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November 25: Establishment and Early Management of Young Forests in Sweden
December 2: Comparative evaluation of site treatment options to enhance forest productivity
April 28, 2023: Establishment and Early Management of Young Forests in Sweden
November 25, 2022: Establishment and Early Management of Young Forests in Sweden
Dr. Mostarin Ara
Abstract
Demands on forests have shifted from just fibre production to multiple ecosystem services. New management strategies need to be developed to balance production with other ecosystem services. This presentation evaluates alternative forest management strategies which balance production, economic returns, and multiple ecosystem services with an emphasis on young Swedish forests. No negative effect of rectangular planting design during forest establishment was found on the production of coniferous plantations. Despite establishment of regenerating stands with either Norway spruce or Scots pine alone, young forests mostly contain a mix of these species together with naturally regenerated broadleaves. Different pre-commercial thinning (PCT) strategies were experimentally applied in such young mixed forests (Norway spruce and birch in this case). Some PCT techniques in these stands can provide forage for ungulates without sacrificing volume production in Norway spruce. Moreover, such mixtures might also provide a wide range of ecosystem services with no or little economic loss in the long term. Finally, PCT can increase the full rotation profitability of Norway spruce stands compared to no-PCT stands. However, the timing of PCT appears to have little effect on the profitability of Norway spruce production. Overall, alternative forest management strategies tested, show potential to provide multiple ecosystem services and flexible forest management strategies along with profitable production.
Presenter Bio
Dr. Mostarin Ara is currently a postdoctoral fellow at the University of Alberta’s Department of Renewable Resources. Her research is focused on forest silviculture and growth and yield modeling. She earned a Doctorate in Forest Management from the Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre in Alnarp, Sweden. Her research focused on silvicultural systems that combine forest production with other ecosystem services. Mostarin has broad experience working in an array of forest biomes including tropical, temperate, boreal, hemi-boreal and mangrove forests. Mostarin’s PhD Thesis, which forms the basis of this presentation, can be downloaded at: https://pub.epsilon.slu.se/27495/
December 2: Comparative evaluation of site treatment options to enhance forest productivity
Abstract
Reforestation within the Weyerhaeuser Grande Prairie FMA has relied heavily on the use of glyphosate coupled with a minimum soil disturbance approach. However, since 2019, incorporation of mechanical site preparation began to be employed more widely and in 2020, a corporate decision to discontinue use of glyphosate was made due to stakeholder concerns. This has prompted silviculture staff to re-examine available tools to managing competing vegetation of harvest blocks in the absence of this tool. In the Weyerhaeuser FMA, competing vegetation of concern may be classified into two broad groups: hardwoods and herbaceous vegetation. Unlike other FMAs, graminoids (Calamagrostis canadensis in particular) are not necessarily the primary constraint but it is rather a broad range of species that may be very productive under the right conditions with the short-term risk of seedling mortality as well as slower rates of productive tree growth. For richer sites and sites where significant herbaceous or hardwood (if conifer leading stands are the target) competition are anticipated, the consequences are largely related to reduced rates of growth and potentially lower stocking of conifers. These issues have potential consequences for future growth and yield projections, extended harvested rotations and annual allowable cut.
There are a range of potential site treatments as well as seedling-scale treatments that may be employed and many have been tested in various ways over the decades; however, many of these tools, until recently, have not been widely employed in the Weyerhaeuser FMA and there are knowledge gaps in terms of the relationship between historical management approaches and the utilization of these approaches. This project will evaluate four mechanical site preparation treatment options, including an untreated-straight planting reference and combine these treatments with and without use of a pre-planting herbicide treatment (Arsenal PowerlineTM). Until recently, Arsenal PowerlineTM was not available for broadcast deployment; this proposed study will provide well-replicated quantitative evidence on where the best-use case is for this treatment versus where mechanical site preparation alone will be sufficient in managing short-term competition control. Ultimately, the proposed study is intended to provide quantitative data that will allow for informed decision making when implementing herbicide or mechanical site preparation tools on the landscape as we expect that there will be trade-offs when managing for multiple forest values.
As this project is just beginning with the first set of sites being planted in spring 2023, this presentation will focus on describing more detailed rationale for the treatments being compared, the planned experimental design, measurement approaches as well as operational considerations that we have experienced thus far in setting up a complex, large-scale project of this size.
