Converting Forests to Farms: The Economic Benefits of Clearing Forests in Agricultural Settlements in the Amazon

Agricultural expansion into tropical forests is believed to bring local economic benefits at the expense of global environmental costs. The resulting tension is reflected in Brazilian government policy. The national agrarian reform program has settled farm families in the Amazon region since the 1970s, with the expectation that they will clear forests in order to farm the land. On the other hand, recent Brazilian policy initiatives seek to reduce deforestation to mitigate climate change. We contribute to the policy debate that surrounds these dual goals for the Amazon by estimating the marginal effects of new agricultural land on the full income and assets of farm settlers over a 13-year period from 1996 to 2009. Using micro panel data from agrarian settlements where forest was being rapidly cleared, and controlling for factors that would otherwise confound the relationship, we estimate the effect of converting forest to agriculture on total household income to estimate the opportunity cost of conserving forest. Our measure of income reflects any re-allocation of resources by utility maximizing households and any productivity effects due to loss of forest ecosystem services. The estimated effect of new agricultural land on income is positive, but small relative to the income per hectare of previously cleared land. However, we show that income increases investment in physical assets, which raises households’ income generating capacity and future accumulation of assets. Thus, while there is only a small immediate income gain from clearing more forest, the long-term effects on wealth are still substantial. This demonstrates that given the right conditions, conversion of forest to agricultural land can be an impetus for asset accumulation by smallholders. It also highlights the importance of considering the indirect and long-term welfare benefits of new agricultural land when assessing the opportunity costs of forest conservation.     

Does poverty constrain deforestation? Econometric evidence from Peru

This paper examines the relationship between income and land clearing for households living in tropical forest regions. A simple model of the agricultural household that clears land for agriculture is developed to investigate the relationship between lagged income and cleared land holdings. Analysis of panel data from Peru suggests that lagged income is positively correlated with clearing, though at a decreasing rate, and, because of labor market constraints, clearing is positively correlated with household labor availability. This work suggests that small increases in the incomes of the poorest are unlikely to reduce deforestation in this context.     

基于NPP生态足迹模型的贵州农业可持续发展

利用生态足迹模型对贵州1978～2008年的农业生态足迹和生态承载力进行分析研究。结果表明,改革开放30年来贵州农业平均生态足迹为0.4693hm2。改革开放以来,贵州的农业生产及人民的生活水平有了较大的改善,贵州农业生态供给严重依赖于耕地、林地;30年来,贵州林地在均为生态盈余,这说明贵州实施林业生态工程建设秀美山川取得了初步成效;贵州农业生态效率一直处于增长状态,贵州的农业资源利用效率在逐年提高。最后基于研究结果分析了影响贵州农业可持续发展能力的资源及生态因素,并提出了相应的对策建议。     

Ecosystem services, agriculture, and rural poverty in the Eastern Brazilian Amazon: Interrelationships and policy prescriptions

Policymakers seeking to modify financial incentives to increase the flows of ecosystem services in and around tropical moist forests must consider where to focus their attention and what collection of incentives can effectively achieve policy objectives. In most cases, policymakers focus on extensively forested areas where the flows of ecosystem services between agriculture and the environment is generally characterized by massive flows of carbon and soil nutrients from forests to agriculture. In these forest margin areas the stock of primary forest is eventually exhausted and the cheap ingredients provided by nature to agriculture become increasingly scarce. At this point, policy interest generally wanes, and agriculture and the environment begin slow declines in ecosystem service exchange, often with negative consequences for rural poverty. How does one promote increased flows of ecosystem services from agricultural lands without increasing poverty when forests and soils have been depleted? Can the standard instruments, e.g., payments for ecosystem services, be effective in such situations, and if so, do the costs to society of securing these services increase? Here we focus on the flows of ecosystem services at the end of the cycle of converting primary forest to agriculture. Primary data from the Bragantina area in the southeastern Brazilian Amazon, an area cleared of primary forest decades ago, are used to characterize smallholder production systems, to describe the flows of ecosystem services into and from these systems, and to develop a bioeconomic model of smallholder agriculture capable of predicting the effects of several types of policy action on ecosystem services provided by and to agriculture, and on-farm household incomes and food self-reliance. Of particular interest is the Proambiente Pilot Program in Brazil, which uses smallholder payment schemes to induce farmers to manage land and forest resources in ways that generate more ecosystem services. Baseline results suggest that smallholder agriculture leads to a gradual loss of ecosystem services (mainly above-ground and root carbon) provided by secondary forest fallows, and that reduction in fallow age leads to reductions in plant diversity. Intensifying agricultural activities accelerates this process, but considerably increases smallholder incomes. Paying farmers for ecosystem services linked to the retention of secondary forests and the Proambiente program both increase area in forest fallow, but the latter substantially reduces farm income because of input use restrictions. In general, programs aiming to promote the production of ecosystem services should not limit farmers' choices of ways to provide them. Employment and food self-reliance issues associated with policy options for increasing on-farm stocks of carbon and plant biodiversity are also explored.     

