Diversity and ecology of Salvia officinalis communities in the Western Balkans

Abstract Vegetation diversity and ecology of grassland communities with Salvia officinalis were assessed in the natural range of the species in the Western Balkans, using the Braun-Blanquet approach. With the aim of defining the differences among the communities and identifying the main environmental gradients, cluster analysis (Flexible Beta method) and non-metric multidimensional scaling ordination were applied. From a total of 346 phytosociological relevés (259 relevés were used from the literature, and 87 new relevés were collected recently in Montenegro and the Middle Dalmatian Islands of Croatia), seventeen associations were identified. Three associations (Brachypodio retusi-Salvietum officinalis, Salvietum brachyodonti-officinalis and Salvio officinalis-Phlomidetum fruticosae) and one subassociation (Stipo-Salvietum officinalis campanuletosum lingulatae) were described for the first time. Most of the associations belong to the alliances Saturejion subspicatae and Chrysopogono grylli-Koelerion splendentis, separated along an altitudinal and thermal gradient. They were classified in the order Koelerietalia splendentis and in the class Helianthemo cani-Seslerietea nitidae, whose presence in the western Balkans is a syntaxonomic novelty. Three associations belong to three other vegetation classes, Festuco-Brometea erecti, Lygeo sparti-Stipetea tenacissimae and Ononido-Rosmarinetea.


Introduction
Salvia officinalis L. (Lamiaceae) is a long-lived perennial subshrubby sub-Mediterranean species, occurring in many southern European countries, from Spain to Ukraine (Euro + Med 2006Pignatti et al. 2017Pignatti et al. -2019. Known since ancient times for its medicinal properties, S. officinalis has been traditionally cultivated and used as folk medicine, spice, food and ornamental plant (Grdiša et al. 2015). Having been spread and cultivated throughout Europe, it is often difficult to distinguish natural from naturalized populations (Pignatti et al. 2017(Pignatti et al. -2019. Some authors consider S. officinalis native and endemic to the Western Balkans and Italy (e.g., Pignatti et al. 2017Pignatti et al. -2019Jug-Dujaković et al. 2020), where it has a disjointed range, including Trieste and several other localities in the central and southern part of the Italian Peninsula (e.g., Poldini 1989Poldini , 2009Cutini et al. 2007;Ciaschetti et al. 2018).
In the Western Balkans S. officinalis is distributed from Trieste to the northwest of the Greek mainland and Ionian Sea (Karousou et al. 2000). Relict and disjunct inland populations indicate a wider continuous range in the past (Stojanović et al. 2015). In the Western Balkans, S. officinalis is quite common and occurs in several habitat types, such as open forests, garrigues (e.g., Horvatić 1958Horvatić , 1963, limestone cliffs (e.g., Terzi et al. 2018) and rocky grasslands (e.g., Horvat 1962;Horvatić 1963). However, it is more frequent in open to semi-open, sunny, dry and shallow calcareous rocky grasslands, which mostly develop from the evergreen forests zone of the alliance Fraxino orni-Quercion ilicis, along the Croatian coastal areas, to the Fraxino orni-Ostryion toward the hinterland, due to the influence of the warmer local climate through deep karstic canyons and related valleys (e.g., Trinajstić 1992a; Bulić et al. 2008). In Serbia, it occurs within the zonal forests of the alliance Quercion confertae, or in more xerothermic, extrazonal, polydominant vegetation of a relict character of the alliance Syringo-Carpinion orientalis (Mišić 1981(Mišić , 1982. Horvatić (1934) was the first to study S. officinalis grasslands in the Balkan Peninsula from a phytosociological point of view. Since then, many grasslands types with S. officinalis have been described, although the most frequently reported association is the Stipo-Salvietum officinalis (e.g., Horvatić 1963;Trinajstić 2008).
Although S. officinalis grasslands have been intensively studied in many areas of the Balkans, there are still little phytosociological data for several areas, some of which are of particular phytosociological importance. The Kornati Archipelago (Croatia), for instance, is a national park near which Horvatić (1962) originally proposed the 'Stipo-Salvietum var. Brachypodium ramosum' , but with only one phytosociological relevé. Very few phytosociological data are available also for Montenegro, although this country lies in the center of diversity of the S. officinalis Balkan range (Liber et al. 2014;Rešetnik et al. 2016).
Furthermore, until now, a total synthesis of the ecology and syntaxonomy of the S. officinalis grasslands in the Balkans has not yet been completed. Such a comprehensive overview would be very useful for several reasons. Those grasslands, in fact, constitute an important germplasm and genetic reserve for food, cosmetic and pharmaceutical industries. In addition, they play an important ecological role in secondary successions from degraded skeletal limestone substrates (Horvat 1962). Knowledge of their phytocoenological diversity is therefore essential for their management, recovery and conservation.
This paper aims to: (i) provide new phytosociological data on S. officinalis grasslands for the Kornati Archipelago (Croatia) and Montenegro; (ii) interpret the new data and classify them in the syntaxonomic context of grasslands with S. officinalis of the Western Balkans, (iii) characterize the different types of S. officinalis grasslands from an ecological point of view, looking for drivers of the syntaxonomic pattern.

