Smithsonian Institution

Collaborative Research: Nsfdeb-nerc: Spatial and Temporal Tradeoffs in CO2 and CH4 Emissions in Tropical Wetlands -wetlands Are a Critical Habitat for Carbon Storage, as Well as a Potential Source of Greenhouse Gas (carbon Dioxide and Methane) Emissions. Little Is Known About How Wetlands Function, Especially in the Tropics. With Changing Climate, It Is Expected That Tropical Wetlands, Especially Seasonal Ones, May Shift Between Carbon Consumption and Release of Carbon. Methane, Which Is a More Powerful Greenhouse Gas Than Carbon Dioxide, Is Typically Produced Under Flooded Conditions, Although Some Evidence Suggests That Shifts Between Wet and Dry Conditions Also Lead to Its Release. Savannas (cerrado) in Brazil Have a Range of Grassland Types Including Ever-wet Peatlands, Seasonally Wet Grasslands, and Dry Grasslands That Are Never Flooded, With the Seasonal Wetlands Shifting in Water Levels Between Dry and Wet Seasons. It Is Expected That These Ecosystems Will Become Hotter and Drier in the Future. Brazilian Savannas Have Been Understudied and Under Protected; They Are Also at Risk of Conversion for Example to Agribusiness and Urban Development. They Are the Source of the Headwaters for River Systems Such as the Amazon, Meaning They Are Important for Providing Clean Water and Other Resources to the People and Other Organisms Dependent on Them. Understanding Brazilian Savanna Carbon Dynamics Now and Under Future Environmental Conditions Is Critical for the Region. They Can Also Be Used as Models to Understand Tropical Savannas Around the Globe. This Proposal Makes Use of the Natural Gradient, From Ever-wet Peatlands to Dry Grasslands, and Seasonal Shifts Through Time to Collect Data on the Amount and Frequency of Greenhouse Gases Emitted Today and the Changing Extents of Wetlands Seasonally. Researchers Will Use These Data to Predict How Savannas May Store and Release Carbon Under Future Warming and Drying Climates. as Part of This Project, Student Biologists Will Be Trained, Including in Classes on Savanna Field Ecology and Workshops on Using Field Data to Predict Changes in Greenhouse Gas Release in the Future. Biologists and Indigenous Artists Will Also Collaborate on Artwork to Demonstrate the Importance of Savanna Systems for and to Public Audiences. This Proposal Will Answer Three Questions: Q1. What Are the Drivers of Spatial and Temporal Heterogeneity in Carbon Storage and Flux Across Saturation Gradients? Q2. How Do Saturation Extents (areas and Perimeters) in Tropical Grasslands Change Over Seasonal and Decadal Scales? Q3. How Will Rates and Forms of Carbon Emissions From Tropical Grasslands Change Under Future Climates? to Test Q1, Spatially Distributed Measurements Will Be Coupled With High-temporal Resolution Measurements to Understand Greenhouse Gas, Soil, and Vegetation Carbon Dynamics Across the Saturation Gradient. Greenhouse Gas Variability Will Be Measured Spatially and Temporally With Chambers. Site Changes Through Time Will Be Determined by Initial Soil Characterization, Combined With Seasonal Measurements of Plant Phenology, Stomatal Conductance, Porewater Chemistry, Environmental and Groundwater Measures. to Test Q2, High Resolution Remote Sensing and Field Reference Data Will Be Combined to Map Wetland Extent Seasonally. Carbon and Lead Isotope Dating Will Be Used to Understand Wetlands Extent Changes at Decadal Scales. to Test Q3, Data From Q1 and Q2 Will Be Utilized in Earth System Models. Estimates of Carbon Sequestration Patterns and Greenhouse Gas Emissions Will Be Spatially Simulated With Projections of Carbon Balance Changes and Greenhouse Gas With Expected Shifts in Regional Climate and Hydrology. 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.- Subawards Are Not Planned for This Award.