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Research on the dynamics of tropical forest land use and cover change (LUCC) has focused on the three scenarios: (1) deforestation/degradation; (2) settled, degraded areas in recovery, and (3) sparsely settled, expansive, intact forest. Through examination of a central Quintana Roo, Mexico case study we propose a fourth scenario of a ‘sustainable landscape’: an inhabited, productively used, forested landscape that nonetheless shows little change or net gains in forest cover over the last 25 years. We use Landsat images to demonstrate a low incidence of net deforestation, 0.01% for the 1984–2000 period, the lowest recorded deforestation rate for southeastern Mexico. Institutional innovations such as an agrarian reform process that established large common property forests for non-timber forest product extraction, and later innovations such as sustainable forest management institutions have driven the outcome of low net deforestation, added to multiple organizational processes that promote sustainable land use.  相似文献   

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The ‘direct costs’attributable to 30 different endemic diseases of farm animals in Great Britain are estimated using a standardised method to construct a simple model for each disease that includes consideration of disease prevention and treatment costs. The models so far developed provide a basis for further analyses including cost‐benefit analyses for the economic assessment of disease control options. The approach used reflects the inherent livestock disease information constraints, which limit the application of other economic analytical methods. It is a practical and transparent approach that is relatively easily communicated to veterinary scientists and policy makers. The next step is to develop the approach by incorporating wider economic considerations into the analyses in a way that will demonstrate to policy makers and others the importance of an economic perspective to livestock disease issues.  相似文献   

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English agricultural practice changed dramatically in the late 18th and early 19th centuries as enclosure, the dominance of commercial short‐term leases for tenant farmers, and the proletarianization of the agricultural labour force completed what has been called an agricultural revolution. A less often noted aspect of this change was what was called “a war on cottages” and cottage gardens. The Board of Agriculture and Arthur Young were important cheerleaders for this process. Yet many of the most prominent members of the Board of Agriculture made impassioned appeals for the provision of land for English cottagers as a way to reduce poverty and stressed that cottagers produced remarkable returns from their small farms. Arthur Young became the most vocal proponent of land for cottagers. This article suggests that their appeals for land for cottagers were limited by both farmers' desire for easily controlled labour and misplaced concerns about the supposed inevitability of the poverty inherent in very small farms.  相似文献   

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Historically, soils have always underpinned civilisation. Their role is fundamental to the provision of food and water, along with a wide range of ecosystem goods and services. Soils are arguably the most complex systems on Earth, and are intimately linked to human security and the integrity of the wider environment. In this paper we propose 18 ecosystem services that are critical for soils and land use in the UK. Soils are extremely heterogeneous and not all soils can fulfil the full spectrum of services required for the future of the UK, so there is a need to protect their multifunctional attributes in order to preserve national and international natural capital. There are concerns that anthropogenically induced changes in land use or management will result in soils not being utilised to provide the functions to which they are best suited. For example, soils primarily suited for food supply may be given over to provide a platform for construction. This is an all-pervading and recurring concern and highlights the importance of critical decisions, thresholds and potential ‘tipping points’. Once critical soil functions are lost they are irrecoverable, potentially for millennia, representing a loss of resource that is fundamental to the UK's national livelihood and well-being. Pressures from changes in climate and to the Earth system will bring about complex and systematic change to soils and their abilities to provide essential functions. We therefore recommend national needs for ensuring the sustainability for soils and future land use in the UK. They are to maintain the long-term base for soil science through education and intellectual investment, including communication of the value of soils and land as natural capital; to manage soil resources so that multi-functionality prevails and critical tipping points are avoided; to audit the national soil resource through soil mapping; preparation of appropriate databases and provision of long-term monitoring networks and observatories; and to synthesise adaptable predictive frameworks for soil system science through integrated modelling.  相似文献   

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Food regime analysis is concerned with interpreting possibilities and conflicts inherent to the 21st‐century food system in historical terms. This paper summarizes the theoretical discussion of the food regime method, and of the identification of different “food regime periods” throughout modern history. While it is widely accepted that the so‐called “second food regime” has already ended, there is much discussion on whether or not it is possible to talk about a more recent third food regime. This paper traces the evolution of the “wheat complex” over the “second food regime” (1947–1973) and over the next 45 years, and offers an explanation for the evolution of world wheat trade distribution, based on food regime analysis. Certain authors have claimed that the collapse of the WTO Doha round of negotiations may be understood as a “hangover” from the second food regime. Similarly, this paper argues that the increasing wheat dependence of poor and insecure countries over the past 40 years may be considered as a path dependence outcome of a process initiated during the second food regime.  相似文献   

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In the first of two essays in this Journal, I seek to unify the historical geography of early modern ‘European expansion’ (Iberia and Latin America) with the environmental history of the ‘transition to capitalism’ (northwestern Europe). The expansion of Europe's overseas empires and the transitions to capitalism within Europe were differentiated moments within the geographical expansion of commodity production and exchange – what I call the commodity frontier. This essay is developed in two movements. Beginning with a conceptual and methodological recasting of the historical geography of the rise of capitalism, I offer an analytical narrative that follows the early modern diaspora of silver. This account follows the political ecology of silver production and trade from the Andes to Spain in Braudel's ‘second’ sixteenth century (c. 1545–1648). In highlighting the Ibero‐American moment of this process in the present essay, I contend that the spectacular reorganization of Andean space and the progressive dilapidation of Spain's real economy not only signified the rise and demise of a trans‐Atlantic, Iberian ecological regime, but also generated the historically necessary conditions for the unprecedented concentration of accumulation and commodity production in the capitalist North Atlantic in the centuries that followed.  相似文献   

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