Forest Productivity Council Policy

DEFINITION AND ESTIMATION OF TOP HEIGHT FOR SITE INDEX

Table of Contents

Executive Summary

1. Introduction

1.1 Scope
1.2 Objective
1.3 Problem Statement
1.4 Technical and Historical Perspective
1.5 Current Status of Stand Height Usage

2. Issues Involved in Defining Top Height

2.1 Choice of Plot Size
2.2 Definition of Valid Top Height Trees
2.3 Choosing Largest Diameter versus Tallest Trees

3. Potential Top Height Definitions

3.1 Option 1 - Top Height 1998: One largest diameter tree per 0.01 ha plot
3.2 Option 2 - Top Height 1995: one largest tree per 0.01 ha plot (TH95)
3.3 Option 3 - Top Height 1997: Four Trees per 0.04 ha Plot (TH97)
3.4 Option 4 – Status Quo

4. Recommended Top Height Definition

4.1 Rationale
4.2 Implications

Literature Cited

List of Tables and Figures

• Figure 1. Notional effects of plot size on top height estimate relative to 1 tree in a 0.01 ha plot
• Table 1. Definitions of stand height used in British Columbia.
• Figure 2. Notional relative magnitudes of different stand height definitions.
• Table 2. Current top height definitions used in different applications.

Last updated: 01/13/99