The role of microorganisms in the carbon cycle of the various soil ecosystems

Vance等人的烟雾提取方法测定土壤中的微生物质（1987年），《日本西部的三种不同森林、松树、槲寄生和Cryptomeria》。Pinus、Quercus和Cryptomeria森林中的土壤基微生物量（千克C/公顷）为99-110、97-104和73-87，相应地，以及矿物中0-5厘米层为403、324和549，根据Tateno方法估计的微生物量的转折时间（1988年）和Joergensen等人（1990年）。120天后，在14 C的培养下，微生物生物量和呼吸率在稳定状态下被确定。使用这些价值观，在Pinus、Quercus和Cryptomeria Forest A_0层估计为14- 1 - 8、1-8和11-14，相应地，并在矿物0-5厘米层为70-74、45-52和110-120，重新确定，然后碳流动利用微生物量和转折时间的价值观计算。碳的流动（ton C/ha·yr）在Pinus、Quercus和Cryptomeria Forest的A_0层为2.0-2.9、4.4和1.5-2.9，适当地，以及在0-5厘米的地层为2.0-2.1、2.3-2.6和1.7-1.8，相应地：碳流与每年落在每一个森林里的数量相比较。showing quantitatively the important role in the carbon cycle of the forest ecosystems。

Microbial biomass in the soils were determined by the fumigation-extraction method of Vance et al. (1987) in the 3 different forests, Pinus, Quercus and Cryptomeria, in western Japan. Microbial biomass on a ground area basis (kg C/ha) in the A_0 layr of Pinus, Quercus and Cryptomeria forests were 99-110,97-104 and 73-87, respectively, and those in the mineral 0-5 cm layr were 403,324 and 549, respectively.The turnover times of microbial biomass were estimated by the methods of Tateno (1988) and Joergensen et al. (1990). After 120 days' incuation at 14ﾟC,microbial biomass and respiration rates in the steady state were determined. Using these values, the turnover times (days) in the A_0 layr of Pinus, Quercus and Cryptomeria forests were estimated to be 14-18,1-8 and 11-14, respectively, and those in the mineral 0-5 cm layr were 70-74,45-52 and 110-120, rewpectively.Then the carbon flows were calculated by using the values of microbial biomass and turnover time. The carbon flow (ton C/ha・yr) in the A_0 layr of Pinus, Quercus and Cryptomeria forests were 2.0-2.9,4.4 and 1.5-2.9, respectively, and those in the mineral 0-5 cm layr were 2.0-2.1,2.3-2.6 and 1.7-1.8, respectively.The carbon flow thus obtained is comparable to the amount of annual litter fall in each forest, showing quantitatively the important role in the carbon cycle of the forest ecosystems.