新时期中国农村土地综合整治逻辑体系框架

在问题剖析和内涵辨析的基础上,从5个方面构建了农村土地综合整治逻辑体系框架。研究认为,新时期农村土地综合整治在指导理念上应以理—工—管等多学科交叉融合的基本理念为指导;在目标定位上应形成包含现实目标、基本目标、中级目标、战略目标的层次化目标体系;在宏观战略上应明确今后一段时期内综合整治的战略重点与方向;在统筹安排整治项目方面可按照战略区—类型区—潜力区—项目区的空间层次逻辑思路,从国家、区域、亚区、项目4个层级构建综合整治项目空间层级体系;在功能作用方面,可通过土地整治、空间重构、要素整合与机制创新来推进乡村转型发展和城乡一体化进程

《产业转移与中国区域空间结构优化》评介

<正>十三五期间,全面促进区域协调发展,优化区域空间结构,仍然是国民经济社会发展的重大任务。我国将在深入实施区域发展总体战略的基础上,以一带一路建设、京津冀协同发展、长江经济带发展为引领,形成沿海沿江沿线经济带为主的纵向横向经济轴带,塑造要素有序自由流动、主体功能约束有效、基本公共服务均等、资源环境可承载的区域协调发展新格局。产业转移是要素流动的体现,合理有序的产业转移将促进区域产业结构调整,形成区域产业分工

开发克拉运河的VRTS分析及启示

在一带一路与两洋战略背景下,基于各种目标的战略与工程被大量提出,并进行了论证。其中关于开发克拉运河的提议,被认为具有破解马六甲困局的重大意义。对此,本文运用VRTS分析法,从战略价值、战略风险和开发时机、开发(时序)策略四方面进行综合分析,指出该提议存在战略价值高估、战略风险低估,以及战略时机误判和战略时序安排不够合理等问题,建议暂时搁置,并探索其他可行替代方案。本文关于开发克拉运河的分析,对于其他战略项目论证也有一定参考意义

《中国自然资源通典》介绍

<正>自然资源是自然界天然存在的、可以为人类利用的物质与能量的总称,是人类生存的物质基础和社会发展的动力源泉。按照联合国环境规划署(UNEP)的定义,“所谓资源,特别是自然资源,是指在一定时间和一定条件下,能产生经济效益,以提高人类当前和未来福利的自然因素和条件”。自然资源是一个复杂的系统,各类资源要素既相互区别、各具特色,又互相联系、互相制约。按照存在形态,自然资源可以分为有形自然

Allocation of photosynthestically-fixed carbon in plant and soil during growth of reed (Phragmites australis) in two saline soils

Aims Terrestrial carbon (C) sequestration is derived mainly from plant photosysthetically-fixed C deposition but soil organic C (SOC) content in saline soils is generally low due to low deposition of C from restricted plant growth. It is important to explore the effects of soil salinity on the allocation of photosynthetically-fixed C to better understand C sequestration in saline wetland soils. Methods We conducted a pot experiment in which reed (Phragmites australis) was grown in a low salinity (LS) soil and a high salinity (HS) soil from the Yellow River Delta under flooded conditions. The allocation of photosynthetically-fixed C into plant tissues, SOC, dissolved organic C (DOC), microbial biomass C (MBC), particulate organic C (POC), and mineral-associated organic C (MAOC) was determined using a C-13 pulselabeling method after four labeling events during the 125-day-long reed growing season and destructive sampling immediately at the end of six hours of pulse labeling (end 6-h) and on the final harvest day (final day). Results In most cases soil salinity, reed growth stage, or reed biomass significantly (P < 0.05) affected the deposition of photosynthetically-fixed C into the plant-soil system. At all four pulses at end 6-h the high salinity soil had significantly (P < 0.05) lower percentage net assimilated C-13 in the roots and significantly higher (P < 0.05) percentage net assimilated C-13 in the soil than did the low salinity soil. At both end 6-h and on the final day the high salinity soil had significantly (P < 0.05) lower (SOC)-C-13, and significantly (P < 0.05) higher (DOC)-C-13/(SOC)-C-13 ratio than the low salinity soil except for pulses 3 and 4 on the final day. The majority of photosynthetically-fixed C in soil was deposited into MAOC pools and > 80 % of deposited (SOC)-C-13 was present as MAOC in the high salinity soil due to its significantly (P < 0.05) higher clay content compared with the low salinity soil. Conclusions Soil salinity affected the allocation of photosynthetically-fixed C in the plant-soil system, and soil texture altered the allocation of rhizodeposition C in different soil particles

