The Biogeochemistry Lab at the Smithsonian Environmental Research Center (SERC) is conducting their annual census of the Global Change Research Wetland, a marsh that SERC scientists have been studying for nearly 30 years to track the impacts of high carbon dioxide and nutrient levels on plant growth. We are looking for volunteer citizen scientists on weekdays from July 20 to July 30 from 8AM to 4PM. Volunteers are need for a minimum of one half-day, however it is best to have people come for a whole day, ideally for multiple days in a row. The work involves working in the tidal marsh (on boardwalks) at SERC to count and measure all of the plants in the experimental plots and working in the lab to sort samples and conduct analyses. Volunteers must be at least 16 years old to participate.