利用陆地卫星TM影像进行森林土地面积调查的方法

文章介绍了利用陆地卫星ＴＭ影像通过建立解译标志进行地类划分及面积计算的方法，为能科学地应用此项技术提供参考。

自然资源调查对土地森林资源保护的重要性探讨

本文聚焦于自然资源保护,尤其是土地与森林的维护,强调全面深入的自然资源调查至关重要。科学整合地理学、生物学、社会经济学等多学科视角,以精准信息为基石,为资源保护政策制定及森林、土地可持续管理提供坚实依据。通过定期监测与评估,资源调查确保政策灵活调整,有效应对环境变化。在城市化加速、生物多样性保护的复杂背景下,其指导作用愈发凸显。本文还揭示了自然资源调查与公众意识觉醒、科技进步、制度完善的紧密联系,共同推动绿色发展。因此,文章呼吁加大对自然资源调查的投入,强化技术支持与资金保障,以促进资源可持续利用,达成人与自然和谐共存的愿景。

北京市红门川流域森林植被/土地覆被变化的水文响应

根据北京市红门川流域原有1∶1万土地利用图,结合流域1990年、1995年、2000年和2005年4期遥感影像,在GIS支持下,得到4期土地利用图,采用ArcView分析获得空间数据和属性数据。并利用研究区逐日降水量和径流量数据,从年径流量、汛期(6-9月份)径流量和单次径流量3个层次,分析不同土地利用时期的水文响应。结果表明:不同土地利用变化对流域径流具有显著影响。2001-2005年植被条件较好的土地利用较1990-1995年和1996-2000年产流有所减少,多年平均径流系数下降了70%以上。不同土地利用在相同降水条件下的产流仅在生长季节具有明显差异,也就是说土地利用变化对产流的影响具有季节性,在枯水季节无显著影响。2001-2006年的单次产流均小于1990-1995和1996-2000年的单次产流,仅为前期的1/3,降水利用率提高,发生洪涝灾害的可能性减小。

森林碳汇决策与农村可持续发展研究

认为有必要在基于碳汇的土地利用和当地可持续发展之间建立一种更加明确的联系．依托一个中国-加拿大合作项目，以中国贵州省黎平县为例，阐述了一种将森林碳汇、森林资源管理以及如何促进当地可持续发展联系起来的综合评估方法，并且着重介绍了能帮助资源管理和规划部门实施这种综合评估的土地利用决策支持工具（LUDST）．

县级林地年度变更调查技术方法探讨

落实林地年度变更调查的目的是掌握森林土地利用现状及其增长和变化,确保森林资源"一张图"数据库的时效性、准确性和真实性,以此服务于生态建设和林地保护管理的需要。现简要分析了林地年度变化工作中存在的问题,并讨论解决当前具体问题的方法和对策。

GIS based land suitability assessment along Laos-China border

Assessment of the forest land use change and proposed land suitability for tea for the area along Laos – China Border were the main purpose of this research paper. An integrated GIS-based analysis system （IGAS）, supporting assessment of forest land-use and land suitability for the study area where along Laos-China border was developed. Multi criteria analysis and system dynamics techniques were used to assess forest land use and land suitability and to forecast potential land-use for tea. The total study area is estimated at 10 325.07 km2 according to the field data collection and data analysis. The area of current forest cover decreased rapidly from 6337.33 km2 （61.38%） in 1992 to 5106.28 km2 （49.46%） in 2002 in the study area. The current forest was mainly trans-ferred to potential forest and permanent agriculture especially to rubber plantation areas even in the National Conservation Biodiversity Conser-vation Areas. The main causes of forest land use change are poverty. In order to address the problems, land suitability classification for tea was developed based on the multi-criteria. And finally two options of land suitability classification for tea for the study areas were developed.

Soil Physical and Chemical Properties of Five Subtropical Forests in Lingao of Hainan

