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We show that the Annual Forest Inventory System (AFIS) being developed by the USDA Forest Service and tested in the state of Minnesota is no more costly than the periodic Minnesota forest inventory (12 year measurement cycle). Since very useful results could be generated with AFIS every 4 years in addition to the results from the periodic survey, a continuous inventory would be cost effective. Periodic surveys yield more precise estimates within the first few years of the full survey but afterwards the annual survey would be more precise. Where the changeover in precision occurs still needs to be determined. This cost-neutral advantage of AFIS is quite important to note since the USFS has decided to go to annualized inventories such as AFIS this year. 相似文献