mining activities, hydrogeochemistry and statistical techniques showed that arsenopyrite oxidation may also contaminate water, as in the case of the Independencia aquifer in the Mexican Altiplano. High concentrations of arsenic have also been detected in geothermal areas like Los Azufres, Los Humeros, and Acoculco. Prevalence of dental fluorosis was revealed by epidemiological studies in Aguascalientes and San Luis Potosí states. Presence of fluoride in water results from dissolution of acid-volcanic rocks. In Mexico, groundwater supplies most drinking water. Current knowledge and the geology of Mexico indicate the need to include arsenic and fluoride determinations in groundwater on a routine basis, and to develop interdisciplinary studies to assess the contaminant's sources in all enriched areas.  相似文献   

2.
3.
SUMMARY

This paper explores the roles GIS technology can play in support of land management, focusing in particular on its application in protected environments such as Biosphere Reserves. These ecologically significant areas present complex planning situations since, unlike areas set aside solely for conservation, they must continue to support human populations that depend on natural resources for their economic and social well being. In situations such as marginal tropical locations, land managers often face major economic and political disincentives to the conservation of precious natural resources. The necessity for community participation and local expertise in the planning process becomes increasingly critical as GIS evolves from a basic presentation aid for spatial data to a synthesizing problem-solving tool. Coupled with enhanced community participation is the opportunity for greater education of stakeholders; the potential for GIS to serve as a medium for information gathering and dissemination is discussed. A case study in the Sierra de Manantlán Biosphere Reserve (SMBR), México, is presented.  相似文献   

4.
We used aerial photographs, satellite images, and field surveys to monitor forest cover in the core zones of the Monarch Butterfly Biosphere Reserve in Mexico from 2001 to 2012. We used our data to assess the effectiveness of conservation actions that involved local, state, and federal authorities and community members (e.g., local landowners and private and civil organizations) in one of the world's most iconic protected areas. From 2001 through 2012, 1254 ha were deforested (i.e., cleared areas had <10% canopy cover), 925 ha were degraded (i.e., areas for which canopy forest decreased), and 122 ha were affected by climatic conditions. Of the total 2179 ha of affected area, 2057 ha were affected by illegal logging: 1503 ha by large‐scale logging and 554 ha by small‐scale logging. Mexican authorities effectively enforced efforts to protect the monarch reserve, particularly from 2007 to 2012. Those efforts, together with the decade‐long financial support from Mexican and international philanthropists and businesses to create local alternative‐income generation and employment, resulted in the decrease of large‐scale illegal logging from 731 ha affected in 2005–2007 to none affected in 2012, although small‐scale logging is of growing concern. However, dire regional social and economic problems remain, and they must be addressed to ensure the reserve's long‐term conservation. The monarch butterfly (Danaus plexippus) overwintering colonies in Mexico—which engage in one of the longest known insect migrations—are threatened by deforestation, and a multistakeholder, regional, sustainable‐development strategy is needed to protect the reserve. Tendencias en la Deforestación y la Degradación de Forestal después de una Década de Monitoreo en la Reserva de la Biósfera de la Mariposa Monarca en México  相似文献   

5.
ABSTRACT

The growing demand for natural rubber is increasingly threatening biodiversity and forest ecosystems. Recently, the French Michelin Group started a cooperation with the World Wide Fund for Nature (WWF) to establish environmentally and socially sustainable ‘model’ rubber plantations in Sumatra and Kalimantan, Indonesia. The framing of Michelin’s tyre production as ‘eco-friendly’ and their purported ‘sustainable’ rubber cultivation contradict with statements by villagers living around Michelin’s plantation in Jambi Province, Sumatra, who are reporting environmental destruction and land tenure conflicts. Conceptually, we build on political ecology and critical human geography perspectives to identify conflicts and ambiguities related to sustainability claims, deforestation and dispossession. Empirically, we draw on qualitative research in a village affected by the plantation. We confront and deconstruct the discursive framing of sustainable rubber production with our empirical findings. We show how the plantation restricts access to land and instead of providing additional income, is actually limiting development opportunities.  相似文献   

6.
SUMMARY

Over-population in relation to poor land productivity and cultivation in less fertile lands is resulting in land degradation and deforestation in UP hills. Growing demand of more food production and increasing need for more cash in hand have forced the hill people to cultivate all kinds of land, resulting in the denudation of land resources and soil erosion. These changes resulted in out migration of the area's human resource. A new management system for the revival of natural resources and the sustainable utilization of the area's human population and livestock has been proposed, involving active local participation in order to change the existing land-use to a system based on the soil fertility scale.  相似文献   

