engleski

INITIAL RESEARCH ON FLOWERING AND FRUCTIFICATION OF GROUPS OF EUROPEAN FIELD ELM TREES (ULMUS MINOR MILL.) IN EASTERN CROATIA

Several decades ago a very significant tree species, Field Elm (Ulmus minor Mill.), almost entirely disappeared from the lowland forests of Croatia. Since then there has been no traces of any initiative either in the field of research or attempts to reinstitute them in the stands. At the beginning of l988 records were made of the habitats of groups of vital fully-grown trees in the lowland forests. At the beginning of l993 investigations were continued by monitoring particular phenophases and laboratory research work. Laboratory research on flowering samples (flower buds and flowers) and mature seed of the European Field Elm showed the presence of several types of entomofauna: Anthonomus ulmi Deg., Cecidomyidae sp., Lepidoptrera sp and others, which, with their damaging effect lead to the entire loss of fructificating function. Testing the germinability of the gathered seeds in a germinator determined very low germinating capacity. The average percentage of poor seed amounted to 46.0 %. As the future existence of the Field Elm is in question, for the purpose of preserving the genopool of this tree species, it is necessary to start work on the formation of a clonal seed orchard, in order to avoid the possibility of losing the surviving, still vital trees.

Field Elm; phenology; harmful insects; seed quality

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