Long-term effects of peatland black spruce regeneration treatments in northeastern Ontario

Abstract

Studies of black spruce (Picea mariana (Mill.) BSP) broadcast seeding and of harvest methods for advance regeneration protection were remeasured 17 to 20 years after establishment on peatland sites in northeastern Ontario. The effects of seeding rate on black spruce stocking, density or basal area were apparent at two study locations 20 years after treatment, but high levels of advance regeneration masked seeding rate effects at two other study locations. The effects of different harvest methods on black spruce stocking, density and basal area, which were evident at earlier ages, were no longer statistically significant 17 to 19 years after treatment. Black spruce density increased moderately with time because of gradual recruitment of new seedlings. Density of black spruce stems taller than 1.3 m tall exceeded 4000 ha-1 for nearly all treatments, but these stems were spatially aggregated at the 4-m2 scale. The stand characteristics of these regenerated peatland stands are consistent with site class 2 stands in the Ontario normal yield tables. Key words: black spruce; Picea mariana; advance regeneration; direct seeding; regeneration; peatland; stand dynamics