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This study examined landcover change during 1940–1988 in two contiguous landscapes of approximately 12,400 hectares in central Ohio, USA: an inertial till plain area and a more dynamic moraine area. Agriculture dominated both landscapes throughout, however, the cover of natural vegetation and urban-suburban development increased over time on the moraine while natural vegetation decreased and agriculture increased on the till plain. Markov process models for landcover change were constructed for three 14–17-year time intervals and for the entire forty-eight-year study period. Probabilities of self-replacement for agricultural lands (0.91–0.97) were higher and those for forests (0.54–0.65) lower than those reported for other landscapes. Predictions of landcover percentages for fifty years in the future were made using Markov process models derived from actual cover changes in 1940–1957, 1971–1988, and 1940–1988. All three models produced similar predictions for the inertial till plain area. In contrast, the three models' predictions differed considerably for the moraine area. Only the 1971–1988 transition matrix was sensitive to increases in urbanization and reforestation which began on the moraine in the 1970s. These results indicate that reliance on lengthy study intervals and net rates of change can obscure spatial and temporal patterns of landcover change that are caused by natural and socioeconomic factors operating on shorter time scales.  相似文献   
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This discussion piece addresses two recent debates: entitlement theory and the resilience of rural systems. The authors find that in western Sudan entitlement theory provides a specific and useful framework for understanding the nature of the crisis confronting the society. Arguments about the resilience of rural systems, however, need to be more closely examined and will depend on site-specific factors. The rural economy and society of western Sudan were not found to be resilient.  相似文献   
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Probabilistic preferences and choices and their connections to trip making and to distance-related demand are discussed. They are seen to aid aggregation. Risk aversion in retail shopping behavior and entropy maximizing as rational random behavior are examined. Elasticity of substitution is presented in terms of the covariance matrix. A Markovian phrasing and potential theory allow an analogy with deterministic choice: various applications of potential operators are outlined. Changes in utilities can only be modeled stochastically and some mechanisms are detailed. Price changes are random walked in time and space as a diffusion process. A fairly coherent theory of spatial demand emerges  相似文献   
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Intensive farming is an increasing part of Australian agriculture, including in the multi‐functional landscapes at the edges of Australian cities. The example of intensive “broiler” poultry production reveals the tensions that arise when sites of hyper‐productivity conflict with social change in rural areas. Planning processes for intensive farming in the Australian state of Victoria are predicated on stability and consensus: on assumed static and uncontroversial ideas of agriculture, its place, and the primacy of agricultural productivity. Yet concerns about the industrialisation of agriculture are live political issues at the local level, especially in dynamic peri‐urban locations. This paper explores the emergence of a politics of place outside the bounds of planning consensus through an analysis of planning appeals and associated media relating to planning permits for intensive poultry developments in Victoria over 2011–2016. We highlight tensions that exist in relation to technical planning assessments and categorisations used to assert farming as the orthodox use of rural land, especially when new forms of farming look and feel demonstrably different. Using Mouffe's problematising of the negation of antagonism and Rancière's notion of the risks of a false consensus democracy, we argue that planning processes for intensive farming illustrate critical issues in participatory planning. While ostensibly post‐political decision‐making narrows the politics of place and food systems to decisions about policing the boundaries and buffer distances placed around intensive poultry developments, alternative representations of rural life persist. The certainty offered by code‐based planning does not negate the ongoing (if inconvenient) politics of intensive peri‐urban agriculture.  相似文献   
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