Development and Carbon Fluxes of Tropical Peat Domes

Tuesday, 16 December 2014: 2:55 PM
Alex Cobb1, Alison Hoyt1, Laure Gandois2, Nur Salihah Su'ut3, Kamariah Abu Salim4, Joffre Ali Ahmad5, Jamilah Jalil5, Mahmud Yussof3 and Charles Harvey6, (1)Singapore-MIT Alliance for Research and Technology (SMART), Singapore, Singapore, (2)CNRS, EcoLab, Castanet Tolosan, France, (3)Brunei Heart of Borneo Centre, Bandar Seri Begawan, Brunei, (4)Universiti Brunei Darussalam, Bandar Seri Begawan, Brunei, (5)Brunei Forestry Department, Bandar Seri Begawan, Brunei, (6)Massachusetts Institute of Technology, Cambridge, MA, United States
Tropical peatlands hold large carbon stocks and their degradation has led to large fluxes of carbon dioxide to the atmosphere, from peat decomposition and fires. Existing lumped and steady-state peatland models do not address the development and dynamics of tropical peatlands on the spatial scale of peat domes and time scales of their hydrological response. Our distributed model for tropical peat dynamics, parameterized by measurements in Brunei Darussalam, show that tropical peat domes approach a solution to Poisson's equation as they grow. They approach this stable topography centripetally from the boundaries, so that rates of carbon upake are proportional to the area of the growing interior. Exponentially greater drainage at higher water table leads to strong dependence of peat accumulation or loss on variability of rainfall. Our findings imply a fundamental link between statistics of climate, hydrological properties of peat, metrics of peat landscape topography, and dynamics of carbon sequestration and release.