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1.
Soil is a multifunctional, non-renewable natural resource for Europe as clearly expressed in the European Union (EU) Thematic Strategy for Soil Protection (COM (2006)231). Soil carries out multiple functions, including the support of food production. Urban development and its associated land take poses a major threat to soil and could have significant effects on agricultural production. This paper aims to evaluate the potential productivity losses in European agriculture due to land-take processes between 1990 and 2006. Agricultural land take was calculated using CORINE Land Cover maps of 1990, 2000 and 2006. For 21 of the 27 EU member states, agricultural land take was computed to be 752,973 ha for 1990–2000 and 436,095 ha for 2000–2006, representing 70.8% and 53.5%, respectively, of the total EU land take for these periods. The impact of this land take on the production capabilities of the agricultural sector for the period 1990–2006 for 19 of the 21 states was estimated to be equivalent to a loss of more than six million tonnes of wheat. The paper demonstrates that Europe's intense urbanisation has a direct impact on its capability to produce food.  相似文献   

2.
Satellite images have been used extensively to study temporal changes in land use and land cover (LULC) in China. However, few studies have been conducted in the karst areas despite the large area and population involved and the fragile ecosystem. In this study, LULC changes were examined in part of Guizhou Province of southern China from 1991 to 2001 based on Landsat Thematic Mapper (TM) images of November 7, 1991, December 5, 1994, and December 19, 2001. Land surface temperature (LST) and normalized difference vegetation index (NDVI) were computed based on LULC types. The results show that agricultural land decreased, while urban areas expanded dramatically, and forest land increased slightly. Barren land increased from 1991 to 1994, and then decreased from 1994 to 2001. These changes in LULC widened the temperature difference between the urban and the rural areas. The change in LST was mainly associated with changes in construction materials in the urban area and in vegetation abundance both in the urban and rural areas. Vegetation had a dual function in the temperatures of different LULC types. While it could ease the warming trend in the urban or built-up areas, it helped to keep other lands warmer in the cold weather. The study also reveals that due to the government's efforts on reforestation, rural ecosystems in some of the study area were being restored. The time required for the karst ecosystem to recover was shorter than previously thought.  相似文献   

3.
Urban agriculture projects seek to ameliorate issues of food access and food security for people living in areas with low access to fresh foods, including food deserts. Within this discourse, community gardens have been promoted as vehicles to reclaim unused urban space, produce food locally and connect populations to their food sources and larger community. A variety of community garden models exist; in the Midwestern city of Rockford, Illinois, many community gardens grow food for donation to food pantries as part of a programme to benefit socioeconomically disadvantaged persons in the city. However, the ability of these gardens to involve neighbourhood participants and provide the social capital-related benefits attributed to community gardens in the literature is uncertain. Here we examine community gardens in Rockford, IL to assess the extent to which they contribute to residents’ ability to obtain fresh produce as well as other social benefits. Data for this project come from a combination of interviews with gardeners, focus groups with food pantry users and a survey of pantry users. We find that while non-gardening community members are benefitting from the increased produce that the gardens provide, they are not receiving all of the social and communal benefits associated with actively participating in a garden.  相似文献   

4.
A highly specialized ecosystem can fulfill a specific function more effectively than a multipurpose ecosystem can. However, specialization results in decreased adaptability to the everchanging environment. From the viewpoint of the whole society we must consider both efficiency and adaptability in terms of long term efficiency. The compatibility of different uses depends on their intensity. The concepts of multiple land use and multipurpose land management can be developed through environmental education.  相似文献   

