Bioenergy Crop Production in the United States: Potential Quantities, Land Use Changes, and Economic Impacts on the Agricultural Sector

The U.S. Departments of Agriculture and Energyjointly analyzed the economic potential for,and impacts of, large-scale bioenergy cropproduction in the United States. Anagricultural sector model (POLYSYS) wasmodified to include three potential bioenergycrops (switchgrass, hybrid poplar, and willow). At farmgate prices of US $2.44/GJ, anestimated 17 million hectares of bioenergycrops, annually yielding 171 million dry Mg ofbiomass, could potentially be produced at aprofit greater than existing agricultural usesfor the land. The estimate assumes highproductivity management practices are permittedon Conservation Reserve Program lands. Traditional crops prices are estimated toincrease 9 to 14 percent above baseline pricesand farm income increases annually by US $6.0billion above baseline.At farmgate prices of US $1.83/GJ, anestimated 7.9 million hectares of bioenergycrops, annually yielding 55 million dry Mg ofbiomass, could potentially be produced at aprofit greater than existing agricultural usesfor the land. The estimate assumes managementpractices intended to achieve highenvironmental benefits on Conservation ReserveProgram lands. Traditional crops prices areestimated to increase 4 to 9 percent abovebaseline prices and farm income increasesannually by US $2.8 billion above baseline.     

论我国现行土地制度对物业税的影响

本文基于土地所有权与土地使用权可以相对分离,土地使用权具有物权特性,土地使用权人享有相应期限内的土地收益权,对土地使用权课征不动产税可以弥补土地出让制度的缺陷,可以规范中央与地方的财政分配关系等方面的分析认为,虽然中外土地制度存在差异,但是中国土地公有制并不能成为开征不动产税的障碍。     

Cost-effective compensation to avoid carbon emissions from forest loss: An approach to consider price-quantity effects and risk-aversion

Analyses were carried out on financial compensation to avoid loss of tropical forests and related carbon (C) emissions when marginal financial yield declined for land-use options with extended areas, and when a risk-averting perspective (modeled according to financial theory around the capital asset pricing model) is assumed. The approach in this study was to consider natural forest, forest plantation, pasture, and cropland simultaneously to investigate how an optimized land-use distribution may reduce the amount of compensation necessary to avoid C emissions from forest loss.The financial compensations derived were as high as US$ 176 per hectare per year when comparing natural forests only with the most profitable alternative (croplands). However, compensation decreased to US$ 124 for risk-neutral decision-makers, who would strive for optimized land-use allocation, and to only US$ 47 per hectare per year for risk-avoiders, who would look to maximize the reward-to-variability ratio. Sensitivity analyses indicated that the compensation under risk-aversion increased much less than under risk-ignoring when increased productivity of agricultural land-use or growing demand for agricultural products was simulated. It was concluded that considering appropriate diversification strategies and the well documented human behavior to avoid risks is an important step in developing cost-effective compensation policies.     

基于收益还原法的住宅用地使用权续期定价模式研究

本文以土地使用费的内涵分析为切入点,运用马克思地租理论分析了我国土地定价的发展历程和趋势;以此为基础,从制度层面提出了城镇住宅用地使用权续期定价模式的框架,并以此为依据,着重分析了收益还原法在住宅用地使用权续期定价中的运作过程,为土地使用权续期定价体系的完善与发展提供了新的思路与方法。     

“倒挂型”土地利用总体规划的耕地保护效果评价

研究目的:揭示"倒挂型"土地利用总体规划与耕地保护效果之间的关系,以期为国土空间规划的编制提供参考。研究方法:倾向值匹配法。研究结果:(1)耕地"倒挂型"规划对耕地面积净变化的影响具有统计显著性,2006—2008年,耕保指标"倒挂型"规划使耕地面积净变化量平均减少2.270万hm2;(2)2010—2016年,耕保指标"倒挂型"规划使耕地面积净变化量平均减少0.496万hm2;(3)建设用地"倒挂型"规划对耕地面积净变化量并无显著影响。研究结论:在省级政府耕地保护责任目标考核的制度环境下,耕地"倒挂型"规划对地方政府形成一定压力,促使各级政府采取措施加以应对,从而使得"倒挂型"规划在一定程度上降低了耕地净减少量。     

