2409.13a,20 Contents Page 1 of 1 FSH 2409.13a - TIMBER PERMANENT PLOT HANDBOOK WO AMENDMENT 2409.13a-92-1 EFFECTIVE 1/29/92 CHAPTER 20 - CORE INFORMATION 20.3 Policy 21 IMPLEMENTATION 22 REQUIRED INFORMATION 22.1 Control Variables 22.2 Land and Land Status Variables 22.3 Physiographic Variables 22.4 Vegetation Variables 22.5 Resource and Land Use Variables 23 OTHER STANDARD INFORMATION 23.1 Control Variables 23.2 Ecology Variables 23.3 Physiographic Variables 23.4 Vegetation Variables 23.5 Soil Related Variables