Forest Analysis Techniques: Evaluating economical timber amounts

Introduction

How do you calculate the operable timber yield of a forest by skidding distance (how far felled trees are from roadside transportation)?

A common clearcut harvesting practice involves felling trees, by hand or machine, and skidding them roadside for further processing and eventual transport to a mill. For a stand of trees to be "operable" (justifying operating costs), it must offer at least a minimum volume yield and the felled trees must be accessible via road.

All things considered, the shorter the skidding distances to roadside, the more productive a harvest operation will be. Depending on the harvesting equipment, distances beyond a maximum would be uneconomical. How would you tally up operable timber amounts in a forest by skidding distance?

Location

A small 1,400 ha woodlot in the Acadian-New England forest region of North America

Time to complete the lab

3 hours

Prerequisites

A basic working knowledge of ArcGIS and GIS data, including the geodatabase. Familiarity with forest inventory data is helpful, but not essential.

Data used in this lab

Feature classes and rasters for a forest woodlot (personal geodatabase)

Geographic coordinate system: NAD 1983 CSRS New Brunswick Stereographic

Datum: NAD83 datum

Projection: New Brunswick Double Stereographic Grid (unless otherwise stated)