Vegetation management is essential to regeneration success of red oak (Quercus rubra L.) at its northern range limit: results from a 10-year field experiment

Abstract

The effect of three vegetation management treatments on height, root collar diameter, mortality probability, health, and dominance class were assessed for planted and natural red oak (Quercus rubra L.) regeneration over a ten-year period in a red oak stand in Phelps Township, Ontario. Oak was planted in equally spaced positions in rows or in clusters of three seedlings. One of three vegetation management treatments was applied to both herbaceous and woody competitors within a 2-metre radius: untreated control, brush saw, and herbicide application. Oaks that received vegetation management were significantly taller, had larger root collar diameters, were in better condition, and were more dominant than in untreated control plots, and treatment differences increased with time. We found naturally regenerated oaks were taller and had larger root collar diameters followed by those planted in clusters, with oaks planted in rows being the smallest overall. Our results underscore the need to apply vegetation management around oak regeneration to control competition and promote establishment regardless of whether regeneration is natural or planted. In stands where natural regeneration is not an option and lower future oak stocking is acceptable, managers should consider cluster planting over row planting.