Low soil disturbance during boreal forest well site development enhances vegetation recovery after 10 years

Abstract

Boreal forests are increasingly exposed to industrial well site development. Little information exists on the optimal construction and reclamation strategies needed for vegetation recovery, including methods of well site preparation, soil storage, woody debris management, and revegetation. In this study we examined intermediate-term (10 yr) recovery of vegetation on 33 well sites distributed across NE Alberta, Canada, constructed and reclaimed using different site preparation methods, including high (HD), intermediate (ID), and low intensity (LD) disturbance of surface soils. Comparisons also included soil piling methods on HD sites, debris management on ID and LD sites, and tree planting on all sites. Comparisons were made to adjacent uncut forest to assess similarity, and at a subset of locations to harvested clear cuts. Ten years into recovery, vegetation was most similar between uncut forest and well sites developed using LD construction methods in species richness, diversity, and cover of vegetation growth forms and ground cover components (bare soil, litter, moss and lichen). Well sites using HD and ID had vegetation more dissimilar to uncut forest. Clear cuts harvested at the same time as the well sites also differed in composition from the forested controls, but remained more similar to the LD well sites than the HD and ID well sites. Effects of reforestation (tree planting), the technique of soil piling, and different forms of woody debris management (spreading vs windrowing) had little impact on vegetation recovery. Overall results highlight the importance of using LD well site preparation techniques where possible to keep mineral soil and embedded plant propagules intact to maximize boreal forest recovery following disturbance.