Joint Production of Food and Wildlife: Uniform Measures or Nature Oases?

Intensive agriculture is often bad for wildlife. Does this imply that a goal to boost wildlife on agricultural land is best met through a general reduction in intensity? We argue that such an approach may not be optimal, since cost functions for provision of wildlife on agricultural land may be non-convex, due to fixed costs associated with such provision. This implies that, even when farms are identical, it may be preferable to split them into groups of high providers and low providers. We test our hypothesis in a study of the optimal management of mown grasslands in southern Sweden, where the two products are silage and successful reproduction of ground-nesting birds, and the variable controlled by the farmer is the date of the first mowing. We show that the optimal solution is likely to involve some farmers maintaining profit-maximizing practices while other—identical—farmers delay their first mowing significantly. The superiority of such split solutions may have major implications for agricultural policy.     

Effects of the Chinese arable land fallow system and land-use change on agricultural production and on the economy

This study focuses on economic effects of arable land fallow system and land-use change in China using a dynamic single-country, multi-regional computable general equilibrium model. Land supply is adjusted endogenously in our model. Land use in each of 31 provinces is tracked by a land-use change module, which is calibrated with satellite data. Our results reveal that the expansion of real output can be attributed to the increase in capital stock as a result of the growth of investment due to the imposition of the arable land fallow system in China. And the growth of investment is caused by the release of labor from agriculture The reduced supply of arable land in agricultural land contraction regions is partially offset by the increasing arable land in agricultural land expansion regions. Rural households benefit more than urban households from the arable land fallow policy due to relatively higher income and lower rural CPI.     

小城镇土地创新制度研究

土地利用在小城镇的发展中，有着非常重要的作用。文章首先对我国小城镇建设中的存在土地问题进行了分析，进而分析了小城镇发展与土地利用的关系，提出了土地制度创新的基本思路及小城镇用地的具体制度——用地置换制度与农村耕地使用权永租制，并认为强化土地管理仍然是十分重要的。     

经济与生态效益不同情景下的广州市土地利用优化配置

缓解生态保护与经济发展之间的矛盾已成为广州市目前亟须解决的重要现实问题。通过对经济效益和生态效益最大化的不同侧重,基于多目标规划模型与CLUE-S模型对广州市2025年不同情景下的土地利用进行优化配置。结果表明:(1)与现状相比,兼顾两者效益情景的土地利用优化方案最为合理:效益提升最为协调分别为9.35%、9.58%,不同景观类型破碎化程度适中;(2)广州市对生态、经济效益的不同侧重主要导致林地、建设用地和水域面积的变化较大,未来规划应注重这三种地类的合理规划;(3)多目标规划与CLUE-S模型的结合,可以有效解决广州市多情景的土地资源优化配置模拟。研究结果对广州市土地利用可持续发展和生态文明建设具有较大的参考价值。     

A science-driven market-based instrument for determining the cost of environmental services: A comparison of two catchments in Australia

An auction-based approach (or MBI for “market-based instrument”) was used to purchase environmental services from landowners and to establish a long-term economic resource (forest plantations) in two catchments in the state of Victoria (Australia). The policy goal of the MBI was to encourage the conversion of cleared land to forest plantations. It was desired to achieve this while also reducing the amount of land affected by dryland salinity with minimum impact on water available for irrigation. Operationally, interested landowners identified areas on which they would be willing to establish forest plantations, and stated the amount of money they would require from the government to undertake plantation establishment; this constituted a landowner bid. The proposed planting area associated with each bid was processed through a quantitative hydrological model to estimate off-site impacts on dryland salinity and the change in water yield resulting from the conversion of individual non-forested areas to forest plantations. Landowner bids were then accepted or not based on the economic trade-offs among dollars requested by a landowner, reduction in water yield, and decrease in dryland salinity. To enable a comparison of costs, the MBI was independently trialled in two catchments. For both, the cost to government of a hectare of plantation and/or a hectare of salinity benefit was calculated a number of ways. Assuming the existence of a calibrated hydrological model, costs associated with distributing money via such an MBI were publicity, fieldwork, processing the bids through the model, probity, legal, and administration. In the Gippsland catchment, the total cost to establish forest plantations was $5340 per ha whereas it was $1635 per ha in the Corangamite catchment. No salinity benefit was obtained in Gippsland, but in Corangamite, if considered in isolation of the economic forest plantation benefit, the cost per hectare of salinity benefit was $5020.Operational aspects of the MBI are presented and discussed and a comparison is made to the expected costs of a conventional, non-science driven approach to landowner incentives.     

