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691.
692.
LEONARDO A. GALLO†† PAULA MARCHELLI† LUIS CHAUCHARD‡ MARCELO GONZALEZ PEÑALBA§ 《Conservation biology》2009,23(4):895-898
Abstract: Researchers dealing with conservation subjects usually do not put the results of their work into practice, even when the primary purpose of their research is the preservation of biodiversity. In the South American temperate forests we identified an area with the highest genetic diversity in Argentina of Nothofagus nervosa, one of the most relevant southern beech species. Based on the information of our scientific study and our recommendations, the authorities of Lanin National Park changed the protection status of this area to avoid logging. The new forestry management plans include consideration of "high genetic diversity" in decisions on where logging will be allowed. Results of our initial genetic study induced the analysis of biodiversity at the species and ecosystems levels, which yielded results similar to our genetic studies. A strong connection among researchers and managers from the onset of our study and the awareness of the former about the importance of the implementation of the research work were key to bridging the gap between conservation research and conservation practice. 相似文献
693.
Roberto Melotti Ezio Santagata Marco Bassani Milena Salvo Stefano Rizzo 《Waste management (New York, N.Y.)》2013,33(9):1906-1917
Fly and bottom ashes are the main by-products arising from the combustion of solid biomass. Since the production of energy from this source is increasing, the processing and disposal of the resulting ashes has become an environmental and economic issue. Such ashes are of interest as a construction material because they are composed of very fine particles similar to fillers normally employed in bituminous and cementitious mixtures. This research investigates the potential use of ash from biomass as filler in bituminous mixtures. The morphological, physical and chemical characteristics of 21 different ashes and two traditional fillers (calcium carbonate and “recovered” plant filler) were evaluated and discussed. Leaching tests, performed in order to quantify the release of pollutants, revealed that five ashes do not comply with the Italian environmental re-use limits. Experimental results show a wide range of values for almost all the investigated properties and a low correlation with biomass type in terms of origin and chemical composition. Furthermore, sieving and milling processes were found to improve the properties of the raw material in terms of grading and sample porosity. The effectiveness of these treatments and the low content of organic matter and harmful fines suggest that most of the biomass ashes investigated may be regarded as potential replacements for natural filler in bituminous mixtures. 相似文献
694.
Abstract: We reviewed the evidence on the extent and efficacy of conservation of tropical forest biodiversity for each of the classes of conservation action defined by the new International Union for Conservation of Nature (IUCN) classification. Protected areas are the most tested conservation approach, and a number of studies show they are generally effective in slowing deforestation. There is some documentation of the extent of sustainable timber management in tropical forest, but little information on other landscape‐conservation tactics. The extent and effectiveness of ex situ species conservation is quite well known. Forty‐one tropical‐forest species now survive only in captivity. Other single‐species conservation actions are not as well documented. The potential of policy mechanisms, such as international conventions and provision of funds, to slow extinctions in tropical forests is considerable, but the effects of policy are difficult to measure. Finally, interventions to promote tropical conservation by supporting education and livelihoods, providing incentives, and furthering capacity building are all thought to be important, but their extent and effectiveness remain poorly known. For birds, the best studied taxon, the sum of such conservation actions has averted one‐fifth of the extinctions that would otherwise have occurred over the last century. Clearly, tropical forest conservation works, but more is needed, as is critical assessment of what works in what circumstances, if mass extinction is to be averted. 相似文献
695.
Abstract: We examined how differences in local forest‐management institutions relate to disparate anthropogenic forest disturbance and forest conditions among three neighboring montane forests in Tanzania under centralized, comanaged, or communal management. Institutional differences have been shaped by decentralization reforms. We conducted semistructured interviews with members of forest management committees, local government, and village households and measured anthropogenic disturbance, tree structure, and species composition in forest plots. We assessed differences in governance system components of local institutions, including land tenure, decision‐making autonomy by forest users, and official and de facto processes of rule formation, monitoring, and enforcement among the three management strategies. We also assessed differences in frequencies of prohibited logging and subsistence pole cutting, and measures of forest condition. An adjacent research forest served as an ecological reference for comparison of forest conditions. Governance was similar for comanaged and centralized management, whereas communal managers had greater tenure security and decision‐making autonomy over the use and management of their forest. There was significantly less illegal logging in the communal forest, but subsistence pole cutting was common across all management strategies. The comanaged forest was most disturbed by recent logging and pole cutting, as were peripheral areas of the larger centralized forest. This manifested in more degraded indicators of forest conditions (lower mean tree size, basal area, density of trees ≥ 90 cm dbh, and aboveground biomass and higher overall stem density). Greater tenure security and institutional autonomy of the communal strategy contributed to more effective management, less illegal logging, and maintenance of good forest conditions, but generating livelihood benefits was a challenge for both decentralized strategies. Our results underscore the importance of well‐designed institutional arrangements in forest management and illustrate mechanisms for improved forest governance and conservation in the context of Tanzanian decentralization reforms. 相似文献
696.
