Tree species diversity in managed Acadian forests of Eastern Canada

Maintaining forest diversity is an important value in long range management planning. This study was conducted in the ecologically diverse Acadian forest region in the Province of New Brunswick, Canada across 1.65 million hectares of publicly owned (Crown) and privately owned (Freehold) land. Tree species diversity using Hill numbers was evaluated across 21 forest type/age class combinations (groups) using 1691 sample plots to assess tree species richness (D-0), typical species (D-1), and abundant species (D-2). Across the entire study area there were D-0 = 31.0 total tree species observed, D-1 = 11.5 typical species, and D-2 = 7.0 abundant species. Among the 21 forest types/age class combinations, the Hill numbers ranged from D-0 = 16.0-28.3, D-1 = 5.6-11.5, and D-2 = 3.5-8.4. A comparison of public and private land ownerships showed minor differences in tree species diversity at the landscape level. More intensively managed forest types (e.g., planted stands and naturally regenerated stands with silvicultural interventions) had similar levels of landscape-scale tree species diversity as comparable forest stands receiving no silvicultural interventions. This suggests that current management practices are maintaining tree species diversity across the landscape and highlights the importance of tailored management regimes for different forest types to support this diversity.