不同土地利用方式对土壤动物多样性的影响研究

[目的]探讨不同土地利用方式对土壤动物群落结构和生物多样性的影响。[方法]于2006年冬季(12月)和2007年春季(5月),对四川紫色土丘陵区农田边界、农田、果园和退耕林地的土壤动物群落结构进行调查。[结果]共获得土壤动物8 589只,分别隶属于3门9纲31类。在个体数量上,果园、退耕林地和农田边界显著高于农田;在类群数量上,农田边界显著高于农田和退耕林地,果园也显著高于农田;对Shannon-Wiener多样性指数(H')、Pielou均匀性指数(J)、Simpson优势度指数(C)、Margalef丰富度指数(M)和密度-类群指数(DG)5个多样性指标进行分析表明,与H'相比,DG表征的土壤动物多样性更能客观地反映土壤动物分布的真实情况;土壤动物群落主成分分析表明,农田边界、果园和退耕林地的土壤动物群落与农田之间有显著差异。[结论]该研究认为土地利用方式对土壤动物的群落结构有明显影响,农田边界的存在对土壤动物生物多样性保护具有重要意义。     

土地储备的风险及对策

介绍了土地储备制度形成的背景、运作模式,分析了土地储备存在的风险,提出了土地储备风险防范的对策。     

Study on the Utilization and Maintenance of the Supperementary Cultivated Land During Land Exploitation and Consolidation

通过对广东省土地开发整理补充耕地的成因及现状的考察,总结了补充耕地的主要做法,分析了土地开发整理补充耕地利用和管护中存在的问题,并在此基础上探讨了加强土地资源开发利用的意义,提出了可持续发展战略下加强补充耕地利用和管护的对策。     

保证粮食安全的土地银行经营模式

建立农村土地银行是确保国家粮食安全、发展现代农业、解决农村资金瓶颈、建立农民增收长效机制的需要,也是我国实现农村重大变革的战略之举。基于粮食安全,以土地银行为研究视角,利用动态博弈中的相机选择问题分析模型,主要解决其运营需保持的最小经营规模及粮食作物与经济作物的种植比例,并提出相应的政策建议。     

Evaluation of humic substances fertigation through surface and subsurface drip irrigation systems on potato grown under Egyptian sandy soil conditions

The aim of this study was to evaluate the effect of humic substances application in sandy soil under surface and subsurface drip irrigation systems on potato tubers yield quantity, quality, nutrients concentration in tubers and soil fertility after harvesting. For this purpose, field experiment was carried out at the experimental farm of the Agricultural Research Station, National Research Center, El-Nubaria district, Egypt during the winter season of 2007/2008. The used experimental design was split plot design with three replicates, main treatments were presented irrigation systems, i.e. surface and subsurface drip irrigation, while subtreatments were presented rates of humic substances additives which were 0, 60 and 120 kg ha⁻¹. Results showed that increasing humic substances application rates up to 120 kg ha⁻¹ enhanced tubers yield quantity, starch content and total soluble solids. The increase of humic substances application rates was associated with the decrease of nutrients leaching, which was reflected on increasing macro- and micronutrients concentration in potato tubers, as well as increasing concentration of these nutrients in soil after tubers harvesting. Subsurface drip irrigation system was found to be more efficient than surface drip irrigation system on improving tubers yield quantity, quality parameters and nutrients concentration content, in addition to soil fertility after harvesting.     

“3S”技术在土地资源管理中的应用

土地资源日新月异的变化使传统的土地资源管理手段无法满足土地资源信息及时更新的要求。“3S”技术是土地资源可持续利用研究中的高新技术，将“3S”技术应用于土地资源科学研究既可弥补传统调查手段的不足，又为土地资源的调查研究提供了新的途经与技术支持。阐述了“3S”技术优势及其在土地资源中应用原理及应用现状，展望了“3S”技术在土地资源中的应用前景。     

安家岭露天煤矿土地利用结构预测

采用实地调绘、航片判读、统计分析、历史类比与趋势外推相结合的方法 ,对平朔安家岭露天煤矿 1 998～ 2 0 1 9年剧烈扰动的 1 65 2 0h 的土地利用结构进行了预测性研究。结果表明 ,2 2年间 ,共剥离岩土 1 60 980 0万 ,挖损土地 1 2 0 0 0h ,压占土地 45 2 0h ,其中 ,耕地和林牧用地分别消失 874 3h 和 79 0h 。规划后的土地利用结构有了明显的改善 ,其中 ,耕地由原来的 5 5 0 %提高到 67 0 % ;林牧用地由原来的 4 5 %提高到 30 0 % ,基本消除了荒地和其它未利用地。同时 ,耕地总量动态平衡结果表明 ,以 6年为耕地恢复期 ,大约在采矿 2 6年后 ,耕地总量可达到平衡 ;若以 1 0年为耕地恢复期 ,大约在采矿 34年后 ,耕地总量可达到平衡。     

对城市边缘区土地利用问题及对策的研究

城市边缘区作为一个特殊的区域空间，在城市发展过程中起着极其重要的作用，它是城市和乡村联系的纽带，为城市生产和生活日益扩张提供后备空间。城市边缘区土地利用对城市和城市周围地区的居民生产、生活方式，经济要素的流转方式以及生态环境保护都起着重要的影响。及时掌握城市边缘区土地利用变化情况，合理进行土地利用规划，对实现可持续发展，构建和谐社会十分必要。     

土地系统研究理论方法与技术集成

探讨了土地系统的概念，论述了土地系统研究的内容、理论方法，介绍了土地系统研究的程序与步骤，总结了土地系统研究的模型与方法，解析了土地系统研究的技术集成体系。该研究为开展土地利用/土地覆被变化研究、推进全球土地计划研究明确了目标、确定了对象与任务，同时提出的技术集成体系为国土规划、整治和区域开发提供了方法与依据。     

Processing of 13C glucose in mineral soil from aspen,spruce and novel ecosystems in the Athabasca Oil Sands Region

Microbial composition is known, on similar soil types, to vary based on differing organic matter inputs, or stand composition. Fine-textured luvisolic soils, which dominate the upland boreal forests of Western Canada, support a canopy cover of aspen (Populus tremuloides Michx.), white spruce (Picea glauca (Moench) Voss) or a mixture of the two. These soils then reflect different belowground biogeochemical processing of organic matter. Novel, anthropogenic soils formed from a combination of peat litter and fine textured mineral soil, are now also a part of the landscape in the western boreal. This study set out to determine if a simple labeled compound (¹³C glucose) was processed differently by soils from the two dominant stand types (aspen and spruce) and from an anthropogenic (newly reclaimed) site. Results indicate that while all three soils rapidly incorporated and respired the labeled carbon, each maintained a distinct microbial community structure (as evidenced by phospholipid fatty acid analysis) throughout the 300 hour experiment. Therefore soils with different microbial communities from varied organic matter inputs decompose organic carbon by different processes, even in the case of simple labile compounds.