Study On Sampling Plan Of Annual Monitoring Of Forest Stock Volume Based On Round Group Plots

Forest is the main ecological environment for human beings to survive,and forest resources provide material guarantee for social development.The forest volume is also an important indicator of the pros and cons of forest resources.The status quo of the forest volume and its growth and decline is directly related to the development of forestry planning and social development direction.Nowadays,the main means of China’s large-scale monitoring of forest volume is the continuous investigation of forest resources,with the monitoring interval of 5 years.With the improvement of forestry forestry management,technical cultivation and the development of social economy,the forest resource report of forest resources through continuous investigation has been unable to meet the needs of social development because of its low timeliness.The forest volume is taken as the research object in Yanqing District as the research area.In order to improve the accuracy of the monitoring data of forest stock and the representation of sampling plots on the sampling grid,the system is divided into 3000 meters in the whole area.Reasonably design random,systematic and hierarchical sample survey methods for annual forest volume monitoring.One-third of the total round-shaped plots were surveyed each year as sample to obtain the forest volume of the study area.Due to the time limitation of the current data,the study will take three consecutive forest inventories data of the year 2001,2006,2011 in Yanqing district as the auxiliary data.Based on the continuous data of inventory of forest resources in 2001,two consecutive annual forest volume simulation monitoring are carried out.(taking 5 years of monitoring interval as one year).The result of annual monitoring of forest Volume based on Round Group shows that the annual monitoring accuracy of the three sampling schemes is higher than 90%,The annual monitoring accuracy of the random sampling,system sampling and stratified sampling plan for the first monitoring year(2006)was 90.72%,96.96%and 98.06%respectively.The annual monitoring accuracy of the three sampling programs in Yanqing District in 2011 was 95.27%,97.06%and 98.27%respectively.The monitoring accuracy of the three sampling schemes has reached the requirements of the "Technical Regulations for Continuous Inventory of Forest Resources" on the accuracy of sampling and monitoring of standing stock.Therefore,it is proved that it is feasible to carry out the annual monitoring scheme of the volume of the rounds,and application of round group sample design volume of annual monitoring compared to the continuous inventory of forest resources in terms of improving the timeliness of forest resource data,reducing monitoring costs,filling the forest resources in the continuous inventory monitoring interval in the existence of data gaps,to better provide real-time and effective social resources for social development data support.