河北省山地森林保土生态效益计量研究

该研究借鉴国内外森林保土效益研究的成功经验，结合河北省山地土壤流失特点，首次计算出了河北省山地森林年保土总量为６２６６．１５万ｔ；减少废弃土地面积９６４０．２４ｈｍ２，减少泥沙滞留１５９０．６４万ｍ３，减少泥沙淤积１１５６．８４万ｍ３，减少土壤有机质损失２７１．３２万ｔ，减少Ｎ、Ｐ、Ｋ损失１３０．２４万ｔ，经价值计算得出河北省山地森林年保土效益为３８．１５亿元，平均每年每ｈｍ２山地森林保土效益为１９５７．５元。

国外森林保土效能及其环境调查与监测实例分析

通过分析国外森林保土效能和环境调查与监测实例 ,揭示了森林在其中的重要作用 ,提出强化保土的技术措施。

Analysis of Land Degradation in Ethiopia and Countermeasures

In Ethiopia soil conservation is primarily meant to improve agriculture production.Therefore,assessment of the existing erosion hazards and classifying the land according to its capability are essential.This paper depicts the land degradation status and causes,through an integrated assessment,and some measures to alleviate the problem are proposed.

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.

Characterization of Some Typical Soils of the Miombo Woodland Ecosystem of Kitonga Forest Reserve, Iringa, Tanzania： Physico-Chemical Properties and Classification

Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanzania. The current study was carried out to map and classify soils of Kitonga Forest Reserve, which is a typical miombo woodland ecosystem, in order to generate relevant information for their use and management. A representative study area of 52 km2 was selected and mapped at a scale of 1：50,000 on the basis of relief. Ten representative soil profiles were excavated and described using standard methods. Soil samples were taken from genetic soil horizons and analyzed in the laboratory for physico-chemical characteristics using standard methods. Using field and laboratory analytical data, the soils were classified according to the FAO-World Reference Base （FAO-WRB） for Soil Resources system as Cambisols, Leptosols and Fluvisols. In the USDA-NRCS Soil Taxonomy system the soils were classified as Inceptisols and Entisols. Topographical features played an important role in soil formation. The different soil types differed in physico-chemical properties, hence exhibit differences in their potentials, constraints and need specific management strategies. Texture varied from sandy to different loams; pH from 5.1 to 5.9; organic carbon from 0.9 g/kg to 20 g/kg; and CEC from 3 cmol/（＋）kg to 24 cmol/（＋）kg. Sustainable management of miombo woodlands ecosystem soils requires reduced deforestation and reduced land degradation.

Organic carbon storage in trees within different Geopositions of Chittagong （South） forest division, Bangladesh

The organic carbon storage in trees and organic carbon flow with geoposition of trees was estimated in the forest area of Chittagong （South） Forest Division within geo-position 91°47′ and 92°15′ East longitude and 21°45′ and 22°30′ North latitude. The study was conducted through stratified random sampling by identifying each sampling point through Global Positioning System （GPS）. It was found that above ground organic carbon storage （t/hm^2）, below ground organic carbon （t/hm^2） and total biomass organic carbon （t/hm^2） was respectively the highest in Dipterocarpus turbinatus （Garjan） （7.9, 1.18 and 9.08 t/hm^2） followed by Tectona grandis （Teak） （5.66, 0.85 and 6.51 t/hm^2）, Artocarpus chaplasha （Chapalish） （2.32, 0.34 and 2.66 t/hm^2）, Artocarpus lacucha （Batta） （1.97, 0.29 and 2.26 t/hm^2） and Artocarpus heterophyllus （Jackfruit） （1.7,0.25 and 2.26 t/hm^2）. From the study it was revealed that organic carbon stock was the highest （142.7 t/hm^2） in the geo-position 22° Latitude and 92° Longitude and was the lowest （4.42 t/hm^2） in the geo-position 21° 50′ Latitude and 92° 2.5′ Longitude. The forest of the study area is a good reservoir of organic carbon so has a good capacity to sequester organic carbon from the atmosphere. Sustainable forest management may help to sequester more organic carbon so that economic benefit for the country and environmental benefit in the international arena are possible from the study area.

