Environmental change and Wisconsin seepage lake chemistry
Concentrations of dissolved organic carbon (DOC) have increased in many lakes in North America and Europe. Increased DOC or lake “brownification” is thought to be due to decreased deposition-related changes in soil pH or ionic strength (from acid rain recover), climate change, or complex interactions between these drivers. Seepage lakes, which have no stream inlets or outlets and are fed predominately by rain, are both uniquely susceptible to environmental stressors like air pollution and climate change and make great models for teasing about impacts of different environmental drivers. This project, which is a collaboration between UW-Madison (Emily Stanley), the US Forest Service (Randy Kolka and Steve Sebestyen), and the University of Winnipeg (Nora Casson), aims to document historical and current lake conditions and use experiments to determine how decreasing levels of acid rain and climate change may influence lakes in the Chequamegon-Nicolet National Forest. In our first publication, we show how increases in DOC fluxes to seepage lakes are likely increasing fluxes of nitrogen and phosphorus (Corman et al. 2018; EOS coverage). In the next, we find evidence that climate change, vis a vis changes in temperature and soil moisture, will likely change the chemical composition of the soil leachates associated with browning (Bertolet et al. 2018). |
Growing rocks: The effects of calcium carbonate deposition on phosphorus cycling in streams
Phosphorus is an essential nutrient for all life, but its scarce availability in many environments often limits plant and microbial growth. One of the processes that can influence phosphorus availability in aquatic systems is co-precipitation of phosphate with deposition of calcium carbonate (CaCO3). For my dissertation, I studied the role of CaCO3 deposition on phosphorus cycling between streams with CaCO3 deposits in the form of travertine or microbialites using natural and manipulated gradients of CaCO3 deposition rates (Corman et al. 2015, Corman et al. 2016). In both the travertine streams of the Huachuca Mountains in southern Arizona, USA, and the microbialites of Río Mesquites, Cuatro Ciénegas, México, I found that CaCO3 deposition played an important role in lowering phosphorus concentrations in stream water and, at times, leading to phosphorus limitation of microbial growth. This work was done at Arizona State University under the supervision of James Elser. You can read more about my first field season in Cuatro Ciénegas in a 2009 Zócalo Saltillo news piece and blog postings here and here. |
Coupled Natural-Human Systems: Studies of Tropical Lakes
Lakes in tropical regions provide drinking water, fisheries, and other ecosystem services, but when unsustainable resource extraction, changing land use, pollution, and/or climate change impact tropical lake ecosystems, the subsistence communities in the region are often disproportionately affected. I have been involved with several projects that combine fundamental studies of tropical lake ecology with efforts to improve lake management via capacity building, transdisciplinary partnerships, and outreach. You can read about some of my research findings from Lake Tanganyika, Tanzania (Corman et al. 2010), and from Lake Atitlán, Guatemala (Corman et al. 2015), here and about the projects here (http://www.geo.arizona.edu/nyanza/) and here (http://lagoatitlan2010.blogspot.com/). Recently, I received funding from the UW Global Health Initiative to begin a transdisciplinary project with Amber Roegner on “Water, Women, and Fisheries: Addressing Two Ecological Realities Impacting Human Health at Lake Victoria.” Watch the “News and Musings” section for more updates! |
LiWe: Limnology and Wetland Ecology of Cuatro Ciénegas In the Mexican Chihuahuan desert, surrounded by mountains, the oases of Cuatro Ciénegas provide refuge for numerous plants and animals. Nearly 70 endemic species inhabit the valley. The exceptional biodiversity is matched by the valley’s hydrologic diversity: over 500 springs supply water for numerous pools, streams, lakes, and wetlands. This region of the Chihuahuan Desert and its aquatic ecosystems are thought to be supported by both precipitation events and local and regional aquifers, however, the hydrologic influence and connectivity of the springs are not well understood. Along with Jorge Ramos, I have been monitoring the environmental characteristics of these aquatic features to characterize the physicochemical and nutrient landscape of this important region. |
Life in Extreme Environments
When is a limnologist an astrobiologist? Well, when one is studying biogeochemistry of extreme or novel (aquatic) environments. As a graduate student, I was a part of the NASA Astrobiology Institute at Arizona State University. In collaboration with other geologists and biologists, I studied nutrient limitation of microbes in hyper-oligotrophic environments (Cuatro Ciénegas, MX), hot springs (Yellowstone National Park, USA), and novel ecosystems (pumice floating in lakes in Patagonia, Argentina). Collaborators on these projects include Valeria Souza (Universidad Nacional Autonomous de México), Janet Siefert (Rice University), Amisha Poret-Peterson (USDA/University of California, Davis), Ariel Anbar, Everett Shock, and Hilairy Hartnett (Arizona State University), and Esteban Balseiro and Beatriz Modenutti (Universidad Nacional del Comahue, Argentina).
