An Overview of The Efficacy of Vegetation Management Alternatives for Conifer Regeneration in Boreal Forests

Abstract

In this paper, we discuss the broad array of treatments that could be used to control competitive vegetation in conifer plantations in the boreal forests of Canada. We present vegetation management alternatives screened based on their treatment efficacy, which we defined as their ability to (a) control competitive vegetation and (b) not cause undue damage to conifer seedlings. The treatments reviewed range from pre-harvest (preventative) to post-plant release (reactive) treatments, and are organized into five categories: (i) silvicultural and harvest systems, (ii) physical treatments such as mechanical site preparation, cutting, girdling and mulching; (iii) thermal treatments such as prescribed fire and steaming; (iv) cultural treatments such as seedling culture, cover cropping, and grazing; and (v) chemical and biological spray treatments. We based our assessment of treatment efficacy on previous reviews, expert opinion, and published literature. We conclude on the need to further assess the effectiveness of forest vegetation management strategies in the context of multi-purpose plantations that consider ecological, social and silvicultural objectives.Key words: plantation, vegetation management, competition, silviculture RÉSUMÉCet article aborde le large spectre des traitements sylvicoles utilisés pour maîtriser la végétation de compétition dans les plantations de conifères établies en forêt boréale au Canada. Nous présentons les diverses options sous l'aspect de leur efficacité, définie comme étant leur capacité (a) à maîtriser la végétation de compétition (b) sans causer de dommages aux conifères plantés. Les traitements considérés s' étendent des opérations pré-récolte (approches préventives) aux dégagements qui suivent la mise en terre des plants (approches réactives). Ils sont organisés en cinq catégories : (i) les systèmes sylvicoles et de récolte; (ii) les traitements physiques tels la préparation mécanique du terrain, la coupe, l'annelage et le broyage; (iii) les traitements thermiques tels le brûlage dirigé et le passage à la vapeur; (iv) les traitements culturaux tels la production des plants, l'utilisation de plantes de couverture et le broutement; et (v) la pulvérisation de produits chimiques ou biologiques. Nous avons basé notre évaluation de l' efficacité des traitements sur des revues de littérature déjà publiées, des opinions d' experts et la littérature scientifique récente. Nous concluons sur le besoin d'acquérir des connaissances concernant les stratégies de gestion de la végétation de compétition adaptées aux plantations multi-usages, dans lesquelles des objectifs écologiques et sociaux s'ajoutent à ceux de production de matière ligneuse.

Benefit–cost Analysis of Vegetation Management Alternatives: An Ontario Case Study

“…These are: preventive silviculture and natural regeneration, mechanical site preparation, early planting of size-adapted stock, and use of mechanical release where and when needed (Thiffault and Roy 2010). The common alternative to herbicides is cutting either by motor-manual or mechanical means (Wiensczyk et al 2011). We found that applying a cutting treatment once, although not as profitable as aerial application of herbicides, is economically viable.…”

“…Although herbicides are cost-effective, their use in forest management continues to be contentious affecting operations in the forestry sector (Wyatt et al 2011, this issue). At the same time, the need for forest vegetation management to favour certain species and increase the productivity of Crown forests is also recognized (see Wiensczyk et al 2011).…”

Patterns of Early Postfire Succession of Alpine, Subalpine and Lichen-Woodland Vegetation: 21 Years of Monitoring from Permanent Plots

“…Alternatively, with greater fire severity most of the organic matter is consumed and mineral soil is heated, causing local extinction or minimal regeneration [43,44]. On recently disturbed soils, rhizomes of ericaceous shrubs are stimulated by light and high soil temperatures [45], favouring extensive recovery following fire if the ericaceous species were abundant before the fire. Among ericaceous shrubs, rhizomes of Vaccinium angustifolium L. are the most resistant to heat [46].…”

Modelling Landscape-level Effects of Reduced Herbicide Use in Two Forests in Northern Ontario

“…However, landscape-level implications and the indirect effects of herbicide reduction on forest management objectives related to wildlife habitat supply, quantity of old growth, wood supply, and forest management infrastructure (such as road networks) are less well known. While vegetation management alternatives may result in similar composition (Dampier et al 2006), growth rates (Bell et al 2011a), and wildlife habitat at the stand level (Lautenschlager et al 1997, Fortier et al 2005, Swift and Bell 2011, even subtle differences could equate to significant landscape-level changes when applied to millions of hectares over long periods.…”

“…While minimizing competition and providing crop trees with increased access to site resources (Balandier et al 2006, Wiensczyk et al 2011, it is also the primary tool for achieving management objectives related to forest composition and structure. In much of Canada's boreal forest, herbicide, motor-manual, and mechanical treatments are the most commonly used vegetation management options (Thompson and Pitt 2003, Fortier and Messier 2006, CCFM 2008.…”