7.
Achieving ethically responsible decisions is crucial for the success of biodiversity conservation projects. We adapted the ethical matrix, decision tree, and Bateson's cube to assist in the ethical analysis of complex conservation scenarios by structuring these tools so that they can implement the different value dimensions (environmental, social, and animal welfare) involved in conservation ethics. We then applied them to a case study relative to the decision-making process regarding whether or not to continue collecting biomaterial on the oldest of the two remaining northern white rhinoceroses (Ceratotherium simum cottoni), a functionally extinct subspecies of the white rhinoceros. We used the ethical matrix to gather ethical pros and cons and as a starting point for a participatory approach to ethical decision-making. We used decision trees to compare the different options at stake on the basis of a set of ethical desiderata. We used Bateson's cube to establish a threshold of ethical acceptability and model the results of a simple survey. The application of these tools proved to be pivotal in structuring the decision-making process and in helping reach a shared, reasoned, and transparent decision on the best option from an ethical point of view among those available.  相似文献   

8.
SUMMARY

The humid zone of Nigeria has traditionally been considered unsuitable for extensive cattle production because of the prevalence of tsetse fly. Over the years, nomadic pastoralists, mainly Fulani, from the northern part of the country paid seasonal visits to this zone in search of pasture and water for their cattle during the dry season when the threat of the tsetse menace is less. The recent increase in the number of settled pastoralists has been associated with changing trends in the ecology and economy of the zone.

Relying on recent survey data, this paper attempts a systematic analysis of the adaptive strategies of the Fulani in pursuit of a sedentary lifestyle in the humid frontier of southwest Nigeria. Some of the adaptive strategies identified include: establishment of grazing orbits within a 20 km radius of their settlements, adjustment of herd size and structure, adoption of a multiple livelihood system, production of arable crops and appropriation of traditional social structures and kinship networks for herd management.

Long-term insecure land-holding arrangements, incessant seasonal bush burning for regeneration of pasture by the Fulani and the gradual destruction of the native forest cover are some of the problems arising from the sedentarisation of livestock production in the area. It was observed that the present land-use arrangement, even though it appears to guarantee the pastoralists security of tenure in the short term, is not sustainable in the long run, given the increasing commercialization of land in the area and rapid population growth. It was, therefore, concluded that government should put in place a land redistribution arrangement that will ensure secure land ownership by the Fulani. Development initiatives in the area should also focus on reinforcing those traditional practices of the Fulani that would guarantee a sustainable land-use system in the area.  相似文献   

9.
This paper describes the environmental indicators GIS of the Catalan coast, Spain. The spatial data model is based on vector and raster layers with three main modules: the biodiversity, the general biophysical and the socioeconomic. Presently, the database has a number of pressure and impact indicators that have been used to model the components and structure of the system and are suggested to build ecological resilience. Special interest has been given to the analysis of functional groups of species that are relevant to the dynamics of the coastal system, and preliminary results are presented. This system constitutes a user-oriented analytical and monitoring tool for coastal zone managers and researchers. Although, the system is under development it is expected that resulting spatial indicators of environmental condition can be used to promote more sustainable coastal strategies and actions in the Catalan coast.  相似文献   

10.
SUMMARY

During eight years, the Biological Research Center of the Northwest promoted the federal decrees to attain legal protection of three key zones for biodiversity conservation in Mexico: La Sierra de La Laguna, El Desierto del Vizcaíno, and E1 Archipiélago Revillagigedo Biosphere Reserves. In this work, we discuss the biological and socioeconomical importance of these three regions, the necessary steps to attain a Presidential decree in Mexico, and the required strategies to promote local and political support for each decree. In a country like Mexico, the promotion of one Presidential decree to declare a zone as a biosphere reserve must successfully address two different goals: the technical and the political. The technical phase can be successfully completed by a research centre or university in 6 to 12 months; while the political phase may or may not be successfully completed. If successful, in our experience, it can be attained with 2 to 96 months of continuous efforts.  相似文献   

