Spatial autocorrelation among forest stands identified from the interpretation of aerial photographs

Abstract

In an effort to improve on forest inventory regroupment strategies for forest stands in Quebec, spatial adjacency information was obtained for forest stands which had been identified by the interpretation of aerial photographs of a test forest in Quebec, Canada. The Join–Count statistic was used to measure spatial autocorrelation to determine if strata had an unusual affinity for, or repulsion to, other strata. Spatial autocorrelation was measured using a binary contiguity matrix (‘touching/not touching’) and one which used the length of common boundary as the measure of connectedness. Furthermore, basic strata were grouped in four different ways to produce four additional maps of forest strata at different scales of interpretation. In no case was spatial autocorrelation sufficiently strong to allow a satisfactory forest inventory regroupment of strata to be conducted. It is suggested that the reason for this is that the test forest is a managed forest rather than one which ecological processes have been allowed to evolve undisturbed. Operations (e.g. harvesting and planting) on the forest have destroyed the positive spatial autocorrelation expected among natural ecological communities, but have not been conducted long enough to produce significant negative spatial autocorrelation.