Close-to-nature silviculture in eastern Quebec: Advances over the last decade

The increase in intensity of the harvesting of eastern Quebec’s forests has resulted in profound compositional changes at the stand level. The composition and structure of presettlement stands provide key benchmarks when implementing ecosystem-based management (EBM). A core principle of EBM is the emulation of natural disturbances, and it is hypothesized that forest resilience will be maintained. Managers have thus adapted some of their silvicultural activities to better mimic the main natural disturbances in eastern Quebec. These adaptations include using variable retention harvesting systems instead of clear-cuts and converting even-aged stands. Nevertheless, other close-to-nature silvicultural practices must be developed, as gaps between managed and unmanaged stands persist. Most importantly, there is a need to consider global change within EBM, which could be accomplished by prioritizing forest functions rather than composition or structure when establishing silvicultural objectives. Elements of the complex adaptive systems approach to increasing forest resilience can be incorporated into the larger-scale EBM approach. This could be done by considering the functional complementarity of species, forest function, and stand structure in forest management planning. These efforts must not be constrained, however, to allowable annual cut calculations, as these are not sufficiently sensitive to compare different management scenarios.

Intensive moose browsing and small-scale domestic woodcutting impacts on forest successional trajectories in Gros Morne National Park, Canada

Moose (Alces alces L.) browsing in Gros Morne National Park has damaged its balsam fir (Abies balsamea (L.) Mill.)dominated forest. A forest estate model was used to evaluate (i) the impacts of moose browsing and woodcutting on forest succession and (ii) strategies of forest restoration through planting and moose population management. The simulation results show that under current heavy browsing pressure growing stock of balsam fir decreases by 38%, but the area of spruce (Picea mariana (Mill.) BSP and P. glauca (Moench) Voss) increases by 32% over a 100-year planning horizon, compared to that under light browsing scenario which is assumed to be similar to the forest outside the Park due to moose population management. Annual allowable cut (AAC) for the Park’s 19 400 ha domestic harvest area is estimated to be around 120 979 m3 in a light browsing scenario, 21% higher than the sustainable harvest level in a heavy browsing scenario. The model forecasts a 97% reforestation of the Park’s 7 194 ha disturbed area by planting in the heavy browsing scenario, leading to an increase in total forest growing stock by 22% and AAC by 12%. Integration of planting with moose population management could be a more efficient way of restoring forest under high browsing pressure in GMNP.

Twenty-six years of aspen regeneration under varying light conditions in a boreal mixedwood forest

Density, height, and diameter at breast height of trembling aspen (Populus tremuloides Michx.) sucker regeneration were assessed over a 26-year period in openings created by harvesting in a 40-year-old aspen stand in northeastern Ontario (Canada). The opening types were 9- and 18-m diameter circles, 9- and 18- 150-m east-west strips, and a 100- 150-m clearcut, representing a range of light conditions. Density, height, and diameter at breast height of aspen regeneration were significantly affected by opening type, location relative to opening, and time since harvest. By year 26, aspen densities in circular openings declined to 0, despite high initial recruitment, and trembling aspen heights were significantly lower in the 9-m strips than in the 18-m strips or the clearcut. Year 26 aspen density, volume, and basal area increased with increasing initial light intensity, with the highest rate of increase between 80 and 100% light levels. Understory vegetation cover was largely unaffected by opening size; however, substantial understory aspen regeneration occurred in the smaller openings. Results support the traditional view that aspen is best managed under the clearcut silvicultural system, and >80% full light is recommended for adequate long-term aspen regeneration.

Economic potential of adopting genomic technology in Alberta’s tree improvement sector

The adoption of genomic technology and the use of improved seeds are expected to improve timber productivity in Alberta. However, this improvement will need to take place within the confines of the public-private nature of the sector where 93% of the total forest area is publicly owned. The purpose of this study is to explore the extent to which a timber harvest policy known as the allowable cut effect can affect the welfare outcomes of adopting genomics-assisted tree breeding. Using the forest industry of Alberta as the empirical setting, the economic returns to the adoption of this new breeding technology in lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) and white spruce (Picea glauca (Moench) Voss) are calculated by estimating a timber supply model and a spatial equilibrium model. Under certain policy and technology improvement scenarios, the economic returns are negative, which would result in non-adoption of the technology. However, under other feasible conditions, the payoffs of genomics-assisted tree breeding research are large and positive. These results illustrate the important role that government policies can have on the returns to adopting new technologies.

