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The rural people in India, particularly the tribals and poor, depend on forest resources for meeting their energy needs, forest products, and for employment. This paper gives details of one estimation of dependency of people on forests in villages in the Madhya Pradesh, Orissa, and Gujarat states of India. Benefits derived by the people were reflected as a percentage of the total income of the house-hold. The dependency on forests varies from 37% to 76% in these villages. This kind of assessment would create a data base and provide indicators of sustainable forest management, especially for an understanding of the intricacies of Joint Forest Management. This information can be very useful in deriving the overall contribution of the forestry sector in the national economy and thus help the planners, administrators and foresters in evolving better management practices.
The geomorphology of the present day and Holocene (3000 years ago) Humber estuary, United Kingdom, are described. More than 90% of the intertidal area and sediment accumulation capacity of the estuary has been lost to reclamation over this period. A similar situation prevails in many other urbanized estuaries. Nutrient budgets for the modern estuary are presented demonstrating little trapping of nutrients, due to the loss of intertidal areas. A speculative budget for the Humber during the Holocene is constructed, which suggests that the estuary was then an efficient sink for nitrogen and phosphorus. A budget is presented describing how nutrient cycling might operate in the Humber with contemporary nutrient loadings, but with the pre-reclamation geography. This suggests that in this form the estuary would significantly attenuate nutrient fluxes to the North Sea. The results are discussed in terms of options for managed realignment of estuaries in response to predicted sea-level rise.
The increasing interest, and the actual necessity, for adequate means to evaluate how sustainable human activities are, has led to efforts to define indicators of sustainability. We propose the use of ecological indicators of sustainability that take into account the hierarchical structure of biodiversity, distinguishing composition, structure and function at the different levels of biological organization: ecosystem and landscape, community, and population and genetic levels. We evaluated the advantages of selecting and combining indicators of different hierarchical levels by examining several use and management projects. Examples of transformed land like large-scale plantations, perform well when evaluated by ecosystem-level indicators, but lead to neglect of some composition and structure components if evaluated at different levels. Limitations in using a small number of indicators become evident in cases of intensive exploitation of resources, such as the extractive reserves, which yield good results under the ecosystem and community levels, but fail under the population and genetic indicators. Wild species management, a common example of the use of population-level indicators, do not perform well under other indicators at broader scales. We also reviewed projects that are sustainable at different hierarchical levels, like some multispecific exploitation forestry management, in which harvesting of resources is at or below sustainable levels, selective extraction is performed, and where natural regeneration and recruitment of species is allowed. It is evident that the adequacy of indicators is not universal and must take into account the complexity of processes and variables involved in the different biological levels and human components, highlighting possible conflicts and contradictions, while increasing knowledge about maintenance of quality in the use and exploitation of resources that the relevant stake-holders regard as important.
Development planning and resource management in the Irish coastal zone have traditionally followed sectoral, top-down models, with limited opportunities for public participation or concertation of administrative effort. Integrated Coastal Zone Management (ICZM) is often proposed as an appropriate policy response in cases where these approaches have been seen to fail. In this paper, we argue that ICZM may be more sustainable if first introduced at a small scale. Local-level initiatives, designed to produce demonstrable benefits at an early stage, are perhaps more likely to engender long-term support for ICZM. This is particularly relevant where baseline data are lacking and coastal processes are poorly understood. Using seven county Donegal beach and dune systems as demonstration sites, the potential of this approach to provide scientifically-founded, locally-agreed management plans was tested over a range of coastal issues, such as progressive shoreline erosion, habitat loss, tourist development, conflicting recreational activities and traffic management. Progress at each of the sites was partially dependent on the existence, coherence and activity of existing community organizations. In the best example, a local development group already employing many of the central principles of ICZM (e.g. inclusive participation, working with natural processes) was identified. By focussing on local problems, practical solutions and relatively small numbers of stakeholders, agreement was reached on the majority of issues and strategies covered by the management plans. Implementation of the plans will begin in early 2000.
