Mechanical soil disturbance as a determinant of arbuscular mycorrhizal fungal communities in semi-natural grassland

Abstract

While the effect of disturbance on overall abundance and community composition of arbuscular mycorrhizal (AM) fungi has been researched in agricultural fields, less is known about the impact in semi-natural grasslands. We sampled two AM plant species, Festuca brevipila and Plantago lanceolata, from an ongoing grassland restoration experiment that contained replicated plowed and control plots. The AM fungal community in roots was determined using nested PCR and LSU rDNA primers. We identified 38 phylotypes within the Glomeromycota, of which 29 belonged to Glomus A, six to Glomus B, and three to Diversisporaceae. Only three phylotypes were closely related to known morphospecies. Soil disturbance significantly reduced phylotype richness and changed the AM fungal community composition. Most phylotypes, even closely related ones, showed little or no overlap in their distribution and occurred in either the control or disturbed plots. We found no evidence of host preference in this system, except for one phylotype that preferentially seemed to colonize Festuca. Our results show that disturbance imposed a stronger structuring force for AM fungal communities than did host plants in this semi-natural grassland.

AMF Inoculation Enhances Growth and Improves the Nutrient Uptake Rates of Transplanted, Salt-Stressed Tomato Seedlings

“…However, additional studies, covering all developmental stages and testing more varieties under diversified soil conditions are needed to further validate the usefulness of commercial AM inoculate to ameliorate salt stress in commercial tomato production. Previously it has been found that species diversity and species number in AMF communities are significantly higher in soils from organic farms, while being reduced by wastewater pollution, excess fertilization and tillage [63,64]. While other studies conclusively found that AM infection rates are lower under salinity, more research is needed to determine the availability and vitality of natural AM mycorrhizal spores in salt-affected agricultural soils-comparing AM infection Sustainability 2015, 7, 15967-15981 rates of crops under actual and in inoculate-amended soils.…”

Agricultural practices indirectly influence plant productivity and ecosystem services through effects on soil biota

“…As a consequence, tillage-induced changes in AMF communities result in AMF community structures specific to each soil practice and often lead to a reduced mycorrhizal diversity in tilled fields (Boddington and Dodd 2000, Schnoor et al 2011, Brito et al 2012, Yang et al 2012. The soil-tillage-induced shift of the mycorrhizal community structure may have consequences for their functioning, as AMF functional traits differ considerably among and within species (Raju et al 1990, McGonigle et al 2003.…”

Funcionalidad de hongos micorrízicos arbusculares en tres comunidades vegetales de la Reserva Florística Manejada de San Ubaldo-Sabanalamar, Cuba

“…The highest extraradical mycelial biomass:endophyte biomass ratio of AMF in the AG ecosystem, regardless of the season analyzed, supports our hypothesis that there is a disruptive effect of this human activity on the arbuscular mycorrhizal symbiosis. We conclude that agricultural activities, such as tillage, erosion, high levels of nutrients (particularly P) and frequent fallow periods decrease the abundance of AMF propagules, such as spores and infective mycelium (Karasawa, & Takebe, 2011;Schnoor, Lekberg, Rosendahl, & Olsson, 2011). Furthermore, it has been proposed by Johnson, Graham and Smith (1997) that mycorrhizal associations could be considered symbioses that functionally range along a continuum of parasitism to mutualism and that environmental conditions, particularly the abundance of soil nutrients, could determine the position of AMF along that continuum.…”