Biologia (2019) 74:395–404 https://doi.org/10.2478/s11756-019-00199-x ORIGINAL ARTICLE Vegetation classification as a mirror of evolution? Thoughts on the syntaxonomy and management of bramble scrubs of the Prunetalia (Rhamno-Prunetea) Rense Haveman1,2 & Iris de Ronde1 Received: 3 October 2018 /Accepted: 25 January 2019 /Published online: 15 March 2019 # The Author(s) 2019 Abstract In Germany and the Netherlands, many bramble scrub associations are distinguished on the basis of the occurrence of Rubus species. The associations belonging to the Prunetalia spinosae Tüxen 1952 are usually assigned to the Pruno-Rubion radulae Weber Osnabr Naturwiss Mitt 3:143–150, 1974, but published tables show inconsistencies in the occurrence of alliance character species. In this paper, we compare synoptic tables from different sources from the Netherlands and Germany. From this comparison, it is concluded that the associations can be divided over two alliances, the Pruno-Rubion radulae in central Europe, and the Pruno-Rubion sprengelii Weber Osnabr Naturwiss Mitt 3:143–150, 1974 in northwest Europe (excluding the UK). The differential species of both these alliances coincide to a considerable degree with the indicator species of the phyto- geographical Rubus territories as defined by Haveman et al. (J Biogeogr 43:1360-1371, 2016). As can be deduced from recent molecular studies (Sochor et al. Mol Phylogenet Evol 89:13-27, 2015), these territories have an evolutionary background. This is an effect of the unsaturated distribution areas of a large portion of the very young Rubus agamospecies. The same holds true for the two alliances: although they have a different ecology, we argue that their current distribution areas are not a reflection of this ecology, but both their ecology and distribution area are caused by different evolutionary developments. Keywords Apomicts . Inherited ecology . Pruno-Rubion radulae . Pruno-Rubion sprengelii . Rubus . Vegetation geography . Vegetation history Introduction estimated number of species over 1000 in Europe. In the most recent overview in the Atlas Flora Europaea about 700 species The Rhamno-Prunetea Rivas Goday et Borja Carbonell ex are included (Kurtto et al. 2010), but large areas in western Tüxen 19621 are remarkably rich in taxonomically critical gen- Europe are not fully covered, especially France. This country era, like Crataegus, Rosa and Rubus (especially subgen. Rubus). lies in the centre of diversity of the genus, so it might be ex- Of these, Rubus subgen. Rubus is by far the largest, with an pected that many new species still have to be discovered and described here. Rubus subgen. Rubus in Europe consists of a 1 We prefer using the long established name Rhamno-Prunetea Rivas Goday polyploid series with only five sexual species, and numerous & Borja Carbonell ex Tüxen 1962 over the Crataego-Prunetea Tüxen 1962, stabilised pseudogamous lineages (Weber 1995). Already contrary to Mucina et al. (2016). The arguments for this choice are given by Gustafsson (1942) hypothesised a hybrid origin of the Rubus Weber (1999). apomicts, and recent phylogenetical studies have shown that they indeed arose from hybridisation events between only six * Rense Haveman [email protected] sexual parental species: Rubus caesius, Rubus canescens, Rubus idaeus, Rubus ulmifolius, and two unknown species, one of 1 subsect. Rubus and one belonging to the series Glandulosi Central Government Real Estate Agency of the Dutch Ministry of the (Sochor et al. 2015). Sochor et al. (2015) hypothesised the Interior and Kingdom Relations, Expert Centre Technique, Nature Department, P.O. Box 47, 6700, AA Wageningen, The Netherlands Pleistocene climate fluctuations as driver behind the evolution of the subgenus, and a Holocene expansion of the distribution 2 Wageningen University and Research, Graduate School for Production Ecology and Resource Conservation, P.O. Box 47, area of the apomicts. Large-scale biogeographical patterns in 6700, AA Wageningen, The Netherlands Rubus subgen. Rubus in western Europe can be explained by 396 Biologia (2019) 74:395–404 this hybrid background of the species, as was shown by recognises only the Pruno-Rubion radulae for the bramble Haveman et al. (2016): the Rubus flora in the Netherlands and scrubs on neutral and base-rich soils of western and central the North-German plain (from here together indicated as the Europe (Mucina et al. 2016). Northwest Continent (NWC) territory, following these authors) Comparing the existing classifications of the mesophilous is heavily influenced by R. ulmifolius,whereasR. canescens Rubus scrubs from different regions, there seem to be several presseditsstampontheRubus flora of Central- and South- problems which were addressed briefly by Haveman et