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The Novel and Endemic Pathogen Hypotheses: Competing Explanations for the Origin of Emerging Infectious Diseases of Wildlife 总被引:7,自引:0,他引:7
LARA J. RACHOWICZ‡‡ JEAN-MARC HERO†‡ ROSS A. ALFORD§ JOHN W. TAYLOR JESS A.T. MORGAN VANCE T. VREDENBURG† JAMES P. COLLINS†† CHERYL J. BRIGGS 《Conservation biology》2005,19(5):1441-1448
Abstract: Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis , is an emerging infectious disease implicated in declines of amphibian populations around the globe. An emerging infectious disease is one that has recently been discovered; has recently increased in incidence, geography, or host range; or is newly evolved. For any given outbreak of an emerging disease, it is therefore possible to state two hypotheses regarding its origin. The novel pathogen hypothesis states that the disease has recently spread into new geographic areas, whereas the endemic pathogen hypothesis suggests that it has been present in the environment but recently has increased in host range or pathogenicity. Distinguishing between these hypotheses is important, because the conservation measures needed to slow or stop the spread of a novel pathogen are likely to differ from those needed to prevent outbreaks of an endemic pathogen. Population genetics may help discriminate among the possible origins of an emerging disease. Current evidence suggests chytridiomycosis may be a novel pathogen being spread worldwide by carriers; until we know how much genetic variation to expect in an endemic strain, however, we cannot yet conclude that B. dendrobatidis is a novel pathogen. 相似文献
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Abstract: To be successful, conservation practitioners and resource managers must fully integrate the effects of climate change into all planning projects. Some conservation practitioners are beginning to develop, test, and implement new approaches that are designed to deal with climate change. We devised four basic tenets that are essential in climate-change adaptation for conservation: protect adequate and appropriate space, reduce nonclimate stresses, use adaptive management to implement and test climate-change adaptation strategies, and work to reduce the rate and extent of climate change to reduce overall risk. To illustrate how this approach applies in the real world, we explored case studies of coral reefs in the Florida Keys; mangrove forests in Fiji, Tanzania, and Cameroon; sea-level rise and sea turtles in the Caribbean; tigers in the Sundarbans of India; and national planning in Madagascar. Through implementation of these tenets conservation efforts in each of these regions can be made more robust in the face of climate change. Although these approaches require reconsidering some traditional approaches to conservation, this new paradigm is technologically, economically, and intellectually feasible. 相似文献
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Conservation Genetics of the Endangered Isle Royale Gray Wolf 总被引:5,自引:0,他引:5
R. K. WAYNE N. LEHMAN D. GIRMAN P.J.P. GOGAN D. A. GILBERT K. HANSEN R. O. PETERSON U. S. SEAL A. EISENHAWER L. D. MECH R.J. KRUMENAKER 《Conservation biology》1991,5(1):41-51
Abstract. The small group of wolves on Isle Royale has been studied for over three decades as a model of the relationship between large carnivores and their prey. During the last ten years the population declined from 50 individuals to as few as 12 individuals. The causes of this decline may be food shortages, disease, or reduced genetic variability. We address the issues of genetic variability and relationships of Isle Royale wolves using allozyme electrophoresis, mtDNA restriction-site analysis, and multilocus hypervariable minisatellite DNA analysis (genetic fingerprinting). Our results indicate that approximately 50% of the allozyme heterozygosity has been lost in the island population, a decline similar to that expected if no immigration had occurred from the mainland. The genetic fingerprinting data indicate that the seven sampled Isle Royale wolves are as similar as captive populations of siblings. Surprisingly, the Isle Royale wolves have an mDNA genotype that is very rare on the mainland, being found in only one of 144 mainland wolves ThFF suggests that the remaining Isle Royale wolves areprobably derived from a single female founder 相似文献
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Enersol's SOBASEC (SOlar-BASed Rural Electrification Concept) programme demonstrates that stand-alone photovoltaic (PV) systems can be an economical option to grid expansion. Developing a local institutional system to support the dissemination of PV technology at the community level has been a major thrust of the programme. Both a service and parts enterprise and a local credit institution have been established, and technicians have been trained and employed. A modest revolving fund was also established to finance the installations. Field analysis of 100 installed systems suggests that small PV systems are viable for widespread application in the Dominican Republic. 相似文献
