Soil Water Content and Organic Carbon Availability Are Major Determinants of Soil Microbial Community Composition

Abstract

Exploration of environmental factors governing soil microbial community composition is long overdue and now possible with improved methods for characterizing microbial communities. Previously, we observed that rice soil microbial communities were distinctly different from tomato soil microbial communities, despite management and seasonal variations within soil type. Potential contributing factors included types and amounts of organic inputs, organic carbon content, and timing and amounts of water inputs. Of these, both soil water content and organic carbon availability were highly correlated with observed differences in composition. We examined how organic carbon amendment (compost, vetch, or no amendment) and water additions (from air dry to flooded) affect microbial community composition. Using canonical correspondence analysis of phospholipid fatty acid data, we determined flooded, carbon-amended (+C) microcosm samples were distinctly different from other +C samples and unamended (-C) samples. Although flooding without organic carbon addition influenced composition some, organic carbon addition was necessary to substantially alter community composition. Organic carbon availability had the same general effects on microbial communities regardless of whether it was compost or vetch in origin. In addition, flooded samples, regardless of organic carbon inputs, had significantly lower ratios of fungal to bacterial biomarkers, whereas under drier conditions and increased organic carbon availability the microbial communities had higher proportions of fungal biomass. When comparing field and microcosm soil, flooded +C microcosm samples were most similar to field-collected rice soil, whereas all other treatments were more similar to field-collected tomato soil. Overall, manipulating water and carbon content selected for microbial communities similar to those observed when the same factors were manipulated at the field scale.

Comparative study of microbial community structure in different filter media of constructed wetland

“…As all the media were supplied with the same influent, such a significant variation in the microbial community structure is probably due to the differences in the media characteristics (Table 3). Media characteristics such as pH and water content are expected to control microbial community composition (Bååth and Anderson, 2003;Drenovsky et al, 2004). But it is difficult to correlate PLFA profiles to any of the media characteristics perhaps due to the implicitly confounding nature of PLFA data, as different microbial groups share common fatty acids (Lacombe et al, 2009).…”

Plant functional diversity enhances associations of soil fungal diversity with vegetation and soil in the restoration of semiarid sandy grassland

“…2015) and soil water content (Drenovsky et al. 2004). Thus, untangling the response of soil fungal diversity to changes of vegetation and soil properties will improve our understanding of how biotic and abiotic factors affect the soil fungal community, which will be helpful for management of natural ecosystems.…”

Soil organic carbon and soil structure are driving microbial abundance and community composition across the arid and semi-arid grasslands in northern China

“…Microbial communities have been shown not only to be impacted by abiotic factors, such as soil type and texture (Cavigelli et al, 2005;Ulrich and Becker, 2006), pH (Lozupone and Knight, 2007), and carbon availability (Drenovsky et al, 2004), but also by biotic factors, such as vegetation (Saetre, 1999). At a local scale, plant community structure is typically highly correlated with the microbial communities.…”