Stagnate to Extensive： The Design of Capital City Development in Coastal Archipelago Raja Ampat

This discussion of Raja Ampat case, a subdivision of West Papua province, is related to the global warming issue where small islands will be narrowed as a result of sea level rise. Furthermore, it is related to autonomy regulations where each municipality and district has their own policy. The capital of Raja Ampat District in the east of Indonesia is developed from traditional place into central urban area. Raja Ampat, a naturally beautiful island, is located in a remote area famous for its diving spot for foreign tourists, amazing underwater life, bird watching, and to experience a traditional lifestyle with specific tropical fauna and flora. The problem is how to develop a city which needs to be in a stagnant extensive phase but： neither in vertical nor horizontal development to protect forest as conservation area due to limited land area. Identification and design methods used in this research is to develop settlement in Raja Ampat archipelago area which has around 610 large and small islands, atoll, and have 4.860 km shoreline with only 34 islands inhabited. The urban design for this archipelago of 1：6 ratios of land and ocean needs to be different, since it is dominated by water. With the limited land area resources, the development needs to be focused on the ocean area by optimizing land area.

Spatially distributed modelling and mapping of soil organic carbon and total nitrogen stocks in the Eastern Mau Forest Reserve,Kenya

Detailed knowledge about the estimates and spatial patterns of soil organic carbon(SOC) and total nitrogen(TN) stocks is fundamental for sustainable land management and climate change mitigation.This study aimed at:(1) mapping the spatial patterns,and(2) quantifying SOC and TN stocks to 30 cm depth in the Eastern Mau Forest Reserve using field,remote sensing,geographical information systems(GIS),and statistical modelling approaches.This is a critical ecosystem offering essential services,but its sustainability is threatened by deforestation and degradation.Results revealed that elevation,silt content,TN concentration,and Landsat 8 Operational Land Imager band 11 explained 72% of the variability in SOC stocks,while the same factors(except silt content) explained 71% of the variability in TN stocks.The results further showed that soil properties,particularly TN and SOC concentrations,were more important than that other environmental factors in controlling the observed patterns of SOC and TN stocks,respectively.Forests stored the highest amounts of SOC and TN(3.78 Tg C and 0.38 Tg N) followed by croplands(2.46 Tg C and 0.25 Tg N) and grasslands(0.57 Tg C and 0.06 Tg N).Overall,the Eastern Mau Forest Reserve stored approximately 6.81 Tg C and 0.69 Tg N.The highest estimates of SOC and TN stocks(hotspots) occurred on the western and northwestern parts where forests dominated,while the lowest estimates(coldspots) occurred on the eastern side where croplands had been established.Therefore,the hotspots need policies that promote conservation,while the coldspots need those that support accumulation of SOC and TN stocks.

Impact of Demographic Structure on Paddy and Forestland Management

In order to understand the impact of demographic structure on paddy and forestland managementafter the convening of the Third Plenary Session of the 11th CPC (Communist Party of China) CentralCommittee and the implementation of the Household Responsibility System (the government divided upland among peasants for cultivating and the peasants sell a set part of their produced goods to thegovernment at stipulated prices by contract in the countryside of China), 147 households in 6 villages,belonging to Xiangtan County and Zhuzhou County in Hunan Province, were selected as research samples,and interview, questionnaire survey and second hand data analyzing were used as the methods. The resultsshowed: Persons with different ages had different ideas, and young peasants would like to work in townsor cities for more income, so they used and depended on land less; In terms of sex, the male was still themain user of land, and therefore the ability, idea and activity of male played an important role in landmanagement; Generally, the labors with better educational background grasped more knowledge andtechnologies, and they had more opportunity to get jobs and had better working condition and moreincome in town or cities, so they depended on and used land less.

Policy Review on Watershed Protection and Poverty Alleviation by the Grain for Green Program in China

The sustained growth of Chinese economy in the new century is a silver lining in the continuouslydepressed global economy. Meanwhile, the rapid development of Chinese economy is still confronted withconstraints from deteriorating environment and rural poverty issues. It has become a significant policyoption in maintaining high speed, efficiency and sound development of Chinese economy to rehabilitateforest resources, improve ecological conditions, increase farmers income and get on a sustainable roadfeaturing coordinated development of population, resources and environment. The Grain for Green Program,as a CDM activity of Chinese style, launched on trial in 1999 and implemented in 2002 across the country,is the biggest land use transition, watershed management and poverty alleviation program involving thelargest population in Chinese history and across the globe. It covers 25 provinces/regions/cities and gets over1 600 counties, 15 million households and 60 million farmers were involved. Hence the Grain for Tree policyhas a significant bearing on ecological protection and farmers poverty alleviation in the soil and watererosion-prone region. A review and assessment of the background, essentials, effects, problems and trend ofthe Grain for Tree policy is of great significance for both China and the other developing countries in theworld in their efforts to combat the deteriorating environment and alleviate poverty.