Understory Succession following Initial Ecosystem Restoration Treatments in Ingrown Dry Forests

Ingrowth of dry forests in the southern interior of British Columbia often results in the retrogression of understory plant communities, the loss of habitat for sensitive wildlife species, and an increased risk of catastrophic wildfires. In the East Kootenay region, restoration of ingrown stands usually begins with a harvest pass to remove merchantable timber and reduce overstory stocking to between 70 and 400 stems per ha. Slashing is used to eliminate excess intermediate layer trees that cannot be safely removed in a prescribed fire. Two ingrown dry forest stands in the East Kootenay region were selected to study changes in understory plant community following thinning and prescribed burning. The general response of understory vegetation was a decline in production and cover followed by recovery to pre- treatment levels. Two key objectives of dry-forest restoration have not yet been achieved 3 years after treatment. Pinegrass abundance has not declined in favour of important forage bunchgrasses. Shrubs with high wildlife browse value have declined rather than increased.