11.
Abstract: The sustainable production of bioenergy is vital to avoiding negative impacts on environmental goods such as climate, soil, water, and especially biodiversity. We propose three key issues that should be addressed in any biodiversity risk‐mitigation strategy: conservation of areas of significant biodiversity value; mitigation of negative effects related to indirect land‐use change; and promotion of agricultural practices with few negative impacts on biodiversity. Focusing on biodiversity concerns, we compared principles and criteria set to address biodiversity and other environmental and social issues in seven standards (defined here as commodity‐based standards or roundtables, or relevant European legislation): five voluntary initiatives related to bioenergy feedstocks, the Renewable Transport Fuel Obligation (United Kingdom), and the European Renewable Energy Source Directive. Conservation of areas of significant biodiversity value was fairly well covered by these standards. Nevertheless, mitigation of negative impacts related to indirect land‐use change was underrepresented. Although the EU directive, with its bonus system for the use of degraded land and a subquota system for noncrop biofuels, offered the most robust standards to mitigate potential negative effects, all of the standards fell short in promoting agricultural practices with low negative impacts on biodiversity. We strongly recommend that each standard be benchmarked against related standards, as we have done here, and that efforts should be made to strengthen the elements that are weak or missing. This would be a significant step toward achieving a bioenergy industry that safeguards Earth's living heritage.  相似文献   

12.
The study used a combination of fairly standard and often overlapping participatory tools and techniques as well as SWOT analysis in the context of the sustainable livelihoods approach (SLA), which is emerging as a potentially useful way of looking at policies and institutions to address poverty. The adoption of fisheries co-management in Aby Lagoon in Cote d'Ivoire has contributed to improving the sense of ownership, empowerment and access of fishers and other stakeholders to resources. The fishers and other stakeholders attest that the arrangement has also contributed in enhancing the sustainable livelihoods and coping mechanisms against the incidence of poverty in the communities. Fishers would like legal empowerment to enforce fisheries regulations devised by themselves and also assistance to improve their work in collection of information and adaptive research upon which to base their plans. The co-management arrangement in Aby Lagoon is still evolving. However, the study testifies to the existence of many competent actors and to a great wealth and depth of relevant experience and lessons which other actors involved in poverty reduction strategies in small-scale fishing communities can draw on.  相似文献   

13.
The main objective of the MADAM project (Mangrove Dynamics and Management) is to generate the scientific basis enabling the sustainable stewardship of the resources of the Caeté mangrove estuary in Northeast Brazil in the sense of integrated coastal (zone) management. To achieve this, it is necessary to acquire in-depth knowledge of natural processes as well as of the relevant institutional, cultural, economic, social and political dynamics. Causal linkages within the ecosystem, as well as between ecosystem, economy and society, are analysed and explained via dynamic and trophic modelling. Scenario construction is intended to forecast the effects of acute or chronic interference on utilized resources, and to answer wider, management-related questions (e.g. restoration of destroyed areas, utilization potential for aquaculture). This paper describes the project strategy as developed and modified in the context of research results from the initial 2-yr project phase. It is argued that a continuous discussion process is essential to assess the validity of the strategies formulated at the beginning of a medium-time project, particularly if the project is of interdisciplinary nature.  相似文献   

14.
SUMMARY

The contention is examined that forests can contribute to biodiversity conservation either as protected areas or as production forests, especially where the latter are managed for timber extraction. This notion is explored for the Peninsular Malaysian forests, and it is shown that biodiversity conservation would be optimized if the system of protected areas is located within a broader matrix of carefully managed production forests. A model is developed to illustrate how the biodiversity value of protected areas would be enhanced through interaction with production forests. In no way is the suggestion being made here that production forests could serve as critical centres for the conservation of biotic diversity, but then neither should they be dismissed as areas completely devoid of any contribution to the biodiversity cause. These findings are especially significant in Peninsular Malaysia where two-thirds of the forests legally set aside as Permanent Forest Estate is to be managed as production forests. If the incremental biodiversity value of these forests can be captured through improved management practices, then the overall biodiversity status of the country, and the globe, could be greatly increased. The extent to which any country is willing to set aside forests as protected areas, strictly for biodiversity conservation, is limited, hence the integrated approach to the management of protected and production forests advocated here could prove an attractive and feasible strategy. Where funding is limited, as in the case of the Global Environment Facility, it may be worthwhile to provide incentives for improved management of production forests as a means of conserving biodiversity.  相似文献   

15.
Traditional crop diversity and landraces in agricultural land use in Himalaya have great significant for long-term sustainability of agroecosystems, together with conservation and management of the surrounding landscape. Traditional crop varieties and races, which evolved over time through trial and error, not only provide basic nutritional requirements, but also food security. Loss of crop biodiversity has taken place over recent years, principally and inadvertently related to changing lifestyle, growing demand for cash crops in regional markets and burgeoning apple farming, whose acreage has increased with a concomitant decline in area under traditional crops. For sustainable landscape development, on-farm conservation of traditional crop diversity is urgently needed. An empirical study was done to understand the causes and consequences of declines in crop biodiversity and production, effect of apple farming on traditional crops and changing lifestyles of traditional people.  相似文献   

16.
SUMMARY

What is sustainable development? Why is at an issue? Ideally, what needs to be done? and Practically, what can be done? are answered here by relying on the cultural theory of Mary Douglas and her colleagues, more especially Aaron Wildavsky and Michael Thompson, both of whom have used the model to address sustainable development. The implications of cultural theory for sustainable development are substantial.

