Mounding Site Preparation for Jack Pine and Black Spruce in Boreal Ontario: Five Year Results

Eleven plantations of each of jack pine (Pinus banksiana Lamb.) and black spruce (Picea mariana [Mill.] B.S.P.) were established with bareroot stock during a 3-year period beginning in 1980 on sites appropriate for those species between latitudes 48°27' and 5O°22’ N and longitudes 85°10' and 92°03' W. Site preparation provided five kinds of microsite for planting: (a) untreated, (b) Bracke patch shoulder, (c) Bracke patch bottom, (d) mound of mineral soil on the Bracke patch shoulder, and (e) mound of mineral soil on the minimound of material scuffed out of the Bracke patch. On each site, four 30-tree plots per microsite were planted. Five trees per plot were excavated 30 days after outplanting for purposes reported elsewhere. Root growth capacity was determined on subsamples of planting stock; performance in a low-stress (nursery) test planting was determined in other subsamples. Performance data were collected for 5 years. Several evaluations were conducted: height after five growing seasons: relative growth rate (height, years 1 through 5); stem diameter after live growing seasons: stem volume after five growing seasons: relative growth rate (volume, years 1 through 5): and two performance indices that combined survival and growth. The evaluations showed that, though both species performed well on mounded microsites, performance was equally good after outplanting on the shoulder of the standard Bracke patch.