Syntaxonomy of psammophytic communities of the Black and Azov Sea coasts (Krasnodar Territory)

The psammophytic communities on sandy accumulative coasts of the Black and Azov Seas were studied in the Krasnodar Territory (Russia) in 2004, 2006 and 2009, when 1610 relevés were made. Of these, 203 relevés were previously classified and published. In this paper based on 23 relevés two new associations and two new subassociations of the class Ammophiletea Br.-Bl. et Tx. ex Westhoff et al. 1946 and one rankless transitional community (Fig. 1) are described according to Braun-Blanquet approach. The abundance of plants estimated in the field as a percentage of the projective cover was converted to scale points: 5 — > 50 %, 4 — 26–50 %, 3 — 16–25 %, 2 — 6–15 %, 1 — 1–5 %, + — < 1 %. Clustering of the relevés (phytocenon isolation) was carried out by flexible beta linkage (β = –0.25) based on the Sørensen coefficient in PC-ORD 5.0, available through the JUICE 7.1 software package (Tichý, Jason, 2006). As a result four phytocenons were established. Their species composition was compared with the species lists of the lower 676 coastal syntaxa of the Azov-Black Sea region, taken from literature and stored in authors’ syntaxon database (GIVD ID EU-RU-005) based on the TURBOVEG program (Hennekens, Schaminée, 2001). An initial assessment of the similarity of littoral syntaxa and phytocenons was performed using several methods available in the JUICE 7.1 software package. In all cases bryophytes and lichens as well as vascular plant species with frequency less than 20 % in any community were excluded from the analysis. All these excluded species are present in Tables 1 and 2. To classify the established phytocenons, their species composition was compared with similar protologues of the lower syntaxa (Table 1). The vascular plant taxa names are by Tutin et al., (2001). In naming the taxa below, a broad understanding of species (s. l.), their aggregation (agg.), or the combination of several species (with “+”) are used: Artemisia campestris+A. tschernieviana, Cakile maritima s. l. (C. maritima, C. maritima subsp. euxina), Centaurea arenaria s. l.(C. arenaria, C. arenaria subsp. odessana), Leymus racemosus s. l. (L. racemosus, L. racemosus subsp. sabulosus); S. kali aggr. (Salsola kali, S. kali subsp. ruthenica or S. kali subsp. tragus) based on P. Uotila (2011) and S. L. Mosyakin (2017); Xanthium strumarium s. l. (X. strumarium, X. strumarium subsp. italicum, X. strumarium subsp. strumarium × subsp. italicum). Few bryophyte and lichen taxa are given with their authors. The names of the new syntaxa are formed according to the ICPN rules (Theurillat et al., 2021). The terrain in the study area is flat. The natural banks are represented by abrasion and accumulative types. The latter is often in the form of sandy or sandy-shelly spits. There are low-lying near-mouth and delta accumulative banks at the mouths of large rivers. Widespread are solonchaks both not vegetated or with halophytic communities. The climate is temperate with continental features. The month mean temperatures and sums of precipitation amounts for the ten-year period (2001–2010) are reflected in the climate diagrams (Fig. 2). The closest in species composition to the established phytocenons were the lower syntaxa (among the protologues) described in Russia, Romania and Ukraine (Table 1), attributed by their authors to the alliance Elymion gigantei Morariu 1957 (class Ammophiletea Br.-Bl. et Tx. ex Westhoff et al. 1946). However, the identified species differences did not allow us to assign the phytocenons (Table 1) to these syntaxonomical units. All phytocenons are classified as new syntaxa (Table 2). The geographical location of the lower syntaxa presented in Table 1 see on Fig. 3. Ass. Eryngio maritimi–Leymetum sabulosi ass. nov: Table 2, rel. 1–13, Fig. 4; holotypus: Table 2, rel. 6, Krasnodar Territory, Anapa sandbar opposite the settlement Blagoveshchenskaya (coast of the Black Sea), fixed dunes in the distance from the sea, 25.08.2004. Diagnostic taxa (d. t.): Artemisia campestris+A. tschernieviana, Eryngium maritimum, Leymus racemosus s. l. The association includes psammophytic herb–dwarf-semishrub communities on fixed and mobile sandy substrates. Subass. Eryngio maritimi–Leymetum sabulositypicum subass. nov.: Table 2, rel. 1–7; holotypus: Table 2, rel. 6, Fig. 5. The diagnostic attributes of the typical subassociation communities are the same as of the association. Plant communities of the subassociation inhabit both mobile and weakly fixed sandy sediments of the accumulative coasts of the Black and Azov Seas. Subass. Eryngio maritimi–Leymetum sabulosi crambetosum maritimae subass. nov.: Table 2, rel. 8–13, Fig. 6; holotypus: Table 2, rel. 10, Krasnodar Territory, 4 km ENE from the settlement Golubitskaya, coast of the Temryuk Bay (Azov Sea), low dune (1.5–2 m high), 04.09.2004, D. t. of the subassociation: Crambe maritima, Lactuca tatarica. Communities occur on fixed sands on accumulative banks. Community Conium maculatum–Centaurea arenaria: Table 2, rel. 14–18. D. t.: Astragalus onobrychis, Centaurea arenaria s. l., Conium maculatum, Galium humifusum, Torilis arvensis. The communities of this rankless transitional unit occur on flat or depressed terrain areas on the Temryuk Bay coast. Ass. Cakilo euxinae–Glycyrrhizetum glabrae ass. nov.: Table 2, rel. 19–23, Fig. 7; holotypus: Table 2, rel. 19, Krasnodar Territory, Bugazsk Spit, opposite Veselovka village, the coast between the Black Sea and Bugaz Liman, slope of sandy sediment (north-east exposure, 1–2° slope) toward the estuary, 19.08.2004. D. t.: Cakile maritima s. l., Glycyrrhiza glabra, Carex ligerica, Salsola kali aggr. Communities are distributed on the southern part of the Taman Peninsula. They are found on tops of the avandunes, as well as away from them on the elevated parts of the marine spits.