Study area
The investigated area is located between 45°41′ and 39°56′ N and between 13°46′ and 20°08′ E (Figure 1, Supplementary Table 1). This overlaps with the Dinaric Alps and stretches from northeastern Italy (the Italian part of the Illyrian Province) to Albania.
The investigated area in the southern Albania belongs to the Ionian zone of External Albanides. The study area includes the region of the Debar Basin (North Macedonia) and the Svrljig Mt, Serbia. The Dinaric region consists of a carbonate lithology (Mesozoic limestone), which provides the geochemical basis for an extremely fragile karst ecosystem whose soil cover (automorphic soils) is frequently exposed to erosion (Herak and Stringfield 1972;Dragičević and Velić 1994;Vlahović et al. 2005). Mostly Mediterranean limestone soil (calcic cambisol) has developed on this geological formation (Torrent 2005;Bašić 2013).
According to the bioclimatic classification and the Bioclimatic Map of Europe (Rivas-Martínez et al. 2004, 2011, the study area in N Italy, the Istrian peninsula and hinterland of the eastern Adriatic coast exhibit a meso-temperate (mesosubmediterranean) bioclimate. The narrow Croatian coastal area and islands, including those of Bosnia and Herzegovina, Montenegro and Albania, belong to the meso-Mediterranean bioclimate, while sites in inland Montenegro, Republic of North Macedonia and Serbia belong to a Supratemperate (suprasubmediterranean) climate.

Data collection and analysis
New phytosociological data (Supplementary Table 2) were collected in the period 2016-19 in Montenegro (41 relevés) and the Kornati Archipelago, Croatia (46 relevés). In some places, S. officinalis exhibits a continuous coverage, coloring very large areas with its blooms, whereas in other areas it is more scattered, forming patches irregular in shape and of limited extension. Therefore, after a first stratification based on the presence and coverage of this species, which allowed us to sample S. officinalis communities along the entire distribution range, preferential sampling was used locally. We selected homogeneous grassland stands where S. officinalis was dominant, and in a few cases co-dominant (i.e., the second dominant species). The relevés were carried out according to the Braun-Blanquet approach (Westhoff and van der Maarel 1980) on plot sizes of 25-50 m 2 (see Supplementary  Table 2). All vascular plants were recorded and their cover-abundances were visually estimated by using the Braun-Blanquet scale (i.e., r, +, 1, 2, 3, 4, 5) in the Kornati Archipelago (Croatia) and the extended Braun-Blanquet scale, obtained by subdividing '2' in three further subcategories (i.e., 2m, 2a and 2b; see Westhoff and van der Maarel 1980), in Montenegro. The main physical features of the habitat (e.g., slope, exposition) were also recorded.
In order to frame the new relevés in the Balkan syntaxonomic context, they were analyzed together with 259 other relevés of Western Balkan grasslands already available in the scientific literature (Supplementary Table 1). In more detail, relevés belonging to phytosociological tables of grasslands containing S. officinalis with a percentage frequency greater than 10% were included (Figure 1; Supplementary Table 1).
Taxa quoted only at the genus level were omitted from the data set as well as bryophytes and lichens which were inconsistently recorded. The taxon scores originally recorded according to the Braun-Blanquet scale, were replaced by the 1-9 ordinal values as proposed by van der Maarel (in Whestoff and van der Maarel 1980) before the numerical analyses.
The data matrix (346 relevés × 739 taxa) was subjected to cluster analysis by using the flexible beta method (β = −0.25), on a chord distance matrix. The dendrogram was pruned at the partitioning level yielding the highest number Indicator Species (IndSp), as the most ecologically meaningful dendrogram level (cf. McCune and Grace 2002). The IndSp were calculated through the Indicator Species Analysis (Dufrêne and Legendre 1997) for the first 50 partitioning levels, further partitions dealing with minor variations. In order to identify IndSp, Indicator Values (IndVal) were calculated for all taxa present in more than two relevés. The IndVal of taxon j in cluster k is given by the product of the relative abundance of that taxon in that cluster and its relative frequency (Dufrêne and Legendre 1997;McCune and Grace 2002). Each taxon was associated with the cluster for which it yielded the highest IndVal. The latter was tested by means of a Monte Carlo test with 1000 permutations. Taxa with significant IndVal (p < 0.01) were considered IndSp (Supplementary Table 3).
In order to visualize the vegetation pattern, relevés were ordinated by nonmetric multidimensional scaling (NMS, Kruskal 1964;Mather 1976), with the same distance measure used for the cluster analysis (i.e., chord distance). The main clusters (MCs, see Figure 2) obtained from the cluster analysis were represented in the ordination diagram by their centroids. Joint plots were used to show the relationships between MCs and climatic variables, Ellenberg ecological indicator values (EIVs, see Pignatti et al. 2005) and altitude. only variables with an r 2 value (between the variable and the axes) greater than 0.3 were plotted.
A second NMS ordination was performed on the matrix of the synoptic table 'MCs × taxa' (23 × 739), in which taxa scores are given by the mean cover-abundance values (rounded up), to visualize the variation of S. officinalis across MCs (Supplementary Figure 6).
Cluster analysis, indicator species analysis and NMS were performed using Pc-ord software, version 6.22 (McCune and Mefford 2011). NMS ordinations were performed in Pc-ord's 'slow and thorough' autopilot mode.
Elevation of each relevé was retrieved from the original papers (Supplementary Table 1) if provided by the original authors or estimated on the basis of the available information. Weighted mean EIVs were calculated for each relevé using JUICE software (Tichý 2002).
Climatic data were retrieved from the WorldClim 2 data base (Fick and Hijmans 2017) as climatic indexes, called BIo 1-19 (Supplementary 4). Climatic variables and EIVs were checked for collinearity. Because many climatic variables were found to be correlated (Pearson r value > |0.7|), only 8 of them were retained (Supplementary Table 4a). For EIVs, soil reaction was excluded from joint plots since it was found to be negatively correlated with temperature (Supplementary Figure 4b). EIVs in MCs were statistically analyzed using the Kruskal-Wallis test and Dunn's post hoc pairwise comparison test (Supplementary Figure 5).
Taxonomic nomenclature follows Euro + Med (2006. According to this Flora, two subspecies of S. officinalis (subsp. officinalis and subsp. multiflora Gajić) occur in the Western Balkans. Based on the studies of Gajić (1973Gajić ( , 1976, S. officinalis subsp. multiflora occurs in the Sićevo Gorge (Serbia), which is the locus classicus of the Artemisio albae-Salvietum officinalis, although Rešetnik et al. (2016) showed that the populations in this area are genetically close to the populations of the southern Adriatic. In the numerical analysis, we did not consider the distinction between these two subspecies, in order to highlight the differences in the remaining floristic composition. Furthermore, differently from Euro + Med (2006 according to which Koeleria splendens C.Presl is endemic to Italy and replaced by other species (e.g., Koeleria lobata (M. Bieb.) Roem. & Schult.) in the Western Balkans, we considered Koeleria splendens to be present on both sides of the Adriatic (see for instance Trinajstić 2008).

