Land Use and Climatic Controls of Soil Organic Carbon in Diverse Ecoregions of Costa Rica.

The soils of the Tropics hold great importance to the global carbon (C) cycle. However, land use change in Latin America has the potential to destabilize large vulnerable C pools which would release carbon dioxide (CO₂) to the atmosphere and consequently would compel our society to select higher targets of CO₂ emission reductions. Research on the current and potential C pools in these soils is needed in order to inform policy makers on the environmental service that diverse soil management options can provide to climate change mitigation and food security.
This research intended to characterize the soil organic carbon (SOC) pool up to 100 cm depth in representative land uses of the Tropics. Oil palm (PA), pineapple (Pi), banana (BA) and rain forest (RF) were studied in the Atlantic Moist ecoregion of Costa Rica. Sugar cane (CA), pasture (Pas), mango (MA) and dry forest (SR) were selected  in the Pacific Dry ecoregion. At each land use, four soil pits were excavated. Soil samples were collected at 0 – 10, 10 – 20, 20 – 30, 30 – 40, 40 – 50, 50 – 70 and 70 – 100 cm depth. Total organic carbon, bulk density and particle size distribution were determined for the complete soil profile (0 – 100 cm).  Data on C concentration and bulk density were used to calculate the total C pool in Mg ha^-1.