首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
A detailed understanding of multiple human and environmental factors influencing land allocations among agricultural uses can facilitate more efficient and targeted land policy. To show this, we used a comprehensive dataset of socioeconomic, physiographic, and climatic indicators to investigate potential determinants of land-use in Australia’s intensive agricultural region during the period 1992–2010. We applied a seemingly unrelated regressions land-use shares spatial error model with random effects coupled with variance decomposition analysis to identify the statistical significance, direction and magnitude of observed associations between land-use and its drivers.Population: density, rainfall, equity ratio, and access to markets were the most influential policy-relevant land-use factors. Land allocations to cereals and livestock production were significantly influenced by spatiotemporal rainfall and temperature variability. Improved pastures, cereals, annual and perennial crops plantations were larger in regions with better access to markets. Increases in equity ratio (i.e., better financial position) were associated with larger land allocations to improved pastures and annual crops and smaller extensive grazing area. Marginal associations were detected between land-use and output prices, and higher population density was associated with lower shares for all high value agricultural land-uses. The results suggest that improved transportation infrastructure, zoning regulations, and mechanisms to reduce farm debt exposure and risks from climate variability could have significant impact on the configuration of the Australian agricultural landscape.  相似文献   

2.
This paper uses portfolio analysis to study how the Ecuadorian incentive programme for forest conservation and restoration (Socio Bosque), and an incentive programme for timber plantations, may reduce income risk and/or maximise returns for a given level of risk for farmers in the municipality of Loja. The main existing land use in the research area is milk production on pasture, with some farmers having forest land. Our results suggest that most farmers would significantly increase the area under conservation and/or restoration as part of their risk reduction strategies, compared to a decision based solely on expected returns. However, in land use allocations that maximise the return per unit of risk, a small group of milk producers without forest would continue milk production on most of their land. In addition, milk producers with forest would significantly decrease deforestation under the land use allocations made when conservation incentives are available. Against this we also identify a likely shift of milk production from existing pasture to new pasture established on deforested land, which provides evidence of a potential ‘leakage effect’. In addition, the incentive programmes would only lead to small areas of tree plantations being established. None of the land use combinations (portfolios) analysed would increase the income of all households to above the poverty line, as the monetary incentives are too low and many farms are too small. For forest holders all the land use combinations we studied would have a positive impact on income, but we observed a negative impact on household income for milk producers without forest. For producers without any forest, there seems to be a trade-off between maximising household income and risk reduction through combining incentives for restoration and tree plantations.  相似文献   

3.
As agricultural policies affect land use, they have effects on the amount of soil erosion in agricultural regions through changes of the economic conditions of agricultural production. Prices of inputs and outputs, regulations and incentives can change, forcing or encouraging farmers to adopt new crop rotations. This paper shows how a bio-economic model can be used to describe and estimate the effects of policies on agricultural production and the risk of soil erosion at the example of a region in North-Eastern Germany. The model uses both an assessment tool that is based on a fuzzy-logic approach for the estimation of soil erosion risk of cropping practices, and a linear programming model, that simulates farmers’ economic behaviour under the assumption of gross margin maximisation being the main goal of farmers’ actions.The analysed policy options were both a targeted and an untargeted incentive programme for reduced tillage, and a restriction option where high erosive crops are not allowed on high erodible field types. The results show that policy changes can have an impact on soil erosion. Furthermore, soil conservation policies are shown to have different levels of efficiency in terms of reduced soil erosion related to the costs of the policy. In the case of this study, a restriction option was more efficient than the incentive options. The results of such simulations can serve as a decision support for the development of soil conservation policies and help to foresee the effects of general changes of agricultural policies.  相似文献   

4.
A primal production analysis is conducted of 182 farm households producing multiple outputs in the Sri Lankan dry zone. The approach involves systems estimation of the production functions with first-order equations for variable inputs and permits recovery of the production technology for each crop. Land and family labour are regarded as constraining inputs. Shadow prices are computed for the constraining inputs and yield important implications for increasing household profits. Evidence of global homotheticity in a subset of three inputs is found for three of the crops. Weak separability is rejected in all tested subsets except for fertiliser and chemicals used in the production of vegetables. Input demand elasticities are computed for allocations satisfying necessary and sufficient conditions for profit maximisation. Highly elastic conditional input demands and output supplies are implied.  相似文献   

