Coarse Woody Debris Study At Steepbank North Waste Dump

This research determined if woody debris amendments facilitate land reclamation after oil sands mining. Specifically, it assessed if coarse woody debris (CWD) affects vegetation cover and richness, woody species survival and abundance, soil nutrients, temperature and water, microbial biomass carbon and mycorrhizal biomass. A four year old site and a two year old site planted with white spruce and trembling aspen were used to compare treatments with and without woody debris.

Woody debris did not affect initial vegetation emergence, but was beneficial for reclamation, providing microsites for vegetation establishment resulting in greater species richness and planted tree survival. The treatment without woody debris had significantly greater plant canopy cover, but the majority of cover was introduced species, particularly Sonchus arvensis, undesirable from a reclamation perspective. Woody debris treatments had significantly less available nitrogen, suggesting nitrogen immobilization, and more soil available phosphorus, potentially from woody debris leachate.