Allelopathic interactions between the soil microorganisms and dominant plants in Orno-Quercetum virgiliana forest on Avala Mt. (Serbia)

Abstract

We investigated the allelopathic effects of dominant plants in 3-microcomplexes (dominant spp Melica uniflora, Lithospermum purpureocoeruleum, Quercus virgiliana) on 6 ecophysiological groups of microorganisms in soil and litter in Orno-Quercetum virgilianae forest on Avala Mountain (Serbia). Numbers of all investigated microorganisms were much greater in litter than in Surface soil. Except the users of maltose, there were large numbers of all microorganisms in the litter of Q. virgiliana compared to M. uniflora and to L. purpureocoeruleum, this showed the stimulatory effects of oak litter oil majority of microorganisms. The lowest number of cellulolytic, humifying, ammonifying and oligonitrophyllic microorganisms were found in litter of L. purpureocoeruleum indicating its allelopathic inhibitory effects. The maximum number of cellulolytic microorganisms were found in fitter of Q. virgiliana and M. uniflora, which showed the stimulatory effects of these plants. L. purpureocoeruleum completely inhibited the mould development in soils, than M. uniflora and Q. virgiliana and also strongly inhibited the development of humifying moulds in plant litters. In soils, investigated plants showed different plant-microorgan isms interactions. Possible role of phenolics in regulation of microorganism's numbers has also been discussed.