Strong elevational trends in soil bacterial community composition on Mt. Halla, South Korea

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• 作者：Dharmesh Singh ; Larisa Lee-Cruz ; Woo-Sung Kim ; Dorsaf Kerfahi ; Jung-Hwa Chun ; Jonathan Miles Adams
• 关键词：Jeju ; Mt. Halla ; Elevation ; Pyrosequencing ; Bacteria ; Volcanic
• 刊名：Soil Biology & Biochemistry
• 出版年：January, 2014
• 年：2014
• 卷：68
• 期：Complete
• 页码：140-149
• 全文大小：1735 K

文摘

Elevational trends in the ecology of macroorganisms have been studied extensively; by contrast very little is known of such trends in microbial diversity. Previous studies on soil bacteria have found either a diversity decline, a 鈥榩eak鈥?in mid altitudes, or no trend with increasing elevation. Here we studied bacterial diversity and community composition in relation to elevation on Mt. Halla, Jeju Island, South Korea, a massive shield volcano. Samples were taken along two transects, from 100聽m.a.s.l. to the summit at 1950聽m.a.s.l., at elevational intervals of 200聽m. PCR-amplified soil DNA for the bacterial 16S rRNA gene targeting V1 to V3 region was 454-pyrosequenced, and taxonomically classified against EzTaxon-e database.

Elevation was the best predictor of variation in bacterial community composition along the two transects, even when considering other soil parameters. Elevation was itself highly correlated with mean annual temperature (MAT) and mean annual precipitation (MAP), suggesting that soil bacterial community composition on Mt. Halla is more strongly affected by climate than by geochemical or soil textural factors. The two transects showed certain consistent differences in bacterial phyla composition, with one transect having significantly higher abundance of Planctomycetes and Gemmatimonadetes than the other. Certain other phyla (e.g. Acidobacteria) also showed striking trends in abundance with elevation, but the trends differed between the two transects.

Bacterial diversity and richness were also most strongly correlated with elevation, MAT and MAP, although soil pH explained a part of the variation. Moreover, vegetation cover type, irrespective of elevation, had an effect on soil bacterial diversity and richness. We found a 鈥榙ip鈥?in diversity at lower mid elevations (700-1300聽m) in both transects; a trend which has not been found before. Our results, when compared with other studies, emphasize that no simple rule can be applied to mountain systems in general, but that climate itself is a major influence on community composition.