Hierarchical clustering and indicator species analysis
The dendrogram ( Figure 2) was pruned at the 22nd partitioning level, yielding 23 main clusters (MCs). Most of these MCs group together relevés already ascribed to a single association/subassociation so that there is a clear correspondence between them and the relevant syntaxon (Supplementary Table 1). For instance, all relevés previously assigned to the Salvio officinalis-Euphorbietum fragiferae are grouped in MC 2, those of the Cymbopogono-Brachypodietum ramosi in MC 10, and those of the Koelerio splendentis-Festucetum illyricae brachypodietosum ramosi in MC 11. The MC 15 includes relevés previously assigned to two associations, Salvio officinalis-S eslerietum juncifoliae a n d Koelerio macranthae-Brachypodietum retusi, whereas MCs 18 and 19 include relevés of the Centaureo rupestris-Caricetum humilis. In contrast, relevés previously ascribed to the Stipo-Salvietum officinalis are scattered throughout several MCs (i.e., 1, 3-7, 12, 18, 21). However, the nomenclatural type relevé of this association is included in MC 3 which therefore represents the typical aspect.
The new relevés from the Kornati Archipelago (Croatia) are included in MCs 12 and 13, together with the original relevé published by Horvatić (1962) to describe the 'Stipo-Salvietum var. Brachypodium ramosum' . The new relevés from Montenegro were split into two main clusters, MCs 6 and 7, which merge with other MCs previously ascribed to the Stipo-Salvietum officinalis (Supplementary Table 1).
Some of the larger clusters resulting from the merging of two or more MCs are of particular ecological interest. The second node of the dendrogram separates a group of associations (i.e., MCs 14-23) that for the most part have been ascribed to the alliance Saturejion subspicatae as, for instance, the Genisto-Globularietum bellidifoliae (MC 23, Tomić-Stanković 1970), Astragalo croatici-Seslerietum robustae (MC 17, Trinajstić 1987) and Minuartio capillaceae-Genistetum pulchellae (MC 20, Šegulja and Bedalov 1988).
on the other side of the dendrogram, the third node separates a group of relevés (MCs 10-13) characterized by a high frequency and coverage of Brachypodium retusum (Pers.) P.Beauv. and representing the Cymbopogono-Brachypodietum ramosi (MC 10) and the most thermophilic fringe of the Chrysopogono grylli-Koelerion splendentis. The new relevés from the Kornati Archipelago belong to the latter group.
The seventh node separates on one side two MCs (8 and 9), which are clearly distinct from each other and from all the others (see below), and on the other side (MCs 1-7) some associations already classified in the alliance Chrysopogono grylli-Koelerion splendentis, such as the Stipo-Salvietum officinalis and the Salvio officinalis-Euphorbietum fragiferae (see Terzi 2015).
Some MCs are floristically well distinguished from others by having numerous IndSp with high IndVal (i.e., >25, Supplementary Table 3

