Authors: Lõhmus, Asko;

Forest and wetland landscapes have been long transformed into semi-natural ecosystems for economic purposes such as timber production. Hydrological reconstruction into dense linear ditch networks has been a fundamental intervention behind such transformations, but its long-term perspectives for biodiversity conservation and landscape functioning are poorly understood. I introduce a basic framework and an ongoing research project in Estonia, which are focused on the key elements for such perspectives: positive vs negative feedback mechanisms of the drainage, irreversible ecological changes vs resilience in the terrestrial realm, socio-economic lock-ins, and their indicators. One can identify major disciplinary gaps of knowledge between freshwater and terrestrial ecology that have inhibited landscape perspectives to hydrological transformations. Our main field design to address some of those gaps comprises 23 forested catchments (up to 10 km2 in size) that represent different combinations along artificial drainage and logging intensity gradients. This is complemented with specific systems addressing reversibility (ecological restoration) and alternative stable states (long-term trends). The ultimate challenge is to link ecological and hydrological spatial models with land-use scenario analyses.