Many Swedish lakes have become greener and browner over the past century, largely due to human activities such as land use change and modern forestry. These changes are likely to have major consequences for lake ecosystems, yet many questions remain unanswered. To help close this knowledge gap, Magnus Huss (SLU, Uppsala) and Karin Nilsson (SLU, Umeå) are investigating how forest fertilizers and dissolved organic matter (DOM) leaking from soils affect plankton communities in Swedish lakes.
To explore this, they carried out controlled mesocosm experiments in two SITES lakes: Stortjärn (Svartberget Research Station) and Erken (Erken Laboratory) during June-July 2025. These lakes are equipped with advanced mesocosm facilities for studying aquatic ecosystems under realistic field conditions as part of the SITES AquaNet Thematic Program. By manipulating plankton communities and nutrients supply, the researchers examine how phytoplankton and zooplankton respond—and whether lake type, brown or clear, makes a difference.
The hope is that the results will provide valuable insights into the links between forest management and aquatic environments, helping to strengthen Sweden’s broader efforts in sustainable forestry and water management.
From top left to bottom right: project managers Magnus Huss and Karin Nilsson; SITES technician Johannes Tiwari with project assistant Tino Neumann; the mesocosm facility at Stortjärn; and project assistant Alfred Flood Hases with SITES technician William Colom Montero together with Karin at the lake Erken facility (photo: Magnus Huss and Karin Nilsson).