- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences
- National Research Institute for Agriculture, Food and Environment (INRAE)
Liziniewicz, Mateusz; Barbeito, Ignacio; Zvirgzdins, Andis; Stener, Lars-Goran; Niemisto, Pentti; Fahlvik, Nils; Johansson, Ulf; Karlsson, Bo; Nilsson, Urban
Investing in planting genetically unproved silver birch (Betula pendula Roth) in Swedish plantations requires understanding how birch stands will develop over their entire rotation. Previous studies have indicated relatively low production of birch compared to Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.). This could result from using unrepresentative basic data, collected from unimproved, naturally-regenerated birch (Betula spp.) growing on inventory plots often located in coniferous stands. The objective of this study was to develop a basal area development function of improved silver birch and evaluate production over a full rotation period. We used data from 52 experiments including planted silver birch of different genetic breeding levels in southern and central Sweden. The experimental plots were established on fertile forest sites and on former agricultural lands, and were managed with different numbers of thinnings and basal area removal regimes. The model best describing total stand basal area development was a dynamic equation derived from the Korf base model. The analysis of the realized gain trial for birch showed a good stability of the early calculated relative differences in basal area between tested genotypes over time. Thus, the relative difference in basal area might be with cautious used as representation of the realized genetic gain. On average forest sites in southern Sweden, improved and planted silver birch could produce between 6-10.5 m(3) ha(-1) year(-1), while on fertile agriculture land the average productivity might be higher, especially with material coming from the improvement program. The performed analysis provided a first step toward predicting the effects of genetic improvement on total volume production and profitability of silver birch. However, more experiments arc needed to set up the relative differences between different improved material.
Betula pendula; generalized algebraic difference approach; genetic gain; planting; stand basal area starting function
2022, Volume: 56, number: 1, article number: 10512
Publisher: FINNISH SOC FOREST SCIENCE-NATURAL RESOURCES INST FINLAND