20 - Studia Geobotanica. An international journal - Vol. 20 (2001)

A study on the vegetation related to streams and rivers of the Nevadense sector of Sierra Nevada (Southern Spain) has been carried out by detennining its main structural, floristic, ecological, chorologic and dynamic characteristics. A total of nine new syntaxa have been highlighted: four associations (Caricetum camposii-cuprinae, Ranunculo granatensis-Cochlearietum megalospermae, Cirsio micranthi-Scripetum holoschoeni, Carici camposii-Salicetum atrocinereae), two subassociations (Myrrhoidi-Alliarietum petiolatae nepetosum granatensis, Carici camposii-Salicetum atrocinereae, Salicetosum capreae), two variants (Rubo-Rosetum corymbiferae variant with Adenocarpus decorticans, Rubo-Coriarietum myrtifoliae variant with Adenocarpus decorlicans) and one community (Cratoneuron commutatum and Anagallis tenella community).

An updated checklist of lichens of Crete is presented. A total of 440 taxa is reported. The checklist distinguishes 4 administrative subdivisions (prefectures) in Crete. Strong degradation of the vegetation throughout the island limits the abundance of corticolous lichens, only the woody patches in the Western part contain a number of otherwise rare oceanic species.

TWO NEW ASSOCIATIONS OF ROADSIDE VEGETATION FROM ABRUZZO (CENTRAL lTALY). This study describes the perennial nitrophilous and meso-igrophilous vegetation, occurring along the main roads of Abruzzo up to 900 m a.s.l. Two roadside phytocoenoses are described, one with Senecio inaequidens and the other with Plumbago europaea. They are attributed to two new associations of the Artemisietea vulgaris class, Artemisia absinthii-Senecionetum inaequidentis, belonging to the Dauco-Melilotion alliance (Onopordetalia acanthii arder) and Galio albi-Plumbaginetum europaeae, belonging to the Inulo viscosae-Agropyrion repentis alliance (Agropyretalia repentis arder).

Vegetation with eucalypts of the mallee type along four roadside transects in the South-West of Western Australia has been studied. Mallee communities occur under dry-Mediterranean climate conditions. Species composition, diversity and turnover, local endemism with particular regard to Eucalyptus and Acacia species and habitat conservation are discussed.

STUDIA LICHENOLOGICA IN CENTRAL ITALY. III. SPECIES NEW TO UMBRIA. 31 infrageneric taxa are reported as new to the lichen flora of Umbria (Central Italy). Notes concerning their ecology and distribution are given. The new combination Phaeocalicium mildeanum (Hepp) Puntillo is proposed.