Variations Of Soil Microbial Diversity Along An Elevation Gradient In The Wuyi Mountains

We examined the soil microbial diversity by measuring the amount of soil microbes(bacteria, fungi, actinomucetes) and soil microbial major physiological group (nitrogen fixingbacteria, cellulose decomposing microbes, nitrifying bacteria and ammonifying bacteria) and theactivities of four soil enzymes (urease, sucrase, acidic phosphatase, catalase and polyphenoloxidase) at four typical vegetations along elevation i.e. evergreen broadleaf forest (EBF) at500m above sea level (asl), coniferous forest (CF) at1150m asl, sub-alpine dwarf forest (SDF) at1750m asl and alpine meadow (AM) at2150m asl, respectively, in the natural reserve of theWuyi Mountains in Fujian Province, China. We studied the distribution of soil microbialdiversity along elevation and the microbial effect of environmental changes along altitude fromthe point of view of the biogeography, and stated the relationship of soil microbial diversity withsoil, environment and vegetation along elevation. The major findings are as following:1. The amount of microbes altered along an elevation gradient. The amount of fungiincreased with altitude, the amount of actinomucetes increased with altitude (except EBF), theamount of bacteria and cellulose decomposing microbes increased with altitude (except SDF),the amount of nitrogen fixing bacteria and ammonifying bacteria decreased with altitude (exceptAM), the amount of nitrifying bacteria was very little. We did not find nitrifying bacteria at AM.The amount of microbes altered with seasons, and the peaks of microbes were in spring, summerand autumn, the bottoms of microbes were in winter. The ratio of soil bacteria increased withaltitude, and the ratio of fungi decreased with altitude. The degree of correlation of the amountof microbes with physical and chemical properties of soils receded with altitude.2. The AWCD of soil microbes and microbial functional diversity increased with altitude,with the order of AM>CF>EBF≈SDF, and the order changed with season and soil depth.Sole-carbon-source utilization profiles of soil microbial community were different betweendifferent sites and seasons, and pasture soil and forest soil had distinct differences of microbialcommunity carbon utilization profile. Micobial functional diversity at the four sites correlatedwith physical and chemical properties of soils, fine root biomass, and litter. Generally, soiltemperature was the most factors for micobial functional diversity.3. The activity of soil enzymes distinctly altered with elevation. The activity of soilenzymes increased with altitude (except polyphenol oxidase). The seasonal difference of theactivity of sucrase, acidic phosphatase and polyphenol oxidase were distinct, and that of ureaseand catalase were not significant. The activity of soil enzymes also decreased with soil depth.The activity of soil enzymes were highly correlated with physical and chemical properties ofsoils, soil temperature and soil moisture and, microbial diversity...