China’s Potential of Grain Production Due to Changes in Agricultural Land Utilization in Recent Years

The changes in utilization of agricultural land have gradually grown into one of the major factors impacting grain output in China. This study explores the various components of agricultural production in China from the land utilization perspective, involving changes in grain production per unit area, multi-cropping index, and adjustment of agricultural structure. Compared with the record values, different research methodologies are used to analyze the po- tential of above three components. The results indicate that grain production potential of 65.68×109kg was unexploited in 2006, in which 45.8×109kg came from the restructuring in agriculture. So we can infer that the reduction of grain production in China could be primarily attributed to agricultural restructuring in recent years. So the productive poten- tial can be fully restored by increasing agricultural investment, or recovering agricultural structure in favorable condi- tions. So we can say that China’s current condition of food security is good.

A Study of the Driving Force Model Revealing Changes in Land Utilization Level Based on 3S Technologies ——The Example of Yuanmou, Yunnan, China

This paper introduced the theory and approaches of building driving forcemodels revealing the changes in land utilization level by integrating RS, GPS, and GIS technologiesbased on the example of Yuanmou County of Yunnan Province. We first created the land utilizationtype database, natural driving forces for land utilization database, and human driving forces forland utilization database. Then we obtained the dependent and the independent variables of changesin land utilization level by exploring various data. Lastly we screened major factors affectingchanges in land utilization level by using the powerful spatial correlation analysis and maincomponent analysis module of GIS and obtained a multivariable linear regression model of thechangesin land utilization level by using GIS spatial regression analysis module.

Relationship between Rural Industry Revitalization and Land Resource Utilization and Its Practice in Ganning Town, Wanzhou District of Chongqing

[Objectives]To explore the relationship between rural industry revitalization and land resource utilization.[Methods]Starting from the connotation of rural industry revitalization and land resource utilization,this study explores the relationship between rural industry revitalization and land resource utilization,Taking Ganning Town with typical mountain industry as the research area,this paper analyzed the relationship between rural industry revitalization and land resource utilization through a combination of field research and literature analysis,found out the existing problems and came up with pertinent recommendations.[Results](i)Rural industry revitalization is both mutually reinforcing and mutually restrictive.(ii)In this study,the land use types of Ganning Town were divided into nine categories,including farmland,garden land,forest land and grassland,and their industrial functions and development models were identified,and the corresponding framework of land resource utilization and rural industry revitalization in Ganning Town was constructed.(iii)In view of the problems existing in Ganning Town,this paper proposed to change the ideological concept and enhance understanding,improve the utilization rate of idle land and promote rural industry revitalization,and accelerate land consolidation and restoration,and promote sustainable development.[Conclusions]It is necessary to correctly understand the two-way role and dynamic change relationship between rural industry revitalization and land resource utilization,solve the problem from the perspective of development,adopt development strategies according to local conditions,and take the road of sustainable development.

Do land utilization patterns affect methanotrophic communities in a Chinese upland red soil?

Soil samples were collected from three plots under different land utilization patterns including degradation, farming, and restoration. The abundances of methanotrophs were quantified using real-time polymerase chain reaction （PCR） based on the pmoA and 16S rRNA genes, and the community fingerprint was analyzed using denaturing gradient gel electrophoresis （DGGE） aiming at pmoA gene. Significantly lower 16S rRNA and pmoA genes copies were found in the degradation treatment than in farming and restoration. Higher abundances of Type I than those of Type II methanotrophs were detected in all treatments, The treatment of farming was clearly separated from degradation and restoration according to the DGGE profile by cluster analysis. The lowest diversity indices were observed in the F （farming plot）, suggesting that the community structure was strongly affected by farming activities. There were significantly positive correlations between the copy numbers of pmoA also Type II-related 16S rRNA genes and soil available K content. Strong negative and positive correlations were found between Type I and soil pH, and available P content, respectively. We concluded that the vegetation cover or not, soil characteristics including pH and nutrients of P and K as a result of anthropogenic disturbance may be key factors affecting methanotrophic communities in upland soil.

Problems and countermeasures for land exploitation and utilization in China's development areas

s: The planning area and developing area in China's l29 national and 584 provincial development areas cover 8000 km2 and l500 km2 respectively. By typical field investigations we found that China's development areas have the characteristics of abundant categories, excessive quantities, large scales and dense localities in coastlands, border areas and river banks. And their utilization have 4 features of mainly collecting and occupying agricultural lands, minor rebuilding of old city; mainly taking up cultivated lands, minor exploiting and utilizing barren mountains and bleak sloping lands; collecting and occupying lands at first, utilizing afterwards; using large quantities of lands but obtaining comparatively fewer benefits. According to the analyses, China's development areas can be concluded into one of the four categories: constructed from cultivated lands, reconstructed from old cities, constructed from coastlands and islands, and constructed from barren mountains and desolate sloping lands. Their corresponding problems of unsuitable planning and distribution leaving cultivated lands unused, low remission price and chaotic management measures are analyzed in detail and the countermeasures are put forward. These include planning and distribution the lands in an integrated way, managing all these lands in a unified system. improving the growth pattern of their economy, and advancing their utilization and output ratios.

Analysis to the Driving Force Model and Driving Factor on the Utilized Changes of Cultivated Land in Gonghe County

Using gradually regression analysis to establish the driving force model of utilized change of cultivated land in Gonghe County, and using path analysis, correlation analysis, partial correlation analysis and system dynamics method to inspect the effect of driving changing on cultivated land change under different change situations. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed from the county territory scale level. At last, some corresponding policies and measures were put forward.

