Tree regeneration and spatial patterning among midtolerant tree species following gap-based harvesting in a temperate hardwood forest

Introduction Field experiments of gap-based harvest systems in temperate northern hardwood forests have provided inconsistent support for the theory that such regeneration approaches can improve success among increasingly underrepresented tree species intermediate shade tolerance. We established a field experiment Wisconsin, USA testing long-term response to group selection harvesting created small (50 m 2 –D:H 0.32), medium (200 —D:H 0.64) and large (380 0.88) gaps. Materials methods Light levels were modeled test assumption resource heterogeneity within across these gap sizes. Spatial statistics used assess whether point patterns saplings several midtolerant ( Betula alleghaniensis , Carya cordiformis Fraxinus spp.) mapped gaps evidence partitioning gradients 9 years post-harvest. Finally, we measured occurrence height all effects size deer exclusion fencing on density total shade-tolerant regeneration. Results discussion progressively increased with size, varied by position gaps, significant heterogeneity. The complex light formed both three sizes may partially explain statistically clustering spp. centers north east into forested edge C. west sides transitions surrounding B. Densities tolerant similar after nine growing seasons, though averaged two meters taller Our results show silvicultural create are sufficient regenerate mixtures high tolerance shade. However, prescriptions beyond be necessary recruitment canopy positions.