This paper discusses the history of atmospheric lead pollution, the past geographic distribution of atmospheric lead deposition in Sweden, and the fate of the pollution lead in boreal forest soils. The paper is based on analyses of 206Pb/207Pb isotope ratios and lead concentrations in lake sediments, peat deposits and soil profiles from Sweden. The first signs of atmospheric lead pollution date back to 3500 to 4000 years ago. There was a small, but clear peak during the Greek-Roman period around 0 AD. About 1000 AD a major and unreversed increase occurred; varved lake sediments disclose pollution peaks at about 1200 AD and 1530 AD, which match peaks in metallurgy in Europe. With the Industrial Revolution atmospheric lead pollution increased, however, not as much as usually suggested, and not at all from what can be called background values. Lead pollution increased markedly after World War II, peaked about 1970, and will, if the present trend continues, soon be back to Medieval levels. The distribution of pre-industrial pollution was similar to the contemporary pattern with a strong south to north gradient, as a result of northward atmospheric transport from continental Europe and the British Isles. The cumulative load of pollution lead through time is 2 to 3 g m−2 in S Sweden, and of this load at least 50% was deposited prior to 1800 AD. In boreal forest soils, the main part of this pollution lead has accumulated in the B horizon. Present-day concentrations in the mor layer are up to 1000 times higher than in the pristine forest prior to pollution.
Night-time satellite imagery acquired between October 1994 and March 1995 is here exploited to derive economic and energy-related global maps. By considering the lit area of a city, and combining this with ancillary statistical information, an analysis was performed designed to investigate the potential of night-time imagery for quantitative estimation of global socioeconomic parameters. An attempt to estimate global urban population using correlations of lit area and urban populations to derive country-level relationships accounted for over 90% of the quoted total. Furthermore, the total lit area of a country has a statistically significant high correlation value with other parameters, specifically Gross Domestic Product (GDP) and total carbon dioxide (CO2) emission. The new technique is limited by the spatial resolution of the sensor and the poorer correlation using night-time lights for centrally-planned economies. These findings offer great potential for synoptic global mapping of such parameters in the future.
Although motorways could affect wildlife species, only few studies have been documented on their effects on mortality and isolation. With 2266 road-killed animals representing 97 species, the results of a study on a motorway section emphasized that traffic considerably affected vertebrate populations (14.5 animals day−1100 km−1). Road-killed animals were mainly mammals (43.2%), with predators also suffering critical impacts (21.7% vertebrates). Rare or endangered species such as the Midwife toad, the Blue throat, the little Horseshoe bat, or the European otter were among the victims. Animal mortality exponentially increased with traffic volume. Mortality reached almost 100% of migrants when no passage existed, and this barrier effect was only reduced when underground passages crossed the road restraining the mortality to 31% of migrants in Field mice and 23% in Common toads, while mortality always exceeded 74% in a road section with fauna ducts. It is reasonable to conclude that traffic severely influenced both wildlife species demography and population exchanges resulting in effective population isolation.
Cacao (Theobroma cacao) is a crop of the humid lowland tropics produced largely by small-scale producers and often on farms with a canopy of shade trees. Where a diverse shaded canopy is used, cacao farms support higher levels of biological diversity than most other tropical crops. A host of viral and fungal diseases, loss of soil fertility, and numerous socioeconomic problems facing producers, often makes cacao production locally unsustainable. Continued clearing of new lands threatens biodiversity. Moreover, new frontiers for cacao expansion are rapidly disappearing. Such problems can be addressed by increasing the long-term productivity of existing cacao farms and restoring abandoned lands. Improved shade management offers guidance along this path. Institutions involved with cocoa should establish collaborations with groups concerned with development, environmental protection, and most importantly producers themselves to pursue a program of research, extension and policy initiatives focused on the ecologically and economically sustainable cacao production on farms with a diverse shade canopy.
Thailand has been the world's largest exporter of cultured shrimp since 1991. Despite problems with poor environmental conditions and disease outbreaks that led to the failure and abandonment of numerous farms along the coast, Thai shrimp production has remained high. A primary factor has been the establishment of low salinity shrimp farming for black tiger shrimp (Penaeus monodon) in areas much further inland from the coast than once thought feasible. The rapid development of low salinity culture in freshwater areas that are predominantly used for paddy rice cultivation, however, now represents a major land and water management challenge. The debate over the potential environmental impacts of inland shrimp farming revolves around three key questions: i) the ability of so-called “closed” production systems to minimize environmental impacts, ii) the capacity of the Thai government to enforce environmental protection regulations, and iii) the potential emergence of cumulative environmental impacts. This paper concludes that a ban on inland shrimp farming is a prudent measure, needed to protect soil and water quality in freshwater areas.