Corresponding author: Marina Allegrezza ( m.allegrezza@univpm.it ) Academic editor: Daniele Viciani
© 2021 Giulio Tesei, Marina Allegrezza, Sandro Ballelli, Giampiero Ciaschetti, Carlo Console, Silvia Montecchiari, Cecilia Ottaviani, Gianfranco Pirone, Annarita Frattaroli.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Tesei G, Allegrezza M, Ballelli S, Ciaschetti G, Console C, Montecchiari S, Ottaviani C, Pirone G, Frattaroli A (2021) The oldest Pinus nigra plantations in the central Apennines: distribution and floristic-vegetational characterisation. Plant Sociology 58(2): 15-28. https://doi.org/10.3897/pls2021582/02
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This paper represents the first syntaxonomic study on the Pinus nigra subsp. nigra artificial stands in the Apennines. It refers exclusively to the mature Pinus nigra forest plantations in the central Apennines that were planted before the 1950s, and then not managed. The mature Pinus nigra forest plantations in the central Apennines are distributed within four National Parks, on limestone substrata, mainly with southern aspects and rugged slopes, and at elevations ranging from 655 m to 1670 m a.s.l.. Two new phytosociological associations are described here and classified in the alliance Junipero communis–Pinion nigrae: Orthilio secundae–Pinetum nigrae and Digitalidi micranthae–Pinetum nigrae. The association Orthilio secundae–Pinetum nigrae comprises the relative mesophilous mature pine forests of the supratemperate thermotype in the plant landscape context of the alliance Aremonio agrimonioidis–Fagion sylvaticae potential vegetation belt. The Digitalidi micranthae–Pinetum nigrae comprises the thermophilous pine forests occurring on rocky stands within mesotemperate and lower supratemperate thermotypes in the potential belt of alliance Carpinion orientalis woods. The comparison of these two new associations and the phytosociological literature concerning the natural communities of Pinus nigra in the Apennines highlights their floristic and coenological autonomy.
distribution, mature forest plantation, phytosociology, Pinus nigra subsp. nigra, syntaxonomy, vegetation
Pinus nigra J.F. Arnold is a collective species with a wide but fragmented distribution that extends from north-west Africa through southern Europe to Anatolia and the northern Black Sea region, predominantly in mountain areas (
At the syntaxonomic level, the communities dominated by Pinus nigra s.l. in the mountain systems of the Mediterranean basin are currently referred to two classes: Junipero-Pinetea sylvestris and Erico-Pinetea (
A recent syntaxonomic revision of the order Erico-Pinetalia for the Apennines-Balkan province allowed the proposal of the new order Junipero communis-Pinetalia nigrae within the class Erico-Pinetea class (Biondi & Allegrezza 2020). The order Junipero communis-Pinetalia nigrae represents the vicariant of the order Erico-Pinetalia in the central-southern Apennine-Balkan mountain ranges.
For the Italian peninsula, the class Junipero-Pinetea is considered exclusively for the Pinus nigra subsp. laricio communities of the supraMediterranean belt of Sicily and Calabria, on siliceous or metamorphic substrate. As far as Erico-Pinetea, is concerned, two orders are currently considered in the EuroVegChecklist: Erico-Pinetalia, with the alliances Erico carneae-Pinion Br.-Bl. in Br.-Bl. et al. 1939 nom. invers. propos.
