Black spruce growth and survival in boreal open woodlands 10 years following mechanical site preparation and planting

Abstract

Since 1950, the creation of open woodlands has increased in Canada's northeastern continuous boreal forest and recent studies have demonstrated that the mechanisms underlying their creation are similar to those found in the lichen woodland zone. Since no natural re-densification of open woodlands has been observed to date, afforestation is necessary to counteract an increase of these types of stands in the continuous boreal forest. The aim of this study was to test the operational feasibility and success of afforestation efforts in open woodlands, 10 years after planting. The experimental design included different containerized seedling stocks and site preparation approaches, such as patch and disk scarification, and covered most of the geographical range of accessible continuous boreal forest in Quebec. In open woodlands, regardless of black spruce stock size, disk scarification increased planted seedling survival and growth compared with patch scarification and direct planting, possibly due to a beneficial effect on seedling nutrition. However, even if seedling growth in open woodlands and feathermoss stands submitted to disk scarification was comparable, growth was higher in the latter stands. Nonetheless, we conclude that disk scarification followed by planting is an appropriate method to afforest boreal open woodlands.