| 英文摘要: | Salt marshes have the potential to store large amounts of carbon, because they are highly productive ecosystems but have low organic matter decomposition rates. Unfortunately, these ecosystems are threatened by disturbances such as sea-level rise, land-use change, nutrient runoff, and ocean acidification. Changes in the spatial and temporal dynamics of processes regulating carbon fluxes could ultimately dictate the role of these ecosystems as net sources or sinks of carbon. The project will provide new insights regarding the biological and physical processes that regulate carbon fluxes in tidal salt marshes. The project also has a significant educational component that will integrate minority Science, Technology, Engineering, and Math undergraduate and graduate students into research, educational, and outreach activities. Specifically, the project will empower underrepresented students by providing research and networking opportunities, and to enhance social capital by strengthening the network of students, science professionals, and researchers. An outdoor laboratory will be maintained at a tidal salt marsh at the St Jones Reserve in Delaware, and the carbon cycle in salt marshes will be used as the engaging phenomenon to provide real-world learning, so students can explore, examine, and use science ideas to explain the ecosystem functions of salt marshes.
This project will integrate multiple sensors and techniques to better understand the processes and timescales that control carbon fluxes in salt marshes. By combining a variety of measurements such as micrometeorological techniques, near-remote sensing of canopy phenology with discrete sampling techniques of sediment and water carbon dynamics, this project tackles three interrelated research objectives. The goal is to investigate ecological processes underlying vertical and lateral carbon fluxes in salt marshes: a) assess the influence of plant phenology on ecosystem scale CO2 and CH4 fluxes, b) elucidate the role of sediment CO2 and CH4 on ecosystem fluxes, and c) determine the influence of tides (i.e., neap vs. spring tides) on vertical and lateral carbon fluxes. The project will provide educational opportunities for 8th grade students and will be aligned with the Next Generation Science Standards (NGSS). Finally, the outcomes of this project will provide a baseline for interaction with science professionals and policy makers through outreach activities in collaboration with ongoing state and national initiatives. |