al. Germany and Denmark (the Southeast Continent (SEC) (1999) and more in detail by Haveman (2017). The most territory). prominent problem is the apparent incongruence of alliance Modern phytosociological research on Rubus scrubs had its character species of the Pruno-Rubion radulae in the different starting point in the 1960-s, with the publication of Weber’s regions. In the Synopsis,Weber(1999) mentioned Rubus dissertation (1967) on hedgerow communities in Sleswig- bifrons, Rubus montanus and Rubus radula as such for Holstein in North-Germany. In this study, the Rubus rich Germany, and, additionally in the overview of scrubs in mesophilous hedgerows of the Prunetalia spinosae Tüxen Niedersachsen (Weber in Preising et al. 2003), Rubus 1952 were placed in two new associations, viz. the Pruno- goniophorus, Rubus hadracanthos and Rubus orthostachys. Rubetum vestiti Weber 1967 and the Pruno-Rubetum These species are lacking almost completely in the sprengelii Weber 1967, with the remark that both associations Netherlands, and they play no role in the Dutch bramble probably better could be considered as separate alliances. In scrubs. In contrast, here Rubus geniculatus, Rubus several key-stone publications based on studies by himself lindleianus,andRubus macrophyllus are frequently occurring, and others (Reif 1983; Reif 1985; Rosskamp 1999; Wittig andtoalesserextentalsoRubus confusidens, Rubus 1976; Wittig 1977), Weber modified this initial scheme by conspicuus, Rubus egregius, Rubus stereacanthos,and distinguishing more associations and changing the status of Rubus winteri (Haveman et al. 2017). The underlying cause the distinguished associations to alliance (the Pruno-Rubion for this phenomenon might be the relatively small, only partly radulae Weber 1974 and the Pruno-Rubion sprengelii Weber overlapping distribution areas of many bramble species. 1974 respectively) and later to suballiance level under one Although Haveman (2017) elaborated a little on the effect of alliance, the Pruno-Rubion macrophylli Weber 1981a, a su- this problem on the stability of species combinations over perfluous synonym of the Pruno-Rubion radulae (Weber larger areas, it was never studied in detail. In a revision of 1990). According to Weber, the Pruno-Rub(en)ion radulae the Dutch national vegetation overview, Haveman et al. comprises the bramble scrubs on base rich and nutrient rich (2017) argued that this difference in species composition be- soils, whereas the bramble scrubs on slightly acidic and less tween the German and the Dutch Rubus scrubs should be nutrient rich soils are accommodated in the Pruno-Rub(en)ion rewarded in the recognition of two separate alliances though, sprengelii. Both in the Synopsis (Weber 1999) and in the and they again recognised the Pruno-Rubion sprengelii for the Pflanzengesellschaften Niedersachsens (Weber in Preising Rubus scrubs in the Netherlands. However, this choice was et al. 2003), the scheme with one bramble-rich alliance (i.c. never substantiated with data. the Pruno-Rubion radulae) with several associations in the In this paper, we will compare published vegetation tables of Prunetalia was maintained. It was also adopted in the Dutch mesophilous Rubus scrubs from different regions to answer the national vegetation classification, in which two associations question of the tenability of the classification scheme with two and one alliance were distinguished, viz. the Pruno-Rubetum alliances - the Pruno-Rubion radulae and the Pruno-Rubion vestiti and the Pruno-Rubetum elegantispinosi Weber 1981a, sprengelii - for the accommodation of the Rubus-rich which are placed in the Pruno-Rubion radulae (Haveman Prunetalia scrubs in north-west and central Europe. The results et al. 1999). In the accompanying text, the authors mention of this comparison will be evaluated in the framework of the theoccurrenceofthePruno-Rubetum sprengelii in the recent evolutionary and biogeographical literature on the genus, Netherlands, but at that time, relevés of this association were to conclude about the underlying causes of the found patterns. lacking completely. In France, Royer (2013) described several new associations which were also placed in the Pruno-Rubion radulae. The thermophilous scrubs of France, which are also Methods found in Spain, Switzerland, Belgium, and probably the southwesternmost part of the Netherlands, are placed in an The data for the analysis are extracted from the tables published separate alliance, the Pruno-Rubion ulmifolii Bolós 1954. by Haveman et al. (2017) for the Netherlands, Weber (1999)for The Rubus species composition of these thermophilous scrubs Germany, and Weber in Preising et al. (2003)for have not been explored in detail, which makes their Niedersachsen. Rubus species data for the