North Temperate Lakes

An important aspect of aquatic invasive species (AIS) management is the role humans play in their dispersal. For the spread of AIS among inland lakes, the typical pathway for dispersal is boaters moving from lake to lake. We aim to develop a spatial dynamic model of species invasions within a freshwater lake system in which a set of managing agents is concerned with the inter-seasonal spread of invasive species across lakes (where a season is defined in this case as the annual boating season), and recreational boaters/anglers make a series of intra-seasonal trip decisions to maximize random utility during the course of the season, subject to the actions taken by the manager.

The overarching theme of this research is to determine how lake variables (e.g. ice cover, thermal structure, water level) have changed during the past century, and how they may continue to change under a changing climate. Currently, I am focusing on one dimensional and three dimensional hydrodynamic modeling of the NTL-LTER study lakes. Development of hydrodynamic models allows for understanding of lake dynamics that cannot be captured by field measurements, and also provides the ability to predict how changes in external ...

Part of this research is about long-term heterotrophic bacterial community patterns in Lake Mendota, Wisconsin. Heterotrophic bacteria are responsible for nutrient cycling in aquatic systems. These preliminary abundance data indicate seasonal patterns in bacterial taxa (OTU’s). We will perform time-series analysis with these data together with environmental variables (water chemistry and meteorological factors) in order to investigate drivers of the bacterial community ...

Emerging research shows that hot spots for biological processing of elements such as nitrogen and phosphorus can be important in water bodies. We are exploring the importance of potential hot spots as well as cold spots for biological processing of these nutrients. The north temperate lakes (NTL) LTER has immediate access to diverse water bodies, including not only lakes but also abundant streams, rivers, and wetlands of various sizes and shapes. We are studying these habitats to answer questions related to ecosystem structure, functioning, hydrology, and biogeochemistry, with an emphasis on habitats ...

How do lake levels affect invaded ecosystems in northern Wisconsin? Lake levels in northern Wisconsin are currently at historic lows, and climate models predict this trend to continue.  Lowered lake levels affect littoral habitats and associated communities; however specific effects on native and invasive species are poorly understood ...

My research is generally concerned with understanding the impacts of changing environmental conditions on natural and managed vegetation ecosystems. To perform my research I use a dynamic global vegetation model which simulates ecosystem processes such as carbon, water and energy cycling at both large and small spatial scales. Future work as a PhD student will investigate the impact of land management as well as changing climate on landscapes within the Yahara Watershed. Other general interests include the relationship between climate and vegetation and the role of computer modeling within environmental science.

We’re researching algae dynamics in Lake Mendota in attempt to explain and predict harmful algal blooms and scums that form in eutrophic lakes. The current emphasis is on characterizing and understanding how spatial differences in algal growth and aggregation are affected by physical processes and movement of water masses in the lake. The research leverages automated sensing techniques to measure phytoplankton at high-res both in time and through space.

This research investigates the sensitivity of phytoplankton communities to historical droughts and terrestrial disturbances in northern Wisconsin. Questions that motivate me include: To what extent have disturbances, namely clear-cut logging and forest fire, interacted with droughts over time to influence phytoplankton communities in northern Wisconsin lakes? Did phytoplankton dynamics depend upon site-specific characteristics of the lake, namely the lake's landscape position?  To answer these questions, I have collected sediment cores from six lakes situated along a gradient of landscape position...