The influence of vegetation type, soil properties and precipitation on the composition of soil mite and microbial communities at the landscape scale

Abstract

Aim We used a landscape-scale study of birch invasion onto heather moorland to determine the consistency of changes in vegetation type and soil properties and in the community composition of five soil organism groups. Our aim was to determine whether the degree to which soil organisms respond to natural changes and/or induced changes (e.g. changes in land-use type and climate) in habitat is consistent across trophic and taxonomic groups in the context of conservation policies for birch woodland and heather moorland. Location Mainland Scotland.Methods We sampled mesostigmatid mites, oribatid mites, fungi, bacteria and archaea in adjacent patches of birch woodland (dominated by Betula pubescens) and heather moorland (dominated by Calluna vulgaris) at 12 sites for which annual rainfall ranged between 713 and 2251 mm. Differences in community composition were visualized using non-metric multidimensional scaling based on Bray-Curtis dissimilarities. The factors contributing to differences between habitats within sites were explored using general linear models and those among sites using redundancy analysis. ResultsThe communities of all groups differed between habitats within sites, but only the oribatid mites and fungi differed consistently between habitats across sites. Within sites, dissimilarity in fungal communities was positively related to the difference in C. vulgaris cover between habitats, whereas dissimilarities in bacteria and archaea were positively related to differences in soil pH and C:N ratio between habitats, respectively. Main conclusionsThe influence of vegetation type and soil properties differed between groups of soil organisms, albeit in a predictable manner, across the 12 sites. Organisms directly associated with plants (fungi), and organisms with microhabitat and resource preferences (Oribatida) were strongly responsive to changes in habitat type. The response of organisms not directly associated with plants (bacteria, archaea) depended on differences in soil properties, while organisms with less clear microhabitat and resource preferences (Mesostigmata) were not strongly responsive to either vegetation type or soil properties. These results show that it is possible to predict the impact of habitat change on specific soil organisms depending on their ecology. Moreover, the community composition of all groups was related to variation in precipitation within the study area, which shows that external factors, such as those caused by climate change, can have a direct effect on belowground communities.

Examining the global distribution of dominant archaeal populations in soil

“…Soil C:N ratio was the only measured variable that was consistently correlated with relative archaeal abundances across all data sets, a result that parallels previous research showing that C:N ratios were strongly related to the composition of soil archaeal communities at the landscape scale (Nielsen et al, 2010). The pattern that relative archaeal abundances were typically higher in soils with lower C:N ratios was highly significant in all cases (Table 1).…”

Microbial Community Structure and Activity Linked to Contrasting Biogeochemical Gradients in Bog and Fen Environments of the Glacial Lake Agassiz Peatland

“…Unpublished data from our group in another peatland site show a sharp decline of fungal 18S gene abundance below 50 cm, further supporting the potential importance of oxygen governing the abundance and activity of fungi. Several studies have demonstrated the relationship between fungal community distribution pattern and plant species composition in mineral soils (50,53). However, to our knowledge, this is the first study to report the feature that fungal community pattern differentially responds to quantity, quality (e.g., C/N ratio), and reactivity of DOM in peatland ecosystems.…”

The Effects of Various Land Reclamation Scenarios on the Succession of Soil Bacteria, Archaea, and Fungi Over the Short and Long Term

“…Crenarchaeota are often found in plant rhizospheres (Timonen and Bomberg, 2009), so Crenarchaeotadominated archaeal communities were more susceptible to reclamation of vegetation than soil properties (Figures 1B, 2). At the landscape scale, the variation in archaea was also more strongly related to the changes in vegetation type, rather than soil properties (Nielsen et al, 2010). Crenarchaeota are influenced by soil organic matter (Zinger et al, 2011), and Crenarchaeota increased with the enhancement of soil total N ( Table 4).…”