Ecological Effects of Land Use Patterns in Red Soil HillyRegion

Plant biomass and biodiversity, element accumulation and return, water loss and soil erosion, and changesin soil properties were studied for up to 10 years after conversion of sparse tree-shrubby grass land into thefollowing four land use patterns: masson pine (Pznvs massonzana Lamb.) land, beautiful sweetgum (Ltq-uidambar fomosana Hance) land, vegetation reservation land, and artificial mowing land. The annualbiomass production of the masson pine land was 5060 kg ha￣-1 being 4.9, 2.1, and 6.0 times that of the beau-tiful sweetgum land, the vegetation reservation land, and the artificial mowing land, respectively. Comparedwith the background values, the number of plant species for the vegetation reservation land increased by 10species after 10 years of land utilization, while for the masson pine and the beautiful sweetgum decreased by4, and for the artificial mowing land by 9. For masson pine land, total amount of N, P, K, Ca, and Mg neededfor producing 1000 kg dry matter was only 3.5 kg, annual element return through litter was 22 kg ha￣-1, bothof which were much lower than those of the other patterns. Vegetation reservation was an effective measureto conserve soil and water and improve soil fertility in the red soil hilly region. Artificial mowing arousedserious degradation of vegetation and soil. Some measures and suggestions for management and exploitationof the red soil hilly region such as masson pine planting, closing hills for afforestation, and stereo-agricultureon one hill are proposed.

Analysis to the Driving Force Model and Drives Factor on the Utilized Changes of Cultivated Land in Qinghai Lake Area

Using path analysis, correlation analysis, partial correlation analysis and system dynamics method to study the driving force of cultivated land in Qinghai Lake Area, and using gradually regression analysis to establish the driving force model of utilized change of cultivated land. Driving factors, action mechanism and process of utilized change of cultivated land were analyzed, and the differences during all factors were compared. The study provides some decision basis for sustainable utilization and management of land resources in Qinghai Lake Area.

Engineering Geological Mapping and Land-Capability Analysis in Tangshan City

Geological environment in Tangshan City is under investigation with referenceto the Tangshan Urban Earth Science, geo-hazards maps. The expected loss for urban land utilizationis calculated by employing relevant economic mathematic models. Quantitative analysis andcomprehensive evaluation are then exercised for the capability of land utilization and a series ofcharts for the analysis of land-use capability are worked out to provide the basis for theformulation of controlling measures for urban planning and to ensure the utmost conformity betweenland-use and geological environment in urban planning.

Research on urban land information system based on GIS

Urban land utilization plays an important role in city development. We establish the ＂Urban Land Information System based on GIS＂ in order to inspect urban land structure and utilize a model automatically. A series of codes abstracted from urban land sustainable utilization significance are used as measures in land inspection. GIS tools combined with ＂Urban Land Information System＂ make visible codes calculations and statistical results possible. Useful mathematic methods are cited to analyze the degree urban land sustainable and optimize land structure. By scientific system analysis, relationships among modules and system structure are illustrated clearly. As a result this study has drawn out the ＂Urban Land lnibrmation System＂ model.

GIS approach for assessment of land suitability for different land use alternatives in semi arid environment in Jordan:Case study(Al Gadeer Alabyad-Mafraq)

The semi arid lands of Jordan are fragile and severely degraded due to low rainfall and mismanagement of natural resources.As human demands increase,sustaining the productivity of land becomes more and more important.Land suitability evaluation can contribute towards better land management;mitigation of land degradation;and designing land use pattern that prevents environmental problems through segregation of competing land uses.Suitability analysis allows identifying the main limiting factors for the agricultural production and enables decision makers to develop crop managements able to increase the land productivity.The purpose of this study was to develop a Geographic Information System(GIS)based approach for land use suitability assessment in order to assist land managers to identify areas with physical limitations for different land use alternatives based on research criteria developed by FAO and modified by stakeholders.This study was conducted using various data and maps incorporated within(GIS)in order to derive potential suitability for different Land Utilization Types(LUTs).Land suitability mapping was developed using an innovative approach that integrates soil and climatic data for land suitability assessment.Suitability maps for each land use were developed to show the suitability classes and display the spatial representation of soils suitable for agriculture.The output of suitability analyses provided not only the type of land use for which the land was suitable,but also information about the type of limitation(s)facing the utilization of the land.Optimum land use alternatives(scenarios)were formulated to improve and optimize the agricultural production in the study area.

Suitable Size of Nature Reserves in Tibet,P.R.China Based on Endangerment Degree of Species

In a view of natural conditions of establishing nature reserve,an index system was prepared for quantitative assessment on status of endangered species,and thus degree of endangered species in Tibet was evaluated.Taking a sub-ecozone as basic unit,top 5 animals and 1 plant with high E as well as the number of species in each unit were enumerated;and the degree of land utilization was figured out.Afterward,we selected 6 coefficients,assigned weight,and framed formula to reckon proportion of nature reserve,thus an area of nature reserve in each sub-ecozone was obtained.In 5 schemes of weight assignment,a scheme with medium area of nature reserve was selected.All sub-ecozones were classified into 4 grades prior conservation,1 was in grade A,2 in grade B,2 in grade C,and 11 in grade D.Total planned area was approximately 365 135 km2,about 48 834 km2 smaller than the actual area of 413 969 km2,ratio of nature reserve in Tibet diminishes from 34.4% to 30.38%.Based on 3 factors of human disturbance,ratio of buffer-experimental zone in proposed nature reserve was calculated.It was demonstrated that existing size of nature reserves is excessive on the whole,and their distribution is not reasonable entirely.The size of nature reserves in 3 sub-ecozones of northern Changtang should decrease,and decrement of area is apportioned among other 13 sub-ecozones which should increase nature reserve.Heterogeneity of regional distribution of rare species in Tibet is quite obvious,so proposed area distribution of nature reserves is more scattered than the existing.