The effects of pre-commercial thinning on the abundance of herbaceous species in naturally regenerated forests in New Brunswick, Canada
University of New Brunswick
Pre-commercial thinning (PCT) is an important management tool for producing high quality wood products and is widely applied across the Maritime Provinces, thus, it is important to understand the impacts of this treatment on other ecosystem components. The objectives of this project were: 1) to identify differences in stand structure and microsite environmental features between PCT and unthinned stands and to document these changes over time; 2) to determine the initial impact of PCT on herbaceous species and the long-term influence on species composition; and 3) to identify patterns of plant life history traits between treatments over time. In some cases there were very little data to analyse for uncommon species or those species which inherently had low percent cover values. As a result, the species addressed in this study are generally the most abundant species on the landscape: Despite the changes in the environment related to PCT, patterns of species composition and species guilds were related to increasing stand age rather than treatment. We conclude that the effects of PCT on individual species and species guilds do not exceed the range of natural variability encountered among these forest stands in New Brunswick. Key Words: herbaceous layer, diversity, precommercial thinning, stand structure, microsite, life-form, natural regeneration.