Bacterial succession in a glacier foreland of the High Arctic

Abstract

Succession is defined as changes in biological communities over time. It has been extensively studied in plant communities, but little is known about bacterial succession, in particular in environments such as High Arctic glacier forelands. Bacteria carry out key processes in the development of soil, biogeochemical cycling, and facilitating plant colonization. In this study we sampled two roughly parallel chronosequences in the foreland of Midre Lovén glacier on Svalbard, Norway and tested whether any of several factors were associated with changes in the structure of bacterial communities, including time after glacier retreat, horizontal variation caused by the distance between chronosequences, and vertical variation at two soil depths. The structures of soil bacterial communities at different locations were compared using terminal restriction fragment length polymorphisms (T-RFLP) of 16S rRNA genes, and the data were analyzed by sequential analysis of log-linear statistical models. While no significant differences in community structure were detected between the two chronosequences, statistically significant differences between sampling locations in the surface and mineral soils could be demonstrated even though glacier forelands are patchy and dynamic environments. These findings suggest bacterial succession occurs in High Arctic glacier forelands but may differ in different soil depths.

Bacterial community structure on two alpine debris-covered glaciers and biogeography of Polaromonas phylotypes

“…This interpretation is corroborated by the observations that distance from the terminus is represented by a vector opposite to those representing the other two variables in the redundancy analysis plot (Figure 3). The results from the multivariate analysis therefore suggest that glacier debris cover may host chronosequences similar to those observed in glacier forefields Nicol et al, 2005;Nemergut et al, 2007;Schmidt et al, 2008;Sattin et al, 2009;Schutte et al, 2009Schutte et al, , 2010Philippot et al, 2011;Knelman et al, 2012;Zumsteg et al, 2012).…”

“…Indeed, in Alpine environments, microbial succession studies have typically been conducted only on glacial forefields, where the distance from the receding glacier front served as a proxy for time since organism colonization Nicol et al, 2005;Nemergut et al, 2007;Schmidt et al, 2008;Sattin et al, 2009;Schutte et al, 2009Schutte et al, , 2010Philippot et al, 2011).…”

Bacterial Communities Involved in Soil Formation and Plant Establishment Triggered by Pyrite Bioweathering on Arctic Moraines

“…Moreover, Verrucomicrobia and Acidobacteria, known to be among the soil bacterial groups with the lower cultivability levels, can indicate a shift from r to K growth strategy along with soil age and development and increase of carbon sources complexity, yet described in Puca glacier [9] and in Dammaglacier (Switzerland) [10] forelands. Bacterial succession and development of soil ecosystem along with time after ice retreat have been reported in several glacier forefronts [7,9,35].…”

“…Between 100 and 2,000 years since exposition from ice cover, plant species diversity did not increase, and soil development was similar [3]. A succession in soil bacterial communities, analyzed by T-RFLP of 16S rRNA gene, was demonstrated to occur in the Midtre Lovénbreen glacier, with a significant change in population structure along the chronosequence [7]. Very few works nevertheless analytically described the microbial succession along glacier forefronts.…”

Abundances and potential activities of nitrogen cycling microbial communities along a chronosequence of a glacier forefield

“…Each of the replicate samples consisted of five subsamples taken within an area of 1 m 2 , avoiding plant roots. The distance between the sampling areas for each replicate was 5-10 m. In the field, the soil was sieved (2 mm) and kept on ice for chemical analyses and enzyme assays (Schutte et al, 2009); soil for molecular analysis was stored on dry ice.…”