Ordination and environmental gradients
The NMS ordination resulted in a three-dimensional solution (Figure 3), with a final stress of 17.4, explaining 68.8% of the total proportion of variance. Axis 1 accounts for most of the variance (32.6%), whereas axes 2 and 3 account for 21.7%, and 14.4%, respectively. The Saturejion subspicatae (MCs 14-23) lie on the left side of the diagram, separated along axis 1 from the Chrysopogono grylli-Koelerion splendentis (MCs 1-7, 11-13) and the other MCs. 'Ass. Phlomis fruticosa + Salvia officinalis' (MC 8) and Cymbopogono-Brachypodietum ramosi (MC 10) are on the far right side of the diagram but are separated from each other on axes 2 and 3. Axis 2 separates also MC 9 (Artemisio albae-Salvietum officinalis) from all others.
The joint plots ( Figure 3) indicate that axis 1 is negatively correlated with altitude (r 2 = 4.8) and positively correlated with temperature (mean annual temperature, r 2 = 3.0 and temperature of wettest quarter, r 2 = 3.8). The EIV temperature is positively correlated with axis 1 (r 2 = 4.9) whereas soil reaction (not shown) is negatively correlated (r 2 = 3.3) with it. Axis 3 is negatively correlated with annual precipitation (r 2 = 45.4) so that the wettest conditions characterize the MCs in the lower part of the axes 1-3 diagram. The relevés from the Kornati islands and Montenegro lie in the right part of the diagram, together with the other associations of the Chrysopogono grylli-Koelerion splendentis. As stated above, those from Kornati represents the most thermophilic belt of that alliance.
NMS ordination based on the synoptic table 'MCs × taxa' (Supplementary Figure 6a) clearly confirms that the relevés from southern Albania ('Ass. Phlomis fruticosa + Salvia officinalis') and those from Serbia (Artemisio albae-Salvietum officinalis) are floristically well distinguished from all the others, as observed above. In addition, NMS shows that S. officinalis is most abundant in the Chrysopogono grylli-Koelerion splendentis, while its coverage decreases toward both ends of axis 1, and thus toward both the Saturejion subspicatae and the Cymbopogono-Brachypodion ramosi (Supplementary Figure 6b).
As far as EIVs are concerned (Supplementary Figure 5), high light intensity is characteristic of the MC 10 (Cymbopogono-Brachypodietum ramosi) whereas the lowest value is for MC 11 (Artemisio albae-Salvietum officinalis). With respect to temperature, the highest values were recorded for MC 10 and MC 13 (from the Kornati Archipelago), while the lowest were for the MCs from the highest altitude, MC 17 (Astragalo croatici-Seslerietum robustae), MC 23 (Genisto-Globularietum bellidifoliae), MC 19 (Centaureo rupestris-Caricetum humilis) and for MC 9 from Serbia. EIV for moisture showed that the wettest sites are those of the South Albanian (MC 8) and the area of Gacko, Krbavsko Polje, Draba, in Croatia (MC 16), while the driest were in the Croatian central and southern Adriatic islands (MC 10 and 13). The vegetation types differed considerably in relation to substrate reaction. The highest reaction value was for the northern Adriatic (MC 2), whereas the lowest were calculated for the South Albanian (MC 8) and for MC 10. The vegetation types did not markedly differ in relation to nutrients with the highest value for the Festucetum illyrico-valesiacae (MC 16). The highest continentality was found for the clusters from Serbia (MC 9), Konavle region (MC 22) and island of Brač (MC 14), whereas the lowest for the MC 10 (Cymbopogono-Brachypodietum ramosi).

Discussion
Based on the results, the main clusters (MCs) identified through cluster analysis represent the following associations, whose diagnostic (IndSp), dominant and most frequent taxa are shown in Supplementary Tables 3a/b.

MC 1: Bromo erecti-Chrysopogonetum grylli
This MC gathers together relevés from the Buna river area, in North Albania, already ascribed to the Asphodelo microcarpi-Chrysopogonetum grylli Horvatić 1963(Fanelli et al. 2015b, and from Dubrovnik (Croatia), classified to the Stipo-Salvietum officinalis by Fascetti and Vieri (1984). This MC is associated with only three IndSp, and among them, Chrysopogon gryllus (L.) Trin. is also the most frequent taxon (79%) and the sole with an average cover > 4. Salvia officinalis is present in only 42% of the relevés and almost always with low coverage. Although part of the relevés of this cluster was originally ascribed to the Stipo-Salvietum officinalis, they represent more an open hemicryptophytic community, with the dominance of Chrysopogon gryllus. For this, we consider this MC as representative of the Bromo erecti-Chrysopogonetum grylli, of which Asphodelo-Chrysopogonetum grylli is currently considered a synonym (Terzi 2015).

