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371.
372.
Castor canadensis ) management in Wyoming, USA, was sent to 5265 private-land managers and 124 public-land managers during 1993. The survey
was developed in response to increasing interest in beaver management and beaver reintroduction possibilities. Private-land
managers responding to the survey supplied information on 62,859 km2 of land area and 20,037 km of streams. Primary concerns about beaver damage centered on (in decreasing order of importance)
blocked irrigation ditches, girdled timber, blocked culverts, and flooded pastures, roads, crops, and timber. Primary benefits
that landowners perceive that beaver give them were, in order of importance, elevated water tables, increased riparian vegetation,
and increased stock-watering opportunities. Public-land managers also listed these benefits and detriments among their top
concerns for beaver. Over 45% of landowners with beaver on their property and all of the public-land managers displayed an
interest in a beaver reintroduction program and in more proactive beaver management. 相似文献
373.
Implications of Rural–Urban Migration for Conservation of the Atlantic Forest and Urban Growth in Misiones,Argentina (1970–2030) 总被引:2,自引:0,他引:2
Global trends of increasing rural–urban migration and population urbanization could provide opportunities for nature conservation,
particularly in regions where deforestation is driven by subsistence agriculture. We analyzed the role of rural population
as a driver of deforestation and its contribution to urban population growth from 1970 to the present in the Atlantic Forest
of Argentina, a global conservation priority. We created future land-use-cover scenarios based on human demographic parameters
and the relationship between rural population and land-cover change between 1970 and 2006. In 2006, native forest covered
50% of the province, but by 2030 all scenarios predicted a decrease that ranged from 18 to 39% forest cover. Between 1970
and 2001, rural migrants represented 20% of urban population growth and are expected to represent less than 10% by 2030. This
modeling approach shows how rural–urban migration and land-use planning can favor nature conservation with little impact on
urban areas. 相似文献
374.
Duretz S Drouet JL Durand P Hutchings NJ Theobald MR Salmon-Monviola J Dragosits U Maury O Sutton MA Cellier P 《Environmental pollution (Barking, Essex : 1987)》2011,159(11):3162-3170
Modelling nitrogen transfer and transformation at the landscape scale is relevant to estimate the mobility of the reactive forms of nitrogen (Nr) and the associated threats to the environment. Here we describe the development of a spatially and temporally explicit model to integrate Nr transfer and transformation at the landscape scale. The model couples four existing models, to simulate atmospheric, farm, agro-ecosystem and hydrological Nr fluxes and transformations within a landscape. Simulations were carried out on a theoretical landscape consisting of pig-crop farms interspersed with unmanaged ecosystems. Simulation results illustrated the effect of spatial interactions between landscape elements on Nr fluxes and losses to the environment. More than 10% of the total N2O emissions were due to indirect emissions. The nitrogen budgets and transformations of the unmanaged ecosystems varied considerably, depending on their location within the landscape. The model represents a new tool for assessing the effect of changes in landscape structure on Nr fluxes. 相似文献
375.
South Africa's moist grassland harbours globally significant biodiversity, supplies essential ecosystem services, supports crop and livestock agriculture, forestry and settlement, yet is poorly conserved. Ongoing transformation and limited opportunity for expanding the protected area network require instead that biodiversity conservation is 'mainstreamed' within other land uses. This exercise sought to identify the relative compatibility of 10 land uses (conservation, livestock or game ranching, tourism/recreation, rural settlement, dryland cropping, irrigated cropping, dairy farming, plantation forestry, and urban settlement) with maintaining biodiversity integrity. This was assessed using 46 indicators for biodiversity integrity that covered landscape composition, structure, and functioning. Data was integrated into a single measure per land use through application of the analytic hierarchy process, with supporting information gained from interviews with experts. The rank order of importance amongst indicators was landscape structure, functioning and composition. Consistent differences among land uses for all three categories revealed two clear groupings. Conservation, livestock or game ranching had the lowest impact and retained substantial natural asset, while that for tourism/recreation was intermediate. All other land uses had a severe impact. Impact on biodiversity integrity depended mainly on the extent of transformation and fragmentation, which accounted for the greatest impact on habitats and species, and impairment of landscape functioning. It is suggested that a strategic intervention for maintaining biodiversity integrity of moist grassland is to support livestock or game ranching and limit ongoing urban sprawl. 相似文献
376.
