Abstract
Soil Ca depletion because of acidic deposition-related soil chemistry changes has led to the decline of forest productivity and carbon sequestration in the northeastern USA. In 1999, acidic watershed (WS) 1 at the Hubbard Brook Experimental Forest (HBEF), NH, USA was amended with Ca silicate to restore soil Ca pools. In 2006, soil samples were collected from the Ca-amended (WS1) and reference watershed (WS3) for comparison of bacterial community composition between the two watersheds. The sites were about 125 m apart and were known to have similar stream chemistry and tree populations before Ca amendment. Ca-amended soil had higher Ca and P, and lower Al and acidity as compared with the reference soils. Analysis of bacterial populations by PhyloChip revealed that the bacterial community structure in the Ca-amended and the reference soils was significantly different and that the differences were more pronounced in the mineral soils. Overall, the relative abundance of 300 taxa was significantly affected. Numbers of detectable taxa in families such as
Acidobacteriaceae, Comamonadaceae, and
Pseudomonadaceae were lower in the Ca-amended soils, while
Flavobacteriaceae and
Geobacteraceae were higher. The other functionally important groups, e.g. ammonia-oxidizing
Nitrosomonadaceae, had lower numbers of taxa in the Ca-amended organic soil but higher in the mineral soil.
Keywords
PhyloChip microarray,
forest soil,
bacterial diversity,
Hubbard Brook,
calcium amendment
Citation
Sridevi, Ganapathi; Minocha, Rakesh; Turlapati, Swathi A.; Goldfarb, Katherine C.; Brodie, Eoin L.; Tisa, Louis S.; Minocha, Subhash C. 2012. Soil bacterial communities of a calcium-supplemented and a reference watershed at the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA. FEMS Microbiology Ecology. 79: 728-740.