A study of virtual land trade between China and ASEAN based on material flow analysis model

In this paper,based on the material flux analysis model（MFA） and its corresponding theories and algorithms of ＂virtual land＂ virtual land contents of five primary agricultural products are calculated and＂Virtual land trade＂hidden in those imported and exported products are also obtained through analyzing the primary agricultural product trade between China and ASEAN. In the process of calculationl following the thought of Changing agricultural products to ＂Virtual land trade＂land content, trade condition and spatiai distribution of agricultural products Were integratedly considered. indicate that China exported 73;057 km^2 of virtual land area to ASEAN by tea, vegetables; maize and grain, ASEAN exported： 57.332 km^2 to China by natural rubber from 2002 to 2005. It obvious; that china has lost 15,725 km^2 arable land through agricultural product trade, Additionally, in order to process： of calculation Virtual land trade, Thailand taker as an example to analyze its international trade of rice and Wheat from 1991 to 2005 and Calculate their ＂Virtual land trade＂ 2001 through 2005. According to and calculation, it is not difficult to conclude that ＂Virtual land trade＂ very important and could be used for China to guide agricultural export or import Structure and maintain Sustainable use of land resources.     

Analysis of nutrient content and assessment of economic value for major salt-tolerant plants in coastal areas: a case study of Dongying City,Shandong Province

Salinization of soil is a worldwide problem concerning resources and ecology,especially serious in coastal areas.Testing of 26 sorts of data or parameters are carried out on leaves of 22 plant species (in 24 plant variety) of existing main salt-tolerant plant of the Yellow River Delta region.Data or parameters include the following elements:contents of K+,Na+,Ca2+,Mg2+ and Cl-,contents of protein,fat,total energy,ash and contents of 17 amino acids.The results show that these tested plants have economic values.For example,according to their uses,they can be divided into edible plants,forage plants,medicine or health plants,and some of them can be used for multipurposes.These plants have played important roles in the sustainable utilization of plant resources in coastal areas.This paper has taken evaluations on the economic uses of salt-tolerant plants and given suggestions for saline soil improvement and resource utilization in coastal areas.Based on the results of investigation and experiments,we suppose that the salt-tolerant plants in coastal areas can be grouped into 9 main groups according to their eeonomic value:pioneer plants for saline land improvement,medicine,edible and forage plants,industry material forestation,breeding material,energy plants and eco-tourism resources.     

农村集体建设用地产权问题及其成因

随着中国工业化和城市化步伐的加速,土地的资产价值已为人们所认识并加以利用,农村集体建设用地产权问题也日益成为人们关注的焦点。中国现有农村集体建设用地产权制度的实施状况,说明这一制度安排的实施绩效并未完全达到立法者的预期目标。其原因可归结为：城乡分割的二元土地制度以及政府对土地市场的垄断,农村集体用地所有权主体模糊,使用权主体不确定以及产权权能不清。     

The future of farming: The value of ecosystem services in conventional and organic arable land. An experimental approach

In the current work, a novel, experimental ‘bottom-up’ approach is used to quantify the economic value of ecosystem services (ES) associated with highly modified arable landscapes in Canterbury, New Zealand. First, the role of land management practices in the maintenance and enhancement of ES in agricultural land was investigated by quantifying the economic value of ES at the field level under organic and conventional arable systems. This quantification was based on an experimental approach in contrast with earlier value transfer methods. Total economic value of ES in organic fields ranged from US $1610 to US $19,420 ha^− 1 yr^− 1 and that of conventional fields from US $1270 to US $14,570 ha^− 1 yr^− 1. The non-market value of ES in organic fields ranged from US $460 to US $5240 ha^− 1 yr^− 1. The range of non-market values of ES in conventional fields was US $50 — 1240 ha^− 1 yr^− 1. There were significant differences between organic and conventional fields for the economic values of some ES. Next, this economic information was used to extrapolate and to calculate the total and non-market value of ES in Canterbury arable land. The total annual economic and non-market values of ES for the conventional arable area in Canterbury (125,000 ha) were US $332 million and US $71 million, respectively. If half the arable area under conventional farming shifted to organic practices, the total economic value of ES would be US $192 million and US $166 million annually for organic and conventional arable area, respectively. In this case, the non-market value of ES for the organic area was US $65 million and that of conventional area was US $35 million annually. This study demonstrated that arable farming provides a range of ES which can be measured using field experiments based on ecological principles by incorporating a ‘bottom-up’ approach. The work also showed that conventional New Zealand arable farming practices can severely reduce the financial contribution of some of these services in agriculture whereas organic agricultural practices enhance their economic value.     

