First Report of the European Vegetation Classification Committee (EVCC)

The European Vegetation Classification Committee (EVCC) was established in 2017 by the European Vegetation Survey to maintain and update a standard phytosociological classification of European vegetation. Vegetation scientists can send proposals for modification of specific parts of the EuroVegChecklist, which is used as a baseline. The proposals are accepted or rejected based on recommendations issued by a specialist group and after voting by EVCC members. Here we report the results of the first voting, which took place from 4 June to 4 July 2020. EVCC members voted on the recommendations issued for three proposals of change concerning spring and dune vegetation, and mediterranean grasslands. As a result, EVCC accepted to modify the classes Ammophiletea and Helichryso-Crucianelletea, but rejected to include the alliance Philonotidion seriatae and the class Charybdido pancratii-Asphodeletea ramosi. These rejections are not final, and similar proposals can be submitted again with new data supporting the proposed changes. Abbreviations: EVCC = European Vegetation Classification Committee; SG = Specialist Group.


Introduction
European phytosociology has traditionally been characterised by a pluralism of national and regional traditions . The idea to develop a coherent overview of vegetation units for the whole of Europe was revived by the formation of the IAVS working group 'European Vegetation Survey' in 1992, and a first preliminary compilation was published by Rodwell et al. (2002). In the following years, these attempts were intensified, culminating in the publication of the 'EuroVegChecklist' (Mucina et al. 2016).
In 2017, the European Vegetation Classification Committee (hereafter EVCC) was established by the European Vegetation Survey to maintain and update a standard phytosociological classification of European vegetation, taking the EuroVegChecklist as a baseline. The EVCC involves experts whose expertise collectively covers most European vegetation types and most European regions. Its tasks are: (a) receiving proposals for changes of specific parts of the EuroVegChecklist; (b) organising the reviewing of these proposals by international expert groups; and (c) deciding about acceptance or rejection of the proposals. Any vegetation scientist can send a proposal for modification of a specific part of the EuroVegChecklist, typically based on published scientific papers. The EVCC establishes a Specialist Group (SG) for each proposal received. Each SG consists of at least three members of the EVCC whose expertise is close to the topic of the proposal, led by a Coordinating Editor assigned by the Secretary (or Deputy Secretary) of the EVCC. Based on the discussion within the SG, the Coordinating Editor prepares a recommendation about the proposal, which can be ' Accept' or 'Reject' . Once a year, the EVCC members are asked to vote about the recommendations. More details about the whole procedure are available in the document approved at the EVS Business Meeting in Bilbao on 14 September 2017 (available at http://euroveg.org/download/EuroVegChecklist-update-procedures-2017-09-14-APPROVED.pdf).

REPORT
Here we report the results of the first voting, which took place from 4 June to 4 July 2020. In this voting, EVCC members were asked to vote on the recommendations issued for three proposals of change. Recommendation (11 November 2019): The SG noted that this proposal goes beyond merely accepting a new class into the EuroVegChecklist. It also contains syntaxonomic changes of concern for the classes Lygeo-Stipetea Rivas-Mart. 1978 and Trifolio-Geranietea T. Müller 1962. A proposal of a new class should be clearly ecologically and floristically argued. The floristic delimitation would be unequivocally addressed if a synoptic table was presented that would document the status of the new class in relation to other, floristically similar classes. The SG identified at least two classes towards which the Charybdido-Asphodeletea should be delimited, namely towards the Lygeo-Stipetea and the Trifolio-Geranietea. Therefore, the SG recommended rejection, but encouraged the authors to provide additional evidence for their proposal by means of synoptic tables.

Report on proposals, recommendations and voting
Voting: The Recommendation of the Specialist Group was confirmed by the EVCC. Vicherek 1971 as separate class and order, respectively.
Specialist Group: Juan Antonio Campos (Coordinating Editor), Erwin Bergmeier, Jürgen Dengler, Rense Haveman. Recommendation (7 February 2020): The SG concluded that Marcenò et al. (2018) convincingly demonstrated that the variation in species composition of European and Mediterranean coastal dune vegetation is strongly affected by the geographic component (differentiation between Atlantic, Mediterranean and Black Sea regions). TWINSPAN classification and DCA clearly supported the main separation between the Atlantic-Baltic and Mediterranean-Black Sea dune vegetation. This vegetation pattern is also supported by phylogeographic studies (Kadereit et al. 2005;Kadereit and Westberg 2007) carried out on some widely distributed dune species such as Cakile maritima, Eryngium maritimum, Euphorbia paralias, which point to the importance of the Strait of Gibraltar as a barrier in the gene flow of many coastal species. Therefore, the SG recommend acceptance of the proposal with minor wording adjustments that were accepted by the authors of the proposal.
Voting: The recommendation of the Specialist Group was confirmed by the EVCC. The proposal is therefore accepted.

Summary and outlook
The modifications as indicated in Proposal 003 will be implemented in the next EuroVegChecklist update. However, we would like to emphasise that the rejection of Proposals 001 and 002 is not final. In both cases, the main reason why the expert committees recommended rejection was the lack of a pan-European revision with synoptic tables. Thus, it is possible that the same or similar proposals are submitted again when new data supporting the proposed changes have been presented.
Two more proposals are now in the evaluation process. We would like to remind vegetation scientists who are willing to submit a proposal to follow the abovementioned procedures, especially regarding the documentation supporting the proposal, e.g., scientific papers including synoptic tables showing the floristic delimitation between the target syntaxon/syntaxa and other related ones.
Proposals have to be sent to the acting EVCC Secretary or Deputy Secretary (see http://euroveg.org/evc-committee).

Author contributions
W.W. planned the report, I.B. wrote it with important inputs from W.W.