Plant diversity affects culturable soil bacteria in experimental grassland communities

Abstract

Summary1 Utilization of carbon sources by culturable soil bacteria can be assessed with BIOLOG microtiter plates (contain 31 C sources). We used this technique to investigate bacterial community structure at various levels of plant diversity. Plant diversity levels were replicated and we investigated the in¯uence of three plant functional groups, grasses, legumes and non-leguminous herbs, as well as the in¯u-ence of individual plant species. 2 Catabolic activity and catabolic diversity of culturable soil bacteria were used to estimate their density (abundance) and functional diversity, respectively. Both increased linearly with the logarithm of plant species number and with the number of plant functional groups in experimental grassland ecosystems. These eects may have been caused by an increased diversity and quantity of material and energȳ ows to the soil. They may also have been mediated by increased diversity of soil microhabitats via a stimulation of the soil fauna. 3 The presence of particular plant species or functional groups in the dierent experimental communities stimulated the activity and functional diversity of the culturable soil bacteria in addition to their contribution via plant diversity. The legume Trifolium repens had the strongest eect and may be regarded as a keystone species with regard to plant±microbial interactions in the systems studied.

Field <sup>13</sup>CO<sub>2</sub> pulse labeling reveals differential partitioning patterns of photoassimilated carbon in response to livestock exclosure in a <i>Kobresia</i> meadow

“…Thus, the decrease of plant richness under exclosure could impact the carbon inputs by affecting the aboveground biomass in the community. Besides, several investigators demonstrated that the increased plant richness could affect the carbon cycling in soil by increasing microbial biomass and activity (Steinbeiss et al, 2008;Wardle et al, 1999;Hooper et al, 2000;Stephan et al, 2000). In addition, the decrease of legumes abundance in the fence meadow could decrease soil C sequestration as suggested by Fornara and Tilman (2008).…”

Non-linear impacts of Eucalyptus plantation stand age on soil microbial metabolic diversity

“…Although the outcomes reflected only patterns of carbon source utilization during the Ecoplate incubation period and only select metabolic functions were represented in the Ecoplates (Preston-Mafham et al 2002;Zheng et al 2005), CLPPs provide a fast and sensitive way to equally compare functional characteristics of soil microbial communities. Moreover, functional diversity can provide a minimum estimate of taxonomic diversity (Stephan et al 2000). In this study, cumulative averaged metabolic activity of soil microbial communities demonstrated a quadratic change with Eucalyptus plantation stand age (see Fig.…”

Positive effects of plant diversity on soil microbial biomass and activity are associated with more root biomass production

“…However, actual observations showed positive (Stephan et al 2000;Zak et al 2003;Eisenhauer et al 2011;Lange et al 2015), negative or no response (Johnson et al 2008) of soil microbial biomass, activity and diversity to increasing plant diversity (Zhang et al 2010;Rottstock et al 2014). Soil micro-organisms are mostly heterotrophic; thus, they decompose plant material for food or use plant exudates (LorangerMerciris et al 2006).…”