Quantifying restoration success via natural recovery in forested areas following pipeline construction

Abstract

Natural recovery is a restoration technique that relies on natural ecological processes to reestablish native ecosystems. This “minimal intervention” approach is typically more cost‐effective, less labor intensive, and can result in more diverse communities than more intensive restoration techniques. The purpose of this study was to determine if boreal forest vegetation can reestablish naturally after pipeline construction, and whether a site can be identified as similar to adjacent undisturbed areas within 10 years of pipeline construction. Four naturally recovered pipeline segments (1, 3, 5, and 10 years postreclamation) in west‐central Alberta were assessed. Plots were established on and off each pipeline segment right‐of‐way (ROW) in upland, transitional, and wetland habitats. Vegetation percent cover, vigor, and tree seedling density data were used to determine characteristic and indicator species, regulated weeds and agronomic species, richness, diversity, evenness, and tree establishment for each pipeline segment, habitat type, and site type (on‐ vs. off‐ROW). Threshold values for species richness and community diversity were determined using data collected from sites off‐ROW. Sites which fell within established thresholds were identified as on a trajectory toward restoration within 10 years postconstruction. Metrics for the older pipeline segments, including species richness, diversity, evenness, and seedling count were typically closer to threshold values, and sometimes exceeded them. Only the youngest pipeline segment had tree establishment values below calculated thresholds. This study is the first to provide empirical evidence and a method for identifying successful restoration trajectories for natural recovery of pipeline ROWs in boreal forest.