MC 2: Salvio officinalis-Euphorbietum fragiferae
This association was originally described for the plant communities with S. officinalis and Euphorbia fragifera Jan from the Trieste Karst, Italy (Lausi and Poldini 1962). Subsequently, Poldini (1989) considered this association as a synonym of the Stipo-Salvietum officinalis. However, in most recent works (e.g., Poldini 2009;Terzi 2015), the Salvio officinalis-Euphorbietum fragiferae is treated as an autonomous association. We continue to support this interpretation even though there are some similarities between the two syntaxa.
The two associations differ markedly in EIV soil reaction and mean annual precipitations, higher for the Salvio officinalis-Euphorbietum fragiferae. Among the IndSp of this MC, there are Campanula sibirica L. and Euphorbia fragifera that were indicated as character species of the Stipo-Salvietum officinalis by Horvatić (1963Horvatić ( , 1973. More likely, this means that the Stipo-Salvietum officinalis was conceived in the past with a wider circumscription than the current one, since Campanula sibirica was not found in all other relevés of the Stipo-Salvietum officinalis in our data set. The strongest IndSp are Teucrium flavum L. and Seseli kochii Breistr. (Supplementary  Table 3). The former is a western Mediterranean taxon, often associated with xerothermic cliff vegetation (Terzi et al. 2018), whose presence in this associations is due to the stony substrate with shallow soils. Seseli kochii, on the other hand, is an Illyrian taxon, frequent in the prealpic montane rocky grasslands of the Centaureion dichroanthae, which replaces westward the Saturejion subspicatae (Terzi 2015). Indeed, in the ordination diagram (Figure 2, Supplementary Figure 6b) the Salvio officinalis-Euphorbietum fragiferae is in an intermediate position between the Saturejion subspicatae and the Chrysopogono grylli-Koelerion splendentis.

MCs 3-7: Stipo-Salvietum officinalis
The Stipo-Salvietum officinalis was described by Horvatić (1957) as one of the most widespread associations along the degraded sub-Mediterranean Croatian karst where S. officinalis became the main dominant taxon. Nevertheless, other taxa (e.g., Helichrysum italicum (Roth) G.Don, Stipa eriocaulis Borbás) can be locally well represented and determine some local facies (Horvatić 1963). The Stipo-Salvietum officinalis was validly published with an original diagnosis (see Horvatić 1963) including two species of the genus Stipa, without any indication of which of them was the name-giving taxon, and therefore no specific epithet can be added to the association name (Recommendation 10 C of the ICPN, International Code of Phytosociological Nomenclature, see Theurillat et al. 2021).
Salvia officinalis is quite common on the western side of the Balkan Peninsula. Its mere occurrence possibly led some authors to classify their phytosociological tables into the Stipo-Salvietum officinalis. This association, however, should be restricted to those grasslands dominated by S. officinalis (Supplementary Table 3b and Figure 6b), developing on limestone skeletal substrates, from the Kvarner (Croatia) to Montenegro and North Albania. The Stipo-Salvietum officinalis shares many species with other grassland associations, such as the Bromo erecti-Chrysopogonetum grylli, so that the boundaries between them could be somewhere not very clear. In fact, at first, the Stipo-Salvietum officinalis was treated as a facies ('Stiposum') of the subassociation Bromo erecti-Chrysopogonetum grylli asphodeletosum microcarpi by Horvatić (1934). Nevertheless, it is usually characterized by the lack or low cover of Chrysopogon gryllus and Asphodelus ramosus L., which are instead more abundant in the Bromo erecti-Chrysopogonetum grylli.
The relevés belonging to the Stipo-Salvietum officinalis are included in several MCs, however the most typical aspect is represented by MC 6, which contains the nomenclatural type of the association, from the island of Unije (HR, see Terzi 2011).
The Stipo-Salvietum officinalis has an important ecological role as it invades the unfavorable habitats of the bare Karst on very shallow soils and leads to the stages of scrubs and forests along the succession pathway (Horvat 1962). The high contribution of phanerophytes (e.g., Quercus ilex L., Juniperus phoenicea L.) on the island of Cres (MC 4) indicates advanced processes of natural succession (Krstonošić et al. 2016). In southern Croatia, the Stipo-Salvietum officinalis is enriched by several taxa of the Ononido-Rosmarinetea (e.g., Fumana ericifolia Wallr., Erica manipuliflora Salisb.) possibly due to the presence of dolomitic soils. These aspects are here considered as variants. The relevés from Montenegro (MC 6 and MC 7), on the other hand, are quite distinct and are treated here as a new subassociation.

Stipo-Salvietum officinalis subass. campanuletosum lingulatae subass. nov. [holotypus: see Appendix A]
This new subassociation is restricted to Montenegro where two other subassociations ('inuletosum viscosae'and 'genistetosum sericeae') were invalidly proposed in the area of Mount Lovćen by Tomić-Stanković (1970). our data, however, do not support any of them. Most of our relevés, from Lake Skadar in the south to Bogetići in the north, were included in one main cluster (MC 6), although some differences in floristic composition (e.g., presence of Globularia meridionalis (Podp.) o.Schwarz) differentiate the communities further north. Probably, new phytosociological data from Mount orjen, especially from the Bosnian and Herzegovinian side, will allow the recognition of a new vegetation type (see Lakušić et al. 1984).
MC 7 is an heterogeneous cluster that includes some relevés from Rumija Mountain, which certainly belong to the new subassociation, and others collected along the border with Albania, representing an interesting community type with S. officinalis, Phlomis fruticosa L., Asphodelus ramosus, and Chrysopogon gryllus, deserving of further investigation, especially in the north of Albania. Horvatić (1957) mentioned the association 'Chrysopogoneto-Phlometum fruticosae' , from Montenegro, but unfortunately without publishing any relevé. MC 7 also includes three relevés from the Republic of North Macedonia sampled at about 900 m asl by Matvejeva and Nikolovski (1974), with some important floristic peculiarities indicating different habitat conditions, possibly due to altitude and distance from the sea. Again, the low number of relevés available for this area does not allow any new syntaxa to be described.
Campanula lingulata Waldst. & Kit., the name-giving taxon of the new subassociation, is a Balkan endemic, widespread in the central part of the peninsula (Aleksić et al. 2018). In addition to the IndSp reported in Supplementary Table 3, other three IndSp (with an IndVal < 25) can be considered as differentials for this subassociation: the endemic Sideritis romana L. subsp. purpurea (Talbot ex Benth.) Heywood, the north-eastern Mediterranean Clinopodium suaveolens (Sm.) Kuntze and the Euroasian Geranium columbinum L., a widespread taxon that nevertheless has higher frequency in this subassociation than in the other plant communities in our dataset.