With 5 types of typical forests as research object, the physical and chemical properties of different types of forests were analyzed by sample plot investigation method. The results showed that： the soil total porosity was the highest in the Casuarina equisetifolia forest （46.168%）, but the lowest in the Encalyptus robusta forest （39.46%）. The soil capillary porosity was the highest in the Acacia mangium forest （22.57%）, but the lowest in the secondary forest （18.95%）. The soil water content was the highest in the C. equisetifolia forest, with a mean value of 27.85%, but the lowest in the secondary forest, with a mean value of 4.34%. The soil pH values were in the range of 4.81-6.59, the soils in the A. mangium forest, C. equisetifolia forest and E. robusta forest were strongly acidic （pH 4.5-5.5）, and the soils in the secondary forest and C. nucifera forest were weakly acidic. The soils had organic matter contents in the range of 0.34-28.68 g/kg, and showed an order of A. mangium forest〉C. equisetifolia forest〉E. robusta forest〉secondary forest〉C. nucifera forest, with a decreasing trend with the soil depth increasing. The soil total N contents were in the range of 0.10-1.63 g/kg, the A. mangium forest showed the highest soil total N contents, while the C. nucifera forest exhibited the lowest soil total N contents; the soil total P contents were in the range of 0.21-1.74 g/kg, and the E. robusta forest had the highest soil total P contents; and the soil total K contents were in the range of 0.16-2.15 g/kg, and the A. mangium forest exhibited the highest soil total K contents. The soil available P contents were in the range of 0.98-132.46 mg/kg; and the secondary forests had the highest soil available P contents; and the soil rapidly available K contents were in the range of 3.03-27.35 mg/kg, and the C. nucifera forest exhibited the highest soil rapidly available K contents. The soil ammonium N contents were in the range of 1.38-5.15 mg/kg, and the nitrate N contents were in the range were in the range of 0.56 -3.51 mg/kg. The A. mangium forest showed the highest soil nitrate N contents （with a mean value of 2.29 mg/kg） and ammonium N contents （with a mean value of 3.93 mg/kg）. For the same forest type, with the increase of soil depth, the nitrate nitrogen and ammonium nitrogen content also showed a decreasing trend.

开发利用自然资源,提升学生的思维创造能力

课程资源的开发与利用不能局限于编写教材,更 重要的是教师能把地方文化资源合理地、有机地融入自己的教 学,作为教学内容必要的扩展、延伸和补充,丰富了美术课堂。地方资源融入教学大大地激发了学生的求知欲和积极性,在浓 厚的文化和艺术氛围中既培养了学生的艺术情操和审美观,又 提高了美术素养。使学生愉快地学习了艺术知识和实践技能,达到了以美育促智育,以智育促发展的目的。

Comparison and Analysis of Agricultural and Forest Land Changes in Typical Agricultural Regions of Northern Mid-latitudes

The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The westem Europe has a longer history of agricultural land development than the eastem United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic bene- fits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though per- sistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulner- ability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects.

Land Use Structure in Wuhai City on Basis of Ecological Green Equivalence

The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program.

Assessment of forest geospatial patterns over the three giant forest areas of China

Geospatial patterns of forest fragmentation over the three traditional giant forested areas of China （Northeastern, southwestern and Southern China） were analyzed comparatively and reported based on a 250-m resolution land cover dataset. Specifically, the spatial patterns of forest fragmentation were characterized by combining geospatial metrics and forest fragmentation models. The driving forces resulting in the differences of the forest spatial patterns were also investigated. Results suggested that forests in southwest China had the highest severity of forest fragmentation, followed by south region and northeast region. The driving forces of forest fragmentation in China were primarily the giant population and improper exploitation of forests. In conclusion, the generated information in the study provided valuable insights and implications as to the fragmentation patterns and the conservation of hiodiversity or genes, and the use of the chosen geospatial metrics and forest fragmentation models was quite useful for depicting forest fragmentation patterns.

Effects of Chinese Fir，Loblolly Pine and Deciduous Oak Forests on Nutrient States of Soils in Northern Subtro－pics of China

This paper deals with a study on the effects of Chinese fir, loblolly pine and deciduous oak forests on thenutrient status of soils in northern subtropics of China, adopting the principle of forest ecology in the caseof similar climate and soil type. The experimental area was situated in the Xiashu Experimental Centre ofForest, where the soil is yellow-brown soil derived from siliceous slope wash. Sample plots of these 3 standswere established to study the nutrient status in litter, the amount of nutrient uptake by roots, the quantityof nutrient output by percolating water outside the deep layer of soil, and the seasonal dynamics of availablenutrient in surface soil. It was shown that the intensity of nutrient cycling in soil under deciduous oak wasthe highest, and the effect of oak in improving soil fertility was the best. The result of improving soil fertilityby Chinese fir was the most inferior, though the intensity of nutrient cycling under that stand was higherthan that under loblolly pine stand. The influence of loblolly pine on the improvement of soil fertility wasbetter than that of Chinese fir, in spite of its lowest intensity of nutrient cycling.

