GENS consists of volume growth functions for natural stands of pine, pine-hardwoods, upland hardwoods, and bottomland hardwoods (including cypress). Yield tables can be produced with client-specified format.
ModelIDs used in GENS
| ModelID |
Description |
| BH |
Bottomland Hardwoods, including cypress |
| UH |
Upland Hardwoods |
| PH |
Pine-Hardwood |
| NP |
Natural Pine |
Inputs are supplied to GENS by importing an Excel workbook as the batch file template. Required initial data for each stand includes: StandID; site index (base age 50); initial age; initial volume by product and species group; maximum age; and ModelID. Optional data include trees/acre and basal area/acre. Yield tables can be produced with client-specified format.
GENS batch template
| Field |
Description |
| StandID |
Stand name (1 – 60 characters) |
| Age |
Initial age (years) |
| SI |
Site index (base age 50) |
| PPW |
Initial pine pulpwood (tons/acre) |
| PCS |
Initial pine chip-n-saw (tons/acre) |
| PST |
Initial pine sawtimber (tons/acre) |
| HPW |
Initial hardwood pulpwood (tons/acre) |
| HST |
Initial hardwood sawtimber (tons/acre) |
| CPW |
Initial cypress pulpwood (tons/acre) |
| CST |
Initial cypress sawtimber (tons/acre) |
| MaxAge |
Maximum age for growth (years) |
| ModelID |
BH=bottomland hardwood; UH=upland hardwood; PH=pine-hardwood; and NP=natural pine |
| TPA |
Initial trees/acre (optional) |
| BA |
Initial basal area/acre (optional) |
Volume growth of each species group and product is obtained by applying a compounded growth rate calculated from initial volume and volume for the grown age and site index. Cypress volume is grown for only the bottomland hardwood ModelID; for all other ModelIDs, cypress volume is added to hardwood volume before growth. Dominant height, trees/acre, basal area/acre, quadratic mean dbh, MAI, and CAI can also be exported.
Initial values and grown volume by species group and age are stored in the NaturalStands and NaturalStands_Growth tables, respectively, in an Access project database (*.accdb) or in SQL Server.
NaturalStands_Growth table in SQL Server and exported workbook that includes optional data
Example of a yield table formatted for Woodstock