中国旅游景区功能演变与用地分类构想

研究目的:基于中国旅游景区功能演变、用地特征及问题分析,构建旅游景区用地分类体系,以期为旅游景区用地纳入区域土地利用提供理论基础,为旅游景区规划的深度编制提供实践依据。研究方法:通过调研和问卷厘清现状景区用地情况,对比借鉴相关用地分类体系,基于此构建旅游景区用地分类方案。研究结果:分析并阐明了旅游景区的功能演变、用地特征和现状问题,构建了2大类、9中类、28小类的景区用地分类体系,并与《土地利用现状分类》进行衔接。研究结论:建立可衔接且具可操作性的旅游景区用地分类体系,是实现旅游景区健康可持续发展与用地规范化管控的关键。     

基于GIS的辽宁省可利用土地资源综合评价

基于GIS手段,根据《省级主体功能区划分技术规程》的技术方法,结合辽宁省的实际情况对《规程》做出一定的改进,以辽宁省各县市区为基本评价单元,借助1km^2动态网格进行地形分析并提取各类土地利用类型的面积,以可利用土地资源和人均可利用土地资源为基础、土地利用综合程度指数为依据进行评价,为辽宁省主体功能区定位提供重要依据。     

土地利用的尺度和尺度转换

研究目的:研究和分析生态地理学中有关尺度及尺度转换的概念及内涵,探讨土地利用模式的尺度转换方法.研究方法:图示法,多元线性回归反演法,目标规划法.研究结果:为土地利用模式在不同尺度间的转换提供了方法参考,丰富了生态地理学中有关尺度及尺度转换的研究.研究结论:尺度和尺度转换涉及生态学、地理学等多个领域,更深层次的研究需要各学科的联合.     

桂西北喀斯特山区土地用地结构变化及驱动因素分析

利用土地利用变化幅度、单一土地利用动态度、综合土地利用动态度、土地利用程度综合指数等模型,对河池市土地利用动态变化分析,采用因素相关性分析法对其驱动因素进行分析;2001-2007年农业用地面积减少,园地面积逐步增长,建设用地面积一直呈现增长态势,累计增长量达5990．380hm2,2001年、2004年、2007年河池市土地利用程度综合指数分别为178．56,178．80,178．41,土地呈现从高度开发利用向合理调整转变的趋势;政策因素、经济和交通的快速发展、人口增长等都是促进土地利用变化的主要驱动因素。     

Dynamics of agricultural land use change in Kerala: a policy and social-ecological perspective

Land-use change is a phenomenon highlighting significant shifts in human interaction with the natural environment. Different patterns of agriculture and a trend towards non-agricultural land use challenge the sustainability of farming systems. This study aims to identify the causes of changes in land use and cropping patterns, with a special focus on paddy, the staple crop in Asia. In the case of Wayanad, a district in Kerala, South India, we argue for an interdisciplinary analysis of rapid land-use change to unpack the multiple dimensions of sustainability: economic, ecological and social factors, aggregating up to 70% reduction in the area under paddy by 2010. The results rest on empirical field research, participatory rural appraisals and stakeholder workshops conducted during the 4-year period from 2010 to 2013, along with state- and district-level data covering the 1983–2011 period. Reduced economic viability, labour shortages and population pressure on land are the major drivers for the transformation of paddy fields to other land uses. Changes in land use and agrarian structure reflect not only the livelihood strategies adopted by farmers in response to these drivers, but also the impacts of unintended policy idiosyncrasies. At a more fundamental level, they are the consequences of policy conflicts and inadequate sectoral integration of policies and implementation strategies.