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Pitt D.G.,Canadian Wood Fibre Center | Comeau P.G.,University of Alberta | Parker W.C.,Ontario Ministry of Natural Resources | Hoepting M.K.,Canadian Wood Fibre Center | And 3 more authors.
Forestry Chronicle | Year: 2015

In Canada's boreal forest region, mixedwood stands dominated by trembling aspen (Populus tremuloides Michx.) and white spruce (Picea glauca [Moench] Voss) are prominent and provide important timber and non-timber values. A paucity of silvicultural tools for regenerating mixedwood conditions prompted the establishment of an experiment in 2002, replicated in west-central Alberta and northeastern Ontario, to test a strategy for regenerating a single-cohort, intimate mixture of aspen and white spruce. After ten growing seasons, spruce planted at 5-m spacing, each free of woody and early (first two years) herbaceous competition within a 2-m radius, had equivalent or better survival, height growth and health status than spruce growing competition-free for the duration of the experiment (α = 0.05). Select aspen situated in the vicinity of these spruce were at least as large as aspen crop trees situated in undisturbed plots. The year-10 results of this long-term experiment suggest the hypothesized mixedwood regeneration strategy may offer a practical means of establishing mixedwoods capable of producing an early fibre rotation of aspen (∼ age 30) and long term (> 60-years) sawlog crop of spruce. © 2015 Published by NRC Research Press.

Thompson D.,Natural Resources Canada | Leach J.,Tembec Forest Resources Management | Noel M.,Natural Resources Canada | Odsen S.,Incremental Forest Technologies Ltd. | Mihajlovich M.,Incremental Forest Technologies Ltd.
Forestry Chronicle | Year: 2012

Herbicide use in forest management is subject to controversy due to potential risks to human and environmental health. Provinces with substantial forest herbicide use are the focus of this comparative assessment of risk mitigation strategies for aerial application of forestry herbicides. This paper explores risk mitigation procedures surrounding treatment prescriptions, herbicide planning and permitting, and operational treatment, against a background of legislative and regulatory requirements. The three major-use provinces have similarly high levels of risk mitigation, including detailed herbicide application plan requirements, use of electronic guidance systems, buffering of environmental sensitivities, pre-spray reconnaissance flights and post-spray auditing. Notable differences include standardizing use of rotary-wing aircraft, use of low-drift nozzles, the rigor applied to aircraft calibration and use of block monitors for detailed meteorological monitoring. These techniques are generally unique to Alberta and are considered best management practices. The routine use of validated aerial dispersal and expert decision support systems (e.g., AgDisp, SprayAdvisor) is recommended, as it could provide significant added value to generic and spatially explicit risk mitigation with multiple applications. It is the opinion of the authors that aerial herbicide applications as performed in all three major-use jurisdictions are highly protective of human and environmental health.

Mihajlovich M.,Incremental Forest Technologies Ltd. | Odsen S.,Incremental Forest Technologies Ltd. | Chicoine D.,Incremental Forest Technologies Ltd.
Forestry Chronicle | Year: 2012

This report reviews herbicide use for forest management purposes in Alberta between 1995 and 2009. Data for this review are drawn from the National Forestry Database, Government of Alberta records, anecdotal review of herbicide activities from participants, and the published literature. Alberta moved toward operational use of herbicides for forest management in a carefully monitored, step-wise process, with full adoption occurring in 2001-2002. Stakeholder engagement processes and the development of operational guidelines for risk identification and mitigation are described. A metric (Herbicide Excursion Intensity) has been developed and used to assess risk identification and mitigation efficiency independent of extent of herbicide use. Review of the temporal trends in this metric demonstrates that identification and mitigation of this element of risk associated with forest herbicide use in Alberta has been generally successful following initial learning experiences. Factors contributing to Alberta's success in risk mitigation are: use of helicopters for all aerial application of forestry herbicides, adoption of drift control (AccuFlow™) nozzles, and quantitative prediction of spray cloud behavior in the Ag-Drift and SprayAdvisor models allowing gaming of weather conditions, buffer widths and nozzles to develop integrated risk mitigation processes. The report provides several recommendations, including the development of a Vegetation Management Strategy, to more explicitly link forest herbicide use with forest management planning.

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