Associations of dominant plant species with arbuscular mycorrhizal fungi during vegetation development on coal mine spoil banks

Among plants colonizing mine spoil banks in Northern Bohemia the first colo nizers, mainly ruderal annuals from Chenopodiaceae and Brassicaceae were fo und not to be associated with arbuscular mycorrhizal fungi (AMF). These spe cies cultivated in pots with soil from four sites in different succession s tages of the spoil bank did not respond to the presence of native or non-na tive AMF All grass species studied (Elytrigia repens, Calamagrostis epigejo s and Arrhenatherum elatius) were found moderately colonized in the field a nd they seemed to be facultative mycotrophs, because their response to myco rrhiza in the experiment was negligible. Carduus acanthoides was found to b e highly colonized in the field, however, it did not show growth response t o AMF in the pot experiment. The AMF native in four sites on the spoil bank s showed high infectivity but low effectiveness in association with coloniz ing plants compared to the non-native isolate G. fistulosum BEG23. In gener al, dependence on AMF in the cultivation experiment was rather low, regardl ess of the fact that plants were found to be associated with AMF either in the field or in pots. Occurrence and effectiveness of mycorrhizal associati ons might relate primarily to the mycotrophic status of each plant species rather than to the age of the spoil bank sites studied.