The Effect of Land Use Change on Soil and Water Quality in Northern Iran

Rapid urbanization has led to extensive land-use changes,particularly in developing countries.This research is aimed to investigate the role of land use and its effect on soil and water quality in Ziarat watershed focusing on four land uses:forest,pasture,cultivated and urban development.Soil samples were taken from a depth of 0-30 cm on each land use and were analyzed by completely randomized split-plot design in two geographical directions.Results showed that bulk density(BD),electrical conductivity(EC),pH,calcium carbonate equivalent(CCE),and soil particle density(DS) of the soil samples in pastures,cultivated and urban areas increased and the mean weight diameter(MWD),soil porosity(F),organic carbons(OC),total nitrogen(TN),exchangeable cations(Ca 2+,Mg 2+,K +,Na +),cation exchange capacity(CEC) and soil microbial respirations(SMR) decreased,respectively in comparison with the forest soils.For water quality evaluations,sodium adsorption ratio(SAR),electrical conductivity(EC),pH,total dissolved solids(TDS),bicarbonate(HCO 3),chloride(Cl),total hardness(TH),calcium(Ca 2+),potassium(K +),sodium(Na +) and magnesium(Mg 2+) were investigated in two areas:Nahrkhoran and Abgir stations.Results showed that the concentration of TDS,EC and HCO 3 in Naharkhoran station is higher than that in Abgir station.On the other hand,the concentration of TDS,EC and HCO 3 in Abgir station are the relatively higher due to its location.Total hardness had the same trend during the study years except in the last three years;however,TH showed an increase of 25% TH in Naharkhoran for the last two years.Cl,K + and SAR in Naharkhoran station increased by 61%,22%,78% and 56% respectively,in comparison with Abgir station.This study demonstrated that the trend of soil degradation and mismanagement of land use may increase the frequency of urban floods and human health problems.

Soil N Pools and Transformation Rates Under Different Land Uses in a Subalpine Forest-Grassland Ecotone

Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5) tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P ＜ 0.05) in the soils, which was in contrast to the significant increases (P ＜0.05) of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification.

Effect of Afforestation on Soil Properties and Mycorrhizal Formation

A study was conducted on Cambisols in Northern Germany to analyze the effect of fast growing trees （Salix and Populus spp.） used in agroforestry on soil chemical and physical properties and also on endo- and ectomycorrhizal colonization of the fine roots. Representative plots of three trials, Giilzow （GUL）, Vipperow （VIP） and Rostock （ROS）, were used to measure the topsoil inventories at the very beginning and after six （GUL）, seven （VIP） and ten （ROS） years of afforestation with fast growing trees. The effect on soil organic carbon, plant available nutrients, reaction, bulk density, porosity and water conditions was analyzed, Arable soils without tree coppice were used as controls. Additionally, the endoand ectomycorrhizal colonization of two Salix and two Populus clones were investigated at one site （GUL） in 2002. The amounts of organic carbon in the topsoil increased significantly （P 〈 0.01） presumably induced by leaf and root litter and also by the lack of tillage. The soil bulk density significantly decreased and the porosity of the soil increased significantly （both P 〈 0.01）. The proportion of medium pores in the soil also rose significantly （P 〈 0.05 and 0.01）. Generally, afforestation of arable soils improved soil water retention. Ectomycorrhizas dominated the mycorrhizal formation of the Salix and Populus clones, with the accumulation of organic matter in the topsoil suspected of supporting the ectomycorrhizal formation. Thus, agroforestry with Salix and Populus spp. conspicuously affected chemical and additionally physical properties of the top layer of Cambisols within a period of six years.

Optimization of Land Use Structure Based on Ecological GREEN Equivalent

Optimization of land use structure consists of economic and social and ecological optimization.Applying the minds of system engineering and principles of ecology,this paper presents such thoughts:the optimal forest_coverage rate calculated according to the reality of a district is set as main standard of ecological rationality in the district;through considering the value of ecosystem services of the land with GREEN equivalent (mainly cultivated land and grassland)and based on the rule,GREEN equivalent,this paper introduces the area conversion between woodland and cultivated land,also between woodland and grassland;this paper establishes a multi_dimension controlling model of optimization of land use structure.In addition,a multi_objective linear programming model for optimization of land use structure is designed.In the end,this paper tests and verifies this theory of ecological optimization,taking Qionghai city in Hainan Province as an example.

Deforestation Trends and Spatial Modelling of its Drivers in the Dry Temperate Forests of Northern Pakistan–A Case Study of Chitral

Deforestation is a major environmental challenge in the mountain areas of Pakistan. The study assessed trends in the forest cover in Chitral tehsil over the last two decades using supervised land cover classification of Landsat TM satellite images from 1992, 2000, and 2009, with a maximum likelihood algorithm. In 2009, the forest cover was 10.3% of the land area of Chitral(60,000 ha). The deforestation rate increased from 0.14% per annum in 1992–2000 to 0.54% per annum in 2000–2009, with 3,759 ha forest lost over the 17 years. The spatial drivers of deforestation were investigated using a cellular automaton modelling technique to project future forest conditions. Accessibility(elevation, slope), population density, distance to settlements, and distance to administrative boundary were strongly associated with neighbourhood deforestation. A model projection showed a further loss of 23% of existing forest in Chitral tehsil by 2030, and degradation of 8%, if deforestation continues at the present rate. Arandu Union Council, with 2212 households, will lose 85% of its forest. Local communities have limited income resources and high poverty and are heavily dependent on non-timber forest products for their livelihoods. Continued deforestation will further worsen their livelihood conditions, thus improved conservation efforts are essential.

