Diversity of fungi associated with hair roots of ericaceous plants is affected by land use.

Culture-independent molecular studies have provided new insights into the diversity of fungi associating with ericaceous plant roots. However, there is little understanding of the distribution of these fungi across landscapes, or the effects of environmental heterogeneity on ericoid mycorrhizal (ERM) fungal diversity and distribution. Terminal-restriction fragment length polymorphism and selective sequence analyses of the internal transcribed spacer regions of rDNA were used to infer fungal diversity of bait Vaccinium macrocarpon grown in soils from nine peatland sites in Ireland, representing three different land uses (bog, rough grazing and forest plantation) and the fungal communities of field-collected Calluna vulgaris for five of these nine sites.

The role of local environment and geographical distance in determining community composition of arbuscular mycorrhizal fungi at the landscape scale.

Arbuscular fungi have a major role in directing the functioning of terrestrial ecosystems yet little is known about their biogeographical distribution. The Baas-Becking hypothesis ('everything is everywhere, but, the environment selects') was tested by investigating the distribution of arbuscular mycorrhizal fungi (AMF) at the landscape scale and the influence of environmental factors and geographical distance in determining community composition. AMF communities in Trifolium repens and Lolium perenne roots were assessed in 40 geographically dispersed sites in Ireland representing different land uses and soil types.

Phosphatases of ericoid mycorrhizal fungi: kinetic properties and the effect of copper on activity.

Ericoid endomycorrhizal fungi (two isolates of Hymenoscyphus ericae obtained from unpolluted heathlands and two H. ericae-type endophytes isolated from Calluna vulgaris growing on Cu-contaminated mine spoil) were grown for 14 d on 10% Rorison's solution containing sodium phytate as the sole P source and either trace (0.16 microM) or elevated (0.

Influence of pH on copper and zinc sensitivity of ericoid mycobionts in vitro.

The effect of pH on growth, metal uptake and toxicity in four isolates of ericoid mycobionts (two Hymenoscyphus ericae from unpolluted heathland sites and two H. ericae-type mycobionts from metal-contaminated mine spoil) was assessed in vitro. These isolates were incubated in liquid medium (10% Rorison's medium, glucose at 10 g l(-1)) containing either 0.

Ectomycorrhizas associated with a relict population of Dryas octopetala in the Burren, western Ireland. I. Distribution of ectomycorrhizas in relation to vegetation and soil characteristics.

The distribution of ectomycorrhizas on Dryas octopetala L in grass heaths of the 450 km2 karst region known as the Burren in Western Ireland was examined in relation to soil factors and vegetation type. Ectomycorrhizas were identified or characterised from 56 soil cores from 30 sites, and the occurrence of each ectomycorrhizal (EM) type was quantified by estimating the total length of mycorrhizal tips of each type. Soil organic matter, total nitrogen, extractable phosphorus, pH and depth were the soil factors determined.

Ectomycorrhizas associated with a relict population of Dryas octopetala in the Burren, western Ireland II. Composition, structure and temporal variation in the ectomycorrhizal community.

The composition, structure and temporal variation of ectomycorrhizal (EM) communities associated with mountain avens (Dryas octopetala) in grass heaths of the Burren, western Ireland were assessed by using soil core sampling in two permanent plots and 30 other sites (196 cores in total). Of the 34 different EM types observed, 11 were common and constituted over 80% of the EM biomass. Four EM types, Craterellus lutescens, Tomentella sp.

Nutritional influences on the solubilization of metal phosphate by ericoid mycorrhizal fungi.

Four ericoid mycobionts (two isolates of Hymenoscyphus ericae, and two dark, sterile ericoid mycobionts isolated from metal-contaminated mine sites) were grown on solid agar plates supplemented with zinc phosphate (0.25 %) containing different forms of nitrogen (nitrate, ammonium or alanine) and different concentrations of carbon (glucose) and phosphorus (K2HPO4). The influence of nutrient variation on solubilizing ability of the fungi was assessed by measuring the zones of solubilization appearing beneath the growing colonies.

Responses of mycorrhizal and non-mycorrhizal Erica cinerea and Vaccinium macrocarpon to Glomus mosseae.

An investigation was carried out on the mycorrhizal colonisation, growth and nutrition of two members of the Ericaceae in close proximity to an arbuscular mycorrhizal (AM) association. This was undertaken by separating mycorrhizal (EM) and non-mycorrhizal (NEM) Erica cinerea and Vaccinium macrocarpon from AM (inoculated by Glomus mosseae) and non-mycorrhizal (NAM) Plantago lanceolata using a 30 micro m nylon mesh in a sand culture/pot system. Ericoid mycorrhizal colonisation by Hymenoscyphus ericae on root systems of E.