Résumé - CAFD

Negligible structural development and edge influence on the understorey at 16-17-yr-old clear-cut edges in black spruce forest.

Karen Harper, Pierre Drapeau, Daniel Lesieur, Yves Bergeron.

What is the distance of edge influence on the structure and understorey composition at 16–17-yr-old cut edges in black spruce boreal forest? How do these edges compare with more recent 2–5-yr-old cut edges in the same region? Northwestern Quebec, Canada. Forest structure and understorey composition were sampled along transects perpendicular to ten 16–17-yr-old clear-cut edges, and compared to published results from 2–5-yr-old cut edges. We used randomization tests to assess the magnitude and distance of edge influence, and to compare edge influence between different edge ages. Black spruce forest next to the 16–17-yr-old cut edges was structurally and compositionally very similar to interior forest, with little edge influence from harvesting beyond 5 m into the forest. Edge influence on the understorey was weak (low magnitude) and not very extensive (short distance) at these edges, with no significant edge influence on the abundance of individual species. Logs peaked in abundance on the forest side of the edge, with values higher than in either adjacent ecosystem. Overall, 16–17-yr-old cut edges in black spruce forest showed little evidence of further structural change compared to the 2–5-yr-old cut edges. Structural development of these edges as well as regeneration of the disturbed areas also resulted in reduced edge influence on the understorey. Instead, clear-cut edges in black spruce forest may experience more forest influence on the regenerating disturbed area.