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21.
IAN S. SEIFERLING RAPHAËL PROULX PEDRO R. PERES‐NETO LENORE FAHRIG CHRISTIAN MESSIER 《Conservation biology》2012,26(4):610-618
Abstract: Protected areas cover over 12% of the terrestrial surface of Earth, and yet many fail to protect species and ecological processes as originally envisioned. Results of recent studies suggest that a critical reason for this failure is an increasing contrast between the protected lands and the surrounding matrix of often highly altered land cover. We measured the isolation of 114 protected areas distributed worldwide by comparing vegetation‐cover heterogeneity inside protected areas with heterogeneity outside the protected areas. We quantified heterogeneity as the contagion of greenness on the basis of NDVI (normalized difference vegetation index) values, for which a higher value of contagion indicates less heterogeneous land cover. We then measured isolation as the difference between mean contagion inside the protected area and mean contagion in 3 buffer areas of increasing distance from the protected‐area border. The isolation of protected areas was significantly positive in 110 of the 114 areas, indicating that vegetation cover was consistently more heterogeneous 10–20 km outside protected areas than inside their borders. Unlike previous researchers, we found that protected areas in which low levels of human activity are allowed were more isolated than areas in which high levels are allowed. Our method is a novel way to assess the isolation of protected areas in different environmental contexts and regions. 相似文献
22.
Little research has been done on characteristics of successful self-managed work group members, despite the fact that almost every major U.S. corporation is considering implementing such teams. This study examined the relationship between the Big Five personality dimensions and self-efficacy for participating in self-managed work groups. A questionnaire was administered to 126 workers in a manufacturing organization that is planning the implementation of self-managed work groups. Results indicated that Neuroticism, Extraversion, Agreeableness, and Conscientiousness were significantly related to self-efficacy for participating in self-managed work groups. Due to the relationship between self-efficacy and performance, one implication of these findings is that organizations should consider personality when deciding whether or not to implement self-managed work groups or who should be selected to work in this type of structure. Future research should include measures of individual and group performance and withdrawal behaviors to extend these findings. 相似文献
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24.
Multiple-species habitat conservation plans (MSHCPs) are designed to eliminate project-by-project review and minimize species-by-species conflicts; but these one-time, short-term processes invariably compress the divergent expectations of interest groups into an exercise driven by economic, amenity, and aesthetic values rather than scientific values. Participants may define an MSHCP as an exchange of habitat preserves for federal permits to take populations of endangered animals and plants, but the outcome is typically driven by overarching arguments over land development and suburban sprawl. Existing land uses also constrain the size, shape, and linkages among wildlife habitats, leading to a divergence of MSHCPs from the scientific preserve selection and design literature. Problems created by constraints to preserve configuration (e.g., land costs, fragmentation, pre-existing amounts of edge, lack of connectivity) must be resolved by long-term, post facto management. To date, estimates of preserve persistence have not been used in MSHCPs. Rather than focus on map-based exercises of preserve elements, it may be more productive to set goals for the persistence of species (states) and ecosystems (processes) within the preserves-accepting that preserve configurations and arrays will be defined by the landscape and politics of suburban areas and that long-term management will provide the primary means of maintaining biodiversity along the wildland/urban interface. 相似文献
25.
Maintaining Volunteer Commitment to Local Watershed Initiatives 总被引:1,自引:0,他引:1
Australia's Landcare program is advanced as a successful international example of local watershed groups and governments working
together to improve natural resource management. One of the aspects considered critical in the success of watershed groups
is engaging widespread participation. This paper draws on two regional surveys that explored burnout, or loss of engagement,
among Landcare participants in the state of Victoria using the Maslach Burnout Inventory. Survey findings indicated that a
large proportion of respondents were experiencing high burnout in terms of low personal accomplishment and suggested that
there was potential for burnout to increase. The authors suggest that the expectations of watershed groups must be based around
a realistic assessment of the capacity for volunteer groups to deliver improved environmental and social outcomes. 相似文献
26.
An analysis of the historic record of typhoons in the Marshall Islands has identified a significant association between the occurrence of the El Niño/Southern Oscillation phenomenon (ENSO) and the occurrence of typhoons in the Marshall Islands. Whilst typhoons normally occur further to the east, the warming of the ocean waters around the Marshall Islands, as part of the ENSO phenomenon, generates typhoons further to the west. The results suggest that typhoons are 2.6 times more likely to occur during ENSO years, with a 71 per cent chance of a typhoon striking during an ENSO year, and only a 26 per cent chance of one happening during a non-ENSO year. This has implications for planning and public safety, which the relevant authorities may wish to take note of. 相似文献
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28.
