不同二氧化碳浓度条件下红松和长白赤松幼苗根际土壤微生物数量研究

以连续5年不同CO₂浓度(开顶箱700μmol·mol^-1、500μmol·mol^-1、对照箱和裸地)处理的长白赤松和红松幼苗为研究对象,在2003年7～9月分别对幼苗根际土壤细菌、真菌、放线菌数量进行比较研究.结果表明,高浓度CO₂处理对长白赤松幼苗根际土壤细菌数量起显著的(P≤0.001)促进作用,对根际真菌和放线菌数量的促进作用却不明显;对红松来说,除8月份700μmol·mol^-1CO₂处理和7月份500μmol·mol^-1CO₂处理之外,在各月份中受高浓度CO₂处理的根际土壤细菌数量均较对照箱和裸地显著增多(P≤0.001),而根际土壤真菌数量变化除9月份(P≤0.001)外均不明显,放线菌数量受高浓度CO₂的影响亦不明显.

Effects of elevated CO2 concentration on rhizosphere soil microbes under Pinus koraiensis and Pinus sylvestriformis seedlings

The study showed that under Pinus sylvestriformis seedlings, the amount of rhizosphere soil bacteria, but not fungi and actinomyces, increased significantly (P < or = 0. 001) with CO2 enrichment (700 and 500 micromol x mol(-1)), and the same (P < or = 0.001) was under Pinus koraiensis seedlings, with the exceptions of 700 micromol CO2 x mol(-1) in August and 500 micromol CO2 x mol(-1) in July, compared to the ambient chamber and the ambient in each month. No significant effect of elevated CO2 was found on the amount of rhizosphere soil fungi except in September ( P < or = 0.001), and the response of actinomyces to elevated CO2 was also insignificant.