نتایج جستجو برای: conservation
تعداد نتایج: 101170 فیلتر نتایج به سال:
■ Abstract Over the past ten years the scientific basis for reserve selection and design have rapidly developed. This period has also been characterized by a shift in emphasis toward large spatial and organizational scales of conservation efforts. I discuss the evidence in support of this shift toward larger scale conservation by contrasting the success of fine-filter (genes, populations, speci...
Based on 2004 CEAP-ARMS Phase II data, higher-sales farms not participating in a conservation programme adopted farmland conservation structures much more intensively on wheat fields than did any other farm-size type among conservation programme participants or non-participants. Survey results suggest that wheat farms not participating in a conservation programme more frequently adopted infield...
Our ability to identify cost-efficient priorities for conserving biological diversity is limited by the scarcity of data on conservation costs, particularly at fine scales. Here we address this issue using data for 139 terrestrial programs worldwide. We find that the annual costs of effective field-based conservation vary enormously, across seven orders of magnitude, from <$0.1 to >$1,000,000 p...
Although the application of population and evolutionary genetic theory and methods to address issues of conservation relevance has a long history, the formalization of conservation genetics as a research field is still relatively recent. One of the periodic catalysts for increased research effort in the field has been advances in molecular technologies, leading to an increasingly wider variety ...
Soil erosion is one of the most important forms of land degradation that threatens continued and sustained agricultural production in Ghana. The most severely affected areas are the three northern regions especially Upper East Region, where large tracts of land have been destroyed by water erosion leading to soil depth reduction and decline in soil fertility. This study was carried out in Talen...
The moist temperate Himalayas, as one of the major ecological zone of Pakistan, deserve specific attention to the conservation of environment and the sustainable development of natural resources. During the last hundred years, the area has been subjected to major structural changes leading to a decrease of about fifty per cent of the potential forest area. The decrease in forest cover, combined...
forests and rangelands are the most important natural ecosystems which provide many economic benefits to the society due to their biodiversity and ecological functionalities. dashtenaz wildlife refuge, sari, is a sylvan region, covering 55 ha of rangeland with abundant diversity, is refuge of an endangered species of deer called dama mesopotamica. in this study, contingent valuation method (cvm...
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