照葉樹林の土壌呼吸に関する研究

抄録

KIRITA, Hiromitsu (Dept. Biol., Fac. Sci., Osaka City Univ., Osaka) Studies of soil respiration in warm-temperate evergreen broadleaf forests of southwestern Japan. Jap. J. Ecol. 21,230-244 (1971) Daily rates of soil respiration were measured periodically through the year by the 'sponge method' (KIRITA 1971) in two evergreen oak forests, the climax vegetation of warm-temperate Japan. No daily rhythm was recognized in CO_2 evoluntion from the forest floor, while the soil respiration rate (SR) showed a marked annual cycle closely following the seasonal change in soil surface temperature (t). The temperature dependency could be approximated by SR=β exp (at), in which a was nearly constant in all stands at 0.105/℃. The annual rates of soil respiration ranged between 3.4 and 4.6 kgCO_2/m^2・yr or 0.92-1.25 kgC/m^2・yr, and were 2.5-4.0 times as large as the rate of dead organic matter supply to the soil as litterfall (0.54-0.80 kg/m^2・yr or 0.27-0.40 kgC/m^2・yr). It was suggested that the carbon budget in the soil-vegetation systems was nearly balanced if the respiration and turnover of the roots were taken into consideration. The transport and turnover of CO_2 in the soil air were also briefly discussed.