Check out some of the papers I was involved with for this work (Modenutti et al. 2016, Elser et al. 2015, Lee et al. 2014) or some of the news coverage about pumice floating in lakes.
When is a limnologist an astrobiologist? Well, when one is studying biogeochemistry of extreme or novel (aquatic) environments. As a graduate student, I was a part of the NASA Astrobiology Institute at Arizona State University. In collaboration with other geologists and biologists, I studied nutrient limitation of microbes in hyper-oligotrophic environments (Cuatro Ciénegas, MX), hot springs (Yellowstone National Park, USA), and novel ecosystems (pumice floating in lakes in Patagonia, Argentina). Collaborators on these projects include Valeria Souza (Universidad Nacional Autonomous de México), Janet Siefert (Rice University), Amisha Poret-Peterson (USDA/University of California, Davis), Ariel Anbar, Everett Shock, and Hilairy Hartnett (Arizona State University), and Esteban Balseiro and Beatriz Modenutti (Universidad Nacional del Comahue, Argentina).
Check out some of the papers I was involved with for this work (Modenutti et al. 2016, Elser et al. 2015, Lee et al. 2014) or some of the news coverage about pumice floating in lakes.
Science Policy Interactions
Ecological research has the ability to help better manage our natural resources by informing decisions and policies regarding the environment. Likewise, management and policies can influence the type of ecological studies that are performed by scientists. Since working at the National Science Foundation, I have been interested in the interaction between science and policy. While at ASU, I was involved with the Consortium for Science, Policy & Outcomes (CSPO) as both a participant (2009) and student mentor (2012) for the “Science Outside the Laboratory” summer immersion experience. |
Networked science: GLEON
The Global Lakes Ecological Observatory Network (GLEON) has done an amazing job at connecting limnologists across the world. I joined GLEON as a fellow in 2013 (check out the fellowship program here) and went on to collaborate with other fellows to determine the influence of model selection on estimates of lake metabolism (publications forth-coming). Currently, I am involved with the Lake Metabolism working group to investigate how stream nutrient fluxes influence primary production and respiration in lakes.
The Global Lakes Ecological Observatory Network (GLEON) has done an amazing job at connecting limnologists across the world. I joined GLEON as a fellow in 2013 (check out the fellowship program here) and went on to collaborate with other fellows to determine the influence of model selection on estimates of lake metabolism (publications forth-coming). Currently, I am involved with the Lake Metabolism working group to investigate how stream nutrient fluxes influence primary production and respiration in lakes.
Sustainable Phosphorus Initiative
Human activities have profoundly altered the global biogeochemical cycle of phosphorus to increase food production with detrimental environmental effects. As a graduate student, I explored possibilities for a sustainable societal approach to phosphorus, leading a transdisciplinary conference, the 2011 Sustainable Phosphorus Summit, co-authoring and co-editing an article (Childers et al. 2011) and book (Phosphorus, Food, and Our Future), serving on the United Nations Environment Programme Year Book workshop (2011; published book is available here), and initiating the Sustainable Phosphorus Initiative. |