Phytoliths of six woody species important in the Carpathians: characteristic phytoliths in Norway spruce needles

Phytoliths—also known as plant opals—are preserved in soils and sediments and have taxonomical relevance, therefore phytoliths can be fingerprints of the vegetation of the period from which they originated. Comparative phytolith studies are essential for finding phytolith morphotypes with taxonomic relevance. These are used to build reference collections for future palaeoecological and archaeobotanical studies. Biogenic silica extracted from the leaves of six woody species commonly occurring in temperate climate plant communities was examined using light and scanning electron microscope methods (Deciduous broad-leaved species: Corylus avellana, Fagus sylvatica, Quercus robur. Coniferous species: Abies alba, Picea abies, Pinus sylvestris). The element content of phytoliths was analysed by SEM EDX and the phytolith taxonomic diagnostic potential of element content was tested by discriminant analysis. An inventory of phytolith types with their anatomical origin was provided and type-frequencies were assessed. Three species have been systematically screened here for the first time in detail (C. avellana, F. sylvatica, Q. robur). This is the first time that a characteristic cubical phytolith morphotype (“Picea—blocky type”) originating from transfusion tissue was described as a distinct layer encompassing the central cylinder of the needle. High concentrations of aluminium and magnesium in phytoliths are associated with two of three conifer species. A. alba and P. sylvestris could be differentiated statistically on the basis of elemental content. Our findings open up the possibility to identify these taxa based on their phytoliths and it is anticipated that this could be a useful tool for phytolith identification originating from soils and sediments as well. Moreover, Picea—blocky type allows comparative, in situ studies (amongst others isotopic) to provide the possibility of finding further measurable proxies.