ISSN: 2168-9776
Brian Oswald*, Jason Grogan, William Wedge, Kenneth Farrish, Frantisek Majs
Understanding ecosystem carbon dynamics is of increasing importance with atmospheric carbon dioxide (CO2) concentrations on the rise. Land management strategies such as land use conversion, effect ecosystem carbon cycling dynamics and can alter the quantity of carbon sequestered in vegetation and soils. In East Texas and much of the southern United States, there has been a trend of converting marginal pastureland into loblolly pine (Pinus taeda) plantations. This afforestation, like other land use conversions, leads to a redistribution of carbon in vegetation and soil carbon sinks. Three marginal pastures in East Texas were afforested with loblolly pine and monitored to quantify the organic carbon sequestered as a result of this land use change. Fifteen years after plant, soils were sampled to assess the change in soil organic carbon in the top 40 cm of soil, as well as the accumulated 0 horizons. Two years later tap root systems and coarse roots on each of the three sites were excavated to quantify belowground biomass. All sites experienced increases in carbon sequestered belowground in coarse roots, tap roots, and O horizons. Only one site had a statistically significant increase in soil organic carbon (SO). Afforestation of these former pasturelands appears to result in significant increases in sequestered soil carbon.