Regulation impact on submerged macrophyte communities in some Norwegian lakes

Abstract

The results from a study of submerged macrophyte communities in regulated Norwegian lakes are summarized. Impact assessment is equivalenced to analysis of the vertical niche displacement, due to a fluctating water level. Vertical niche size is shown to be limited by unfavourable physical environmental factors. Lower niche limits might be controlled by low-light induced mortality, whereas upper niche limits related to the extent of ice-scour. Statistical models of the environmental impact due to water-level fluctations, and of the apparent underwater light fields, are discussed.