Responses of microbes in rhizospheric soil of Abies faxoniana to elevated atmospheric CO2 concentration and temperature
岷江冷杉根际土壤微生物对大气CO2浓度和温度升高的响应

With independent and top-enclosed chamber system, this paper studied the responses of culturable bacteria, fungi, and actinomycetes in rhizospheric soil of Abies faxoniana sapling to elevated atmospheric CO2 concentration (ambient +350( +/- 25) micromol x mol(-1), EC), temperature (ambient + 2. 2 (+/- 0.5) degrees C; ET), and their combination (ECT) under high-frigid conditions of West Sichuan Province. The results showed that in comparing with the control, treatments EC and ET increased the number of rhizospheric bacteria by 35%, 164% and 312%, and 30%, 115% and 209% in June, August and October, respectively, but had little effects on the numbers of rhizospheric actinomycetes and fungi. In treatment ECT, the numbers of rhizospheric actinomycetes and fungi increased by 49%, 50% and 96% ,and 151%, 57% and 48% in June, August and October, respectively, while that of rhizospheric bacteria had little variation. EC, ET and ECT had significant effects on the total number of rhizospheric microbes, with the R/S being 1.93,1.27 and 1.46, respectively,but had little effects on non-rhizospheric microbes.