MC 9: Artemisio albae-Salvietum officinalis
This association was ascribed to the Chrysopogono grylli-Koelerion splendentis by Nikolić and Diklić (1966). According to Horvat et al. (1974), however, the Artemisio albae-Salvietum officinalis belongs to the Saturejion montanae, which is currently framed into the Stipo pulcherrimae-Festucetalia pallentis (EVC). Terzi (2015) pointed out that this association contains many endemic taxa 'indicative of a different ecological context' with respect to that of the Scorzoneretalia villosae. our results confirmed that this association is floristically and ecologically well distinguished from all the others in the data-set. It occupies a limited area and experiences a supra-temperate climate which also coincides with the influence of the Mediterranean climate from the Aegean Sea along the lowlands and valleys of large rivers ensuring the presence of (sub) Mediterranean taxa (Zlatković et al. 2009). The dominant taxon of the Artemisio albae-Salvietum officinalis is S. officinalis which, however, is represented in that area by the subspecies multiflora instead of the subspecies officinalis (see Gajić 1973Gajić , 1976. Thirty-two IndSp (with IndVal > 25), many of them endemics or Balkan-Pontics, are associated with the Artemisio albae-Salvietum officinalis (Supplementary Table 3a). Among these IndSp, there are many common taxa in the Saturejion montanae (e.g., Satureja kitaibelii Wierzb. ex Heuff., Achillea clypeolata Sm., Hyacinthella leucophaea (K.Koch) Schur, Hypericum rumeliacum Boiss., and others: see Vassilev et al. 2012;Pedashenko et al. 2013;Matevski et al. 2018). This alliance was found in an area very close to the locus classicus of the Artemisio albae-Salvietum officinalis (see Matevski et al. 2018). For these reasons, we keep this association in the Saturejion montanae and in the Stipo pulcherrimae-Festucetalia pallentis.

MC 11: Koelerio splendentis-Festucetum illyricae brachypodietosum ramosi
In the Koelerio splendentis-Festucetum illyricae, S. officinalis is not present or is present with a very low frequency (see Horvatić 1963;Trinajstić 1992b), except in the subassociation brachypodietosum ramosi where it has a percentage frequency of more than 70%. This subassociation is found in the more thermophilic fringe of the Chrysopogono grylli-Koelerion splendentis.

MC 12 and 13: Brachypodio retusi-Salvietum officinalis ass. nov. [holotypus: see Appendix A]
This community type was originally described by Horvatić (1962) as a variant of the Stipo-Salvietum officinalis ('var. Brachypodium retusum'), which occur over large areas on extremely degraded rocky substrates in the eastern, storm-exposed slopes of the southern part of the island of Dugi otok and on large part of the Kornati (Croatia). MCs 12 and 13 include relevés made in those areas, at low altitude, in Eu-Mediterranean conditions, in the hottest and driest habitats. Alongside S. officinalis subsp. officinalis, this vegetation type is dominated or co-dominated by Brachypodium retusum. Those MCs are characterized by a very low average number of taxa which is, for instance, of 11 taxa (±4.0 s.d.) in MC 13. The number of taxa increases in this community after one year of wildfire events (M. Pandža, unpbl. data). only one IndSp with IndVal >25 was found to be associated with these two MCs, which are therefore clearly distinguished from the typical Stipo-Salvietum officinalis by the climatic conditions, the coenological role of Brachypodium retusum, together with S. officinalis, and the low number of taxa.

MC 14: Bromo erecti-Festucetum lapidosae
This association was described by Trinajstić (1992b) from the island of Brač (Croatia), at an altitude of nearly 500 m asl, and was originally ascribed to the alliance 'Chrysopogono-Saturejion' . Salvia officinalis is present in 75% of the relevés but with a coverage <25%. The association is characterized by Festuca lapidosa (Hack.) Markgr.-Dann., the most important IndSp of this MC.

