Locating Discontinuities along Ecological Gradients

Cost-efficient ecological and natural resource surveys need: (1) flexible, logistically simple, and statistically sound sampling methods, and (2) sensitive, computationally simple, and ecologically robust data analysis methods. "Gradsects" (gradient-oriented transects) have recently been shown to be a more efficient sampling method than random sampling using nongradient-oriented transects, especially when surveying large, biologically diverse areas. If biotic (e.g., vegetation) sampling is oriented along a defined environmental gradient, and the purpose is classification, then simple, efficient analysis techniques are needed. This note briefly reviews appropriate analysis techniques in order to identify ecotones or boundaries along gradsects.