In the Apennines, Pinus nigra has been widely used for extensive plantations of non-forested areas since the early 1900s (Amorini & Fabbio 1992; Nocentini 1999). Most of these areas were originally covered by deciduous forests, but intensive grazing and farming had destroyed the original forest cover. The forests plantation was necessary as a response to the marked hydrogeological instability that has affected wide areas of the Apennines since the end of 1800s, and in particular the montane south-facing slopes where the anthropogenic effects over the centuries have been more intense (
Although the pine plantations are included as forest ecosystems in the Apennines ecoregion (C39_ Peninsular and Sicilian mountain supra and oroMediterranean forest ecosystems dominated by Pinus nigra, P. leucodermis and/or P. laricio) (
Owing to the maturity and complexity of pine forest plantations in the Apennines, it would be legitimate to ask: does it make sense to compare natural and artificial communities with each other, and to trying to classify these artificial ones in phytosociological terms? With regard to the mature pine forests, we would say yes. As these are very old (almost centenarians) and have now reached full structural and biological complexity, and as they have also undergone renewal, which indicates the stability of these coenoses over time. The structure of these communities after a century, is no longer orderly, of the same age and monoplane as in a planted stand, and the forest dynamics are now completely natural, with the presence of renewal and crashes / re-closure of the clearings. On the basis of this (by now) reached naturalness, they fall within the same vein of the Aleppo pine and chestnut woods, probably planted and now treated as natural also from a phytosociological point of view. Furthermore, Pinus nigra was not a foreign plant in the Apennines as shown by the numerous palynological (
Thus the objectives of this study that focussed on mature Pinus nigra plantations were: (i) to shed light on the distribution of the oldest artificial stands (planted before 1950) in the central Apennines at elevations above 600 m a.s.l., which are not managed; (ii) to perform a floristic-vegetational analysis and a syntaxonomic classification; and (iii) to highlight similarities and differences between the pine forests of anthropogenic origin identified in this study and the syntaxa of the Pinus nigra subsp. nigra natural forests described in the literature for the Apennines.
The study area included the Apennine and pre-Apennine ridges of central Italy, from Mount Carpegna in the North (43°48'04.32''N, 12°19'13.44''E) to Villetta Barrea in the South (41°46'36"48 N, 13°56'21"84 E), at elevations over 600 m a.s.l. (Fig.
The selection of the oldest Pinus nigra plantations (planted before 1950) were documented through the cartography of the Istituto Geografico Militare (Military Geographical Institute), and forest archives and historical photos. The pure plantations of Pinus nigra subsp. nigra that had not been managed for many years were then selected by exploratory field surveys.
The vegetation study was conducted according to the phytosociological method (Braun Blanquet 1928) for a total of 59 phytosociological relevés, of which 41 were not published, 8 were published (
Braun-Blanquet’s cover-abundance values were transformed according to the Van der Maarel scale (
Dendrogram A) and non-metric multidimensional scaling ordination (stress 0.24) B) of the phytosociological relevés of the mature Pinus nigra plantations in the study area: Orthilio secundae-Pinetum nigrae [(cluster I in A); group I in B)], and Digitalidi micranthae-Pinetum nigrae [(cluster II in A); group II in B)].
