Phytosociological naming committee recommends conserving selected plant-community names

The Committee for Change and Conservation of Names (CCCN), a topic committee of the Working Group for Phytosociological Nomenclature (GPN), has issued its third report on controversial plant-community names, requests for binding decisions and proposals to conserve or reject syntaxon names. The committee evaluates cases under the International Code of Phytosociological Nomenclature (ICPN), and its recommendations on new cases remain provisional until the GPN Assembly makes the final decisions.

The report was prepared by a six-member committee comprising chair Wolfgang Willner and Andraž Čarni, Federico Fernández-González, Jens Pallas, Massimo Terzi and Jean-Paul Theurillat. Massimo Terzi was co-opted in May 2022. Publication was delayed by two years because several cases raised fundamental questions about interpretation of the ICPN and exposed ambiguities that may need to be addressed in the Code’s next edition. The report covers final decisions on earlier recommendations, four published requests for binding decisions, several additional requests arising during discussions, and nine published conservation or rejection proposals.

GPN members voted by email from 10 March to 10 April 2023 on recommendations from the committee’s previous report. They accepted conservation of Berberidion Braun-Blanquet 1950 against Prunion spinosae Soó 1931 by 22 votes to none and conservation of Aceretalia pseudoplatani Moor 1976 against Tilietalia Moor 1973 by 23 votes to none. The original version of the Festucetalia valesiacae proposal received 12 votes in favor and six against, while a modified version with a conserved type passed unanimously, 21 votes to none. All recommendations, including those opposed by the committee, were accepted, and the relevant entries are to be added to Appendix 3 of the ICPN.

The committee recommended that Xerobromion and Mesobromion be regarded as validly published by Zoller in 1954. Braun-Blanquet and Moor had proposed both names as suballiances in 1938, but their original use of the “-ion” termination was ambiguous because the same ending was then applied to alliances and suballiances. Although Zoller did not state the rank consistently, he explicitly used “Xerobromion-Verband” and “Mesobromion-Verband” at a few locations. A modified proposal to conserve Mesobromion erecti against Bromion erecti Koch 1926 received three votes in favor, two against and one abstention.

Several recommendations addressed the naming of European oak-hornbeam forests. The committee supported conserving Galio sylvatici-Carpinetum betuli Oberdorfer 1957 against Querco roboris-Carpinetum Klika 1928 because the earlier name would have replaced a widely used name and could have been misleading about the communities’ natural tree composition. It also recommended the modified proposal to conserve Lithospermo-Carpinetum betuli against Carpinetum betuli Issler 1924, after a majority concluded that Issler’s synoptic species lists with ranges of cover values constituted a sufficient diagnosis for valid publication. By contrast, the committee did not recommend conserving Stellario holosteae-Carpinetum betuli against Alno glutinosae-Carpinetum betuli: members had unresolved doubts about whether the names referred to the same association, and the vote was one in favor, three against and two abstentions.

Recommended binding decisions concerned the identity of name-giving taxa. These included Cyperus flavescens for Nanocyperetalia Klika 1935, Isoetes durieui for both Isoetetalia Braun-Blanquet 1936 and Isoetion Braun-Blanquet 1936, and Quercus robur for the two Molinio arundinaceae-Quercetum names. The committee also recommended conserving Nanocyperetalia against Nanocypero-Polygonetalia Koch 1926. The latter was considered valid and legitimate even though, to the authors’ knowledge, it had not been used since its first publication. A further recommendation would conserve Isoetetalia with a conserved type, avoiding an inappropriate change to a commonly used name.

Two conservation proposals were not recommended. The proposal concerning Omphalodo nitidae-Coryletum avellanae received two votes in favor and four against. Its holotype had been selected deliberately and was dominated by Quercus robur, while the name-giving Corylus avellana occurred mainly in the shrub layer, prompting discussion of the Code’s requirement that a name-giving taxon belong to the highest dominant stratum. The proposal for Polysticho setiferi-Fraxinetum excelsioris received two votes in favor, three against and one abstention. The report noted that the original relevés had been regarded as atypical by their authors, that the earlier lectotypification therefore required rejection, and that neotypification was necessary, but found no immediate need to conserve a type.

The report records several points of interpretive uncertainty, including the treatment of inverted names and the relationship between a type and the rules governing the order of name-giving taxa. It also states that no data were used. Authors may submit proposals or requests as independent articles in Vegetation Classification and Survey, with article-processing charges potentially applying depending on country and status, or by email to the report’s first author using the same structure. Publication within the next CCCN report is free of charge, and proposals and requests published in the journal are automatically processed by the committee under the ICPN rules.

Subject of Research: Phytosociological nomenclature decisions on conservation, rejection and name-giving taxa

Article Title: Report 3 of the Committee for Change and Conservation of Names ( CCCN )

Article References: Willner, W., Čarni, A., Fernández-González, F., Pallas, J., Terzi, M., & Theurillat, J.-P. (2024). Report 3 of the Committee for Change and Conservation of Names (CCCN). Vegetation Classification and Survey, 5, 257-265. https://doi.org/10.3897/vcs.142803

Image Credits: AI Generated

DOI: 10.3897/VCS.142803

Keywords: phytosociological nomenclature, plant community names, syntaxon conservation, binding decisions, name-giving taxa, ICPN, taxonomy, GPN Assembly, Report, Committee, Change, Conservation