SG: The ecosystem ecology of lake ice loss in north-temperate lakes

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

The field of limnology is the study of inland waters. Historically, limnologists have dedicated their efforts to studying lakes in the summer, while overlooking winter. Winter field work is challenging. Most lakes in the United States, however, freeze over for at least part of the winter. A bias for summer research has left gaps in knowledge on lake chemistry and biology under ice. More pressingly, with anticipated changes in environmental conditions, there is a need for information on how lakes and reservoirs function in the winter for a more complete understanding of lakes. This knowledge is also critical to future management of freshwater resources in a future with shorter winters and less lake ice. The project advances the growing field of winter limnology by using long-term data collected on northern lakes in Wisconsin in conjunction with a snow-removal experiment to look at under-ice algae and the implications for ice-loss on spring algae blooms. This research will also provide hands-on research experience for students, including K-12, undergraduates, and graduate students. This project will advance the understanding of under-ice ecology by leveraging the rich winter limnology datasets of the North Temperate Lakes Long Term Ecological Research (NTL-LTER) site, high-frequency sensors, and the resources of a year-round limnological field station. To address the overarching question of how lake ice loss will impact lake productivity, this project focuses on three questions: is there a seasonal succession of planktonic events under lake ice; what are the major drivers of winter productivity; and how do seasons with less ice, or early-ice off, alter spring phytoplankton blooms? These three questions will be addressed through a combination of long-term data analysis, comparative and experimental studies, and modeling. The seven study lakes are in Northern Wisconsin and have been routinely monitored since 1981. Additionally, a bog lake will be the site of a snow manipulation experiment. This project will produce multiple outcomes, including insight into under-ice community dynamics and productivity, the dynamic nature of chlorophyll and oxygen production under ice, and the role of light availability in under-ice productivity. All of these analyses will further our ability to predict how a future with less lake ice will alter lake ecosystem dynamics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.