A large share of forests in Nordic and Baltic regions have been artificially drained to increase productivity. However, as climate change is predicted to lead to more frequent and prolonged droughts, these drainage systems may exacerbate negative impacts. This project aims to investigate how seasonal water availability affects tree growth, water quality, and biodiversity in drained hemiboreal forests, and whether simple, low-cost adaptive drainage solutions (e.g. overflow dams, adjustable culvert gates) can help mitigate these impacts. While adaptive drainage has shown promise in agricultural drainage systems, its potential in forest ecosystems remains largely unexplored. By extending the water retention in the drainage systems, these solutions have the potential to reduce drought stress, support tree growth, improve water quality, and enhance biodiversity.
The research combines hydrological modelling with field experiments in Estonia and Latvia, assessing the effects of adaptive drainage on water retention, nutrient and sediment dynamics, tree physiology, aquatic primary production, the abundance of aquatic invertebrates and amphibians, and the biomass of emergent aquatic insects. This holistic, ecosystem-level approach will help to fill key knowledge gaps in forest water management, offering evidence-based recommendations for forest managers, policymakers, and conservation agencies to implement climate-smart forestry practices across the Nordic and Baltic region.
