Canadian Forest Service Publications
Effects of 80 years of forest management on landscape structure and pattern in the eastern Canadian boreal forest. 2015. Boucher, D.; De Grandpré, L.; Kneeshaw, D.; St-Onge, B.; Ruel, J.-C.; Waldron, K.; Lussier, J.-M. Landsc. Ecol. 30:1913-1929.
Issued by: Laurentian Forestry Centre
Catalog ID: 36146
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Context Forest management alters patterns generated by natural disturbances, particularly in ecosystems with infrequent fires. Management effects can differ according to spatial scale and affect ecological processes.
Objectives To assess the effect of 80 years of forest management at both the landscape and burn/harvest scales on forest age, composition, density, spatial pattern and heterogeneity.
Methods Forest inventory maps and satellite images were used to compare two contiguous landscapes, respectively managed and unmanaged, of the eastern boreal forest of Canada, in a region with infrequent fires. Burns and harvests occurring from 1920–1950 were also compared.
Results In addition to reducing the proportion of old-growth stands in the landscape, forest management changed forest composition at both scales, favouring the late-successional species balsam fir. Landscape metrics indicated that old-growth forests and spruce-dominated ones were more fragmented, less connected, and confined to smaller patches in the managed landscape than in the unmanaged one. Forest management increased heterogeneity at the landscape scale, but decreased it at the burn/harvest scale. Logging had a homogenizing effect at the burn/harvest scale by attenuating the effect of the physical environment on forest density.
Conclusions This study provides knowledge to help reduce effects of forest management at both scales. In this forest region with low fire recurrence, the goal should be to manage for greater forest heterogeneity at the burn/harvest scale whereas, at the landscape scale, restoration strategies should aim to create large contiguous patches of coniferous forests to increase spatial continuity as these were reduced by past management activities.
Plain Language Summary
In Eastern Canada boreal forests, the effects of forest management may be reduced by practising a form of forest management that promotes heterogeneous composition of stands at the operational level. At the landscape level, mitigation strategies that aim to promote large areas composed of conifers should be adopted.
These findings result from a study that verified the effects of 80 years of landscape-scale and operational-scale forest management on the age of forests, their composition, density, distribution and heterogeneity. Landscape-scale forest management reduces the percentage of old growth forests and increases heterogeneity. In addition, old growth forests and black spruce dominated forests are more fragmented and contained within smaller parcels. As well, operational scale forest management reduces the heterogeneity of forests, compared with post fire forests.