Biographies
Tyler Niles joined Weyerhaeuser Grande Prairie in 2019 as a Silviculture Forester. Shortly after, Tyler was tasked with leading Weyerhaeuser’s Silviculture Alternatives Program aimed at diversifying the tools for competition control and early stand survival. Such tools include designing a custom ground-based sprayer for the application of Imazapyr, and the successful implementation of sheep grazing on over 800 hectares. Tyler’s focus has now shifted to increasing precision within Weyerhaeuser’s silviculture operations through the use of automated planting technologies, A.I seedling counting software, and UAV herbicide application.
Dr. Amanda Schoonmaker obtained a BSc in Forest Sciences from the University of British Columbia in 2006 and completed a PhD in Forest Biology and Management at the University of Alberta in 2013. She joined the NAIT Centre for Boreal Research in 2011 as a Reclamation Field Research Coordinator. In 2015, she was awarded a 5-year renewal federal research chair grant by the National Sciences and Engineering Research Council (NSERC). Her research program is focused on methods and practices of reclamation and reforestation of upland forest landscapes that have experienced anthropogenic disturbances.
January 27, 2023: Growth Trends in Swedish forests under Management and Climate change – Historical and Future Perspectives
Abstract
To achieve global targets on mitigation of and adaptation to climate change, information about forest growth changes is essential, especially for the forests in higher latitudes. Important questions regarding growth are to what extent management and climate change have influenced it, and how it might respond in the future. Current information about forest growth changes is also essential to determine the forest resource capacity to supply raw materials, to enhance biodiversity and to estimate the potentials for future carbon balance. Using empirical data from long-term monitoring systems such as the National Forest Inventory and permanent plots in Long-term Forest Experimental sites, this presentation highlights in one hand, the impacts of changed forestry practice and environmental conditions on forest growth changes, and at the other hand, the short- and the long-term potentials for carbon storage in forests and harvested wood products via alternative forest management strategies in Sweden.
Biography
Dr. Alex Appiah Mensah is a researcher in empirical forest modelling at the Department of Forest Resource Management, Swedish University of Agricultural Sciences (SLU). He has a Ph.D. in forestry (2022) from the same department. Alex’s research works span broadly on forest biometrics, with focus on growth trends, site productivity and inference of forest biomass within the frameworks of design-based, model-based and hybrid inference to support SLU’s environmental monitoring as well as practical forestry operations. He works mostly with data from national forest inventory, forest experiments and remote sensing.
April 28, 2023: Establishment and Early Management of Young Forests in Sweden
Abstract
In the absence of other treatments, regenerating intimate mixtures of aspen and white spruce by relying on natural regeneration of aspen and planting of spruce generally results in a very long spruce rotation. Spot treatment with herbicide or cutting treatments can improve growth of spruce while retaining a matrix of aspen and lead to creation of intimate mixtures of aspen and spruce. In this presentation I will present results to age 20 from the Judy Creek Mixedwood Experiment established in the Swan Hills near Blue Ridge, Alberta in 2002. The core of the study involved vegetation control within 2-m radius spots centered on spruce planted at 5-m spacing. The study also included broadcast complete, broadcast woody, and herbaceous control as well as untreated. At age 10, thinning of spot treated plots to 800, 1 200 and 2 000 stems/ha was added to the study.
In 2022, after 20 growing seasons, spruce survival ranged from 67 to 100% in the thinned radial treatments with spruce survival, DBH and height in the radial treatments being intermediate between untreated spruce growing under a dense aspen canopy and spruce growing without aspen in the treatment with broadcast repeated application of glyphosate herbicide. Repeated browsing by snowshoe hare, associated with reduced height of spruce, lead to severe reductions in spruce survival and size in the untreated, which had an average of 14 000 stems/hectare of aspen and 16% spruce survival at age 20. While spot treatment alone did not significantly affect aspen height or diameter at age 20, thinning of the aspen matrix at age 10 in spot treated stands resulted in increases in diameter of both aspen and spruce at age 20. Mixedwood Growth Model (MGM21) projections suggest that radial treatments result in spruce culmination ages that are intermediate between broadcast complete control (with vision herbicide) and untreated, with a lower conifer MAI due to the much lower spruce planting density in radial (400 stems/ha) than broadcast (1600 stems/ha) treatments together with reductions in growth of the spruce. The aspen matrix in the spot treatments can provide merchantable deciduous volume, with deciduous MAI in the unthinned spot treatment averaging 1.4 m3/ha/y in contrast to 4.0 m3/ha/y in the untreated control. In summary, results indicate that radial spot herbicide treatments can effectively improve early survival and growth of white spruce through control of aspen, shrubs, herbs, and grasses and that adding precommercial thinning can provide additional increases in growth of both aspen and spruce.
