Fellow Bios
Allyson Smith
Thesis Title: Nutrient Cycling in Midwestern Agricultural Wetlands in Response to Altered Hydrologic Regimes
Graduate Dept: Earth Science
Degree Sought: MS
Research Advisor: Pierre Andre Jacinthe
Lab Website: Click Here
Teacher Partner: Brooke Furge, DSE Education Specialist
Partner School: NA
School URL: Click Here
Research Goal
To gain a better understanding of how to manage agricultural wetlands for improved nitrogen and phosphorus retention.
Description of Your Research
The export of nutrients (N and P in particular) from intensively managed agricultural areas of the US Midwest has resulted in the eutrophication of surface waters and a host of related ecological problems. Past studies have shown that constructed wetlands are efficient N and P sinks and thus could provide a means of reducing these nutrient exports. With the understanding that the nutrient retention capacity of treatment wetlands depends on soil conditions, antecedent land-use and hydrologic regimes, results of these past studies may not be directly applicable to the Midwest where regional climate is projected to becoming more variable (frequent wet-dry cycles) and wetlands are established on nutrient-enriched soils resulting from several decades of mineral fertilizer application. My study is a mesocosm study, involving using intact soil cores (L: 30 cm; diam: 10 cm) in order to gain an understanding of the response of Midwestern wetlands to changing hydrologic conditions. Cores were taken from two operating wetlands and a poorly-drained cropland soon to be converted into a treatment wetland. Several hydrologic conditions (dry, moist, and wet) were imposed in the laboratory for four weeks (3 cores per site) followed by flooding of all cores. The fluxes of organic (DOC, DON, DOP) and mineral nutrients (NO3-, NH4+, PO4-3) were measured periodically for 4 weeks. Results will be evaluated in conjunction with P distribution in the wetland soils (Fe, Al, and Ca-bound) and with temporal variation in N gas emission, phosphatase activity, redox status and dissolved Fe in the flooded cores.
Examples Of How My Research Is Integrated Into My GK-12 Experience
Soil FBI (fungi, bacteria and invertebrates) drive many of the reactions in the N and P cycles. One way scientists measure microbe activity is to examine CO2 production over time. Using quantification and observation skills, students explore soil biological activity; learn about different types of microbes and their function, and explore why microbes are important for ecosystem regulation. Using Vernier LabQuest scientific handhelds and O2 and CO2 sensors, students calculate changes in microbial respiration over time. By measuring soil temperature, moisture, pH, soil texture and infiltration rates, students will be able to investigate other soil properties that have an impact on microbial activity. Collected data is then used to draw conclusions about the productivity of the soil at their school site.
Currently, My GK-12 Classroom Is Investigating
This fall, the DSE program will be visiting many nearby public schools providing a plethora of outdoor science programs including plant biodiversity and photosynthesis, ecosystem investigations, soil studies, and water quality studies.
Links of Interest