Canadian Forest Service Publications
Fifteen-year results of black spruce uneven-aged silviculture in Ontario, Canada. 2014. Groot, A. Forestry 87:99-107.
Issued by: Great Lakes Forestry Centre
Catalog ID: 35419
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An uneven-aged silviculture experiment was established in second-growth peatland black spruce (Picea mariana [Mill.] B.S.P.) stands in the boreal forest of northeastern Ontario, Canada in 1994. Three harvest treatments along with an unharvested control were applied in three replications. Fifteen-year results indicate that light- and medium-intensity harvest treatments maintain stand structure suitable for the continued application of uneven-aged silviculture treatments. Based on basal area growth trends and the development of stand structure, a cutting cycle of 20–25 years appears to be feasible for these treatments. Future harvests will likely yield a higher proportion of larger diameter trees with a greater value. The heavy harvest intensity treatment will result in a greater fluctuation of the growing stock and a longer cutting cycle. Without cutting treatments, the control treatment may eventually develop a stand structure that is unsuitable for the implementation of uneven-aged silviculture.
Plain Language Summary
We are interested in testing the uneven-aged management approach in particular boreal stands in Ontario. Experience with this type of silviculture in Canadian boreal forests is very limited, but has been successfully carried out in Europe. Certain black spruce stands on peatland sites may be suited to uneven-aged management due to their irregular structure. We tested three levels of harvesting intensity in second-growth peatland black spruce stands in northeastern Ontario. Fifteen-year results indicated that light- and medium-intensity harvest treatments (35-50% basal area removal) maintained a stand structure suitable for continued uneven-aged management. We recommend a cutting cycle of 20–25 years to maintain this type of harvest. We expect future harvests to yield a higher proportion of larger diameter trees with a greater value, which will increase the financial return of uneven-aged management over time. These results indicate that uneven-aged silviculture is applicable in peatland forests with irregular structure.