Synoptic table of Pinus nigra syntaxa belong to the Junipero communis-Pinetalia nigrae in Apennines. Abbreviations of associations in column: JUN-PIN: Junipero hemisphaericae-Pinetum nigrae; ORT-PIN: Orthilio secundae-Pinetum nigrae; DIG-PIN: Digitalidi micranthae-Pinetum nigrae; GEN-PIN: Genisto sericeae-Pinetum nigrae. Values in the columns are percentage frequencies, phi coefficient value percent is given in brackets for species with Fisher’s exact test value < 0.05 (see also Suppl. material
Vegetation type | JUN-PIN | ORT-PIN | DIG-PIN | GEN-PIN |
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No. of releves | 6 | 32 | 27 | 6 |
Junipero hemisphaericae-Pinetum nigrae Biondi et Allegrezza 2020 | ||||
(typus of alliance Junipero hemisphaericae-Pinion nigrae Biondi et Allegrezza 2020) | ||||
Rosa spinossima | 100 (100) | |||
Cotoneaster pyrenaicus | 83 (87) | 6 | ||
Oreoherzogia fallax | 50 (62) | 4 | ||
Daphne oleoides | 83 (85) | 3 | ||
Arctostaphylos uva-ursi | 67 (75) | 3 | ||
Brachypodium genuense | 100 (100) | |||
Armeria gracilis subsp. majellensis | 50 (65) | |||
Dianthus longicaulis | 100 (98) | 3 | ||
Galium lucidum | 50 (65) | |||
Gymnadenia conopsea | 50 (65) | |||
Linaria purpurea | 50 (65) | |||
Trifolium repens | 33 (52) | |||
Verbascum mallophorum | 33 (52) | |||
Veronica chamaedrys | 33 (52) | |||
Helianthemum nummularium subsp. obscurum | 33 (45) | 6 | ||
Orthilio secundae-Pinetum nigrae ass. nov. | ||||
Orthilia secunda | 63 (75) | |||
Polygala chamaebuxus | 38 (55) | |||
Cephalanthera rubra | 25 (44) | |||
Epipactis helleborine | 41 (58) | |||
Hieracium murorum (s.l.) | 53 (52) | 19 | ||
Acer pseudoplatanus | 47 (48) | 19 | ||
Festuca stricta subsp. trachyphylla | 22 (41) | |||
Tanacetum corymbosum subsp. achillae | 25 (44) | |||
Acer monspessulanum | 22 (37) | 4 | ||
Digitalidi micranthae-Pinetum nigrae ass. nov. | ||||
Clematis vitalba | 25 | 70 (63) | ||
Hedera helix | 6 | 59 (67) | ||
Prunus mahaleb | 9 | 44 (52) | ||
Lonicera xylosteum | 41 (58) | |||
Asparagus acutifolius | 33 (52) | |||
Lonicera etrusca | 15 | |||
Emerus majus subsp. emeroides | 33 (52) | |||
Crataegus monogyna | 3 | 30 (45) | ||
Daphne laureola | 6 | 30 (42) | ||
Acer campestre | 19 | 63 (61) | ||
Fragaria vesca | 22 (42) | |||
Inula conyzae | 22 (42) | |||
Rubus caesius | 22 (42) | |||
Rubus hirtus (group) | 3 | 30 (45) | ||
Viola alba subsp. dehnhardtii | 41 | 70 (55) | ||
Teucrium chamaedrys | 31 | 27 (55) | ||
Genisto sericeae-Pinetum nigrae
|
||||
Genista sericea | 67 (77) | |||
Onosma echioides | 4 | 83 (89) | ||
Euphorbia barrelieri | 50 (65) | |||
Linum tenuifolium | 3 | 83 (87) | ||
Polygala major | 67 (77) | |||
Hippocrepis comosa | 67 (77) | |||
Plantago maritima subsp. serpentina | 67 (77) | |||
Echinops ritro | 50 (65) | |||
Teucrium montanum | 6 | 50 (60) | ||
Achnatherum calamagrostis | 33 (52) | |||
Carex kitaibeliana | 33 (52) | |||
Convolvulus elegantissimus | 33 (52) | |||
Helianthemum apenninum | 33 (52) | |||
Pinus heldreichii subsp. leucodermis | 33 (52) | |||
Viola cassinensis subsp. pseudogracilis | 33 (52) | |||
Trinia glauca | 17 | 33 (36) | ||
Helictochloa praetutiana | 33 | 50 (42) | ||
Junipero hemisphaericae-Pinion nigrae Biondi et Allegrezza 2020 | ||||
(typus association Junipero hemisphaericae-Pinetum nigrae Biondi et Allegrezza 2020) | ||||
Digitalis micrantha | 50 | 9 | 70 (47) | |
Cytisus spinescens | 72 | 33 | 100 (56) | |
Cytisophyllum sessilifolium | 47 | 19 | 67 (41) | |
Lomelosia crenata s.l. | 16 | 100 (91) | ||
Sesleria nitida | 59 (41) | 52 | ||
Siler montanum subsp. siculum | 38 | 33 | ||
