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61.
Maintaining national parks is an integral policy tool to conserve rare habitats. However, because national parks are funded by taxpayers, they must also serve the needs of the general public. Increasingly, and thanks to today's diverse society, there is evidence that this creates challenges for park managers who are pulled in two opposing directions: to conserve nature on the one hand and to meet different visitor expectations on the other. This tension was explored in the Peak District National Park, a rural landscape dominated by heather moorland and sheep farming in Northern England where research was conducted to determine how social class and ethnicity shaped perceptions of the park. Results uncovered that social class played a very strong role in shaping perceptions of this region with 'middle class' respondents reacting far more favourably to the park than people from more working class backgrounds. We observed ethnicity playing a similar role, though our results are less significantly different.  相似文献   
62.
Increasing on-farm crop diversity is one agroecological approach to enhancing food self-sufficiency that helps small-scale farmers keep their food systems stable by reducing risks associated with stressors, such as a pest outbreaks or droughts. But understanding how crop diversity and food self-sufficiency are related is unknown. To explore this complex relation, this study presents household data (n = 1664) from Nepal to test the hypothesis that families with high crop diversity enjoy greater household food self-sufficiency. Data are presented for three districts that are representative of three distinct agroecological regions of the country: (1) Sarlahi, which is affluent, market-oriented, and on the plains; (2) Makwanpur District in the hills, which has well-developed integrated farm production; and (3) the mountainous District of Humla, which has the poorest quality environment and is the most remote. Results show that in the Humla District, families with greater crop diversity were more self-sufficient. In contrast, farmers in Makwanpur, who have already established a high degree of crop diversity based on vegetable production, do not benefit from additional crop diversity in terms of their ability to provide for themselves. Finally, data from Sarlahi show that families’ food self-sufficiency benefits from crop diversification. We conclude that boosting crop diversity is a viable strategy for maintaining stability in food systems, but this varies depending on the accessibility of a farm and, in particular, access to markets.  相似文献   
63.
Two groups of biologists were responsible for an unprecedented delay in completing a endangered species habitat conservation plan in the Coachella Valley of southern California. While antagonism grew as each group relentlessly promoted their perspective on whether to add a few areas to the habitat preserve, their inability to resolve their differences was not simply a matter of mistrust or poor facilitation. I analyze how these biologists practiced science in a way that supported specific institutional and ecological relationships that in turn provided a setting in which each group’s biological expertise was meaningful, credible, and useful. This tight coupling between scientific practice and society meant that something was more important to these scientists than finishing the plan. For both factions of biologists, ensuring the survival of native species in the valley rested on their ability to catalyze institutional relationships that were compatible with their scientific practice. Understanding this co-production of science and the social order is a first step toward effectively incorporating different experts in negotiation and implementation of technically complex collaborative agreements.  相似文献   
64.
Atmospheric CO2 concentrations are predicted to double within the next century and alter climate regimes, yet the extent that these changes will affect plant diseases remains unclear. In this study conducted over five years, we assessed how elevated CO2 and interannual climatic variability affect Cercospora leaf spot diseases of two deciduous trees. Climatic data varied considerably between the five years and altered disease expression. Disease incidence and severity for both species were greater in years with above average rainfall. In years with above average temperatures, disease incidence for Liquidambar styraciflua was decreased significantly. When significant changes did occur, disease incidence and severity always increased under elevated CO2. Chlorophyll fluorescence imaging of leaves revealed that any visible increase in disease severity induced by elevated CO2 was mitigated by higher photosynthetic efficiency in the remaining undamaged leaf tissue and in a halo surrounding lesions.  相似文献   
65.
A direct, controlled comparison of the photodegradation of imazethapyr has been made between imazethapyr in aqueous solutions, imazethapyr on the surface of epicuticular waxes of corn and soybean plants, and imazethapyr on the surface of intact corn and soybean plant leaves. In some experiments, the imazethapyr solutions were allowed to evaporate partially or fully after application to better model environmental conditions. The photodegradation of imazethapyr was fastest in aqueous solutions (k?=?0.16?±?0.02?h?1) and slowest on the surface of corn and soybean plants (kcorn?=?0.00048?±?0.001?h?1 and ksoy?=?0.00054?±?0.003?h?1). Experiments allowing evaporation during irradiation have intermediate rate constants (e.g., kcorn?=?0.082?±?0.005?h?1). Finally, identification of photoproducts was also examined on epicuticular waxes of corn and soybean plants for the first time.  相似文献   
66.
The high demand for conservation work is creating a need for conservation‐focused training of scientists. Although many people with postsecondary degrees in biology are finding careers outside academia, many programs and mentors continue to prepare students to follow‐in‐the‐footsteps of their professors. Unfortunately, information regarding how to prepare for today's conservation‐based job market is limited in detail and scope. This problem is complicated by the differing needs of conservation organizations in both economically developed and developing regions worldwide. To help scientists identify the tools needed for conservation positions worldwide, we reviewed the current global conservation job market and identified skills required for success in careers in academia, government, nonprofit, and for‐profit organizations. We also interviewed conservation professionals across all conservation sectors. Positions in nonprofit organizations were the most abundant, whereas academic jobs were only 10% of the current job market. The most common skills required across sectors were a strong disciplinary background, followed by analytical and technical skills. Academic positions differed the most from other types of positions in that they emphasized teaching as a top skill. Nonacademic jobs emphasized the need for excellent written and oral communication, as well as project‐management experience. Furthermore, we found distinct differences across job locations. Positions in developing countries emphasized language and interpersonal skills, whereas positions in countries with advanced economies focused on publication history and technical skills. Our results were corroborated by the conservation professionals we interviewed. Based on our results, we compiled a nondefinitive list of conservation‐based training programs that are likely to provide training for the current job market. Using the results of this study, scientists may be better able to tailor their training to maximize success in the conservation job market. Similarly, institutions can apply this information to create educational programs that produce graduates primed for long‐term success.  相似文献   
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There is a dearth of research focusing on the role that urban residential open space plays in climate change adaptation, despite evidence suggesting that environmental benefits accrue when even small pockets of open space are made permeable and vegetated. In densely built New York City, there are 21,448?ha (53,000 acres) of such land. One city block with adjoining contiguous open space was investigated to quantify its existing environmental value and also its potential to provide enhanced services through redesign. The study block's open space was found to be 35% permeable and planted with 96 trees, storing 45,359?kg (100,000?lb) of carbon. Simulations conducted using the United States Environmental Protection Agency Stormwater Management Model contrasting normal, light, and heavy precipitation years suggested that increases in annual precipitation could be fully mitigated by reducing impervious surface cover by 25%. The preservation of the existing vegetated residential urban open space and the conversion of paved surfaces to a pervious condition both appear to be effective strategies for enhancing the city's ability to adapt to and mitigate for climate change.  相似文献   
70.
Climate change is a complex long-run phenomenon. The speed and severity with which it is occurring is difficult to observe, complicating the formation of beliefs for individuals. We use Google search intensity data as a proxy for the salience of climate change and examine how search patterns vary with unusual local weather. We find that searches for “climate change” and “global warming” increase with extreme temperatures and unusual lack of snow. Furthermore, we demonstrate that effects of abnormal weather extend beyond search behavior to observable action on environmental issues. We examine the voting records of members of the U.S. Congress from 2004 to 2011 and find that members are more likely to take a pro-environment stance on votes when their home state experiences unusual weather.  相似文献   
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