资源环境科技发展态势分析平台

Throughout eastern North America, oaks (Quercus) are a foundational tree species, but are regenerating poorly, particularly on mesic sites. This regeneration failure has spurred development of new management practices that create heterogeneous regeneration conditions that better match oak's response to disturbances such as surface fire and windthrow. Expanding group shelterwood systems are designed to produce diverse regeneration conditions and have a high edge-to-forest interior ratio, where intermediate light levels may be beneficial for oak regeneration. We present data on early regeneration patterns from a large-scale experiment designed to assess the combined effects of these silvicultural systems and prescribed fire on oak regeneration, ecosystem resilience, and spatial and compositional heterogeneity in the Central Hardwood Region. Using transect-based surveys, we investigated the spatial patterns of woody regeneration within and outside of burned and unburned 2- or 3-stage group shelterwoods in factorial replicates at two different sites. Two years following the initial harvest, the south-facing site had substantial competitive oak regeneration just outside of the harvested groups on the northern, eastern, and western sides, but the east-facing site did not. On a stand level, tulip poplar (Liriodendron tulipifera) and sassafras (Sassafras albidum) regeneration increased in both sites, oak increased in the south-facing site, hickory (Carya) increased in the east-facing site, and maple (Acer) was relatively unaffected by the treatments. Competitive oak regeneration in the forest matrix just outside of the harvested groups in the south-facing site holds promise to regenerate a stand with a substantial oak component and high overall diversity, given the shelterwood groups will be expanded outward in successive entries and burned repeatedly over time.