Incidenza e relazioni tra flora apistica e gruppi corologici nel Friuli-Venezia Giulia

Abstract

B/OGEOGRAPHIA — vol. XIII - 1987 Biageagrafia delle A/pi Sud-Orienta/i Incidenza e relazioni tra flora apistica e gruppi corologici nel Fiuli—Venezia Giulia (q‘) GUALTIERO SIMONETTI — RENZO BARBATTINI Irtituio dz‘ Dzfem delle Pzkzzzte, UI2z’z2em'zfti dz’ Udzkze SUMMARY As part of a study being carried out on all the plants of apiarian interest in Friuli—Venezia Giulia an analysis was made of the spontaneous flora. The chorological elements were considered in relation to the distribution of single species at various altitudes. The most common chorological groups belong to the Eurimediterrenean orders (more than 50), followed closely (40-30) by the Eurasian, Paleotemperate, European-Caucasian, Circumboreal, South and Sout-East European. In mountain areas plants are mainly of the Orophite South European, European-Caucasian, Eurasian, Euro-Siberian and circumboreal types. In the foothills and lo\ver reaches of the mountains Eurasian, Paleotemperate, Eurimediterrenean plants are found, which is the most representative group of the east part of the Region (Gorizia, Carso, Trieste) together with the SE-European. There are few litoral (lagoon) species, though they are remarkably widespread and numerous. Keeping in mind the ecological niches, uncultivated and waste land has the largest number of millife- rous species (over 100), then follow the thickets, copses and edges of woods (over 50), next (between 40 and 50) plants of thermophylic woods, old ruins, hedgerows, vineyards, weeds. The diffusion of spontaneous melliferous, pollen and honey-de\v bearing species encourages a large scale permanent and migratory beekeeping in these different environments. Alongside the widespread production of heterofloral honey, thanks to the flowering of acacias and meadow wild flowers, it is possible to obtain also monofloral honey mainly from acacias, sweet chestnuts and dandelions. In this Region the flowers most favoured by migratory bee—keepers are the acacias and the sweet chestnuts, but removal of hives to the mountain areas to benefit from the flowering meadows and shrubs is becaming increasingly frequent. The apiarian importance of melliferous plants in certain areas is being notably reduced by the use of chemicals. The insecticides and fungicides used on agricultural ground can affect the pollinating insects attracted to spontaneous flower species. \Weed—killers can eliminate many melliferous plants both in culti- vated fields and along the waysides thus reducing the apiarian activity in that environment. RIASSUNTO Dall’analisi dell’insieme delle piante d’interesse apistico del Friuli—Venezia Giulia, di cui e in corso lo studio, tenendo conto solo della flora spontanea, sono stati presi in considerazione gli elementi corologici in rapporto alla distribuzione delle singole specie nei vari piani altitudinali. I gruppi corologici piu rappre— sentati sono nell’ordine le piante Eurirnediterranee (oltre 50), seguono poi, con presenze vicine (40-30) piante Eurasiatiche, Paleoternperate, Europeo—Caucasiche, Circumboreali, Sud e SE-Europee. Nel piano (*) Lavoro eseguito con il contributo del Ministero della Pubblica Istruzione (Progetto di Ricerca: «Indagini sullo stato dell’apicoltura in alcune regioni italiane per l’incremento della produzione». Coordi- natore Prof. Romolo Prota, Univ. di Sassari). 209