5.
This study develops and estimates a dynamic multi‐output model of farmers’ land allocation decisions that allows for the gradual adjustment of allocations that can result from crop rotation practices and quasi‐fixed capital constraints. Estimation is based on micro‐panel data from Danish farmers that include acreage, output, and variable input utilization at the crop level. Results indicate that there are substantial differences between the short‐run and long‐run land allocation behaviour of Danish farmers and that there are substantial differences in the time lags associated with different crops. To our knowledge, this is the first dynamic micro‐model of land allocation estimated on data from the temperate climate zone. Since similar farming conditions are found in northern Europe and parts of the United States and Canada, this result may be of wider interest.  相似文献   

6.
Land-use models express the relationship between various driving forces of land-use changes and are increasingly employed in practical applications to predict possible future land uses. The relationship between the agricultural land market and land-use changes is often neglected in such models. The objective of this study is to assess the production values of agricultural land to be integrated in an operational land-use model with the aim to improve understanding of land-use changes in all 28 European Union countries. This economic evaluation of agricultural land is based on the Net Present Value (NPV) method, a method that aims at uncovering the operational production values of land rather than real estate market value. The scientific relevance of this work is the development of a comprehensive methodology for the economic evaluation of agricultural land uses in different EU countries, the integration of economic production values of land to the local suitability approach in the studied land-use model and the provision of a EU-wide database of the NPVs of agricultural land uses, including various energy crops.  相似文献   

7.
One of the most ubiquitous forms of agricultural regulation is a restriction on farmland ownership. One Canadian example of a farmland ownership restriction is The Saskatchewan Farm Security Act (FSA), passed in 1974. The purpose of this article is to explain, using a political economy framework, why the FSA was implemented and to estimate the effect of the FSA on Saskatchewan farmland values. A Present Value (PV) model is used to estimate the relationship between land values, rents, and the regulation. The Hausman endogeneity test reveals that the regulation variable is endogenous with the land price. The sign of the regulation variable is negative, which fits with the theory, i.e., the more stringent the regulation the lower the land value. We estimate that the regulation lowered Saskatchewan farmland prices by an average of 4 to 34 US$/acre, depending on whether ordinary least squares (OLS) or two‐stage least squares (TSLS) is employed in the estimation, over the period of 1974–2001.  相似文献   

8.
The impacts of climate change on agriculture in developing countries will depend on the extent to which agricultural production in those regions adapts to climate change’s influences. This study uses a whole-farm land use optimisation approach to explore climate change impacts, when including adaptation, on farm profitability, production and associated greenhouse gas (GHG) emissions in the Loess Plateau of northern China. The results show that with adaptation activities, the losses in smallholder farm profitability caused by the climate change could be moderate. Declining rainfall results in land use changes that generate higher on-farm GHG emissions with the most economically beneficial adaptations. With 5 % or 10 % decline in annual rainfall, the introduction of agricultural carbon tax would generate substantial reduction in on-farm GHG emissions. With 30 % rainfall reduction, agricultural carbon tax is not likely to bring about considerable emission reduction. The economically optimised land uses are generally sensitive to potential changes. When rainfall reductions appear, there is a clear trend toward reducing cropping area and transiting to pasture. With 5–10% rainfall reductions, increasing agricultural carbon tax with same rainfall reduction leads to the expansion in cropping enterprises. However, with 30 % rainfall reduction, land allocations are not sensitive to agricultural carbon tax. When with declining annual rainfall, in the optimal enterprises more oats-pasture rotations are employed to reduce wheat dominated rotations. Besides land use patterns, adaptations through altering farm management practices are also necessary. The economically optimised sheep flock would be increased considerably with declining rainfall. Overall, policymakers are suggested to initial more educational schemes to tell smallholder farmers how to make the best use of available adaptation strategies and consider changes in climate when design and implement agricultural policy.  相似文献   

