CAREER: Past, Present, and Future of the Peatlands of the Caribbean: Implications for the Carbon Cycle in a Changing Climate

Board Of Regents, Nshe, Obo University Of Nevada, Reno, Reno NV

Investigators

Abstract

Tropical ecosystems are subject to some of the highest rates of land-use change and degradation globally. These ecosystems are also being affected by climate variability and warming. Changes in land-use have the potential for important feedbacks on our climate, especially via the carbon cycle. However, the magnitude of these feedbacks on ecosystems are uncertain. This is particularly the case for soil carbon in the tropics. Field measurements of the extent and location of carbon stored in tropical soils, and the processes that control net carbon balance remain sparse. This study specifically looks at tropical peatlands, a very carbon-rich type of habitat. Current maps are believed to significantly underestimate tropical wetland (and peatland) areas resulting in unreliable carbon stock estimates. Likewise, the origin, timing, and developmental history of peatland complexes across the tropics are poorly known, making it challenging to identify and quantify the main controls on peat formation. These data and knowledge gaps make it difficult to predict peatland evolution and their associated carbon content under present and future conditions. As such, ecologists don’t quite understand where or why peat forms under tropical conditions, and what controls accumulation rates. This project is the first to aim at gaining an integrated understanding of the origin and development of Caribbean peatlands, and will use extensive field surveys, detailed peat-core data and synthesis, as well as process-based computer modeling. This CAREER project will contribute to the US world-leading expertise in Earth System Science, advance the peatland community’s research needs, and guide policy and land management decisions. This research project combines new field work with paleoecological and modeling studies as well as extensive student training on the terrestrial carbon balance of Caribbean peatlands. The PI and her team will be integrating 1) new data collection from multiple sites along the Caribbean coast of Nicaragua and Costa Rica, 2) a synthesis of existing data from other Caribbean peatlands, and 3) processed-based ecological simulations. The overarching question this project addresses is: what are the conditions that enable peatland initiation, facilitate peat development, and control peatland C balance over decadal to millennial timescales? The existence of peat deposits across the study region will be mapped and confirmed using extensive field surveys. How and when Caribbean peatlands became established will be determined by using detailed peat-core data and synthesis of published records. C stocks will be estimated, and the relationships between the rate of peat formation and paleoenvironmental change will be examined. Using process-based peatland models, C sequestration rates will be simulated and quantified to elucidate the current function of Carribean peatlands, and forecast how they might respond to natural and anthropogenic forcings in the future. Overall, this project will produce the first comprehensive assessment of the location, extent, genesis, and development of Caribbean peatlands. This work is necessary to assess the past, present, and future resilience of tropical ecosystems and to help inform land management decisions; it will also allow ecologists to benchmark Earth System Models and test hypotheses about the role of tropical peatlands in the Holocene global C cycle. 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.