| Abstrakt: |
Lake ecosystems are increasingly threatened by harmful algal blooms (HABs), which are driven by global warming and rising nutrient inputs. Hydrological and morphometrical characteristics can affect a lake's sensitivity to the risk of HABs, with factors such as low mean depth and long water residence time favoring their occurrence. However, the impact of these characteristics on bloom occurrence at large scales has not been thoroughly investigated. Here, we examined the influence of climate, land use, and lake hydro-morphometry on the occurrence of algal blooms in global and regional lakes using a remote-sensing-retrieved global bloom database. Our results indicate significant differences in climate and hydro-morphometric variables between bloom-affected and non-bloom lakes. Logistic regression analyses reveal that climate variables such as precipitation, summer air temperature, summer light, and summer wind speed exhibit significant but regional-specific influence on algal bloom occurrence. While the lake surface area and mean discharge show consistent positive influence across most regions, the influence of elevation, mean depth, shoreline development, and water residence time vary regionally. Random forest analyses further highlight the strong relative importance of hydro-morphometric variables in influencing bloom occurrence. These findings highlight the importance of considering regional climate and lake hydro-morphometrical variables when assessing a lake's sensitivity to eutrophication and HAB risk. [ABSTRACT FROM AUTHOR] |