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JAY R. MALCOLM†† CANRAN LIU† RONALD P. NEILSON‡ LARA HANSEN§ LEE HANNAH 《Conservation biology》2006,20(2):538-548
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VALUING ECOSYSTEM SERVICES OF CHILEAN TEMPERATE RAINFORESTS 总被引:1,自引:0,他引:1
LAURA NAHUELHUAL PABLO DONOSO ANTONIO LARA DAISY NÚÑEZ CARLOS OYARZÚN EDUARDO NEIRA 《Environment, Development and Sustainability》2007,9(4):481-499
The Valdivian Rainforest Ecoregion (35°–48° S) in southern South America is among the ecosystems with highest conservation
priority worldwide due to its rich diversity, degree of endemism, and critical conservation status. Temperate rainforests
in this vast area are essential as source of biological resources and to maintain different ecosystem services which remain
largely unmeasured and unvalued. Consequently, the benefits they provide are not reflected in decision-making regarding forest
management and conservation. Based on existing studies and results from ongoing research we describe selected ecosystem services
and provide estimates of their economic value. Timber benefits for secondary forests expressed as net present stumpage values
were US$ 3742 ha−1 and US$ 3093 ha−1 for sustainable forest management (SFM) and unsustainable harvesting, respectively. Timber benefits for old growth forests␣equaled
US$ 4546 ha−1 and US$ 5718 ha−1, for SFM and unsustainable harvesting, respectively, using an 8% discount rate. Annual benefits from recreation were US$
1.6 ha−1 and US$ 6.3 ha−1 for the two most important national parks located in the study area. The annual value of maintaining soil fertility was US$
26.3 ha−1 using the replacement cost of nutrient losses due to soil erosion. The annual economic value of water supply for human consumption
using the production function method was US$ 235 ha−1. These results provide valuable information on the kind and magnitude of values that could be relevant in decision-making
concerning conservation and management of native forests in the Valdivian Rainforest Ecoregion. 相似文献
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Neglect of Genetic Diversity in Implementation of the Convention on Biological Diversity 总被引:1,自引:0,他引:1
LINDA LAIKRE FRED W. ALLENDORF LAUREL C. ARONER C. SCOTT BAKER DAVID P. GREGOVICH MICHAEL M. HANSEN JENNIFER A. JACKSON KATHERINE C. KENDALL KEVIN McKELVEY MAILE C. NEEL ISABELLE OLIVIERI NILS RYMAN MICHAEL K. SCHWARTZ RUTH SHORT BULL JEFFREY B. STETZ DAVID A. TALLMON BARBARA L. TAYLOR CHRISTINA D. VOJTA DONALD M. WALLER ROBIN S. WAPLES 《Conservation biology》2010,24(1):86-88
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Payments for Ecosystem Services as a Framework for Community-Based Conservation in Northern Tanzania 总被引:1,自引:0,他引:1
FRED NELSON CHARLES FOLEY† LARA S. FOLEY† ABRAHAM LEPOSO‡ EDWARD LOURE‡ DAVID PETERSON§ MIKE PETERSON§ THAD PETERSON§ HASSAN SACHEDINA ANDREW WILLIAMS†† 《Conservation biology》2010,24(1):78-85
Abstract: Payments for ecosystem services (PES) are an increasingly promoted approach to conservation. These approaches seek to develop financial mechanisms that create economic incentives for the maintenance of ecosystems and associated biodiversity by rewarding those who are responsible for provision of ecological services. There are, however, few cases in which such schemes have been used as a strategy for conserving wildlife in developing countries and very few operational examples of such schemes of any sort in sub-Saharan Africa. In savannah ecosystems, large mammal populations generally depend on seasonal use of extensive areas and are widely declining as a result of habitat loss, overexploitation, and policies that limit local benefits from wildlife. Community-based conservation strategies seek to create local incentives for conserving wildlife, but often have limited impact as a result of persistent institutional barriers that limit local rights and economic benefits. In northern Tanzania, a consortium of tourism operators is attempting to address these challenges through an agreement with a village that possesses part of a key wildlife dispersal area outside Tarangire National Park. The operators pay the community to enforce voluntary restrictions on agricultural cultivation and permanent settlement in a defined area of land. The initiative represents a potentially cost-effective framework for community-based conservation in an ecologically important area and is helping to reconcile historically conflicting local and national interests relative to land tenure, pastoralist livelihoods, and conservation. Wider adaptation of payments for ecosystem services approaches to settings where sustaining wildlife populations depends on local stewardship may help address current challenges facing conservation outside state-protected areas in savannah ecosystems in sub-Saharan Africa and other parts of the world. 相似文献
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