939 resultados para conservation on private lands


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Anderson theorizes that development of the aquaculture of a fish species (also captured in an open-access fishery) favours the conservation of its wild stocks, if competitive market conditions prevail. However, his theory is subject to significant limitations. While this is less so within his model, it is particularly so in an extended one outlined here. These other models allow for the possibility that aquaculture development can impact negatively on wild stocks thereby shifting the supply curve of the capture fishery, or raise the demand for the fish species subject both to aquaculture and capture. Such development can threaten wild fish stocks and their biodiversity. While aquaculture development could in principle have no impact on the biodiversity of wild stocks or even raise aquatic biodiversity overall, its impact in the long-term probably will be one of reducing aquatic diversity both in the wild and overall. The development of aquaculture does not automatically ensure long-term sustainability of fish and other aquatic supplies.

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The history of political and economic inequality in forest villages can shape how and why resource use conflicts arise during the evolution of national parks management. In the Philippine uplands, indigenous peoples and migrant settlers co-exist, compete over land and forest resources, and shape how managers preserve forests through national parks. This article examines how migrants have claimed lands and changed production and exchange relations among the indigenous Tagbanua to build on and benefit from otherwise coercive park management on Palawan Island, the Philippines. Migrant control over productive resources has influenced who, within each group, could sustain agriculture in the face of the state's dominant conservation narrative - valorizing migrant paddy rice and criminalizing Tagbanua swiddens. Upon settling, migrant farmers used new political and economic strengths to tap into provincial political networks in order to be hired at a national park. As a result, they were able to steer management to support paddy rice at the expense of swidden cultivation. While state conservation policy shapes how national parks impact upon local resource access and use, older political economic inequalities in forest villages build on such policies to influence how management affects the livelihoods of poor households.

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Acacia harpophylla F. Muell. (brigalow) used to naturally occur over a range of about 50 000 km(2) in Queensland and New South Wales, Australia. Large scale clearing for agriculture has reduced the area to less than 20 000 km(2) and it is estimated that 20-25% of vertebrate fauna living in brigalow communities will become locally extinct as a result of the current clearing induced loss of habitat. Some coal mining companies in central Queensland have become interested in providing habitat for the endangered bridle nail-tailed wallaby that lives in brigalow vegetation. However, there is little known about establishment techniques for brigalow on mine sites and other disturbed ground; an understanding of brigalow biology and ecology is required to assist in the conservation of this threatened vegetation community and for re-creation of bridled nail-tail wallaby habitat in the post mining landscape. Brigalow is an unusual species of Acacia because it is not hard-seeded and germinates readily without the need to break seed-coat imposed dormancy. Germination trials were undertaken to test the ability of brigalow seed to germinate with a range of temperatures and salinity levels similar to those experienced in coal mine spoil. Optimum germination was found to occur at temperatures from 15 to 38 degrees C and no germination was recorded at 45 degrees C. Brigalow was very tolerant of high salt levels and germinated at percentages greater than 50% up to the highest salinity tested, 30 dS/m. Germination of greater than 90% occurred up to an electrical conductivity of 20 dS/m. The results indicate brigalow seed can be sown in summer when rains are most likely to occur, however, shading of the seed with extra soil or mulch may ensure the ground surface does not become too hot for germination. Because of its ability to germinate at high salinity levels, brigalow may be suitable for use in saline mine wastes which are common on sites to be rehabilitated after mining.