Junipero communis-Pinetalia nigrae Biondi et Allegrezza 2020 | ||||
(typus alliance Fraxino orni-Pinion nigrae Em 1978) | ||||
Pinus nigra | 100 | 100 | 100 | 100 |
Juniperus communis s.l. | 100 (63) | 56 | 26 | |
Sesleria junceifolia complex | 67 | 6 | 100 (66) | |
Juniperus delthoides | 31 | 44 | ||
Trasgressive species | ||||
Fraxinus ornus | 17 | 81 | 100 (49) | 33 |
Sorbus aria | 100 | 59 | 67 | 100 |
Ostrya carpinifolia | 41 | 48 | 83 (46) | |
Erico-Pinetea Horvat 1959 | ||||
Amelanchier ovalis | 34 | 22 | 33 | |
Carex humilis | 33 | 53 (44) | ||
Cotoneaster tomentosum | 16 | 4 | ||
Goodyera repens | 6 | 4 | ||
Epipactis atrorubens | 6 | |||
Other species | ||||
Fagus sylvatica | 33 | 69 (38) | 30 | 17 |
Bromopsis erecta | 17 | 41 | 59 | 50 |
Globularia meridionalis | 67 | 34 | 11 | 33 |
Festuca circummediterranea | 83 (60) | 13 | 7 | 33 |
Euphorbia cyparissias | 67 (56) | 19 | 11 | |
Hypericum perforatum | 50 (47) | 9 | 15 | |
Helianthemum oelandicum subsp. incanum | 83 | 4 | 100 (62) | |
Rosa canina s.l. | 83 (49) | 34 | 48 | |
Viburnum lantana | 33 | 19 | 4 | |
Carex macrolepis | 17 | 28 | 33 | |
Brachypodium rupestre | 41 | 78 (54) | 17 | |
Galium corrudifolium | 16 | 26 | 83 (64) | |
Acer opalus subsp. obtusatum | 56 | 52 | 33 | |
Pteridium aquilinum | 3 | 7 | 33 | |
Quercus pubescens s.l. | 25 | 48 | 50 | |
Quercus ilex | 6 | 41 | 83 (63) | |
Laburnum anagyroides | 19 | 26 | 67 (50) | |
Poterium sanguisorba subsp. balearicum | 3 | 22 | 50 (46) |
The mature Pinus nigra plantations were located within four National Parks (Monti Sibillini; Gran Sasso and Monti della Laga; Maiella; Abruzzo, Lazio and Molise) and three Regional Natural Parks (Sasso Simone and Simoncello; Gola della Rossa and Frasassi; Sirente-Velino). The elevation was from 655 m a.s.l. (Mount Predicatore) to 1670 m a.s.l. (Mount Bove). The exposure was mainly southern, with slopes from 25° to 45°. The oldest plantation was located in Villetta Barrea (planted before 1900) in the Abruzzo-Molise National Park, followed by Mount Roio (planted in 1900) near the town of L'Aquila, finally to Mount Predicatore (planted in 1914-1916) in the Regional Natural Park of Gola della Rossa and Frasassi. The natural forest context was mainly represented by mixed deciduous forests (order Quercetalia pubescentis-petraeae) at the lower elevations (up to ~1100 m a.s.l.) and by beech forests (order Fagetalia sylvaticae) at the upper elevations (above ~1100 m a.s.l.) (
The dendrogram shown in Figure
Orthilio secundae-Pinetum nigrae ass. nov.
Suppl. material
Characteristic and differential species of the association Orthilio secundae-Pinetum nigrae: Pinus nigra subsp. nigra 4, Cytisus spinescens 3, Orthilia secunda 1, Globularia meridionalis 2, Cephalanthera rubra +; differential species of the subassociation typicum: Carex humilis. 1, Polygala chamaebuxus 1, Asperula purpurea +; Characteristic and differential species of the alliance Junipero hemisphaericae-Pinion nigrae, order Junipero communis-Pinetalia nigrae, and class Erico-Pinetea: Fraxinus ornus +, Sorbus aria 1, Juniperus communis (s.l.) 2, Amelanchier ovalis +, Lomelosia crenata ssp. pseudisetensis 2; Other species: Bromopsis erecta +, Rosa canina (s.l.) +, Acer monspessulanum 1, Euphorbia cyparissias 1, Pimpinella tragium +, Lotus corniculatus +, Centaurea ceratophylla 1, Hippocrepis glauca +, Pilosella officinarum 1. Thymus striatus ssp. acicularis 1, Anthericum liliago +; Koeleria splendens +; Dianthus longicaulis +, Leontodon crispus 1, Linum tenuifolium 1.
Orthilio secundae-Pinetum nigrae subass. typicum
rels 1–16; typus rel. 5: the same relevé reported before.
amelanchieretosum ovalis subass. nov.
