Regeneration response of tolerant hardwoods to beech bark disease vegetation management

Abstract

Beech bark disease (BBD) is the most significant natural disturbance affecting the Bancroft Minden Forest (BMF) and other forests across central Ontario. As a response to mortality from BBD or root injuries from harvesting, beech trees regenerate at a quicker rate than other species as they are very shade tolerant and can reproduce asexually from root or stump sprouts or sexually from a parent tree. The dominant regeneration of beech will affect the future composition of the forest as it makes it difficult for more valuable species to regenerate. Several vegetation management treatments are available to remove understory regeneration and mitigate root sprouts, such as mechanical treatments and chemical treatments. This study aims to determine which vegetation management treatment, between a mechanical brush saw treatment and a basal bark application of the herbicide triclopyr, is more effective six years after treatments were applied. Our results show that six years after treatments were applied, there is no significant difference between the two treatments amongst the large beech regeneration. However, the basal bark application of triclopyr may be a more effective long term treatment than the brush saw when looking at the small and medium regeneration size classes likely due to the increased sprouting response after mechanical treatments. We also aim to determine if these treatments had an effect on the regeneration of more desirable species such as sugar maple. We found no evidence that the treatments had any effect on sugar maple regeneration.