5.
A model is used for the dynamic and spatially explicit exploration of near future agricultural land-use changes. In a case study for Ecuador, different plausible scenarios are formulated, taking into account possible developments in national food demand until the year 2010. The protection of nature parks and restrictions due to land degradation are evaluated with respect to their possible spatial impacts on the land-use change dynamics within the country. Under the assumptions of the demand scenarios, agricultural land-use expands significantly, resulting in more use of land in existing agricultural areas and frontier-type expansion into relatively undisturbed natural areas. The patterns of change depend on the increase in demand, competition between land-use types, changes in driving factors of land use, and the area and characteristics of land that is excluded from agricultural use. The modelled land-use dynamics are related to their possible impacts on the natural resource base, specifically soil fertility. The results indicate potential negative effects of land-use changes on the soil nutrient balance and biodiversity. It is argued that spatial and temporal quantification of land-use dynamics at the landscape level can support research and policies aimed at understanding the driving factors of land-use change and the behaviour of complex agro-ecosystems under changing conditions at different scales. In this way, issues dealing with sustainable food production and the management of the natural resource base can be addressed in a more integrated and quantitative manner.  相似文献   

6.
Differences exist in the spatial structure of cities in both the developed and developing world owing to the contradistinctive nature of their urban growth processes. The structure of Nigerian cities is characterised by the preponderance of mixed land uses resulting primarily due to the organic nature of city growth and more fundamentally, owing to the dynamics of informal urban economic activities. This paper examines mixed land‐use patterns in selected Nigerian cities and appraises their relevance in the general city growth process. By suggesting principles and speculative spatial patterns expressing desirable use combinations, an attempt is made to rationalise the utility of the concept such that its environmental impact is understood and given planning resolution.  相似文献   

7.
For more than half a century, research and practice in international development has focused on improving the quality of life of people living in developing regions of the world. Recently, researchers, practitioners, and policy makers have recognized the need to blend insights from experts and community stakeholders in development decisions. Research in the decision sciences tells us that these kinds of multiparty and multiattribute decisions are extremely challenging. However, recent experience using structured decision-making (SDM) approaches suggests that the quality of both expert and stakeholder input, and resulting decisions, can be improved by ensuring that people address a series of basic principles relating to identifying objectives and their associated attributes, estimating the consequences of proposed actions, and directly confronting trade-offs that arise during the evaluation of management alternatives. In this paper, we provide an overview of SDM and then discuss a research initiative aimed at applying the approach to a pressing international development problem in rural Costa Rica: management of the lucrative but also environmentally destructive pineapple industry. The objectives of this research were twofold: First, we sought to help inform policy decisions by eliciting land management preferences regarding the pineapple industry from people living in communities surrounding plantations. Second, we evaluated the effectiveness of the SDM approach in a developing community context.  相似文献   

8.
Insect neurobiology and cognition are most fully understood through studies on European honeybees (Apis mellifera ssp.; Hymenoptera: Apidae). Karl von Frisch (1886?C1982) became a Nobel Laureate in Medicine and Physiology (1973) for his pioneering research on honeybee behaviour, learning and social communication (von Frisch Tanzsprache und Orientierung der Bienen. Springer, Berlin,1965, The dance language and orientation of bees. Harvard University Press, Cambridge,1967). His enduring work stimulated numerous prominent scientists, including Martin Lindauer (1918?C2008) who was mentor to R. M., and whose nomination provided P. K. with a DAAD fellowship to work with his team in the Institut für Neurobiologie of the Freie Universit?t Berlin in 1994. Honeybees are the most important managed pollinators of crop plants and responsible for estimated billions of dollars worth of food production annually. Although these insects make excellent subjects for basic research, understanding their biology often has immediate practical implications. Honeybees, and beekeeping, around the world appear to be facing serious problems to such a grave extent that the popular media are full of stories about their demise and the potential consequences to human food security. How honeybees perceive their world, especially the flowers they pollinate, and how they react to stresses in their environments (management, pathogens, parasites, pesticides, pollutants and landscape changes) are closely interlinked. Therefore, the relationships between basic and applied research become of immediate importance and may lead to a better handling of the ecological conditions under which honeybees perform their economically important contribution to the balance of nature.  相似文献   