MC 15: Salvio officinalis-Seslerietum juncifoliae and Koelerio macranthae-Brachypodietum retusi
This MC includes relevés of two associations that share the presence and (co)dominance of Bromopsis erecta and Brachypodium retusum in the Mediterranean mountain belt of the South Dalmatian coast. only three IndSp are associated with this MC, the most important being Hyacinthella dalmatica Chouard, endemic to the Western Balkans. The two associations, one from Hvar, Korčula, Dubrovnik (Trinajstić 2005), and the other from the island of Hvar and the Pelješac Peninsula (Trinajstić 1977), however, differ in many other species. The Koelerio macranthae-Brachypodietum retusi is differentiated by the presence of the circumboreal Koeleria macrantha (Ledeb.) Schult. Salvia officinalis was only recorded in two relevés with a coverage of less than 5%. In the Salvio officinalis-Seslerietum juncifoliae, on the other hand, S. officinalis has higher frequency and coverage, and the dominant taxon is Sesleria juncifolia. According to Trinajstić (2008), the name of this association should be corrected as 'Salvio-Seslerietum interruptae'. However, Euro + Med (2021) which we are following in this paper, treats Sesleria interrupta Vis. as a heterotypic synonym of S. juncifolia Suffren. The latter is an Amphi-Adriatic taxon, with a wide ecological amplitude, occurring along a wide altitudinal range. Due to its presence in many associations of the montane and subalpine belts, S. juncifolia is considered a character of the Elyno-Seslerietea (see Di Pietro and Wagensommer 2014). Nevertheless, it has also been recorded in some vegetation types at low altitude. In Italy, for example, it has been found on the Gargano Peninsula and in the Alta Murgia, at about 500 m asl, in grassland communities of the Hippocrepido glaucae-Stipion austroitalicae alliance, of the 'Scorzonero villosae-Chrysopogonetalia grylli' order (Di Pietro and Wagensommer 2014). The Salvio officinalis-Seslerietum juncifoliae is found at a similar elevation. Due to the presence of S. juncifolia and other species (e.g., Muscari botryoides (L.) Mill., Bunium alpinum Waldst. & Kit. subsp. montanum (W.D.J.Koch) P.W.Ball) it was originally classified in the Saturejion subspicatae (Trinajstić 1977). However, according to Terzi (2015) and our results, this association occupies an intermediate position between that alliance and the Chrysopogono grylli-Koelerion splendentis.

MC 16: Festucetum illyrico-valesiacae
The Festucetum illyrico-valesiacae covers vast expanses in the Lika and Krbava area (Croatia), and on the slopes around karstic fields (polje) in western Bosnia and Herzegovina. It was originally classified in a separate suballiance of the 'Chrysopogono-Saturejion' because of its ecological and physionomical features (Horvat 1962;Horvat et al. 1974). Trinajstić (2000) raised this suballiance to the rank of alliance, as 'Festucion illyiricae' , whereas Terzi (2015) ascribed it to the 'Chrysopogono grylli-Saturejion subspicatae' , highlighting its intermediate position with the other Balkan alliances of the Scorzoneretalia villosae. our results show that the Festucetum illyrico-valesiacae is floristically and ecologically (e.g., moisture, nutrients: see Supplementary Figure 5) distinguished from the other associations. Salvia officinalis was only recorded in two relevés, but as the dominant taxon, with a coverage between 25% and 75%.

MC 17: Astragalo croatici-Seslerietum robustae
This association was originally described by Trinajstić (1987) for the Biokovo mountain, at an altitude of about 1400 m asl, and was classified in the alliance Saturejion subspicatae. We retain this classification for the time being, but it must be revised because of the high coverage of chamaephytic and phanerophytic taxa (i.e., Juniperus communis L.), especially in those relevés without S. officinalis. The latter species, in fact, was found in only 50% of the relevés, with cover-abundance values ranging from + to 3.
Therefore, we considered this MC as representative of a new autonomous association, which develops in an area seriously threatened by degradation due to wildfires, at almost 900 m asl. Following the results of the cluster analysis (Figure 2), the Salvietum brachyodonti-officinalis is classified in the Saturejion subspicatae but the ordination diagrams ( Figure  Salvia brachyodon was considered a character species of the 'Genisto-Ericetum verticillatae' , a garrigue association dominated by Erica manipuliflora and present in the South Dalmatian mountainous belt (Horvatić 1958(Horvatić , 1963. on the other hand, the Salvietum brachyodonti-officinalis is dominated by S. officinalis and includes few species of the Cisto-Micromerietalia julianae, with low coverage. Most likely, the two associations are linked along the successional pathway.

MC 22: Community with Salvia brachyodon
The relevés of this MC were collected in the Konavle region, South Croatia, and are dominated by Salvia brachyodon, which usually inhabits wetter habitats and at higher altitude than those of S. officinalis (Kosič et al. 2021). Those relevés were ascribed to the Saturejion subspicatae and deemed as intermediate between the 'Lino-Salvietum brachyodoni' , described by Abadžić and Šilić (1982), and 'a certain form of the association Stipo eriocauli-Salvietum officinalis' (Kosič et al. 2021). Also in our analyses, this MC proved to be more similar with other associations of this alliance than with those of the Chrysopogono grylli-Koelerion splendentis. As for S. officinalis, it is present in almost all the relevés of the MC but always with very low coverage (+ or 1). The main IndSp of this MC are Quercus pubescens Willd. and Fraxinus ornus L., two species of the Quercetea pubescentis class and therefore typical of later stages of succession.