Moore SA Wallington TJ Hobbs RJ Ehrlich PR Holling CS Levin S Lindenmayer D Pahl-Wostl C Possingham H Turner MG Westoby M 《Environmental management》2009,43(1):17-27
Current ecological thinking emphasizes that systems are complex, dynamic, and unpredictable across space and time. What is the diversity in interpretation of these ideas among today’s ecologists, and what does this mean for environmental management? This study used a Policy Delphi survey of ecologists to explore their perspectives on a number of current topics in ecology. The results showed general concurrence with nonequilibrium views. There was agreement that disturbance is a widespread, normal feature of ecosystems with historically contingent responses. The importance of recognizing multiple levels of organization and the role of functional diversity in environmental change were also widely acknowledged. Views differed regarding the predictability of successional development, whether “patchiness” is a useful concept, and the benefits of shifting the focus from species to ecosystem processes. Because of their centrality to environmental management, these different views warrant special attention from both managers and ecologists. Such divergence is particularly problematic given widespread concerns regarding the poor linkages between science (here, ecology) and environmental policy and management, which have been attributed to scientific uncertainty and a lack of consensus among scientists, both jeopardizing the transfer of science into management. Several suggestions to help managers deal with these differences are provided, especially the need to interpret broader theory in the context of place-based assessments. The uncertainty created by these differences requires a proactive approach to environmental management, including clearly identifying environmental objectives, careful experimental design, and effective monitoring. 相似文献
377.
Valuation of Spatial Configurations and Forest Types in the Southern Appalachian Highlands 总被引:1,自引:0,他引:1
Site-specific estimates of the values of spatial configuration and forest composition are presented. Amenity values of forest
patches are found to vary the most by urban and sprawling development patterns of specific areas and forest types. For example,
smaller patches of deciduous forest are more highly valued in the urban and sprawling areas of Greensboro, North Carolina,
whereas larger patches of deciduous forest are more highly valued in the urban and sprawling areas of Greenville, South Carolina.
Within the Greenville and Greensboro areas, visible landscape complexity is highly valued for deciduous and evergreen forest
patches, whereas lower visible landscape complexity, i.e., smoothly trimmed forest patch boundaries, is highly valued for
mixed forest patches. 相似文献
378.
Petit S 《Journal of environmental management》2009,90(9):2851-2856
Rural landscapes are highly dynamic and their change impacts on a number of ecological processes such as the dynamics of biodiversity. Although a substantial amount of research has focused on quantifying these changes and their impact on biodiversity, most studies have focused on single dimensions of land use change. This lack of integration in land use change studies can be explained by the fact that data on the spatial, temporal, and ecological dimensions of land use are seldom available for the same geographical location. In this paper, the benefits of taking into account these three dimensions are illustrated with results derived from the Great Britain Countryside Surveys (CS), a large-scale monitoring programme designed to assess change in the extent and ecological condition of British habitats. The overview of CS results presented in this paper shows that (1) changes in land use composition will translate into a variety of spatial patterns; (2) the temporal stability of land use is often lower than can be expected; and (3) there can be large-scale shifts in the ecological condition of the land use types that form our rural landscapes. The benefits of integrated rural landscape studies are discussed in the context of other national monitoring programmes. 相似文献
379.
The integration of socio-economic and environmental objectives is a major challenge in developing strategies for sustainable landscapes. We investigated associations between socio-economic variables, landscape metrics and measures of forest condition in the context of Portugal. The main goals of the study were to 1) investigate relationships between forest conditions and measures of socio-economic development at national and regional scales, 2) test the hypothesis that a systematic variation in forest landscape metrics occurs according to the stage of socio-economic development and, 3) assess the extent to which landscape metrics can inform strategies to enhance forest sustainability. A ranking approach and statistical techniques such as Principal Component Analysis were used to achieve these objectives. Relationships between socio-economic characteristics, landscape metrics and measures of forest condition were only significant in the regional analysis of municipalities in Northern Portugal. Landscape metrics for different tree species displayed significant variations across socio-economic groups of municipalities and these differences were consistent with changes in characteristics suggested by the forest transition model. The use of metrics also helped inform place-specific strategies to improve forest management, though it was also apparent that further work was required to better incorporate differences in forest functions into sustainability planning. 相似文献
380.
Gabriela M. A. de Almeida Marcelo A. Ramos Elcida L. Araújo Cristina Baldauf Ulysses Paulino Albuquerque 《Ambio》2016,45(4):458-467
From the perception of human populations, we can assess the changes occurring in certain landscapes and the factors that cause those changes. Such studies have proven helpful in increasing the knowledge of the history of a landscape, recognizing past formations and projecting its future. Our research objective was to determine how a landscape dominated by the palm tree Attalea speciosa, a species of ecological, economic, and cultural importance, has been changing over time by synthesizing and comparing historical documents and local perceptions. This study was conducted in Araripe Environmental Protection Area, Northeast Region, Brazil. To understand local landscape change, we interviewed active harvesters in four communities in which A. speciosa use has been documented. Historical documents were evaluated as a complement to the interview data. According to local informants, areas previously used for cultivation and animal husbandry that were abandoned or decimated by droughts in the region may have fostered the expansion of a monodominant A. speciosa forest. Furthermore, other forms of landscape management resulting from human population growth may also have affected the current and past distribution of this forest. 相似文献