TITLE:
Microorganisms in Small Patterned Ground Features and Adjacent Vegetated Soils along Topographic and Climatic Gradients in the High Arctic, Canada
AUTHORS:
Grizelle González, Francisco J. Rivera-Figueroa, William A. Gould, Sharon A. Cantrell, José R. Pérez-Jiménez
KEYWORDS:
Soil Microorganisms; High Artic; Canada; Patterned Features; Microbial Biomass
JOURNAL NAME:
Open Journal of Soil Science,
Vol.4 No.1,
January
22,
2014
ABSTRACT:
In this study, we determine differences in total
biomass of soil microorganisms and community structure (using the most probable
number of bacteria (MPN) and the number of fungal genera) in patterned ground
features (PGF) and adjacent vegetated soils (AVS) in mesic sites from three
High Arctic islands in order to characterize microbial dynamics as affected by
cryoturbation, and a broad bioclimatic gradient. We also characterize total
biomass of soil microorganisms and the most probable number of bacteria along a
topographic gradient within each bioclimatic subzone to evaluate whether differences
in topography lead to differences in microbial dynamics at a smaller scale. We found total
microbial biomass C, the most probable number of heterotrophic bacteria, and fungal genera vary along this
bioclimatic gradient. Microbial biomass C decreased with increasing latitude.
Overall, microbial biomass C, MPN and the number of fungal isolates were higher
in AVS than in PGFs. The effects which topographic position had on microbial biomass C varied across the
bioclimatic gradient as there was no effect of topographic position in Isachsen
(subzone A) and Mould Bay (subzone B), when compared to Green Cabin (subzone C,
warmer site).There was no effect of topographic position on MPN counts at Mould
Bay and Green Cabin. However, in Isachsen, MPN counts were highest in the wet
topographic position as compared to the mesic and dry. In conclusion, PGFs seem to decouple the
effect climate that might have on the total biomass of soil microorganisms along the bioclimatic
gradient; and influence gets ameliorated as latitude increases. Similarly, the
effect of topography on the total microbial biomass is significant at the
warmest bioclimatic zone of the gradient. Thus, climate and topographic effects
on total microbial biomass increase with warmer climate.