The article is divided into five sections. The first describes the current controversy over sustainable development. The second sets out the cultural theory model, and the third applies that model to reformulate our understanding of sustainable development. The fourth draws out the implications of a reformulated sustainable development, while the conclusion uses those implications to answer the four questions that started the article.  相似文献   

17.
The unlimited economic growth that fuels capitalism's metabolism has profoundly transformed a large portion of Earth. The resulting environmental destruction has led to an unprecedented rate of biodiversity loss. Following large-scale losses of habitats and species, it was recognized that biodiversity is crucial to maintaining functional ecosystems. We sought to continue the debate on the contradictions between economic growth and biodiversity in the conservation science literature and thus invite scholars to engage in reversing the biodiversity crisis through acknowledging the impacts of economic growth. In the 1970s, a global agenda was set to develop different milestones related to sustainable development, including green–blue economic growth, which despite not specifically addressing biodiversity reinforced the idea that economic development based on profit is compatible with the planet's ecology. Only after biodiversity loss captured the attention of environmental sciences researchers in the early 2000s was a global biodiversity agenda implemented. The agenda highlights biodiversity conservation as a major international challenge and recognizes that the main drivers of biodiversity loss derive from economic activities. The post-2000 biodiversity agendas, including the 2030 Agenda for Sustainable Development and the post-2020 Convention on Biological Diversity Global Strategy Framework, do not consider the negative impacts of growth-oriented strategies on biodiversity. As a result, global biodiversity conservation priorities are governed by the economic value of biodiversity and its assumed contribution to people's welfare. A large body of empirical evidence shows that unlimited economic growth is the main driver of biodiversity loss in the Anthropocene; thus, we strongly argue for sustainable degrowth and a fundamental shift in societal values. An equitable downscaling of the physical economy can improve ecological conditions, thus reducing biodiversity loss and consequently enhancing human well-being.  相似文献   

18.
介绍了黄河三角洲自然保护区内物种多样性和生态系统的多样性,分析了破坏和威胁生物多样性的因素,提出了自然保护区生物多样性保护措施。  相似文献   

19.
The Convention on Biological Diversity (CBD) originating from 1992 today has 190 Parties. In 2000 the convention decided on a programme of work on agricultural biodiversity which explicitly included the diversity of races and types of species used in agriculture. This programme was scheduled for an In-Depth Review at the Ninth Conference of the Parties (COP 9). The preparatory meetings of the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) already indicated that the production and use of biofuels would be a controversial issue during COP. Parties producing biofuels emphasised the CO2 neutrality while importing countries called for standards for sustainable production. Developing countries mentioned the risk of losing agricultural area suitable for food production and indigenous representatives asked for social standards in agricultural production and respecting of their land ownership. A compromise could only be found at ministerial level during the last conference day, agreeing that all production of biofuels should be sustainable in relation to biodiversity and under this condition urging Parties to promote the production and use of biofuels. Research on the positive and negative impacts of biofuels should be conducted.  相似文献   

20.
The reproduction and growth of Isostichopus fuscus (Ludwig, 1875) at Isla Espíritu Santo, Baja California Sur, México from July 1992 to September 1993 and from August 1996 to July 1997 were analyzed. The reproductive cycle was monitored by using histological analysis. Five gonadal stages were described according to cell types present in the gonad; undetermined, gametogenesis, maturity, spawning and post-spawning. This holothurian reproduces annually during summer (July to September), when sea surface temperature reaches 27 °C. The gonad index is related to the gonadal stages. The first sexual maturity for I. fuscus was calculated at 367 g (4 to 5 years old) according to the von Bertalanffy equation, and nearly all the specimens at Isla Espíritu Santo were 5 to 7 years old (including some individuals over 35 years old). Data of the length–weight relationship showed that I. fuscus grows allometrically at the studied site (b = 1.83). The mortality rate was relatively high (M = 0.51), indicating that in a typical cohort, 40% of the recruits does not survive the first year, and less than 20% reaches maturity. Received: 15 July 1998 / Accepted: 19 August 1999  相似文献   

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