Macrophyte succession in Swedish lakes caused by deposition of airborne acid substances

Biological investigations in six lakes in two areas of western Sweden have shown that the supply of acid substances induces long-term biological perturbations at all trophic levels in the lake ecosystem. Sphagnum expansion is believed to have a strong effect on the dynamics of a lake, and the author attempts to quantify Sphagnum expansion at different depth zones of a lake. The consequences of dense Sphagnum mats covering large bottom areas of the lake are discussed. (PJR)