rels 17–24; typus rel. 21: near Arischia (AQ) Gran Sasso e Monti della Laga National Park, geographic coordinates (33T 363875m E, 4699852m N), Implantation date (1930); Elevation (1205 m a.s.l.); Aspect (South-SouthEast); Slope (35°): Area (300 m2); Cover (85%);
Characteristic and differential species of the association Orthilio secundae-Pinetum nigrae: Pinus nigra subsp. nigra 3, Cytisus spinescens 2, Orthilia secunda +, Cephalanthera rubra +; differential species of the subassociation amelanchieretosum ovalis: Amelanchier ovalis 1, Cotoneaster tomentosus +, Viburnum lantana +, Lonicera caprifolium +, Festuca stricta subsp. trachyphylla +, Acer campestre, Inula hirta +; Characteristic and differential species of the alliance Junipero hemisphaericae-Pinion nigrae, order Junipero communis-Pinetalia nigrae, and class Erico-Pinetea: Fraxinus ornus 1, Sorbus aria 1, Juniperus communis (s.l.) +, Cytisophyllum sessilifolium 2, Juniperus deltoides +; Species from the class Querco-Fagetea; Fagus sylvatica +, Acer opalus subsp. obtusatum +, Hieracium murorum (s.l.) + Quercus cerris 1, Viola alba subsp. dehnhardtii 1, Neottia nidus-avis +, Solidago virgaurea +, Hepatica nobilis +; Other species: Bromopsis erecta +, Teucrium chamaedrys +, Asperula purpurea +, Dactylis glomerata +, Knautia calycina +, Hypericum perforatum +, Pimpinella saxifraga +, Carlina vulgaris +, Pilosella piloselloides +, Rosa arvensis +, Acer platanoides +, Fraxinus excelsior 1, Globularia bisnagarica +, Salvia pratensis 1);
saniculetosum europaeae subass. nov.
rels 25–32; typus rel. 25: Rel. 25: Bove Mountain locality, Sibillini National Park, geographic coordinates (33T 351231m E, 4752040m N), Implantation date (1930); Elevation (1590 m a.s.l.); Aspect (South); Slope (35°): Area (300 m2); Cover (95%);
Characteristic and differential species of the association Orthilio secundae-Pinetum nigrae: Pinus nigra subsp. nigra 4, Orthilia secunda 1, differential species of the subassociation saniculetosum europaeae: Sanicula europaea +, Cephalanthera longifolia 1; Characteristic and differential species of the alliance Junipero hemisphaericae-Pinion nigrae, order Junipero communis-Pinetalia nigrae, and class Erico-Pinetea: Sesleria nitida +, Juniperus communis (s.l.) +; Species from the class Querco-Fagetea: Fagus sylvatica 2, Acer opalus subsp. obtusatum +, Hieracium murorum (s.l.) 1, Acer pseudoplatanus +, Epipactis helleborine +, Ostrya carpinifolia +, Neottia nidus-avis +, Festuca heterophylla +, Quercus pubescens (s.l.) +, Acer campestre +; Other species: Brachypodium rupestre +, Rosa canina (s.l.) +, Teucrium chamaedrys +, Asperula purpurea +, Lotus corniculatus +, Digitalis micrantha +, Pilosella piloselloides +, Medicago lupulina +.
The new association Orthilio secundae-Pinetum nigrae includes mature plantations of Pinus nigra subsp. nigra on the slopes of the limestone reliefs of the central Apennines, with predominantly southern exposure and the optimum in the supratemperate thermotype in the context of the potential of the beech forests of the alliance Aremonio agrimonioidis-Fagion sylvaticae. The preferential dynamic contacts are with the vegetation shrubs of the alliance Berberidion vulgaris and with the secondary grasslands of the alliance Phleo ambigui-Bromion erecti and/or the Cytiso-Satureion montanae and Cerastio tomentosi-Globularion meridionalis garrigues. Sometimes where there are rocky conditions at the upper limit of the woods, the pine forests of the new association Orthilio secundae-Pinetum nigrae are in contact with the shrubby coenoses of Juniperus communis subsp. nana from Daphno oleoidis-Juniperion alpinae (class Loiseleurio procumbentis-Vaccinietea). These pine forests have an uneven structure, with a mean height of 15 m to 20 m, with Pinus nigra dominant (cover from 70%–90%) and a mean of 25.6 species per relevé. As well as P. nigra, some deciduous trees can be found in the shrubby layers (upper and lower), such as Fraxinus ornus, Sorbus aria, Fagus sylvatica, Acer obtusatum subsp. obtusatum, Ostrya carpinifolia, Quercus cerris and others, and juniper (Juniperus communis s.l., J. delthoides). The herbaceous layer is mainly represented by chamaephytic species, some of which are common in natural pine forests (Orthilia secunda, Polygala chamaebuxus) and others of which are typical of grasslands and garrigue (Asperula purpurea, Cytisus spinescens, Globularia meridionalis). However, there are also hemicriptophytes of heliophilous edges (Brachypodium rupestre) and grassland species (Bromopsis erecta, Carex humilis, Sesleria nitida). In addition, renewal of the pine is well represented, with its presence in 24 relevés out of a total of 33. The characteristic and differential species of the new association are considered to be: Pinus nigra subsp. nigra, Orthilia secunda, Polygala chamaebuxus, Epipactis helleborine and Cephalanthera rubra. The new association Orthilio secundae-Pinetum nigrae is referred to the central-southern Apennines alliance Junipero hemisphaericae-Pinion nigrae, order Junipero communis-Pinetalia nigrae, of the class Erico-Pinetea.
