The Southern Annual Forest Inventory System

The Southern Annual Forest inventory System (SAFIS) is in various stages of implementation in 7 of the 13 southern states serviced by the Southern Res earch Station. The SAFIS design is an interpenetrating design where the Is, units (1/6 acre plots) are divided into k = 5 panels, each panel containin g m = n/k units. Panel 1 plots are measured in year 1, panel 2 in year 2, e tc., such that all plots have been visited by the end of year 5. The panel cycle is repeated into perpetuity. Each panel, in effect, is a 5-year perio dic survey with complete overlap of sample units. Numerous estimation schem es are possible, and we explore five possible options. The five options are (1) use existing periodic inventory programs to produce 5-year survey esti mates by adjusting all five panels to a common year, (2) analyze each annua l panel independently, (3) produce 5-year estimates by combining the five p anel estimates by varying the weight given to each panel, (4) base inventor y estimates on mixed estimation where actual and predicted values are combi ned, and (5) use imputation techniques such that unmeasured plots are fille d in with imputed plots. A two-phase method for forest area estimation that uses the known map marginals from a thematic map is presented as an altern ative to photo interpretation-based estimates.