Fifty-Year Trends Reveal Reversal from Recovery to Re-eutrophication and Reinforced Anoxia in a Managed Mountain Lake.

ABSTRACT: Anoxia in lakes has intensified in recent decades, threatening ecosystem functioning. Yet, the mechanisms driving long-term trends in anoxia intensity and duration are complex, especially in managed ecosystems, where field data are limited. Using a 50-year dataset from a lake affected by both eutrophication and restoration measures, we examined annual oxygen dynamics, assessing the effect of external drivers, such as climate warming and hypolimnetic withdrawal effectiveness, and of in-lake processes influencing anoxia. Breakpoint analysis revealed a major ecosystem regime shift around 1996, reversing the earlier recovery trend. Between 1972 and 1996, both the anoxic factor and hypolimnetic total phosphorus concentrations declined, but both rose significantly afterward, with phosphorus conc

SUBMITTER: Weniger E 

PROVIDER: S-EPMC12397146 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature