A recent study, part of the ECOLOOP project and led by the Estonian University of Life Sciences, explored the growth and leaf gas exchange characteristics of 22 hybrid aspen genotypes (Populus tremula L. × P. tremuloides Michx.) to identify the best-performing trees for biomass production. With afforestation becoming a key strategy for climate mitigation in Europe, understanding the growth potential of different genotypes is essential.
Key Findings
- Northward Transfer Success: Genotypes transferred to northern climates showed twice the growth compared to those transferred southward, with larger diameters at breast height.
- Gas Exchange Differences: Southern-transferred genotypes had higher stomatal conductance and net photosynthesis but lower water-use efficiency (iWUE), though this didn’t translate to better growth.
- Drought Resilience: Smaller, shaded southern genotypes were more resilient to drought, showing higher physiological activity during dry conditions.
The study concludes that final selection for commercial planting should occur 10–15 years after planting, combining physiological traits with traditional growth measures for optimal, climate-adapted selections.
Read the full open-access scientific paper here.