MC 23: Genisto-Globularietum bellidifoliae
This association was described for the Lovćen Mountain, in Montengro, at an altitude between 1100 and 1400 m asl, and it was ascribed to the alliance Saturejion subspicatae (Tomić-Stanković 1970). The Genisto-Globularietum bellidifoliae is well distinguished from other associations by its floristic composition and ecology. Although S. officinalis occurs in almost 40% of the relevés, it is never dominant or co-dominant, and has low cover-abundance values (+ or 1). According to Tomić-Stanković (1970) there are some transitional aspects between the Genisto-Globularietum bellidifoliae and the Stipo-Salvietum officinalis genistetosum sericeae nom. nud. which, however, have been described without publishing any phytosociological relevé.
The idea of replacing the Fesuco-Brometea in the Mediterranean part of Europe with a sub-mediterranean class was conceived by many authors, in different countries. This syntaxonomic concept was extended to the entire southern border of Europe with the class 'Brachypodio-Brometea' , including the Scorzonero villosae-Chrysopogonetalia grylli and other orders, such as the Iberian Festuco-Poetalia ligulatae (Barbero and Loisel 1972). The latter order, in turn, was selected as the nomenclatural type of the class Festuco hystricis-Ononidetea striatae which was proposed with the same purpose in the western Mediterranean Europe (Rivas-Martínez et al. 2002). The EVC retains this last syntaxonomic concept but extends the Festuco hystricis-Ononidetea striatae from the Iberian Peninsula up to Italy. Terzi et al. (2022), however, found that the Festuco hystricis-Ononidetea striatae had been invalidly described and in order to replace it in the EVC, they proposed a new class, the Helianthemo cani-Seslerietea nitidae, which was typified by an Italian order. Matevski et al. (2018) have recently hypothesized the extension of the the Festuco hystricis-Ononidetea striatae further east, to the Republic of North Macedonia, to include the Astragalo onobrychidis-Potentilletalia, an order originally described as at the interface between the 'Thero-Brachypodietea' , Brachypodio-Chrysopogonetea and Festuco-Brometea (see Micevski 1971).
Several authors (e.g., Apostolova et al. 2014; Terzi 2015) have observed the ecological and floristic similarities between the meso-xerophytic alliances of the Scorzoneretalia villosae and the Brachypodietalia pinnati. In a large-scale revision of European semi-dry grasslands, Willner et al. (2019) classified the Scorzonerion villosae, i.e., the nomenclatural type of the Scorzoneretalia villosae, into the Brachypodietalia pinnati.
The arrangement of the Scorzonerion villoase in the Brachypodietalia pinnati (which would then become a synonym for Scorzoneretalia villosae; see Di Pietro et al. 2015), leaves open the question of what to do with the remaining xerophytic alliances of the Scorzoneretalia villosae, which in the Balkans are the Chrysopogono grylli-Koelerion splendentis and Saturejion subspicatae (Apostolova et al. 2014). As noted above, S. officinalis is widespread in xerophytic rocky grassland associations belonging to those two alliances, and predominantly in the Chrysopogono grylli-Koelerion splendentis. This latter is the nomenclatural type of the order Koelerietalia splendentis, an order originally ascribed to the class 'Thero-Brachypodietea' (Horvatić 1973) but then included within the Festuco-Brometea erecti (see Terzi 2011). Following the original idea to put together the submediterranean orders in a class replacing the Festuco-Brometea erecti in the southern fringe of Europe, the Koelerietalia splendentis should be classified in the Helianthemo cani-Seslerietea nitidae.
The Artemisio albae-Salvietum officinalis, the Cymbopogono-Brachypodietum ramosi, and the Salvio officinalis-Phlomidetum fruticosae are instead classified in other orders, and classes, for the reasons explained above.

Conclusion
In the Western Balkans S. officinalis is found in many grassland associations, along an altitudinal range (environmental gradients) from few meter up to nearly 1400 m asl. Most of those associations belong to the Saturejion subspicatae and Chrysopogono grylli-Koelerion splendentis, but it is in the latter that S. officinalis is more frequent and abundant. The S. officinalis grasslands from Montenegro and the Kornati islands were classified into two new syntaxa (Stipo-Salvietum officinalis campanuletosum lingulatae and Brachypodio retusi-Salvietum officinalis), both belonging to the Chrysopogono grylli-Koelerion splendentis.
Regarding the high syntaxonomic ranks, the inclusion of these two alliance in the Koelerietalia splendentis and the Helianthemo cani-Seslerietea nitidae, represents a syntaxonomic novelty that follows the recent description of this class, now rooted in the Italian Peninsula (Terzi et al. 2021). In the new syntaxonomic scheme, therefore, Italian and Western Balkan grassland types, whose similarities have long been known, are kept in the same class. However, this syntaxonomic arrangement needs to be improved by new large-scale assessments, for example, comparing grasslands with S. officinalis from the Balkans with those from the Italian peninsula.
This paper also highlights some gaps in the knowledge of S. officinalis grasslands on the Balkan side, where several areas are still insufficiently investigated, such as those on the border between Montenegro and Bosnia and Herzegovina, or those in North Macedonia and Albania, for which new phytosociological data are needed.

Author contributions
MT and NJ conceived the study, made the statistical analysis, led the writing, and share first authorship; MT, NJ and DC sampled vegetation in Montenegro; MP sampled vegetation in Croatia; MM revised the herbarium collections. All authors critically revised and approved the manuscript.

Disclosure statement
No potential conflict of interest was reported by the author(s).