Grant: CCI Applied Research and Development Grants

It is well known that controlling early competition is beneficial when promoting development of conifer-leading forest stands. While glyphosate has been a routinely-utilized vegetation management treatment in Alberta for the last 20 years for both graminoid and hardwood competition, increased social pressure is changing its use-case with declines expected to continue in the coming years. Concurrently, there has been increased concern from local stakeholders in the utilization of mechanical site preparation (MSP) treatments, particularly those deemed to create longer-term physical heterogeneity in the landscape. These concerns arise from several sources, including issues of accessibility due to rough terrain and the perceived level of disturbance to an otherwise natural landscape. Collectively, changes in societal expectations and concerns have prompted silviculture staff to re-examine available options for managing competing vegetation. This applied research study proposes to explore MSP and larger container seedlings as vegetation management tools to support development of conifer-leading stands in west-central Alberta. Both research trials will evaluate the response of Picea glauca and Pinus contorta as these species are prevalent commercial tree species in this region. While MSP is not new, there is an opportunity to re-examine treatment options considering anticipated reductions in herbicide-based forest management; treatments that may have been previously discarded or not considered due to cost may be viable today. Similarly, large container stock use has not been adopted in Alberta to-date due to the substantial per-seedling cost, perceived risks associated with winter desiccation and the availability of other tools to manage competition. This project is anticipated to provide valuable locally-relevant knowledge to support decision-making for MSP treatments suitable for controlling competing vegetation during conifer establishment, and as an alternative to herbicide application. Data will also provide important information regarding the suitability of larger-sized seedlings on these site types. Ensuring prompt and consistent conifer establishment will ensure the forest industry meets its regulatory requirements and future growth and yield projections.