Economic impacts of partial harvesting: Mitigating mid-term timber supply shortages as a result of pest outbreaks

Natural disturbances such as pest outbreaks have a significant impact on forest dynamics and services, including the loss of mature stands. From a wood production perspective, these disturbances can lead to long-lasting imbalances in the overall age-class structure of the forest, potentially resulting in a shortage of mature harvestable stands. Researchers from Natural Resources Canada’s (NRCan) Canadian Forest Service (CFS) have made a timber supply analysis of the Dunière forest located in the centre of the Gaspé Peninsula (Québec). This region suffers from an age-class structure imbalance caused by an eastern spruce budworm (ESB) outbreak that ended in 1984, and is consequently facing a reduced annual allowable cut, leading to long- term implications for the regional forest sector. The authors suggest that partial harvesting – the removal of a proportion of timber in a mature stand several years before a final cut is carried out – is a promising opportunity in the ESB-affected area for mitigating mid-term timber supply shortages by smoothing the fibre supply over time.

Regeneration of black ash (Fraxinus nigra Marsh.) in hardwood swamps of the Great Lakes – St. Lawrence Forest Region

An inductive, ordination-based approach was used to explore patterns in the microenvironment and natural regeneration of black ash across a range of representative stands in the central Ontario portion of the Great Lakes -St. Lawrence Forest Region (GLSL) near Lake Nipissing, Ontario, Canada. The objective of this study was to describe patterns of regeneration of black ash and determine the associations between multiple indicators of black ash regeneration success and biotic and abiotic factors. Using a randomized sampling design with specific selection criteria, 12 black ash stands were sampled, each with three 400 m2 circular sample plots that contained three 4 m2 sub-plots. A suite of environmental variables such as elevation, topographic wetness index, slope, and soil characteristics (percent moisture, pH, total nitrogen, exchangeable phosphorus, potassium, magnesium) were determined for each stand. Variables capturing regeneration potential, including density, diameter, and height of all germinants, seedlings, saplings and sprouts were also collected. A sample of 15 dominant or co-dominant trees in each stand, as well as numerous black ash seedlings, saplings and sprouts were examined using dendrochronological methods to estimate ages. Principal component analysis ordinations were performed exploring the variation in environment and black ash regeneration variables among the stands. High soil moisture and the presence of canopy gaps, (as indicated by high standard deviation of canopy closure), were key variables associated with greater abundance of regeneration. Black ash was the dominant species in all stands, which were also generally characterized by a common reverse-J diameter distribution. It was observed that black ash in the sapling layer reached substantial ages (up to 60 years), indicating they are capable of withstanding long periods of suppression below the canopy. Collectively, these findings suggest that black ash-dominated stands in the study area are regenerating in multiple cohorts. Based on these patterns, it appears that regeneration in these stands is occurring through gap-phase mechanisms, suggesting single tree selection as the best management option for black ash in the GLSL.

Economic impacts of short rotation woody crops in Canada

Canada is seeking cost-effective means to mitigate greenhouse gas emissions, particularly CO2. One of the promising means is the short rotation woody crops (SRWC) plantation, a silvicultural approach to establishing and managing fast growing plantations on previously cleared lands. This paper utilizes the data set provided by recent harvesting operations at the Ellerslie SRWC Technical Development Site in Edmonton (Alberta) to assess the ability of SRWC using High Yield Afforestation to mitigate GHG emissions and generate more wood fibre and the investment attractiveness to establish future plantations. Results illustrate that at current trading prices for carbon credits and market prices of woodchips, expected rates of return on investment for SRWC were relatively low, despite a positive net present value ($400/ha for 20 year planting cycle without carbon credits). However, estimates from the Ellerslie site indicate that 330 tons of CO2-eq per hectare are captured above and below ground over the 20 year plantation cycle. However, higher future carbon prices, a well-developed market for buying and selling carbon credits, as well as adapted policy including additional government sponsored programs for carbon credits, could make SRWC more attractive and dramatically change the economics of afforestation in the future.

The economic impacts of woodchip storage optimization: Reducing material and energy loss during transportation and storage

The use of woody biomass for domestic bioenergy provides many benefits and opportunities, but also presents a challenge regarding the supply chain required for maintaining the high quality feedstock for sustained bioenergy production. This article focuses on one aspect of that supply chain – woodchip storage. To encourage the establishment of a bioenergy market and to help ensure a safe and stable fuel source, Suzanne Wetzel and Christopher Helmeste from the Canadian Forest Service, Canadian Wood Fibre Centre (CFS/CWFC) and collaborators contributed their scientific expertise to the development of a solid biofuels guide based on existing national standards from the Canadian Standard Association’s (CSA). This paper explores the potential economic impacts for bioenergy producers of implementing the CSA guidelines. These impacts include reducing material and energy loss during transportation and storage. Potential benefits were determined by cost-benefit analysis. The results of this economic impact study have significant potential implications for bioenergy producers, including the integration of economic considerations in the development of policies for biomass feedstock optimization for the Canadian bioenergy industry.