Collaborative Proposal: MRA: Linking land-to-water transport and stream carbon cycling to inform macrosystem carbon balance

Carbon is the energy currency of ecosystems. Carbon emissions from streams and rivers are important sources of carbon to the atmosphere. Scientists rarely measure the movement of carbon from air to plants, into soils and groundwater, through streams and rivers, and back to the atmosphere. This research will develop new methods and data to measure terrestrial carbon cycling through freshwaters. This project will also train diverse students and professionals to conduct research linking terrestrial and freshwater carbon flows. Educators will complete summer research projects using environmental sensors and public datasets to enhance K-12 student understanding of research. Collaborations with industry partners will create common standards for freshwater sensor measurements. The project will also develop open-source software to improve water quality and carbon cycling research with data collected by sensors. <br/><br/>The movement of terrestrial carbon across land-water boundaries controls the carbon balance of watersheds and the metabolism of freshwater ecosystems. Streams are the primary interface between terrestrial and freshwater ecosystems. They are ideal testbeds to advance understanding of land-water carbon transfers and meta-ecosystem ecology (i.e., the study of multiple ecosystems linked by energy and material transfers). This research seeks to answer the questions: (1) What is the magnitude and variability of land-to-water carbon transfers and stream carbon emissions in watershed carbon balances? (2) What controls carbon form, cycling, and fate in meta-ecosystems? (3) How does meta-ecosystem carbon cycling in different parts of the United States vary within and among years? The factors regulating carbon metabolism and emissions are predicted to operate at different spatial and temporal scales. Environmental sensors and water chemistry sampling will capture the temporal variability in carbon cycling and losses in soils and streams at paired terrestrial-aquatic National Ecological Observatory Network (NEON) research sites across the United States. Project outcomes will advance a predictive understanding of the daily, seasonal, and annual processes controlling watershed carbon cycling through measurements and models that cross land-water boundaries and approaches that integrate biology, geology, and chemistry across space and time.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.