基于LUCC的南昌市生态资产价值演变及生态经济协调性研究

生态资产是经济社会发展过程中复合生态系统功能的价值表征,也是判断土地利用结构合理性的重要依据。论文通过GIS地理空间方法解析南昌市2008年、2013年、2018年的Landsat TM影像获得土地利用数据,利用相关模型分析南昌市土地利用幅度、速度、强度和生态资产价值的变化情况,并测算生态环境与经济发展的协调水平。结果表明:南昌市土地利用类型以耕地为主;生态资产价值主要源于耕地、林地和水域,但草地质量的下降、林地面积的缩减和建设用地的快速扩张使得生态资产价值下降了2.45%;并且生态环境与经济发展协调水平较低,生态环境在经济发展过程中承受了较大压力,从而提出要合理调整土地利用结构、注重生态经济协同发展,并建立绿色长远发展的生态保护屏障等政策建议。     

新农村建设与生态保护协同发展模式研究——以贵州乌蒙山区为例

生境脆弱而经济贫困的乌蒙山区,人地关系紧张、＂三农＂问题尖锐。以破解＂三农＂问题为主要目标的新农村建设,须立足区域喀斯特自然本底,综合运用人文、社会、政策、制度等要素类聚因地制宜地展开。根据恢复生态学原理建设不同类型、不同模式的新农村,以人为本地推进生态保护与经济脱贫协同发展。     

破解“三农“难题的对策和出路

农业是国民经济的基础,在我国现代化建设中具有重要的战略地位.长期以来,三农即农业、农村和农民问题一直成为困扰我国经济发展的瓶颈.因此,解决三农问题,要有针对性,从实际出发,开出良方.要深化农村土地制度改革,加大农业产业结构调整力度,进行农村行政体制改革,加快非农业人口的转移和小城镇建设,建立对农村的"反哺"机制,在"三农"之外寻求新的突破,用市场法则解决农村剩余劳动力、土地流转、物流、信息和资金等问题.     

Uncertainty and sustainability in the management of rangelands

We analyze a dynamic and stochastic ecological-economic model of grazing management in semi-arid rangelands. The ecosystem is driven by stochastic precipitation. A risk averse farmer chooses a grazing management strategy under uncertainty such as to maximize expected utility from farming income. Grazing management strategies are rules about which share of the rangeland is given rest depending on the actual rainfall in that year. In a first step we determine a myopic farmer's optimal grazing management strategy and show that a risk averse farmer chooses a strategy such as to obtain insurance from the ecosystem: the optimal strategy reduces income variability, but yields less mean income than possible. In a second step we analyze the long-run ecological and economic impact of different strategies. We conclude that a myopic farmer, if he is sufficiently risk averse, will choose a sustainable grazing management strategy, even if he does not take into account long-term ecological and economic benefits of conservative strategies.     

Assessing Effects of Mitigation Strategies for Global Climate Change with an Intertemporal Model of the U.S. Forest and Agriculture Sectors

A model of product and land markets in U.S. forest and agricultural sectors is used to examine the private forest management, land use, and market implications of carbon sequestration policies implemented in a" least social cost" fashion. Results suggest: policy-induced land use changes may generate compensating land use shifts through markets; land use shifts to meet policy targets need not be permanent; implementation of land use and management changes in a smooth or regular fashion over time may not be optimal; and primary forms of adjustment to meet carbon policy targets involve shifting of land from agriculture to forest and more intensive forest management in combinations varying with the policy target.     

Economic considerations in the optimal size and number of reserve sites

The debate among ecologists on the optimal number of reserve sites under a fixed maximum total reserve area—the single large or several small (SLOSS) problem—has so far neglected the economic aspects of the problem. This paper argues that economic considerations can affect the optimal number and size of reserve sites and should therefore be taken into consideration in the SLOSS discussion. The paper presents a tractable analytical model to determine the socially optimal number of reserve sites to be allocated in a farming area under a fixed total reserve area, taking the opportunity costs of nature conservation (in this case, agricultural profits) into consideration. Furthermore, the effect of land trade and related transaction costs on the socially optimal number of reserve sites is analyzed. The analysis suggests that in the presence of diminishing returns to farming area, the socially optimal number of reserve sites (which maximizes social welfare) is generally larger than the ecologically optimal number (which maximizes an ecological objective such as population viability). When the opportunity costs of conservation can be offset by land transactions, however, the socially optimal number of reserve sites might be closer to the ecological optimum.     

