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The urban-rural interface: Urbanization and tropical forest cover change   总被引:4,自引:0,他引:4  
Browder  John O. 《Urban Ecosystems》2002,6(1-2):21-41
A considerable body of empirical and theoretical literature on the causes of tropical deforestation has emerged over the last twenty years. Recognizing that small-farmers in the Amazon Basin are a key agent in the process of primary forest conversion, a growing genre of studies at the household level have attempted to quantify the influence of various factors on small-farmer land-use decisions. Many of these studies have acknowledged the seeming importance of urban centers as hubs of propulsive activity and information, yet none have comprehensively captured the urbanization factor in rural land use decisions. I argue that this methodological shortcoming in empirical work to-date reflects an inadequate conceptualization of the range of urban-based networks and their inter-relationships. In an effort to overcome this roadblock to further empirical discovery, I review several leading schools of thought that might be pressed into service in developing a framework for interpreting the urban influences on rural landscapes. I call this construct the Urban-Rural Interface. This is not a complete theoretical model or a unique methodology, but rather an initial effort to develop a general framework from which more sophisticated formulations might proceed.  相似文献   
2.
Environmental management scenarios: Ecological implications   总被引:1,自引:0,他引:1  
The measure of whether a management scenario is capable of establishing regional-scale ecosystem sustainability is the degree to which it recovers the historical characteristics of the regional landscape mosaic. This study examines the ability of alternate management scenarios to recover the defining ecological features of the Everglades and South Florida landscape. Five conceptual scenarios are evaluated for recovering and sustaining the ecological characteristics of the wetland systems in South Florida. First, the regional-scale physical characteristics are identified that created and supported the major organizing and driving forces in the predrainage Everglades and Big Cypress basins. Eight hypotheses are proposed to explain how human-caused modifications to these defining characteristics have been responsible for the substantial level of ecological deterioration that has been documented in South Florida wetlands during the last century. The restoration scenarios are evaluated on their proposed ability to correct the physical and biological problems identified by the hypotheses. Our assessment of the five scenarios shows that all would improve the problems addressed by the eight hypotheses, as all could more effectively move increased volumes of water across broader expanses of contiguous wetlands than do existing management programs. This would result in longer hydroperiods over larger areas, reflecting historical patterns. Two of the scenarios would be successful in increasing flows into Florida Bay and the Gulf coast estuaries because removing internal structures increases the spatial extent of the upstream areas that could be devoted to natural hydropatterns.The benefits of eastern boundary buffer zones include improved flow into the Taylor Slough basin. Using Lake Okeechobee as a site for increased water storage, followed by the addition of eastern buffer zones and portions of the Everglades Agricultural Area, would produce increased flexibility in providing the storage capacity required to meet sustainability goals. Scenarios with maximum areas of buffer not only are more successful in reducing groundwater seepage losses to the east but also are more likely to reduce the level of nutrients and other contaminants entering the natural wetlands.  相似文献   
3.
Using ecological theory, this study investigated how low-income rural Latino immigrant families succeeded or failed to meet their food needs over time. Interviews with ten families purposively selected to represent consistently food secure, fragile, and consistently food insecure groups were intensively analyzed using a case study approach. Achieving and maintaining food security was a complicated task and a constant struggle for families. Success or failure was influenced by factors at multiple ecological levels including family characteristics, access to social networks and community support, and the local economy. These findings can inform practitioners and policymakers seeking to identify strategies and policies that will support Latino immigrant families as they work toward improving their well-being.  相似文献   
4.
In this qualitative study, rural women caregivers for elderly relatives or friends were interviewed about their decision-making. Women deliberating decisions differed from women implementing decisions in how they perceived their caregiving tasks and in their experience of stress. The difference in deliberative and implemental accounts suggests that mindset is a mediating factor for the women in the present study. Women in the process of implementing decisions regarding caregiving described their experiences in a more positive light and reported less stress. Deliberating decisions regarding caregiving, however, was likely to color the experience of caregiving, leaving the caregiver feeling vulnerable, doubtful about herself, and more stressed.  相似文献   
5.
The natural South Florida system II: Predrainage ecology   总被引:2,自引:0,他引:2  
Browder  Joan A.  Ogden  John C. 《Urban Ecosystems》1999,3(3-4):245-277
The goal of the South Florida restoration process is to reestablish a sustainable ecological system that approximates the predrainage system (i.e., the system that existed before canals and water control structures were built). A critical step in the restoration process is to describe the predrainage system with sufficient detail to capture the essential landscape features (e.g., space, connectivity, patterns) that gave the region its defining character and supported its natural abundance and diversity of plants and wildlife.A previous attempt at reconstruction of predrainage (circa 1870) vegetation patterns covered only the Everglades (Davis et al., 1994) but introduced a concept of landscape mosaics that should be extended to South Florida. We propose 16 landscape units that include freshwater landscapes, upland landscapes, coastal wetlands, and estuaries (particularly Florida and Biscayne Bays), the Florida Keys and Reef Tract, and the Inner Southwest Florida Shelf.The predrainage area, because of its enormous size, supported a landscape heterogeneity that was advantageous to animals with several distinct habitat-related life strategies. Five species have been selected to illustrate different dependencies on landscape patterns in predrainage South Florida: wood stork (Mycteria americana), American alligator (Alligator mississippiensis), snail kite (Rostrhamus sociabilis), Cape Sable seaside sparrow (Ammodramus maritimus mirabilis), and pink shrimp (Penaeus duorarum). As individuals or as populations, these animals operated across several spatial and temporal scales. The predrainage system's large spatial extent and complex hydropatterns allowed wood storks and other animals with large feeding ranges to take advantage of the strongly seasonal rainfall pattern, while at the same time providing a refuge somewhere in the system for survival of all other species. Landscape heterogeneity and large spatial extent promoted the region's natural wildlife abundance and species diversity.  相似文献   
6.
Developing hypotheses for sustainability requires an understanding of the natural forces that shaped the historical Everglades prior to extensive engineering of the landscape. The historical Everglades marsh covered 10,000 km2 in a 100-km-long basin that has an extremely low gradient (slope of only 3 cm · km-1). The region is characterized by a heterogeneous landscape that has developed over the past five millennia, functioning as an interconnected mosaic of wetland, upland, estuarine, and marine ecosystems. The boundaries of this system were defined as the historic drainage basin from the Kissimmee River system through Lake Okeechobee, the Everglades, Florida Bay, and out through the Florida Keys to the coral reef tract. This geographic area is interconnected through the regional hydrology, with its unifying surface and subsurface freshwater transport system. However, in the final analysis, the interaction of geologic and climatic processes determine the system's hydrology, a major determinant of community and landscape structure and the point of connectivity between natural and human systems. This review examines the role of climate, geology, soils and sediments, topography, and hydrology in shaping and modifying ecological systems through time. However, it is clear from the wetland nature of this system that the predrainage hydrologic features were critical to the sustainability of the Everglades. Important hydrologic features include sufficient water quantity, storage, and sheetflow, and the appropriate hydroperiod and timing of water releases over both annual and interannual variations in precipitation.  相似文献   
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