Mycorrhizal Development and Plant Growth in Inoculated and Non-Inoculated Plots of California Native Grasses and Shrubs

Local soil, but not commercial AMF inoculum, increases native and non‐native grass growth at a mine restoration site

“…In this study, inoculation with local soil had effects on the growth of native S. pulchra, non-native grasses, and non-native forbs; however, commercial AMF inoculum did not significantly affect plant biomass or nutrient content. Similar studies have likewise shown negligible effects of commercial AMF inocula, or greater effects of local soil relative to commercial AMF (Rowe et al 2007;Cook et al 2011;Williams et al 2012), or have shown negligible effects of both commercial and local soil inocula (Salyards et al 2003;White et al 2008). Possible explanations for the lack of plant response to commercial AMF in this study could be a lack of ecological "matching" (Ji et al 2010) between commercial AMF taxa, plant taxa, and environmental conditions, or the greater diversity of AMF (and/or other soil microbes) in the local inoculum.…”

“…AMF inoculation may be unnecessary or ineffective at many restoration sites where the in situ community has adequate infectivity. Previous studies have found that initial effects of inoculation receded over a period of 1–3 years (Salyards et al ; White et al ; Cook et al ), and an existing AMF community present in field soil can outweigh the effects of AMF inoculum, potentially due to the relatively small number of AMF propagules added compared with an in situ community (Paluch et al ). Other key factors to consider regarding the use of AMF inocula in restoration include the potential response of non‐native species, as well as methodological considerations such as inoculum type, application method, and temporal variability.…”

“…Effects of inoculation treatments may also vary by year for a number of reasons. The benefits of inoculation have been observed to wane over time in some studies (Salyards et al ; White et al ), possibly due to recovery of resident AMF in non‐inoculated field plots. In addition, variations in climate (e.g.…”

Competition effects of mycorrhizae on two California grasses and B. hordeaceus

“…Although harsh growing conditions are typical of a disturbed site, the subterranean component of restoration sites is often overlooked (Salyards et al 2003). Soil is usually degraded in disturbed habitats, and mycorrhizae are lacking (Salyards et al 2003). Mycorrhizae play a crucial role in many ecosystem functions, such as conferring overall sustainability, one of the main goals of restoration (St. John et al1997).…”

“…hordeaceus plant and one B. carinatus plant. A greenhouse study was chosen over a field study to avoid contamination of the controls with mycorrhizal spores (Salyards et al 2003) and to minimize variability.…”