Soil CO₂ evolution in Florida slash pine plantations. II. Importance of root respiration

Abstract

Respiration of live roots was the single largest contributor to soil CO 2 evolution in two mature slash pine (Pinuselliottii) plantations. Root respiration accounted for 51% of soil CO 2 evolution at the 9-year-old plantation and 62% at the 29-year-old plantation. Additional estimates, calculated from data recorded from two small trenched plot sites at the 29-year-old plantation and based on possible variations in initial root biomass and subsequent decomposition rates, also averaged 62% of soil CO 2 evolution. Specific root respiration averaged 0.40 g•g −1 •year −1 , varying from 0.34 to 1.70 g•g −1 •year −1 . Plots with larger proportions of fine roots had faster soil CO 2 evolution rates.