基于地形因子的北京山区沟域土地利用变化研究(英文)

由于人口的增长和经济的快速发展,发展中国家正经历着日益剧烈的土地利用变化,其变化的范围不仅发生在平原,甚至已经扩展到山区。作为山区基本的地理单元,沟域是山区经济活动的主要场所、因此,沟域土地利用的优化调控对山区绿色化发展至关重要。本文基于1995年和2012年北京山区的土地利用数据,系统分析了沟域的土地利用变化情况,同时根据典型沟域地形因子(如海拔和坡度)的土地利用变化评估结果,提出土地利用的优化调控路径。研究结果表明,沟域是评估山区土地利用变化趋势的有效地理单元,可以为未来山区的绿色化展提供科学依据。从1995年到2012年,北京山区沟域最显著的土地利用变化表现在草地面积的减少和建筑面积的增加(草地转换为建筑用地),而这些土地利用变化主要发生在海拔0-400米和坡度6-15°的区域范围内。考虑到近年来北京山区经济的快速发展,建筑用地和耕地的数量将会持续增加,但目前的结果显示地形较陡区域土地利用变化最为显著,意味着未来山区沟域土地利用优化调控应充分考虑地形因子的影响,在这些区域的土地利用政策中要着重考虑实施保障山区生态屏障和水土涵养的功能设施

南昌市固定燃烧点源大气污染物排放清单及特征

大气污染物排放清单是了解区域污染物排放特征、准确模拟空气质量的重要资料,而工业点源是大气污染的重点排放源。通过收集相关活动水平信息和合理的排放因子,采用自下而上的方法建立了南昌市2014年点源大气污染物排放清单,结果表明,SO2、NOx、CO、PM10、PM2.5和VOC排放总量分别为29576.2t、17115.1t、25946.6t、4689.4t、922.9t和1190.4t,其中,金属炼制行业对SO2、CO和VOC的贡献最高分别占37.75%、30.59%和38.45%;火电行业是NOx的主要来源,其贡献率为47%;水泥等建材制造行业对PM10和PM2.5排放贡献最高,分别为26%和25%。根据排放源污染物排放量及地理坐标信息,建立了0.4km×0.4km的污染物排放量空间分布特征图,结果表明南昌市大气污染物排放较为集中,青山湖区北部和新建区北部是SO2、NOx、CO和VOC的主要排放区,而PM10和PM2.5的排放量相对分散,并在安义县出现排放高值区。通过将计算结果与统计数据结果进行对比,了解所估算清单的准确程度。对比SO2和NOx的计算值和统计值进行统计分析,结果显示NMB(标准化平均偏差)和NME(标准化平均误差)值均小于50%,清单计算精度较高。同时为了解清单数据质量,对清单的不确定性进行定量分析,结果显示SO2和VOC不确定性较低而PM10和PM2.5的不确定性相对较高,清单整体不确定性与其他研究结果相差不大。建议后期研究可以从提升基础数据质量和建立具有区域代表性的排放因子数据库着手,从而减小排放量的不确定性,获得精准可靠的大气污染物清单并应用于空气质量模型预报等更深入的研究

