Prescribed burning for boreal forest restoration: Evaluating challenges and conservation outcomes.

Prescribed burning is applied as a restoration tool to promote biodiversity in boreal forests. Common objectives include promoting multilayered pine forests, increasing deadwood, and generating fire-scars. However, the extent to which these objectives are achieved and how they relate to weather conditions and stand characteristics remains poorly understood. We surveyed 32 prescribed burns in Sweden to evaluate the outcomes of key conservation objectives and their relationship to weather conditions and stand characteristics. In addition, we compared weather patterns and seasonal timing between prescribed burns and wildfires. We found that conservation objectives were met with large variations between sites but were generally better achieved under drier weather conditions and at sites with higher proportion of spruce. Wildfires occurred under significantly drier conditions and later in the summer than prescribed burns. We conclude that optimizing prescribed burning as a restoration tool requires better alignment between conservation objectives, stand characteristics, and weather conditions.