9.
The problem of multiple-use forestry arises because (1) a forest can be managed to provide a wide range of products and services, (2) the different uses are not perfectly compatible with each other, and (3) some products are not priced in markets and many of the services a forest provides have the characteristics of public goods. Examples of major forest products include, in addition to timber, edible berries, fungi, and hunting games. Forests also provide recreation opportunities and various environmental services (such as regulating local climate, reducing soil erosion, reducing pollutants in the atmosphere, regulating the global climate, providing habitats for wildlife, etc.). The outputs of nontimber goods in general depend on the quantity and structure of the forest, which can be changed by various forest management activities. However, a forest state most suitable for the production of one good is usually not optimal with respect to another good. Typically, there does not exist a set of management activities that simultaneously maximize the outputs of timber and all other goods.Another way to understand the conflicts between different uses is to view standing timber as an intermediate product of forestry investment, which is employed as an “input” for the production of timber products and nontimber goods. Thinking in this way, the conflicts arise partly because timber production and nontimber uses compete for the same input, and partly because of the differences in the “production technology” among different nontimber goods. A change in the standing timber may have positive impacts on some nontimber uses, but have negative effects on others. Because of the conflicts among different uses, it requires that both timber products and nontimber goods should be explicitly incorporated into forestry decision-making in order to achieve the greatest benefits to the forest owner and/or the public.Most of the economic analyses of multiple-use forestry decisions have explicitly or implicitly adopted the view that multiple-use should be achieved in individual stands. Each stand should be managed to produce an optimal mix of timber products and nontimber goods. Another view of multiple-use forestry is to manage each stand for a primary use, whereas multiple-use concerns are addressed by allocating different stands in a forest to different uses. A general argument in support of the primary-use view is that specialization makes for efficiency. The production of timber and nontimber goods is a joint process, however. Strictly speaking, one cannot separate timber production and the production of different nontimber goods. For example, managing a stand for timber production does not exclude the possibility of producing some nontimber goods in the stand. Since every stand usually produces more than one product, efficient multiple-use forestry requires that each stand should be managed for an optimal mix of timber and nontimber outputs. On the other hand, it may well be the case that the optimal multiple-use mix for a particular stand consists of a maximum output of one product. In this case the optimal multiple-use management decision would coincide with the optimal decision pertaining to a single use. In other words, it may be optimal to manage a particular stand for one primary use. Using the terminology of economics, primary-use may be efficient for stands in which the multiple-use production set is nonconvex. Recent research has explored several sources of nonconvexity in the multiple-use production set. However, there is no evidence supporting the argument that specialization is always more efficient than multiple-use management of individual stands. From an economics viewpoint, efficient primary-use is special cases of multiple-use stand management.A widely recognized limitation of multiple-use stand management is that, by considering each stand separately, one neglects the interdependence of nontimber benefits and ecological interactions among individual stands. The nontimber benefits of a stand depend on the output of nontimber goods from other stands. Likewise, the nontimber output from one stand affects the value of nontimber goods produced in the other stands. Ecological interactions among individual stands imply that the output of nontimber goods from two stands in a forest differs from the sum of the outputs from two isolated stands. These interdependence and interactions imply that the relationship between the nontimber benefits of a stand and the stand age (or standing timber stock) cannot be unambiguously determined - it depends on the flow of nontimber goods produced in the surrounding stands. Therefore, it is improper to determine optimal decisions for the individual stands independently. In stead, efficient multiple-use forestry decision should be analyzed by considering all the stands in