从“家庭农场”到“农民合作”:恰亚诺夫的合作化思想及其对中国现代农业发展的启示

农民经济理论和农民合作社理论是恰亚诺夫农业经济思想的两个重要组成部分。恰亚诺夫以家庭农场研究为基础,关注如何在以小农户为主体的基础上实现农业的大生产,提出了以合作社为载体的纵向一体化,构建了"小农场+合作社+支持型国家"的现代农业发展模式。本文通过介绍和补充恰亚诺夫关于农民合作社的研究论述与主要观点,强调指出了恰亚诺夫农业经济思想对当下促进小农户与现代农业有机衔接的中国农业发展所具有的实践价值与理论意义。     

The relation between forest clearance and household income among native Amazonians: Results from the Tsimane' Amazonian panel study, Bolivia

The Amazon rain forest harbors some of the world's richest biological diversity. During the twentieth century, two types of actors cleared that forest: native Amazonians and outside encroachers. Of the two actors, we know more about what drives outside encroachers to clear forest than about what drives native Amazonians to clear forest. The past research focus has served well because during the twentieth century outside encroachers cleared most of the Amazonian forest. But the past research focus needs to be expanded because native Amazonians are claiming de jure stewardship of the forests they inhabit, and with tighter jurisdiction over those forests will likely come changes in the amount of forest native Amazonians clear. Prior research in rural areas of low-income nations suggests that household income affects household forest clearance. To estimate the effects of household real income on the total forest area (old-growth + fallow) cleared by households we use a panel composed of five annual household surveys (2002-2006, inclusive) from 324 households of a native Amazonian society in Bolivia (Tsimane'). We control for household and village fixed effects and use an instrumental variable for household income. We find positive and significant household real income elasticities of forest clearance of 0.35 and 0.47 and an increase in forest clearance of 5.3%/year. The main finding stood up well to sensitivity analysis. These estimates suggest that in the near future, the forest in the Tsimane' territory will likely face increasing pressure from the Tsimane' themselves, not just from outside encroachers.     

The Economics of Forest Land Use in Temperate and Tropical Areas

This paper presents economic rules for harvest timing when timber and nontimber goods, services, and ecological functions are produced from forest stands. Forests include stands that are heterogeneous in age, land quality, and distance to market. Rules for allocating land between forest and nonforest use are developed. Key land use margins are identified that are important to land use allocation in temperate and tropical regions (e.g., between unmanaged forest, forest management, and forest conversion). Processes that can change key land use margins are discussed and used to organize recent empirical and theoretical studies of regions where forest land use is in transition, such as where forest land is being converted to alternative nonforest land uses.     

退耕还林对延安地区农业经济的影响

对延安地区11个农业县退耕前后耕地/播种总面积、种植业结构、农业投入、粮食、油料产量与单产量以及农民年均纯收入的变化进行了研究,探讨了退耕还林对延安地区农业经济的影响及其作用机制。退耕还林优化了农村的种植业结构与产业结构,全面带动了农村经济的发展。但仍然存在着一些亟待解决的问题,并给农村经济带来了一定的负面影响。     

都市农业旅游与都市可持续发展研究--以广州为例

都市农业旅游近年来成为都市旅游和都市可持续发展研究的新领域,并以其独特的社会、经济和生态功能成为当前我国城市可持续发展研究的热点之一。以广州为例,在明确都市农业、都市农业旅游概念及其发展意义的基础上,详细分析了广州都市农业旅游发展的优势、现状特点和存在问题;深入探讨并提出了设施农业旅游、园艺农业旅游、体验参与农业旅游、休闲度假农业旅游、农业博物馆旅游等5个适合广州发展的都市农业旅游主要类型;结合广州新的城市发展规划提出了北部山区森林观光度假区、中部城区农业商贸休闲区、城郊田园体验休闲区、南部海滨观光休闲区4大都市农业旅游区的空间布局和发展构想;并针对性地提出了政府主导、科学规划,突出特色、品牌带动,挖掘文化内涵、凸显农业科技,培养专业人才、提高管理水平等4点推进广州都市农业旅游开发策略。