9.
This paper presents an approach to modeling land-cover change as a function of land-use change. We argue that, in order to model the link between socio-economic change and changes in forest cover in a region that is experiencing residential and recreational development and agricultural abandonment, land-use and land-cover change need to be represented as separate processes. Forest-cover change is represented here using two transition probabilities that were calculated from Landsat imagery and that, taken together, describe a Markov transition matrix between forest and non-forest over a 10-year period. Using a three-date land-use data set, compiled and interpreted from digitized parcel boundaries, and scanned aerial photography for 136 sites (c. 2500 ha) sampled from the Upper Midwest, USA, we test functional relationships between forest-cover transition probabilities, standardized to represent changes over a decade, and land-use conditions and changes within sample sites. Regression models indicated that about 60% of the variation in the average forest-cover transition probabilities (i.e. from forest to non-forest and vice versa) can be predicted using three variables: amount of agricultural land use in a site; amount of developed land use; and the amount of area increasing in development. In further analysis, time lags were evaluated, showing that agricultural abandonment had a relatively strong time-lag effect but development did not. We demonstrate an approach to using forest-cover transition probabilities to develop spatially-constrained simulations of forest-cover change. Because the simulations are based on transition probabilities that are indexed to a particular time and place, the simulations are improved over previous applications of Markov transition models. This modeling approach can be used to predict forest-cover changes as a result of socio-economic change, by linking to models that predict land-use change on the basis of exogenous human-induced drivers.  相似文献   

10.
This paper addresses issues of access to land for food production in Toronto by offering fresh perspectives on urban agriculture in the neo-liberal city of the global north. It examines attempts to scale up urban agriculture that emphasise changing the relationships between land access, property and new collaborative relationships among different stakeholders. These initiatives involve renegotiating access to land for growing food between private property owners and landless growers, concomitant shifts in control over valued resources and commercialisation. These shifts are often based on relations of trust within a sharing economy rather than public battles over political decisions to develop urban agriculture lands. Growing food on private lands in the city is political in challenging taken-for-granted ideas and practices of property and urban agriculture. New approaches offer options for training and income, as well as expanding the land base for urban agriculture. Small-scale farming projects are affirmative political manoeuvres. They challenge urban residents to consider land for food production across the categories of public and private property. We document three approaches that challenge current property relations: temporary use of a development site through “soft” squatting; redesignating suburban backyards for farmer training and community-based and private food production; and garden sharing of private home backyards for urban food production and commercial growing. Such initiatives articulate alternative visions of sustainability and food security that rely on principles of collaboration and a sharing economy that challenge prevailing notions of property ownership and food security.  相似文献   

11.
12.
There is a lack of information on urban heat island impact on the thermal environment due to low populated urban sprawl, although densely populated urban sprawl impact has been identified by several researchers. The Takamatsu area has recently developed in a low populated urban sprawl style without any increase in population. This paper examined the impact of a low populated urban sprawl on the thermal environment through an analysis of the last 30 years data set and investigated the contribution of vegetation fraction and population density to the temperature trend. As a consequence, it was shown that one of the most significant causative factors of temperature increase is an expansion of non-vegetated area even without population growth. This result implied that vegetated zones should be maintained in urban areas in order to realize sustainable urbanization.  相似文献   

13.
A central government Consultation Paper issued in 1984 argues the case for simplified planning zones. These are seen to offer greater speed and certainty to developers and are closely related to the Enterprise Zone concept. This paper examines the context to the proposal, reviews the details of the Consultation Paper, and identifies the nature of the response to the idea.  相似文献   

14.
Efficient use of phosphorus (P) for producing food, preventing water pollution, and managing a dwindling rock P reserve are major challenges for China. We analyzed P stocks and flows in the Chinese food chain to identify where P use efficiency can be improved, where P leaks to the environment, and the research, technologies, and policies needed to improve P use. We found a high degree of inefficiency; of 6652 Gg P entering the food chain, only 1102 Gg P (18%) exit as food for humans. The greatest inefficiencies were a large build-up of soil P (3670 Gg P yr; 52% of P inputs) and high P losses to the environment from animal production (1582 Gg P yr; 60% of excreted P). Improving P use in China must focus on national-scale nutrient management strategies, better animal nutrition, and adoption of technologies and policies to reduce P discharges from the animal sector and recycle P as manures in agriculture.  相似文献   