Changes of Soil Water, Organic Matter, and Exchangeable Cations Along a Forest Successional Gradient in Southern China

Information on the distribution patterns of soil water content （SWC）, soil organic matter （SOM）, and soil exchangeable cations （SEC） is important for managing forest ecosystems in a sustainable manner. This study investigated how SWC, SOM, and SEC were influenced in forests along a successional gradient, including a regional climax （monsoon evergreen broad-leaved forest, or MEBF）, a transitional forest （coniferous and broad-leaved mixed forest, or MF）, and a pioneer forest （coniferous Masson pine （Pinus rnassoniana） forest, or MPF） of the Dinghushan Biosphere Reserve in the subtropical region of southern China. SWC, SOM, and SEC excluding Ca^2＋ were found to increase in the soil during forest succession, being highest in the top soil layer （0 to 15 cm depth） except for Na^＋. The differences between soil layers were largest in MF. This finding also suggested that the nutrients were enriched in the topsoil when they became increasingly scarce in the soil. There were no significant differences （P = 0.05） among SWC, SOM, and SEC. A linear, positive correlation was found between SWC and SOM. The correlation between SOM and cation exchange capacity （CEC） was statistically significant, which agreed with the theory that the most important factor determining SEC is SOM. The ratio of K^＋ to Na^＋ in the topsoil was about a half of that in the plants of each forest. MF had the lowest exchangeable Ca^2＋ concentration among the three forests and Ca^2＋：K^＋ in MPF was two times higher than that in MF. Understanding the changes of SWC, SOM, and CEC during forest succession would be of great help in protecting all three forests in southern China.

Landform Instability and Land-use Dynamics in Tropical High Mountains, Central Mexico

This investigation is an analysis of the influence of landform instability on the distribution of land-use dynamics in a hydrographical basin, located in the Mexican Volcanic Belt mountain range (central Mexico), currently affected by substantial changes in land use and deforestation. A landform map was produced, in addition to seven attribute maps - altimetry, drainage density, slope, relief energy, potential erosion, geology and tectonics - which were considered as factors for determining landform instability through Multi-criteria Evaluation Analysis. Likewise, the direction and rhythm of land-use dynamics were analyzed in four dates - between 1976 and 2000 - and cross tabulations were made between them, in order to analyze the trends and processes of land-use dynamics. Afterwards, the databases obtained were cross tabulated with the landform variables to derive areas, percentages and correlation indices. In the study area, high-instability landforms are associated with most ancient volcanic and sedimentary landforms, where high altitude, drainage density, slope and potential to develop gravitational and fluvial processes are the major factors favouring a land-use pattern, dominated by the conservation of extensive forest land, abandonment of human land use and regeneration of disturbed areas. In contrast, low-instability landforms correspond to alluvial plains and lava hills covered by pyroclasts, where low potential erosion to develop fluvial processes, added to water and soil availability and accessibility, have favoured a land-use pattern dominated by the expansion of agroforestry plantations and human settlements, showing a marked trend towards either intensification or permanence of the current land use and with little abandonment and regeneration.

Micromorphology and Quality Attributes of the Loess Derived Soils Affected by Land Use Change:A Case Study in Ghapan Watershed,Northern Iran

In order to study the effects of different land vegetative covers on soil quality attributes, a loess hill slope was selected in eastern Golestan Province, Ghapan watershed, Iran. Four profiles in four land uses, including Quercus natural forest; Pinus artificial forest; Cupressus artificial forest and a cultivated land, were studied. Results showed that MWD was significantly different in the studied land uses, and it varied between 1.6 mm in Quercus natural forest and o.31 mm in cultivated land use. The lowest CEC, microbial respiration rate and organic carbon were 28.4 cmol·kg^1, 177 μgCO2·g^-1·day^-1 and 1.32 % found in cultivated land use, respectively. The organic matter was considerably higher content in the forest areas than that of cultivated land use. The studies on soil profile development revealed that the natural forest soils were highly developed. The soils of the Quercus natural forest were classified as Calcic Haploxeralfs with a well developed argillie horizon unlike the cultivated soils which showed the minimum development and classified as Typic Xerorthents. The soils of the artificial forests had both mollic epipedons and were classified as Typic Calcixerolls with moderate profile development. Micromorphological studies revealed that argillic horizons had speckled and partly crystallitic b-fabric in the natural forest indicating the high landscape stability. In contrast, the crystallitic b-fabric of other land uses shows the absence of enough leaching of carbonate and the subsequent migration of clay particles indicating the unstable conditions and high soil erosion. Intense erosion of the surface horizons of cultivated land use has resulted in the outcropping of the subsurface carbonate rich horizons preventing soil development.