a forest simultaneously.Another serious limitation of multiple-use stand management is that each stand is treated as a homogenous management unit to be managed according to a uniform management regime. One implicitly assumes that the boundaries of each stand is exogenously given and will remain unchanged over time. This assumption imposes a restriction on the multiple-use production set, thereby creates inefficiency. As an example, consider a large stand with a nonconvex production set. It may be possible to eliminate nonconvexity in the production set and push the production possibility frontier outwards by dividing the stand into several parts and managing each part for a primary-use. It may also be efficient to combine two adjacent stands into one to be managed following a uniform regime, because of the presences of fixed management costs, and/or because the relationship between some nontimber outputs and stand area is not linear.In contrast to income from timber production, nontimber goods produced at different time points are not perfect substitutes. The rate at which a forest owner is willing to substitute a nontimber good produced at one time point for that produced at another time point changes with the outputs of the nontimber good at the two time points. In general cases, the nontimber goods produced at one time point cannot be consumed at another time point, and the marginal utility of a nontimber good decreases when its output increases. This provides a motivation for reducing the variation in the output of nontimber goods over time. An effective approach to coordinating nontimber outputs over time is to apply different management regimes to different parts of a stand, or apply the same regime to adjacent stands, which would change the boundaries of the stands. Preserving the existing stand boundaries would limit the possibility of evening out the nontimber outputs over time, and thereby lead to intertemporal inefficiency in multiple-use management.In previous studies of multiple-use forestry decisions the nontimber outputs or benefits are usually modeled as functions of stand age or standing timber stock. Future flows of nontimber goods or benefits are incorporated into a stand/forest harvest decision model to explore the implications of nontimber uses for optimal harvest decisions. While stand age and standing timber stock may have significant impacts on nontimber outputs, other forest state variables, e. g. the spatial distribution of stands of different ages/species, may be of great importance to the production of nontimber goods. Recognition of such forest state variables could change the relationship between timber production and nontimber outputs and therefore change the optimal forest management decisions.In summary, multiple-use forestry is not simply an extension of timber management with additional flows of benefits to be considered when evaluating alternative management regimes. Recognition of multiple uses of a forest leads to two fundamental changes of the forestry decision problem. First, the optimal intertemporal consumption of forestry income is no longer separable from forest management decisions. In general, the optimal intertemporal consumption of forestry income depends on future flows of nontimber goods, implying that the consumption-saving decision should be made simultaneously with the decision on the production of timber and nontimber goods over time. Secondly, it is no longer appropriate to optimize the management regime for each stand separately. The nontimber outputs from a forest depend on the age distribution of individual stands, and on a wide range of other forest state variables such as the spatial distribution of stands of different ages and tree-species composition. Ecological interactions and interdependence among stands imply that management regimes for different stands should be optimized simultaneously. In addition to changing rotation ages and harvest levels, efficient multiple-use forestry requires optimizing the spatial allocation of harvests, redefining the boundaries of stands, coordinating the choices of tree species in regeneration of harvested area and so on.The lack of rigorous production functions for nontimber goods imposes a severe restriction on attempts to perform comprehensive economic analyses of multiple-use forestry decisions. This restriction in itself is no justification for ignoring many of the key aspects of multiple-use forestry problem and modeling the problem as one of determining the optimal rotation age or optimal harvest level. It requires that economic models of multiple-use forestry should be developed with special consideration of the vague and imprecise information regarding the relationships between nontimber outputs and forest state variables.Peichen GongDepartment of Forest EconomicsSE-90183 UmeåSweden  相似文献   

