Susanne Wallnoefer’s scientific contributions

In this study, the Hedero helicis-Alnetum glutinosae (Alnenion glutinoso-incanae, Alnion incanae) is newly described on the basis of phytosociological releves. The forest type dominated by black alder is found in the colline and submontane belt on south-facing slopes in the inneralpic, precipitation-poor Vinschgau Valley (South Tyrol, Northern Italy). It colonizes banks of rivulets with shallow to intermediate soil depth. In the understory widespread species of deciduous forests and species of nutrient-rich sites dominate. A tabular comparison with Central European alluvial forest types rich in Alnus glutinosa (Pruno-Fraxinetum, Stellario nemorum-Alnetum glutinosae, Carici remotae-Fraxinetum) shows clear floristic differences. Differential species of the Hedero helicis-Alnetum glutinosae include thermophilous species; it is also negatively differentiated by the absence of species indicating wet soil and of the trees Fraxinus excelsior and Prunus padus. Also from the association of alluvial black alder forests in Northern and Central Italy (Aro italici-Alnetum glutinosae) the Hedero helicis-Alnetum glutinosae is clearly distinguished, inter alia by the absence of species preferring wet soils. However, by the dominance of Hedera helix it resembles generally the South European alluvial forests. Besides, floristic affinity to Carpinion-communities of Insubria exists. Because of the restricted distribution area and the smallness of the stands the Hedero helicis-Alnetum glutinosae must be considered as an endangered plant community.

Wallnöfer S. and Hotter M. 2008. Syntaxonomy and site ecology of mixed oak forest communities in the Inner and Intermedial Alps of Tyrol (Austria). Bot. Helv. 118: 21 – 43. Mixed oak forest communities dominated by Quercus robur, Q. petraea and Tilia cordata are the natural vegetation of valley bottoms in Tyrol, but only small remnants of these forest remain nowadays. We carried out a comprehensive survey of all remaining stands to document the diversity of forest types, their distribution in the area and their conservation status. Six associations are described based on phytosociological analyses according to the Braun-Blanquet approach combined with correspondence analysis. These are: Genisto germanicae-Quercetum roboris, a species-poor forest type on very acidic soils dominated by Quercus robur; Luzulo niveae-Quercetum petraeae, thermophilous open forests dominated mostly by Q. petraea on moderately acidic base-rich bedrock; Erico-Ostryetum, an association on calcareous soil rich in submediterranean species confined to the south-eastern study area; Sileno nutantis-Quercetum petraeae, a thermophilous oak forest type on calcareous soil developed in the Central Alps; Carici albae-Tilietum cordatae, moderately thermophilous forests on base-rich soil co-dominated by Tilia cordata, Fraxinus excelsior and Quercus robur; Milio effusi-Quercetum roboris, a newly described association dominated by Q. robur and rich in mesophilous tree species, found on moist base-rich soil. This large variety of forest types is attributable to the steep phytogeographical and ecological gradients within the area as well as the local absence of Fagus sylvatica in the most continental parts of the region. However, mixed oak forest communities are nowadays extremely rare and endangered, and oak regeneration was found to be insufficient to maintain the dominance of the species at its present sites. Given the prospective importance of oak due to climatic warming, all oak forest stands should be protected to maintain the species in Tyrol.

Checklist of the Habitats of South Tyrol This paper presents a comprehensive, hierarchically structured habitat classification system for South Tyrol (Alto Adige), Italy. It includes natural habitats and those created by man, both with and without vegetation cover. The checklist contains five hierarchical levels. The two upper levels are defined on the basis of landscape structure, site factors and vegetation physiognomy. Units of the lower hierarchy levels are primarily characterized by the indication of vegetation types (syntaxa). It is intended as a general basis for the interdisciplinary work of scientists active in the province.