15.
An evaluation was conducted to establish the feasibility of a Natural Food Resources Bank (NFRB), in the form of forestry or grassland, to achieve both continuous food production and an accumulation of primary nutrients in living perennial plants. The development of an NFRB protects our living environment from deterioration (especially soil erosion) by increasing the surface coverage of the world's land, even in mountainous areas. Additionally a functioning NFRB enhances food sustainably and security, representing a tangible and renewable food resource production system. Research has identified the prospects of cultivating the NFRB in the form of forestry and also grassland. The review investigated the distinct differences of an NFRB from a range of approaches and discusses the environmental advantage and feasibility of cultivating NFRB. The ability of the NFRB to realize sustainable food resources production for ensuring food security is evaluated in terms of environmental and economical feasibility. A NFRB can attenuate climatic change by increasing CO2 absorption and fixation. It is worth considering the replacement of the annual food production system by the NFRB (especially in steeplands) in environmental law, and replacing the policy of maintaining annual food reserves by the NFRB in food security policy.  相似文献   

16.
Belief network models of land manager decisions and land use change   总被引:8,自引:0,他引:8  
A two-stage model of land use change is described, which is driven by the types of decisions that land managers make when changing their broad styles of use. The first stage uses decision modelling techniques to assess if a manager is currently satisfied with the present situation, when compared to various potential alternatives. If this evaluation indicates satisfaction, it is assumed that the present land use will continue. However, if it indicates dissatisfaction, Belief Network techniques are used to estimate, in more detail, both how dissatisfied the manager is and whether the costs of changing, from the present use to a potentially better one, will be out-weighed by the anticipated benefits. The proposed models can use a variety of cost and benefit criteria (e.g. financial, social and ecological). The approach is illustrated with a case-study of the factors that might influence changes from farming to forestry in marginal upland areas of the UK.  相似文献   

17.
Myanmar's water‐related sectors are subject to intensive changes, as the country's abundant land and water resources provide substantial scope for development. Recent steps towards economic reform in Myanmar have led to a surge of foreign investment directed towards intensified natural resource extraction. Both the agricultural and the energy sector are increasingly affected by foreign investments that will impact the status of water, energy and food security in the country. With these on‐going developments, Myanmar's future is largely dependent on how its natural resources are managed and how the benefits from the resource extraction are shared. With various institutional changes and new actors welcomed to the sectors, existing livelihoods and ecosystems dependent on the land and water resources are to face increasing competition for the shared resources, while lacking secured access to them. There are increasing concerns that this sectoral development is occurring at the expense of environmental and social sustainability. As one way to tackle these challenges, the water‐energy‐food nexus approach could help in finding synergies and co‐benefits across sectors by addressing the imbalances along the nexus and externalities derived from the on‐going intensification.  相似文献   

18.
19.
Food security and food self-sufficiency are important regional goals for the Southern African Development Coordination Conference (SADCC). In the long run, success in these areas would reduce the incidence of drought-related mass starvation and the epidemic of malnutrition and undernutrition that exists among some tribal groups. For food production to improve, the governments must commit themselves to increasing the access of peasant farmers to critical agricultural inputs. If they do not take proper action in this area of development planning, domestic food production is likely to stagnate or decline. This study is a broad examination of the relationship between government expenditures on imported inputs and the performance of the domestic food subsector. Because much data on government spending and agricultural production in Africa are unavailable, and those in published form are of suspect validity, the study is undertaken largely as a conceptual overview. The empirical analyses are conducted, therefore, largely to provide a staging ground for the conceptual arguments.  相似文献   

20.
The British Ecological Society has suggested that computer‐based techniques could be used in the coordination of policies across different land uses in upland planning. This paper looks briefly at one such technique — a linear programming model — and describes its use at a regional scale for the Sedburgh area in north‐west England. The paper concludes with consideration of why such models are not in more common use.  相似文献   

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