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Abstract

A coupling of above-ground plant diversity and below-ground microbial diversity has been implied in studies dedicated to assessing the role of macrophyte diversity on the stability, resilience, and functioning of ecosystems. Indeed, above-ground plant communities have long been assumed to drive below-ground microbial diversity, but to date very little is known as to how plant species composition and diversity influence the community composition of micro-organisms in the soil. We examined this relationship in fields subjected to different above-ground biodiversity treatments and in field experiments designed to examine the influence of plant species on soil-borne microbial communities. Culture-independent strategies were applied to examine the role of wild or native plant species composition on bacterial diversity and community structure in bulk soil and in the rhizosphere. In comparing the influence of Cynoglossum officinale (hound's tongue) and Cirsium vulgare (spear thistle) on soil-borne bacterial communities, detectable differences in microbial community structure were confined to the rhizosphere. The colonisation of the rhizosphere of both plants was highly reproducible, and maintained throughout the growing season. In a separate experiment, effects of plant diversity on bacterial community profiles were also only observed for the rhizosphere. Rhizosphere soil from experimental plots with lower macrophyte diversity showed lower diversity, and bacterial diversity was generally lower in the rhizosphere than in bulk soil. These results demonstrate that the level of coupling between above-ground macrophyte communities and below-ground microbial communities is related to the tightness of the interactions involved. Although plant species composition and community structure appear to have little discernible effect on microbial communities inhabiting bulk soil, clear and reproducible changes in microbial community structure and diversity are observed in the rhizosphere.

Temporal Dynamics in Rhizosphere Bacterial Communities of Three Perennial Grassland Species

“…Some studies have shown that non-legume forbs can invest more long-term carbon storage into roots, reducing the amount of root exudation and potentially exerting a stronger selective force on rhizosphere communities compared to grass species [11,30,39]. Further grasses and forbs have distinct root architectures (fibrous vs. taproot, respectively), which can influence rhizosphere microbial communities [3].…”

“…Within this region, abiotic and biotic factors, such as rhizodeposition (including water-soluble exudates, sloughed cells and mucilage), water uptake, soil pH and competition for nutrients, create a unique environment for soil microbes compared to bulk soil [5][6][7][8]. The rhizosphere habitat commonly displays increased microbial biomass and activity, decreased diversity and microbial compositions that are distinct from those of the bulk soil [9][10][11][12]. This phenomenon is commonly referred to as the "rhizosphere effect" [1,3,13].…”

Characterization of Composted Organic Amendments for Agricultural Use

“…Prior to DNA extraction, samples were washed with 20 mM K 2 PO 4 to remove extracellular DNA (Kowalchuk et al, 2002). DNA extracts were stored at −20 • C. Real-time PCR was carried out to determine the relative abundance of the class 1 integronintegrase intl1 gene.…”

Soil conditioning effects ofPhragmites australison native wetland plant seedling survival

“…Although all plants have species‐specific effects on soil they colonize (Bardgett & van der Putten, 2014; Berg & Smalla, 2009), invasive plants often appear to alter soils to their advantage, creating positive plant–soil feedback and promoting dominance (Berg & Smalla, 2009; Bever, 1994; Diez et al., 2010; Fitzsimons & Miller, 2010; Flory & Clay, 2013; Klironomos, 2002; Kowalchuk, Buma, De Boer, Klinkhamer, & van Veen, 2002; Peterman, Fergus, Turnbull, & Schmid, 2008; van der Putten et al., 2013; van Grunsven et al., 2007). Soil biota contribute strongly to these plant–soil feedbacks, and seedling survival appears to be a critical demographic stage in determining invasive success (Blaney & Kotanen, 2001; Packer & Clay, 2000; Reinhart & Clay, 2009; Reinhart, Tytgat, van der Putten, & Clay, 2010).…”