EFFECTS OF ORGANIC HORIZON REMOVAL, ASH, WATERING REGIME, AND SHADINGON RED PINE SEEDLING EMERGENCE

Soil monoliths were used to determine the effects of organic horizon r emoval, ash, water regime, and shading on red pine (Pinus resinosa Ait .) seedling emergence. Soil monoliths were collected from a jack pine (Pinus banksiana Lamb.) stand and taken to the laboratory for prescrib ed burning, leading to 25%, 50%, 75%, and 100% organic horizon removal . One half of each monolith contained ash generated from burning, whil e the other half was kept ash-free. Each half of every monolith was so wn with red pine seeds. The monoliths were then placed in a greenhouse and, in separate experiments, were exposed to different water regimes and shade regimes. Red pine seedling emergence was highest under high water regimes, increased shade regimes, and increased organic horizon removal. Seedling emergence was reduced by the presence of ash.