2002—2017年厦门市景观格局与热环境的时空耦合关系

基于2002、2007、2012、2017年4期Landsat遥感影像,应用景观生态学和统计分析相结合的方法,探讨了厦门景观格局对热环境的影响作用及其变化规律。结果表明,2002—2017年,厦门市相对地表温度(Relative Land Surface Temperature,RLST)呈上升趋势,城区的热岛效应逐步凸显;RLST较高的区域多为耕地、建设用地,RLST较低的区域多为绿地、水体;在类型层面,绿地的景观类型比例、最大斑块指数、聚集度指数、平均斑块面积、形状指数与相对地表温度呈负相关,斑块密度、边缘密度与RLST呈正相关。耕地、建设用地的景观指数与RLST均呈正相关;在景观层面,景观分割指数、形状指数、斑块密度、边缘密度、香浓均匀度指数与RLST呈正相关;景观优势度大、聚集度高的景观类型,如耕地、绿地、建设用地对RLST影响显著。随着城区的扩张与耕地的减少,建设用地景观格局对RLST的影响逐渐加强,而耕地景观格局对RLST的影响不断减弱;景观层面的景观格局对RLST的影响作用与不同景观类型总体的结构组分及空间构型有关。随着景观结构趋于复杂,景观层面的景观格局对RLST的影响逐渐增强。     

采煤塌陷地复垦投资机制研究

在我国的煤炭开采生产中,造成的土地破坏以塌陷地为主,大部分塌陷地需要恢复治理后才能重新利用。在我国,耕地资源繁缺,为改善生态环境,保护耕地,国家加大了土地复垦工作的力度。但是,塌陷地复垦的投资机制不完善,制约着复垦工作的顺利进行。立足采煤塌陷地复垦的投资机制现状,从资金管理制度、复垦土地产权、建立塌陷地复垦市场体系、完善政策法规着手,完善采煤塌陷地复垦投资机制。     

城市空间扩张与土地集约利用

我国自1996年已经进入城市化快速发展时期,城市化快速发展使得大量农村人口涌入城市,经济总量的提升加速城市空间的扩大,大量占用非城市建设用地,而现有自然承载力的限制使得城市化快速发展与城市空间的扩张对土地集约利用提出了更深层次的要求。文章构建了城市化与土地集约利用模型,分析动态城市化对不同行为主体的影响,提出低成本、集约型城市化模式概念,以推动和促进我国城市经济的健康、科学发展,构建社会主义和谐社会。     

鄱阳湖区土地利用演化与对农业经济的影响

以鄱阳湖区为研究对象,利用19851、995、2000、2005年的遥感解译数据,结合地理信息系统的空间分析和数理统计功能以及SPSS统计分析软件,对1985—2005年间的土地利用/覆盖格局和动态演变规律进行分析,揭示了近20年来土地利用变化的时空特点,并对其主要驱动因素进行了重点研究。结果表明:①不同时期土地利用/覆盖的变化既有相似之处,又有所差别。在土地利用/覆盖变化类型中,耕地与水域之间的双向转换非常频繁;草地与耕地,草地与林地之间的转化所占比例也较大;而建设用地是造成对耕地占用最多的土地利用类型;同时每个时段由于发展的目标不同,又有一些独特的土地利用/覆盖变化特征。②近些年来,土地利用/土地覆盖动态演变主要是由政策因素、人口增长和农业经济效应等因素共同驱动作用的结果。     

我国城市工业地价影响因素及力度的计量分析

地价是经济学中的重要课题,它是都市的语言,是都市的环境与功能的综合值。用计量经济学的方法,分供求二方取人口、经济、区位、政府行为等四大板块中的基本要素对我国工业地价的相关性与影响力度进行探讨。从相关性看：城市设施因素与工业地价相关性较弱;大区位因素与工业地价相关性较强。房产税额、耕地占用税额、本年购置的土地面积等政府行为因素与工业地价相关性较强;余者与工业地价相关性较弱。从影响力度看：工业地价对经济、政府行为、区位因素的弹性系数总体呈现一种矛盾、混乱的特征,佐证了中国工业地价违背客观规律性的现象。剔除其混乱因素,仍可看出大区位因素对工业地价影响的力度要大于经济因素,土地类税额对工业地价影响的力度微乎其微;反映了地方政府在工业化过程中对土地的掠夺性开发利用。     

地方政府土地违法行为探析

土地,是人类赖以生存的基础。时至今日,随着人类认识和改造自然能力的增强,土地已成为食物生产、经济发展和生态环境建设“争夺”的焦点。各类“中国特色”的土地违法案件层出不穷,其中以地方政府土地违法问题最为突出。因此,从体制、机制、法制的角度认识和完善当前我国地方政府土地违法行为已成为亟待解决的问题。