As part of the new association Orthilio secundae-Pinetum nigrae ( Suppl. material
Orthilio secundae-Pinetum nigrae subassociation typicum (rels 1–16) represents the more stable and mature aspect of the Pinus nigra plantation in the central Apennines in the supratemperate thermotype. Specifically, it refers to the ancient Pinus nigra stands (most planted before 1900) in the Abruzzo, Lazio and Molise National Park in the south-western part of the study area within the potential beech forests of the alliance Aremonio agrimonioidis-Fagion sylvaticae, at its southern limit and in transition towards those of the southern Apennines endemic alliance Geranio versicoloris-Fagion sylvaticae. These old stands are characterised by the high presence of chamaephyte species such as Polygala chamaebuxus, a common species of natural pine forests of Erico-Pinetea (
Subassociation amelanchieretosum ovalis subass. nov. (rels 17–25) is differentiated by phanerophyte and nanophanerophyte pre-forest species, such as Amelanchier ovalis, Cotoneaster tomentosus and Viburnum lantana, and it refers to the more thermophilous aspect of the new association Orthilio secundae-Pinetum nigrae. It is found on the rugged slopes of Ovindoli (Velino-Sirente mountain ridge) and Arischia (Gran Sasso mountain group) on soils rich in skeleton.
Finally, subassociation saniculetosum europaeae subass. nov. refers to the pioneer coenoses with Pinus nigra that has developed at the highest elevation, with a more significant presence of beech forest species. It is found for the Sibillini mountains and in the northern part of the study area (Mount Carpegna), within the potential of the macrothermic beech woods of the sub-alliance Lathyro veneti-Fagenion sylvaticae (Aremonio agrimonioidis-Fagion sylvaticae).
Digitalidi micranthae–Pinetum nigrae ass. nov.
Suppl. material
Characteristic and differential species of the association Digitalidi micranthae–Pinetum nigrae: Pinus nigra subsp. nigra 3, Digitalis micrantha +, Clematis vitalba +, Quercus ilex +, Asparagus acutifolius +, Lonicera etrusca 1, Characteristic and differential species of the alliance Junipero hemisphaericae-Pinion nigrae, order Junipero communis-Pinetalia nigrae, and class Erico-Pinetea: Fraxinus ornus 1, Juniperus deltoides +, Juniperus communis (s.l.) +; Species from the class Querco-Fagetea: Viola alba subsp. dehnhardtii +, Acer campestre +, Acer opalus subsp. obtusatum +, Quercus cerris +; Other species: Brachypodium rupestre 1, Bromopsis erecta +, Dactylis glomerata +, Galium corrudifolium +, Lotus corniculatus +, Fragaria vesca +, Hieracium murorum (s.l.) +, Rubus ulmifolius +, Eryngium amethystinum +, Carex flacca +, Cotinus coggygria +, Pteridium aquilinum +, Clinopodium vulgare +.
The new association Digitalidi micranthae-Pinetum nigrae brings together the thermophilous and rupestrian forest communities dominated by Pinus nigra subsp. nigra of artificial origin that are typically found from the upper mesotemperate to the lower supratemperate thermotypes with the subMediterranean variant. They are present at elevations from 650 m a.s.l. (Mount Catria) to 1270 m a.s.l. (Mount Velino) on the rugged slopes of the limestone reliefs of the central Apennines with predominantly west, east and south exposures, and as part of the potential of the mixed deciduous forests of the alliance Carpinion orientalis (mainly suballiance Cytiso-Quercenion pubescentis), and to a lesser extent of those of the alliance Fraxino orni-Quercion ilicis. In some cases, such as for the southern slopes of Mount Velino in the inner part of Abruzzo, the Pinus nigra stands of the new association represents the actual limit of the forests that are in dynamic contact with preforest communities of Juniperus communis subsp. hemisphaerica and J. communis subsp. nana.
