Flowering phenology and airborne pollen occurrence of Corylus and Castanea in Trieste (Italy), 1991-2004

The flowering season and the pollen season of Corylus and Castanea were analyzed and compared in Trieste over a period of 14 years (1991–2004). Agreat variability in the flowering phenophase progression was found both among plants and from year to year. The pollen seasons of Corylus and Castanea were longer than the respective flowering seasons. A lack of correlation between the maximum flowering and the maximum pollen concentration was observed, the highest airborne pollen counts occurring two or more weeks after the maximum flowering. Given the geographical complexity of the area around Trieste, the onset of the flowering of Corylus and Castanea does not occur at the same time everywhere, and grains coming from different local and extra-local sources, characterized by a late blooming, were also found. Medium-long range transport from Slovenia should also be considered

Aerobiology of Trieste (1987-1996): annual dynamics of the most common pollen types

A qualitative and quantitative analysis of airborne pollen collected with a Cour trap in Trieste (NE Italy) is presented. The behaviour of 30 pollen types, corresponding to 81.4% of the total collected pollen, was studied. Average results for the period 1987-1996 are presented, together with the highest values found. The highest mean weekly concentrations of total collected pollen are recorded from middle February to middle July, when approximately 86% of the annual total pollen was collected. During the year several peaks occur, principally due to Cupressaceae in early March, and to Quercus, Ostrya, Moraceae, Urticaceae, Pinus and Grarnineae in May. The variation in the annual total concentration over the years shows extraordinary concentrations of Abies, Picea, Fagus and Olea pollen in 1992. Most pollen types are from woody species (56.6%), while a minor contribution comes from herbaceous species (24.8%). The mean composition of the atmospheric pollen spectrum of Trieste reflects well the natural woodlands surrounding the town, and its ornamental and ruderal floras

Relationship between pollen spectrum and vegetation in the Friuli-Venezia Giulia region (NE Italy)

2nonenoneRIZZI L.; MARTINI F.Rizzi, Loredana; Martini, F

Contribution to the systematics of Genista l. Sect. Spartocarpus Spach (Genisteae, Fabaceae) with emphasis on palynological data

A pollen analysis of Genisia sect. Spartocarpus has been carried out on 124 samples from 15 species. The taxa were compared in terms of quantitative and qualitative pollen characters, analysed by LM and SEM. Multivariate analysis subdivides taxa into four clusters. Genisia radiala, G. holopeiala and G. hassertiana, E-Alpine-Balkanic species with capitate inflorescence, form an isolate cluster that is palynologically, morphologically and karyologically homogeneous. The other species, with inflorescences of racemous type, can be grouped in three clusters: the first comprising G. sessilifolia, G. nissana and G. aucheri, Balkan-Anatolian taxa, the second including G. spartioides, G. hoenseleri and G. numidica. Spanish and N-African species, the third comprising the W-Mediterranean G. ephedroides, G. Ihyrrena, G. gasparrinii, G. cilentina, G. aetnensis and G. dorycnifolia. Pollen characters and morphological, karyological ancl biogeographical data appear to be related. The arrangement proposed by Gibbs (1966), who has grouped all the examined species in sect. Spartocarpus, is supported by the pollen analysis. On the basis of pollen characters all taxa of Genista sect. Spartocarpus may be considered as well distinguished. The specific treatment of these taxa in Greuter et al. (1989) is, in generai terms, confined by palynological data. However. the grouping of G. radiata. G. holopetala and G. hassertiana in the G. radiata-group and of G. ephedroides. G. gasparrinii. G. Ihyrrena and G. cilentina in lhe G. ephedroides-group is proposed

La microflora algale delle pareti calcaree del Friuli-Venezia Giulia (Italia nord-orientale)

THE ALGAL MICROFLORA ON CALCAREOUS WALLS OF FRIULI - VENEZIA GIULIA (NE - ITALY). The algal biotopes are mostly populated by Cyanophytes. The most abundant Algae are Gloeocapsa and Scytonema. Microphytic communities are described phytosociologically. The algal vegetation is similar to Scytonemo - Gloeocapsetum described by Golubić (1967). The lithophytic vegetation of three localities of different microecology is compared. Some difference with regard to the relative abundance of coccoid and filamentous species is detected

Pollen cards of the Genista radiata group (Genisteae, Fabaceae)

Pollen cards of the taxa of the Genista radiata group [ G. radiata (L.) Scop. var. radiata, G. radiata var. sericopetala Buchegger, G. holopetala (Koch) Bald., G. hassertiana (Bald.) Buchegger] are presented. The acetolyzed pollen was observed by light and scanning electron microscope