13 - Studia Geobotanica. An international journal - Vol. 13 (1993)

Four species of lichens, Agonimia allobata, Anisomeridium Nyssaegenum, Bintorella monasteriensis and Diplotomma scheideggerianum, are reported for the first time from Italy. A detailed description of each species and critical notes on its ecology and geographic distribution are given.

BIOMONITORING OF AIR POLLUTION BY LICHENS IN THE PROVINCE OF PESCARA (CENTRAL ITALY). This paper presents the results of a study on air quality in the Province of Pescara (Central Italy), carried out in 1991, and based on epiphytic lichens as bioindicators. SO2 pollution was evaluated by means of an Index of Atmospheric Purity (I.A.P.) computed on the frequency of epiphytic lichens within a sampling grid. Relevés were carried out in 77 stations, on Quercus and Tilia spp.: pollution maps for the Province are presented. Altogether, 57 species were recorded, with a prevalence of nitrophytic and neutro-basiphytic lichens, indicating a diffuse secondary eutrophication of the bark. The species can be subdivided in 6 main groups according to their locai distribution patterns: the distribution maps of 6 species are presented. Indicator species, whose distribution is best related to the pollution patterns, were selected. Eutrophication and acidification maps were obtained by calculating an index far each station, based on lichen sensitivity scales derived from existing literature. The results show that most of the Province of Pescara has high air quality standards; the most polluted areas are in the north-eastern part of the Province and along the Pescara valley, corresponding to the town of Pescara and the main industrial and urbanized zones. The main factors affecting lichen distribution are air pollution and eutrophication due to anthropic activities.

Seven wild populations (hypogean and aerial parts) of Aristolochia clematitis, sampling in the North-East Italy, were studied with regard to its aristolochic acids content. Two compounds (aristolochic acids I and II) were identified and quantified by HPLC. The hypogean organs were the most productive parts. Significant quantitative variation was found among populations: two chemical types were identified. The quantitative variability of the two secondary metabolites was correlated with seasonal and sinanthropical factors but not with the climatic variables. The compounds can play a defence role against phytophagous insects.

GORGE-, BEECH- AND FIR-WOODS IN FRIULI (NE ITALY). Syntaxonomy of beechwoods, gorge woods and fir-woods in Friuli is given. Geographic position of the region is enhanced by the heterogeneity syntaxonomy of the forest units. In effect, the coenosis considered are shared between the two orders Fagetalia, sylvaticae Pawlowski 28 and Quercetalia robori R. Tx. 31. The former order presents the illyric alliance Aremonio-Fagion (Ht. .18) Török et al. 89, on calcareous and very basic substrates, and the Centroeuropean alliance Lathyro-Fagion Mayer 74 ad interim on neutrophylous and weekly acid substrates. On acid substrates the beech-woods are included into the order Quercetalia robori represented through the alliance Luzulo-Fagion Lohm. & R.Tx. in R. Tx. 54. The gorge woods are attributed to the suballiance Lamio-Acerenion Marincek 90 (Tilio-Acerion Klika 55) and the fir-woods to the alliance Abieti-Piceion (Br.-BI. in Br.-Bl. et al. 39) So6 64 (Fagetalia).