| Forest is entire nation economy sustained, rapid and healthy development of the foundation, in the national economic construction and sustainable development status and irreplaceable role. Forest inventory for management plan in China Forest Resource Inventory survey system has an important position and role, is the state Bureau of Forestry, forestry and county units in the preparation of forest management plan, based on overall design and planning of forestry work, is the system of forest resources important part.Forest Inventory for management plan at this stage may need further improvements and enhancements. The system sampling method with dense-plots on the base of national forest inventory plots was often used to control the precision of subcompartment survey, but now the method can't be used because of expensive survey and longer survey time. On the other hand, as the forest ecological monitoring of progress, more factors of ecological surveys and environmental factors added, on land and even the valley to mountain top (the combination of subcompartment) as the basic unit of forest resources survey put forward new requirements, the existing Inventory methods are not well to meet this demand.The paper summarizes theory and method of angle measuring in several major factors of subcompartment, such as stand basal area, stand hectares of accumulation and volume growing estimation in permanent point sampling, and analysis the sampling error with method of angle measuring, further proposed techincal methods to eliminate or reduce the error of this method.The angle change method change in angle over time to estimate basal area growth rate, theoretically demonstrates the estimate basal area growth rate is unbiased, and eliminate the phenomenon of zero and jumping extimation of basal area and volume increment. Theoretical analysis and sample verification show that the angle change method is compatible with traditional method of survivor growth estimation when the pre-reserved trees basal area ratio is not too large, particularly Puliesile formula in the traditional method of growth estimation is very close to the angle change method. the angle change method and the method of changing angle factor have same formula form and principle.The comprehensive exposition on methods of Forest Inventory and Monitoring System to improve the main program, the paper analysis and summary of subcompartment division method, improve Measurement indicators of subcompartment measure, put forward Measurement indicators of forest resources and forest ecological status. Measurement of forest resources include plant trees indicators, targets and major forest indicators stand a total of 48 indicators; forest ecological status indicators are divided into levels of forest ecological functions, ecological diversity, forest health degree, type and grade soil erosion, forest landscape level, the main forest community types of forest floor, soil water storage, carbon storage of forest plants, forest plants energy storage. the paper presents subcompartment tissue and estimation methods, and method of angle measuring in volume growing estimation in permanent point sampling.Subcompartment PPS sampling method should try to select closely related auxiliary factor to determine the probability of extraction. Using Guangdong Boluo subcompartment Inventory Data in 2005 and ETM+remote sensing data for example and the main tree species (eucalyptus, pine, falcataria, other soft wide) for by species, age group, and the tree species and age Group portfolio divided type (layered), this paper select the subcompartment size, canopy density, the multiplication of subcompartment area size with its canopy density(the multiplication can be seen to be subcompartment size and crown projection), and extracted using remote sensing technology the multiplication of subcompartment area size with its average NDVI (the multiplication can be expressed as sum of subcompartment pixel NDVI values) as an auxiliary factor, subcompartment cumulative correlation analysis and comparison. The results show that by species composition and age group classification type, the auxiliary factors associated with the accumulation of subcompartment significantly improved. The correlation between the multiplication of subcompartment area size and its canopy density and volume of subcompartment up to 0.90, and the correlation between the multiplication of subcompartment area size and its average NDVI and volume of subcompartment up to 0.84. Considerations from the current situation, the multiplication of subcompartment area size with its average NDVI as a auxiliary cofactor.To verify the feasibility of dynamic monitoring system, the paper investigated a part of Guangxi Province in the southwest part of the point sample plots and the plots fall some combination of subcompartment overall for example in 2000a and 2005a two stage Inventory data, test the sampling survey method and calculate the growth estimation. The results showed that the estimation of volume was 3785.580 cube meter in 2000a, and 4162.119 cube meter in 2005a. The estimated precision was 69% and 78% respectively. The estimation of volume growth was 530.020 cube meter. Added it with the volume in 2000a, another estimation of volume was 4315.600 cube meter in 2005a, witch was among the estimated range (3786.340575, 4537.897487) in 2005a. The results-show that the proposed inventory system thesis and dynamic monitoring method is effective.The paper only explore the theory of improvement on forest inventory for management plan and test the theoretical calculations and summary. The method further dissemination and application needs comparison and analysis the results of sampling control method. Paper made recommendations for future research.
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