10.
The paper introduces and discusses an open-source spatial-based model (called r.green.solar) able to quantify the energy production from solar photovoltaic (PV) ground-mounted panels. Socio-economic and environmental impacts can be evaluated by the model. The model starts from the theoretical quantity of solar PV potential energy and estimates a reduction of total amount of energy based on legal, technical, recommended and economic constraints. Model outputs were used for a trade-off analysis between energy production and traditional crops for food/feed cultivation on not irrigated arable land. The model was tested at regional level for a Mediterranean context (Italy). The results confirm that the economic profitability of PV systems follows a north-south gradient, but the main impacts are related to local peculiarities – such as the disposal of not irrigated arable land and the presence of constraints, in particular the landscape maintenance, the morphological variables and the specialization index – and crop yields.  相似文献   

11.
基于PSR框架的徐州市城市土地集约利用评价研究   总被引:19,自引:1,他引:18  
从城市土地利用的人地关系入手,探讨基于PSR模型的城市土地集约利用指标体系;采用层次分析(AHP)法确定指标权重,选择二次综合函数来评价城市土地的集约利用程度,并进行动态调控;利用所建立的指标体系与模型对徐州市城市土地集约利用状况进行综合评价:徐州市正处于大幅度加强土地集约利用的初期,土地利用状态和环境存在问题,并针对问题提出了建议。  相似文献   

12.
This paper compares three models of input allocation in multicrop systems. In addition to the variable input and satisficing models analyzed in previous research, an allocatable fixed input model of short-run input use is derived. The empirical application studies irrigation water use in the Central Plains region of the United States. Based on results from model specification tests and prediction accuracy measures, the allocatable fixed input model dominates both other models in explaining multicrop water allocation. In addition, the paper presents an alternative approach to the study of deficient data on multicrop production. By transferring econometric results from analysis of ‘non-deficient’ crop-level data, input allocations in deficient data sets can be predicted.  相似文献   

13.
This paper investigates empirically the effect of land invasions on farm production decisions. The main hypothesis is that more invasions in a region are associated with lower investment, and in particular a bias towards annual crops as opposed to long‐term crops. We use a county‐level dataset for the state of Paraná, Brazil, from 2003 to 2007, with 1,995 observations. The panel data structure allows us to control for fixed effects, such as the formalisation of land titles and land concentration, which might be correlated with the intensity of invasions. An instrumental variable fixed effects model was estimated to avoid other sources of bias. Our main finding is that land invasions are associated with lower long‐term crop production and a higher percentage of annual crops, which could accelerate land degradation, and undermine environmental sustainability.  相似文献   

14.
本文基于粮食主产区辽宁省种粮大户的数据,运用Heckman两阶段模型,探究种粮大户信贷约束程度及农地抵押贷款对其影响。研究发现,辽宁省种粮大户的信贷约束程度为70.69%,其中开展农地抵押贷款试点地区种粮大户的信贷约束程度为62.74%,而未开展试点地区信贷约束程度为74.78%。计量结果显示,农地抵押贷款的开展对种粮大户信贷约束程度影响显著,且在其他条件不变的前提下,开展农地抵押贷款地区的种粮大户受到信贷约束的程度要比未开展地区低12.31%。  相似文献   

15.
This article applies a model of innovation to analyze the characteristics of irrigators within the Goulburn–Murray Irrigation District in Australia and examines the efficiency of the early water market in the late 1990s. Using multinominal and binary logit analyses we identify the factors associated with irrigators who sold or bought water allocations during 1998–1999 and irrigators who at that time had never participated in any kind of water trading. Contrary to expectations we find that early adopters of water trading were older farmers with low farm productivity, but that in line with theory they had higher levels of education, had spent less time farming, had larger irrigated area, farm operating surplus and farm assets, owned farms that were more intensively farmed, and were more progressive in their planning. There was only weak evidence to suggest that water moved from lower value uses to higher value uses, suggesting the water allocation market had limited efficiency in its’ initial years.  相似文献   

16.
Food insecurity remains persistent in the Global South due to constraints in food production capacities and intricate land tenure systems that stifle investment in agriculture. In the urbanized regions, uncontrolled urbanization and non-compliant land use systems have further worsened the potentials for urban food production. This research is based on a case study of the Wa Municipality in order to assess the influences of customary land allocation and peri-urbanization on land use planning and foods systems in Ghana using explorative and narrative research approaches. The study identified that customary stakeholders responsible for allocating such lands in the Wa Municipality were indiscriminately converting large tracts of hitherto agricultural lands to urban land uses. Statutorily prepared land use plans are hardly enforced and the planning priorities are on residential and commercial land uses that command higher land values to the detriment of agricultural lands. Weak institutional linkages also characterize the mandated planning and land administration institutions, with a planning system that is reactive rather than proactive in addressing development control challenges across the country. There is the need for planning authorities to adopt participatory land uses planning together with customary landholders and educating them on the essence of comprehensive land use planning approaches. Based on the findings, local governments need to partner landowners to identify and reserve high potential agricultural land for sustainable urban food production.  相似文献   

