Xeric grasslands of the inner-alpine dry valleys of Austria – new insights into syntaxonomy, diversity and ecology

Wolfgang Willner,Elena Belonovskaya,Monika Janišová,Anna Kuzemko,Riccardo Guarino,Idoia Biurrun,Martin Magnes,Christian Berg,Jürgen Dengler,Harald Rötzer,Elías Afif Khouri,Asun Berastegi,Helmut Mayrhofer,Ermin Masic,Itziar García-Mijangos,Philipp Kirschner,Iwona Dembicz

doi:10.3897/vcs/2021/68594

Abstract

Aims: We studied the syntaxonomic position, biodiversity, ecological features, nature conservation value and current status of dry grasslands investigated by Josias Braun-Blanquet more than 60 years ago. Study area: Inner-alpine valleys of Austria. Methods: We sampled 67 plots of 10 m2, following the standardized EDGG methodology. We subjected our plots to an unsupervised classification with the modified TWINSPAN algorithm and interpreted the branches of the dendrogram syntaxonomically. Biodiversity, structural and ecological characteristics of the resulting vegetation units at association and order level were compared by ANOVAs. Results: All the examined grasslands belong to the class Festuco-Brometea. From ten distinguished clusters, we could assign four clusters to validly published associations, while the remaining six clusters were named tentatively. We classified them into three orders: Stipo-Festucetalia pallentis (Armerio elongatae-Potentilletum arenariae, Phleo phleoidis-Pulsatilletum nigricantis, Medicago minima-Melica ciliata community, Koelerio pyramidatae-Teucrietum montani), Festucetalia valesiacae (Sempervivum tectorum-Festuca valesiaca community); Brachypodietalia pinnati (Astragalo onobrychidis-Brometum erecti, Agrostis capillaris-Avenula adsurgens community, Anthericum ramosum-Brachypodium pinnatum community, Ranunculus bulbosus-Festuca rubra community, Carduus defloratus-Brachypodium pinnatum community). Conclusions: The ten distinguished dry grassland communities of the Austrian inner-alpine valleys differ in their ecological affinities as well as their vascular plant, bryophyte and lichen diversity. We point out their high nature conservation importance, as each of them presents a unique habitat of high value. Taxonomic reference: Names of vascular plants, bryophytes and lichens follow Fischer et al. (2008), Frahm and Frey (2004) and Nimis et al. (2018), respectively. Syntaxonomic reference: Names of orders and classes follow Mucina et al. (2016), references for associations and alliances are given in the text. Abbreviations: ANOVA = analysis of variance; DCA: detrended correspondence analyses; EDGG: Eurasian Dry Grassland Group; EIV: ecological indicator value; FL: Fließ; GR: Griffen; GU: Gulsen; KA: Kaunerberg; LA: Laudegg castle in Ladis; MA: Marin; NM: Neumarkt in der Steiermark; OM: Obermauern; PÖ: Pöls; PU: Puxer Loch; TWINSPAN = Two-way indicator species analysis; ZS: Zinizachspitze.

Highlights

The European Alps (“Alps”) form a nearly 1,200 km long arc from Nice in the southwest to Vienna in the northeast, with the widest sector in the centre of the Eastern Alps, stretching approximately 240 km from north to south (Ozenda 1988)
The following soil parameters were measured: skeleton content, percentages of sand, clay and silt, texture class estimated with Robinson pipette method after removing organic matter with 6% H2O2, field capacity (%), drainage rate, available water (%), saturation (%), permanent wilting point (%), pH, electrical conductivity (EC), organic matter, organic carbon (%), N content estimated with the Kjeldahl method (%), C/N, available P (estimated with the Mehlich 3 method (PM3), mg/kg)
The first TWINSPAN division resulted in two groups roughly corresponding to the orders Stipo-Festucetalia pallentis and Brachypodietalia pinnati of the class Festuco-Brometea (Figure 3)

Summary

Introduction

The European Alps (“Alps”) form a nearly 1,200 km long arc from Nice in the southwest to Vienna in the northeast, with the widest sector in the centre of the Eastern Alps, stretching approximately 240 km from north to south (Ozenda 1988). The Alps represent a biodiversity hotspot in Central Europe, with 4,491 observed vascular plant species (Aeschimann et al 2004; Barthlott et al 2005). The inner-alpine valleys are the central parts of the great longitudinal valleys between the highest ridges of the Alps and represent islands of continentality within the relatively oceanic climate of the mountain ranges. While even the driest parts of the Alps are more humid than true steppes (Ozenda 1988), these valleys provide refugial habitats to many species with a distribution centred in the steppe biome of Eastern Europe (Kirschner et al 2020). Similar intra-montane valleys with continental climate and Festuco-Brometea grasslands are known from other high mountain ranges, like the Caucasus (Belonovskaya et al 2016)

Methods

Results

Discussion

Conclusion