Comparative analysis of thinning techniques in pine forests

Abstract

Thinning is a necessary and complex forestry activity. The complexity increases due to theoretical disagreements, contradictory recommendations, and errors of modern practice, which require confirmation through long-time experiments. This article presents a summary of experimental results from plantations established 20-30 years ago and explains concepts of the theory, methods, and regime of thinning in permanent sample plots of pine stands in Gatchinsky forest of the Leningrad region. The research results allow for the clarification of growth patterns and age dynamics of pine stands subject to heavy, low thinning, as well as the results of applying the crown (high) thinning technique and a mixed treatment. A combined thinning and fertilization could improve wood quality and yield compared to conventional methods. Of particular scientific importance is the analysis of change in tree diameter classes during growth and after thinning. The research results allow for optimizing the treatment regime in pine plantations and reducing labor intensity by increasing the intensity of thinning and reducing the number of techniques.