Using landscape metrics to measure suitability of a forested watershed: a case study for old growth

Several metrics for spatial heterogeneity based on distribution of stands suitable for old growth were calculated for the actual and optimal conditions of a watershed in the Medicine Bow National Forest in Wyoming. Optimal conditions were based on expert opinions. The actual condition was compared with target conditions using a multivariate method called profiling, which develops profiles based on various spatial statistics and examines the similarity of these profiles using a multidimensional scaling (MDS) procedure. Profiles for various target landscapes clustered together in MDS space, and this space could be defined and quantified using a kernel density estimator. The distance from the centroid of the target space to the position of the actual stand is used as a measure of dissimilarity. By comparing the condition of a given watershed to that of what experts envisioned would be optimal, we argue that the relative condition of the watershed can be characterized. We make a distinction between stand-scale metrics and landscape-scale metrics. We propose that this method may be useful in quantifying changes in landscape conditions and could be useful as a monitoring method in forest plans.