Coarse Woody Material Guide

Clearing woody materials from reclamation sites (historically usually achieved through burning or mulching) can have short-term benefits in terms of fire control, but can work against long term goals such as forest regeneration and conservation of biodiversity, which is increasingly a priority to government and forward-thinking companies. Leaving woody materials on reclamation sites is a cost-effective way to: (1) provide varied microsites that serve as habitat for native plant species, seedlings and microorganisms essential for forest regeneration, (2) provide habitat for insects and mammals, and (3) play a key role in nutrient cycles over time. This project undertook a literature review to provide recommendations for incorporating woody material into reclamation programs. An integrated approach was taken, which included: (1) site visits to current in-situ oil sand operations; (2) a review of current policy and regulatory guidelines; (3) a review of scientific research; and (4) the development of a series of management implications. The findings will serve as a guide to the use of woody material, and assist with efficient planning of reclamation programs.

Mulching can prevent/slow reclamation; only use if unavoidable or really needed (dry arid soil site). If unavoidable, use rough mulching or hand felling when possible and mulch less than 3 or 4 cm deep. Leave no aspen chip residues within 30 m of riparian sites. Whole logs are preferred: they benefit erosion control, moisture retention, microsite creation and heterogeneity. Recommend woody material volumes of 60 m3/ha to 100 m3/ha, and coverage targets of 10 to 25% of disturbed surface on upland sites and 30 m3/ha to 50 m3/ha on lowland sites. Focus on keeping logs intact, maintain range of sizes and lengths. Explore transporting woody materials from high to low volume sites. Whole logs and coarse woody material can be stored with surface soil. Develop “woody material plan” prior to disturbance. Roll back woody material along access features to help vegetation re-establish; target volumes 60 to 100 m3/ha, higher volumes should be researched. Use old slash piles/other residual woody material. Site prep, such as mounding, can accelerate revegetation. Suggest establishing long-term monitoring programs analyzing animal movements before and after. Associated Master’s project showed continual positive relationship between woody debris and soil cover and soil and vegetation development in year five post reclamation.