Soil Carbon Cycling and Soil CO2Efflux in a Red Pine (Pinus densiflora) Stand

Abstract

This study was conducted to evaluate forest carbon cycling and soil <TEX>$CO_2$</TEX> efflux rates in a 42-year-old pine (Pinus densiflora) stand located in Hamyang-gun, Korea. Aboveground and soil organic carbon storage, litterfall, litter decomposition, and soil <TEX>$CO_2$</TEX> efflux rates were measured for one year. Estimated aboveground biomass carbon storage and increment in this stand were <TEX>$3,250gC/m^2\;and\;156gC\;m^{-2}yr^{-1}$</TEX>, respectively. Soil organic carbon storage at the depth of 30 cm was <TEX>$10,260gC/m^2$</TEX> Mean organic carbon inputs by needle and total litterfall were <TEX>$176gC\;m^{-2}yr^{-1}\;and\;235gC\;m^{-2}yr^{-1}$</TEX>, respectively. Litter decomposition rates were faster in nne roots less than 2 mm diameter size (<TEX>$<220\;g\;kg^{-1}yr^{-1}$</TEX>) than in needle litter (<TEX>$<120\;g\;kg^{-1}yr^{-1}$</TEX>). Annual mean and total soil respiration rates were <TEX>$0.37g\;CO_2m^{-2}h^{-1}$</TEX> and <TEX>$2,732g\;CO_2m^{-2}yr^{-1}$</TEX> during the study period. A strong positive relationship existed between soil <TEX>$CO_2$</TEX> efflux and soil temperature (r=0.8149), while soil <TEX>$CO_2$</TEX> efflux responded negatively to soil pH (r=-0.3582).