Trends in genetic diversity of silver birch: Insights from varied planting scenarios

Abstract

This study explores the impact of planting strategies on genetic diversity in silver birch (Betula pendula Roth) stands using simulation models. We examine the influence of different proportions of planted stands and the number of open-pollinated families on genetic diversity, focusing on the Shannon-Weiner Diversity Index and expected heterozygosity. Results indicate optimal genetic diversity increases with 50–55% planted stands. Additionally, using more families in planting enhances diversity, peaking when 30 families are used compared to five. Simulations suggest that combining natural regeneration with planting seed lots from at least 20 families enhances genetic diversity at the landscape level, supporting sustainable forest management. However, using only the top-performing five families does not harm genetic diversity if planted stands remain below 55%. Acknowledging the limitation, this study considers only a single generation, which may affect long-term applicability of the results over multiple generations.

Keywords: expected heterozygosity; Shannon-Weiner Diversity Index