Calculating Forest Values: Calculating an HSI for an old-growth indicator species

Introduction

How do you use GIS to explore whether a forest ecology is in trouble?

The presence of old growth in a forest is part of a healthy forest ecology. An indicator of old growth is a high habitat suitability index (HSI) rating for a species that is known to prefer old-growth conditions. One such species is the Blackburnian warbler in northeastern North America.

In this exercise, you'll analyze a forest for old-growth value, using the Blackburnian warbler as an indicator species. By calculating a warbler HSI for each stand of trees in the woodlot, you'll be able to compile average size and density of HSI patches and arrive at an assessment of the forest's ecological well-being from an old-growth perspective.

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 software and GIS data, including use of a geodatabase. Some knowledge of computer programming, Visual Basic in particular, and familiarity with forest inventory data and terminology are 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)