17.
目的 基于土地利用功能价值最大化对自然发展情景、农业生产功能优先情景、经济发展功能优先情景及生态保育功能优先情景下的土地利用结构及布局进行优化,得到2026年保定市土地利用合理结构与布局。方法 文章利用MOP模型优化各情景土地利用结构、FLUS模型优化各情景土地利用空间布局、耦合协调模型分析各情景功能协调性。结果 各情景下草地面积都减少,建设用地及水域面积都增长。除农业生产功能优先情景外,耕地面积都呈下降趋势。经济发展功能优先情景土地利用功能总价值最高,农业生产功能优先情景最低;各情景下建设用地都以外延式增长;林地都以外延式及填充式在山地丘陵地区扩张;农业生产功能优先、经济发展功能优先及生态保育功能优先情景的土地利用结构耦合协调度高于自然发展情景,经济发展功能优先情景下功能间关系最协调。结论 在现行土地利用变化趋势下,未来保定市土地利用功能将严重失调,需严格落实耕地及生态用地保护政策、推动建设用地高效利用,实现土地利用功能协调及价值最大化。  相似文献   

18.
In this paper we analyze the indirect land use change (ILUC) effects of ethanol production expansion in Brazil through the use of an inter-regional, bottom-up, dynamic general equilibrium model calibrated with the 2005 Brazilian I-O table. A new methodology to deal with ILUC effects is developed, using a transition matrix of land uses calibrated with Agricultural Censuses data. Agriculture and land use are modeled separately in each of 15 Brazilian regions with different agricultural mix. This regional detail captures a good deal of the differences in soil, climate and history that cause particular land to be used for particular purposes.Brazilian land area data distinguish three broad types of agricultural land use, Crop, Pasture, and Plantation Forestry. Between one year and the next the model allows land to move between those categories, or for unused land to convert to one of these three, driven initially by the transition matrix, changing land supply for agriculture between years. The transition matrix shows Markov probabilities that a particular hectare of land used in one year for some use would be in another use next period. These probabilities are modified endogenously in the model according to the average unit rentals of each land type in each region.We ask whether biofuel expansion is consistent with new laws, limiting forest clearing in Brazil. A simulation with ethanol expansion scenario is performed for year 2020, in which land supply is allowed to increase only in states located on the agricultural frontier. Results suggest that each new hectare of sugar cane requires only 0.14 ha of new land, with another 0.47 ha converted from pasture use. Hence policies limiting deforestation are unlikely to prevent greater ethanol production. Finally, regional differences in sugarcane productivity are found to be important elements in ILUC effects of sugar cane expansion.  相似文献   

19.
首先阐述了林业综合生产能力的内涵,然后借助1990~2004年湖北省的林业数据,用数理统计方法分析湖北省林业投入与产出的关系,得出林业中间消耗和各项物质投入对林业产出的弹性,并按弹性大小对林业各项物质投入的重要性进行了排序。研究结论是湖北省林业生产应该增加中间消耗的投入,并且做好林业病虫害防治工作,提高林地地力,实现林业的电气化和机械化生产。  相似文献   

20.
This article investigates why farmers in Kosovo leave land fallow when their farms’ total land area is small and households, almost fully dependent on farming for their livelihoods, are large. It uses a comprehensive survey carried out during the agricultural year 2005/2006 to explore agricultural households’ perceptions of production, market conditions and general security 6 years after the end of the military conflict in the former Yugoslavia. Several locational, household and farm characteristics empirically approximate the significance of different factors for the amount of land left idle. Two different econometric models are used to address the characteristics of the dependent variable distribution by accounting for endogeneity. The main determinants of the share of land left fallow are found to be related to the economic and institutional structure, and to the general feeling of insecurity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号