Establishing Representative No-Take Areas in the Great Barrier Reef: Large-Scale Implementation of Theory on Marine Protected Areas 总被引:17,自引:0,他引:17
LEANNE FERNANDES JON DAY ADAM LEWIS SUZANNE SLEGERS BRIGID KERRIGAN DAN BREEN DARREN CAMERON BELINDA JAGO JAMES HALL DAVE LOWE JAMES INNES JOHN TANZER VIRGINIA CHADWICK LEANNE THOMPSON KERRIE GORMAN MARK SIMMONS BRYONY BARNETT KIRSTI SAMPSON GLENN DE'ATH BRUCE MAPSTONE HELENE MARSH HUGH POSSINGHAM IAN BALL TREVOR WARD KIRSTIN DOBBS JAMES AUMEND DEB SLATER KATE STAPLETON 《Conservation biology》2005,19(6):1733-1744
Abstract: The Great Barrier Reef Marine Park, an area almost the size of Japan, has a new network of no-take areas that significantly improves the protection of biodiversity. The new marine park zoning implements, in a quantitative manner, many of the theoretical design principles discussed in the literature. For example, the new network of no-take areas has at least 20% protection per "bioregion," minimum levels of protection for all known habitats and special or unique features, and minimum sizes for no-take areas of at least 10 or 20 km across at the smallest diameter. Overall, more than 33% of the Great Barrier Reef Marine Park is now in no-take areas (previously 4.5%). The steps taken leading to this outcome were to clarify to the interested public why the existing level of protection was inadequate; detail the conservation objectives of establishing new no-take areas; work with relevant and independent experts to define, and contribute to, the best scientific process to deliver on the objectives; describe the biodiversity (e.g., map bioregions); define operational principles needed to achieve the objectives; invite community input on all of the above; gather and layer the data gathered in round-table discussions; report the degree of achievement of principles for various options of no-take areas; and determine how to address negative impacts. Some of the key success factors in this case have global relevance and include focusing initial communication on the problem to be addressed; applying the precautionary principle; using independent experts; facilitating input to decision making; conducting extensive and participatory consultation; having an existing marine park that encompassed much of the ecosystem; having legislative power under federal law; developing high-level support; ensuring agency priority and ownership; and being able to address the issue of displaced fishers. 相似文献
29.
Atlantic sturgeon (Acipenser oxyrhynchus) populations have been declared either endangered or threatened under the U.S. Endangered Species Act. Effective measures to repel sturgeon from fishing gear would be beneficial to both fish and fishers because they could reduce both fishery‐associated mortality and the need for seasonal and area closures of specific fisheries. Some chondrostean fishes (e.g., sturgeons and paddlefishes) can detect weak electric field gradients (possibly as low as 5 Μv/cm) due to arrays of electroreceptors (ampullae of Lorenzini) on their snout and gill covers. Weak electric fields, such as those produced by electropositive metals (typically mixtures of the lanthanide elements), could therefore potentially be used as a deterrent. To test this idea, we recorded the behavioral responses of juvenile Atlantic sturgeon (31–43 cm fork length) to electropositive metal (primarily a mixture of the lanthanide elements neodymium and praseodymium) both in the presence and absence of food stimuli. Trials were conducted in an approximately 2.5 m diameter × 0.3 m deep tank, and fish behaviors were recorded with an overhead digital video camera. Video records were subsequently digitized (x, y coordinate system), the distance between the fish and the electropositive metal calculated, and data summarized by compiling frequency distributions with 5‐cm bins. Juvenile sturgeon showed clear avoidance of electropositive metal but only when food was present. On the basis of our results, we conclude that the electropositive metals, or other sources of weak electric fields, may eventually be used to reduce the interactions of Atlantic sturgeon with fishing gear, but further investigation is needed. El Potencial del Metal Electropositivo para Reducir las Interacciones del Esturión Atlántico con Instrumentos de Pesca Bouyoucos, Bushnell & Brill 13–003 相似文献
30.
Hybridization in the Island Endemic, Catalina Mahogany 总被引:3,自引:0,他引:3
LOREN H. RIESEBERG SCOTT ZONA LINDA ABERBOM TERRENCE D. MARTIN 《Conservation biology》1989,3(1):52-58
Abstract: Allozyme data, combined with traditional morphological and anatomical data, were used to evaluate the genetic status of the island endemic, Cercocarpus traskiae (Catalina mahogany). Comprising only seven adult plants and close to 70 seedlings, C. traskiae is confined to Wild Boar Gully on the southwest side of Santa Catalina Island in Los Angeles County, California Electrophoretic examination of 22 enzyme loci revealed that all but two of the seven adult C. traskiae trees were unique allozymically. Furthermore four of the seven C. traskiae individuals were morphologically and/or anatomically intermediate between "true" C. traskiae and the more abundant Cercocarpus species on Santa Catalina, C. betuloides var, blancheae . Further electrophoretic analyses revealed that two of these four individuals possessed an additive "hybrid" enzyme phenotype indicating that these individuals were hybrid. Twenty-five of the seedlings were also assayed but none of the seedlings displayed hybrid enzyme phenotypes.
Given the evidence for hybridization described herein, we make two suggestions to enhance the long-term preservation of C. traskiae . First, it may be desirable to eliminate the single C. betuloides var.: blancheae individual in Wild Boar Gully. Second, we suggest that established cuttings of true C. traskiae be transplanted to areas on Santa Catalina where the probability of hybridization is minimal Our data further demonstrate that accurate taxonomic identification and an understanding of population genetic structure are necessary for the enlightened management of small relict populations or island endemics. 相似文献
Given the evidence for hybridization described herein, we make two suggestions to enhance the long-term preservation of C. traskiae . First, it may be desirable to eliminate the single C. betuloides var.: blancheae individual in Wild Boar Gully. Second, we suggest that established cuttings of true C. traskiae be transplanted to areas on Santa Catalina where the probability of hybridization is minimal Our data further demonstrate that accurate taxonomic identification and an understanding of population genetic structure are necessary for the enlightened management of small relict populations or island endemics. 相似文献