George Foy 《Environmental management》1990,14(6):771-778
The core requirement of sustainability is that current economic activities should not result in an excessive burden on future
generations. This criterion is general enough to imply different decision rules for the preservation of environmental assets.
Neoclassical economics does not have a sustainability criterion for environmental assets independent of the intertemporal
efficiency criterion, which allocates environmental and man-made capital based on projected monetary benefits and costs. This
criterion is examined in terms of the feasibility of valuing the benefits of environmental assets, the substitution possibilities
between natural and man-made capital, and the ethical grounds for using efficiency as the sole determinant of the allocation
of environmental assets. An alternative ecological sustainability criterion is the preservation of safe minimum levels of
environmental assets in physical terms rather than the dollar value of a composite of natural and man-made capital. Safe minimum
standards for environmental assets constrain the efficiency criterion in order to ensure the sustainability of economic systems.
It is argued that the ecological approach to sustainability should limit the economic approach for decisions involving the
allocation of environmental assets. 相似文献
697.
Richard Shearman 《Environmental management》1990,14(1):1-8
Some have argued that the meaning of sustainability varies according to context, forcing us to be as explicit as possible when defining our terms. An argument is offered that disputes this conclusion by maintaining that it is not the meaning of sustainability that changes with respect to context, but rather our understanding of the context itself. This is frequently apparent in contradictions that arise when conceiving each context in terms of sustainability. If this argument is correct, then we should be concerned not with the “meaning” of sustainability but rather the implications of sustainability as they affect the status quo. And in order to do this we must be prepared to answer the question: Why is sustainability desirable? This approach is illustrated through a preliminary conceptual and ethical analysis of ecologically sustainable development. 相似文献
698.
Almost half (354) of all fish kills (805) in South Carolina, USA, between 1978 and 1988 occurred in the coastal zone. These
kills were analyzed for causative, spatial, and temporal associations as a distinct data set and as one integrated with ambient
water quality monitoring data. Estuarine kills as a result of natural causes accounted for 42.8% followed by man-induced (35.1%)
and undetermined causes (22.1%).
Although general pesticide usage was responsible for 53.9% of man-induced kills, weed control activities around resorts and
municipal areas accounted for slightly more kills (20.9%) than did agricultural (19.8%) or vector control (13.2%) uses. A
dramatic decline in agricultural-related kills has been observed since 1986 as the integrated pest management approach was
adopted by many farmers. When taken with the few kills (12.0%) resulting from wastewaters, this suggests that these two land-use
activities have been successfully managed via existing programs (IPM and NPDES, respectively) to minimize their contributions
to estuarine fish kills.
Ambient trend monitoring data demonstrated no coastal-wide dispersion of pesticide pollution. These data confirmed the nature
of fish kills to be site-specific, near-field events most closely associated with the contiguous land-use practices and intensities.
Typically, fish kill data are considered as event-specific data limited to the bounds of that event only. Our analysis has
shown, however, that a long-term data set, when integrated with ambient water quality data, can assist in regulatory and resource
management decisions for both short- and long-term planning and protection applications. 相似文献
699.
A factor analytic study of attitudinal structure and its impact on rural landowners' access policies
Previous research has shown that rural landowners' hunter access policies are determined in large part by their attitudes
towards hunters, legal liability, conservation, and economic incentives. The results of this study support this research and
indicate that East Texas, USA, landowners' decisions to allow or restrict access are based, in part, on attitudes toward hunter
behavior, hunting as a social activity, leasing as a management practice, and a perceived obligation toward wildlife stewardship.
Attitude-based profiles of landowners who adopted one of four access policies are compared. 相似文献
700.