浙江省农业文化遗产保护现状、潜力及对策研究（英文）

浙江省是中国面积最小、经济最活跃的省份之一,同时也是农业文化遗产保护工作开展最早,成效最显著的省份之一。分析与评价浙江省农业文化遗产保护的现状与问题,对指导其它地区农业文化遗产保护工作具有重要借鉴意义。本文基于近10年浙江省农业文化遗产保护工作的实践,对浙江省农业文化遗产保护工作进行了分析,并对遗产保护的潜力进行了评价,同时给出了针对性的发展建议。研究表明:浙江省农业文化遗产保护有利于挖掘传统农业内涵,传承优秀农耕文化,发挥农业遗产价值以及保护农村生态环境,同时可促进农业持续发展、农村文化繁荣、农民就业增收以及美丽乡村建设。此外,浙江省传统农产品品质优良,特色经济林果种类众多,茶文化底蕴深厚,海洋资源利用独具特色,水土资源利用经验丰富,生态农业形式多样,为农业文化遗产保护提供了巨大发展潜力。研究可为浙江省农业文化遗产的保护与传承以及农业可持续发展和农业功能拓展提供一定的参考

Response of the fine root production, phenology, and turnover rate of six shrub species from a subtropical forest to a soil moisture gradient and shading

Knowledge of the fine root dynamics of different life forms in forest ecosystems is critical to understanding how the overall belowground carbon cycling is affected by climate change. However, our current knowledge regarding how endogenous or exogenous factors regulate the root dynamics of understory vegetation is limited. The aims of this study were to test the effects of soil moisture gradient and shading on the fine root production, phenology, and turnover rate of six shrub species from a subtropical forest. We selected a suite of study sites representing different habitats with gradients of soil moisture and solar radiation (shading or no shading). We assessed the fine root production phenology, the total fine root production, and the turnover among six understory shrub species in a subtropical climate, and examined the responses of the fine root dynamics to gradients in the soil moisture and solar radiation. The shrubs included three evergreen species, Loropetalum chinense, Vaccinium bracteatum, and Adinandra millettii, and three deciduous species, Serissa serissoides, Rubus corchorifolius, and Lespedeza davidii. Results We observed that variations in the annual fine root production and turnover among species were significant in the deciduous group but not in the evergreen group. Notably, V. bracteatum and S. serissoides presented the greatest responses in terms of root phenology to gradients in the soil moisture and shading: high-moisture habitat led to a decrease and shade led to an increase in fine root production during spring. Species with smaller fine roots of the 1(st)+2(nd)-order diameter presented more sensitive responses in terms of fine root phenology to a soil moisture gradient. Species with a lower fine root carbon- to nitrogen ratio exhibited more sensitive responses in terms of fine root annual production to shading. Soil moisture and shading did not change the annual fine root production as much as the turnover rate. The fine root dynamics of some understory shrubs varied significantly with soil moisture and solar radiation status and may be different from tree species. Our results emphasize the need to study the understory fine root dynamics in the achievement of a complete understanding of the overall belowground carbon cycling in a forest ecosystem, particularly ecosystems in which the understory fine root highly contributes to the belowground biomass

基于能值理论的三江源区生态系统服务物质当量研究

鉴于生态系统服务的多样性和评估方法的复杂性使得生态系统服务研究难于纳入到政府决策和政绩考核的问题,以三江源区为例,提出生态系统服务物质当量的概念,并发展了基于能值理论的物质当量估算方法;进而通过构建用于调节生态系统类型之间与生态系统内部差异的均衡因子和调整因子,发展了生态系统服务快速核算方法.结果表明:三江源区主导生态系统服务(包括水源涵养、土壤保持和生态系统固碳)所具有的能值量为2.74×1022sej/a,标准物质当量(即物质当量单位)的能值基准值为1.58×1017sej/(km2?a),由此估算的物质当量为173618.80当量/a,单位面积物质当量为0.56当量/(km2?a),其中,水源涵养、土壤保持和生态系统固碳服务分别占比52.72%、28.14%和19.14%.三江源区主导生态系统服务物质当量的空间分布特征表现为从东南向西北逐渐递减的变化趋势.分县(乡)估算的主导生态系统服务物质当量的空间分布与其单位面积物质当量存在较大差异,前者的高值区主要位于治多县、曲麻莱县和杂多县,后者则主要位于尖扎县、同仁县、久治县和班玛县.基于直接评估法估算的各县(乡)单位面积物质当量与基于快速核算方法估算的结果的决定系数为0.72,均方根误差为0.25当量/(km2?a).研究结果有助于实现生态系统服务的快速评估