Soil CO2 evolution in Florida slash pine plantations. I. Changes through time

Abstract

Soil CO2 evolution rates were measured in slash pine (Pinuselliottii) plantations of three ages in north Florida. At the mature (29-year-old) plantation, which had a closed canopy and a well-developed forest floor of litter and humus overlying the mineral soil, C storage in detritus in the mineral soil was relatively low and soil C release was relatively high (13.0 t•ha−1•year−1). C release was highest (22.7 t•ha−1•year−1) at the clear-cut site, presumably because of high temperatures and rapid decomposition of detritus added during the harvest, and lowest (8.2 t•ha−1•year−1) at the 9-year-old plantation. For a range of forest sites, soil CO2 evolution rates and the magnitude and direction of changes after harvesting show latitudinal variation that probably depends not only on the amount of C contained in dead organic matter in the soil and its decomposition rate but also on the treatment of slash left after harvesting.