Final EIS Appendix 6 

APPENDIX 6—CHARACTERISTICS OF OLD-GROWTH 

FORESTS—BLM PINEDALE FIELD OFFICE 

Old growth forests are ecosystems distinguished by old trees and related structural features. Old growth 

encompasses the later stages of stand development that typically differs from earlier stages in several 

ways, including tree size; accumulation of large, dead woody material; number of canopy layers; species 

composition; and ecosystem function. 

Old growth is typically distinguished by the following: 

• Large trees of specific species 

• Wide variation in age classes and stocking levels 

• Accumulations of large, dead, standing and fallen trees 

• Decadence in the form of broken or deformed tops and boles 

• Multiple canopy layers 

• Canopy interspaces and understory patchiness. 

The following are descriptions of old growth forests by species type. Tables were extracted from 

Hamilton, R.G. compiler, 1993. United States Department of Agriculture (USDA) Forest Service 

Intermountain Region 4, Ogden, Utah for BLM Wyoming planning purposes. 

ENGELMANN SPRUCE—SUBALPINE FIR; SOCIETY OF AMERICAN 

FORESTERS (SAF) COVER TYPE 206 

Live Trees (Warm/Moist Environment) 

Diameter at Breast Height (DBH): > or equal 20” 

Trees/Acre: > or equal 25 

Age: > or equal 220 

Variation in Tree Diameter: Yes 

Tree Decadence: Evident dead, broken, or deformed tops and/or bole or root rot 

Multiple Tree Canopy Layers: Yes 

Dead Trees (Warm/Moist Environment 

Standing DBH/ht ft: > or equal 12/15 

Standing Trees/Acre: > or equal 2 

Down Diameter (in): > or equal 12 

Down Pieces/Acre—length in ft: > or equal 1–8 

Live Trees (Cold/Dry Environment) 

DBH: > or equal 15” 

Trees/Acre: > or equal 15 

Age: > or equal 150 to 180 

Variation in Tree Diameter: Yes 

Tree Decadence: > or equal 2; DBH 14; Evident dead, broken, or deformed tops and/or bole or root rot 

Multiple Tree Canopy Layers: Yes 

Pinedale RMP A6-1 
Appendix 6 Final EIS 

Dead Trees (Cold/Dry Environment) 

Standing DBH/ht ft: > or equal 10/15 

Standing Trees/Acre: 2 to 4 

Down Diameter (in): > or equal 8 or > 6 

Down Pieces/Acre—length in ft: > or equal 16 – 8 ft or 100 pieces > 8 feet 

DOUGLAS-FIR; SAF COVER TYPE 210 

Live Trees (Higher Productivity Site) 

DBH: 24” 

Trees/Acre: > or equal 15 

Age: > or equal 200 

Variation in Tree Diameter: Yes 

Tree Decadence: Evident dead, broken, or deformed tops and/or bole or root rot 

Multiple Tree Canopy Layers: Yes 

Dead Trees (Higher Productivity Site) 

Standing DBH/ht ft: > or equal 20/20 

Standing Trees/Acre: > or equal 1 

Down Diameter (in): > or equal 12 

Down Pieces/Acre—length in ft: > or equal 0 - 16 

Live Trees (Lower Productivity Site) 

DBH: 18” 

Trees/Acre: 10 

Age: > or equal 200 

Variation in Tree Diameter: Yes 

Tree Decadence: > or equal 2; DBH 15; Evident dead, broken, or deformed tops and/or bole or root rot 

Multiple Tree Canopy Layers: Yes 

Dead Trees (Lower Productivity Site) 

Standing DBH/ht ft: 16/10 

Standing Trees/Acre: 0 to 3 

Down Diameter (in): > or equal 15 

Down Pieces/Acre—length in ft: Infrequent 4 - > or equal 8 

LODGEPOLE PINE; SAF COVER TYPE 218 

Live Trees 

DBH: > or equal 11” 

Trees/Acre: > or equal 25 

Age: > or equal 140 

Variation in Tree Diameter: Yes 

A6-2 Pinedale RMP 
Final EIS Appendix 6 

Tree Decadence (trees per acre [TPA]-DBH): > or equal 2–11; evident dead, broken, or deformed tops 

and/or bole or root rot 

Multiple Tree Canopy Layers: Yes 

Dead Trees 

Standing DBH/ht ft: > or equal 11 

Standing Trees/Acre: 5 

Down Diameter (in): > or equal 11 

Down Pieces/Acre—length in ft: > or equal 50 - > or equal 8 

LIMBER PINE; SAF COVER TYPE 219 

Live Trees (Lower Timberline) 

DBH: > or equal 16 

Trees/Acre: > or equal 10 

Age: > or equal 250 

Variation in Tree Diameter: Yes 

Tree Decadence: Evident dead, broken, or deformed tops and/or bole or root rot 

Multiple Tree Canopy Layers: Yes 

Dead Trees (Lower Timberline) 

Standing DBH/ht ft: N/A 

Standing Trees/Acre: Few 

Down Diameter (in): N/A 

Down Pieces/Acre—length in ft: Rare 

Live Trees (Montaine Woodlands) 

DBH: > or equal 1 

Trees/Acre: 10 

Age: > or equal 500 

Variation in Tree Diameter: Yes 

Tree Decadence: Evident dead, broken, or deformed tops and/or bole or root rot 

Multiple Tree Canopy Layers: No 

Dead Trees (Lower Productivity Site) 

Standing DBH/ht ft: N/A 

Standing Trees/Acre: Few 

Down Diameter (in): N/A 

Down Pieces/Acre—length in ft: Rare 

ASPEN; SAF COVER TYPE 217 

Live Trees 

DBH: > or equal 12” 

Pinedale RMP A6-3 
Appendix 6 Final EIS 

Trees/Acre: > or equal 10 dry—20 mesic 

Age: 100 

Variation in Tree Diameter: Yes 

Tree Decadence (TPA-DBH): N/A 

Multiple Tree Canopy Layers: Yes 

Dead Trees 

Standing DBH/ht ft: > or equal 10/15 

Standing Trees/Acre: 2 

Down Diameter (in): > or equal 8 

Down Pieces/Acre—length in ft: > or equal 10–10 

ROCKY MOUNTAIN JUNIPER; SAF COVER TYPE 220

Note: Extrapolated old growth characteristics from Pinyon-Juniper old growth characteristics. 

Live Trees 

DBH: 12” 

Trees/Acre: 12 

Age: 200 

Variation in Tree Diameter: Yes 

Tree Decadence (TPA-DBH): N/A 

Multiple Tree Canopy Layers: N/A 

Dead Trees 

Standing DBH/ht ft: 12/5 

Standing Trees/Acre: > or equal .05 

Down Diameter (in): > or equal 10 

Down Pieces/Acre—Length in ft: > or equal 2–5 

A6-4 Pinedale RMP