The structure of the pine forest is irregular and has an average of 29.5 species per relevé. The dominant tree layer is monospecific as Pinus nigra, with an average height of 20 m and mean coverage of 70% to 80%. The shrub layer is well represented; in addition to Pinus nigra and Fraxinus ornus, it is characterised by lianose species (Hedera helix, Clematis vitalba, Lonicera etrusca), pre-forest species (Prunus mahaleb, Juniperus delthoides) and some forest species (Quercus ilex, Q. pubescens s.l.). The herbaceous layer is mainly seen as edge species (Digitalis micrantha, Brachypodium rupestre) followed by those of grasslands (Bromopsis erecta, Sesleria nitida). The renewal is given by Fraxinus ornus (always present) and Pinus nigra (renewal seen for 15 relevés of 27 in total).
The characteristic and differential species of the new association Digitalidi micranthae-Pinetum nigrae are considered to be: Pinus nigra subsp. nigra, Digitalis micrantha, Clematis vitalba, Hedera helix, Prunus mahaleb, Quercus ilex, Lonicera xylosteum, Asparagus acutifolius and Lonicera etrusca. The new association Digitalidi micranthae-Pinetum nigrae is referred to the central-southern Apennines alliance Junipero hemisphaericae-Pinion nigrae, order Junipero communis-Pinetalia nigrae, of the class Erico-Pinetea.
As part of the new association, the Cephalanthera longifolia variant (rels 21–27 of Suppl. material
For the Pinus nigra s.l. forests of the central southern Apennine-Balkan mountain ranges, the order Junipero communis-Pinetalia nigrae (typus alliance Fraxino orni-Pinion nigrae Em 1978) was recently proposed as vicariant of the order Erico-Pinetalia. These pine communities lie within the temperate macroclimate of the subMediterranean variant. In addition to species with Mediterranean and Mediterranean mountain distribution areas, they are characterised by a strong endemic component. This order includes the alliance Junipero hemisphaericae-Pinion nigrae that brings the pine forests together with Pinus nigra subsp. nigra of the central-southern limestone Apennines, which extends from the Sibillini group down to the Pollino group, mostly of the supratemperate thermotype. However, there are only two associations that are actually described for the natural P. nigra forests in the Apennines: Junipero hemisphaericae-Pinetum nigrae (typus Apennines alliance Junipero hemisphaericae-Pinion nigrae) for the upper supratemperate thermotype of Gran Sasso d’Italia and in dynamic contact with the juniper from the class Loiseleurio procumbentis-Vaccinietea (Biondi & Allegrezza 2020), and Genisto sericeae-Pinetum nigrae for the Pollino mountains (
This study represents the first syntaxonomic analysis of the Pinus nigra subsp. nigra artificial stands in the Apennines. Specifically, it refers exclusively to the mature Pinus nigra forest plantations in the central Apennines at elevations above 600 m a.s.l. that were planted before the 1950s and have not been managed for many years. Two new plant associations are described here: Orthilio secundae-Pinetum nigrae and Digitalidi micranthae-Pinetum nigrae belonging to the alliance Junipero hemisphaericae-Pinion nigrae of the central-southern Apennines. The association Orthilio secundae-Pinetum nigrae brings together the relative mesophilous mature pine forests of the supratemperate thermotype in the plant landscape context of the alliance Aremonio agrimonioidis-Fagion sylvaticae; Digitalidi micranthae-Pinetum nigrae is referred to the thermophilous and rupestrian mature pine forests present typically for the mesotemperate thermotype, but also for the low supratemperate thermotype with the subMediterranean variant in the plant landscape context of the alliance Carpinion orientalis (mainly Cytiso-Quercenion pubescentis). The comparison of the two new associations described with the literature phytosociological data for Pinus nigra natural communities in the Apennines highlights the floristic autonomy of these coenoses within the biogeographic context of the alliance Junipero hemisphaericae-Pinion nigrae. These Pinus nigra artificial communities represent a reference floristic model to deepen the ecology and floristic composition of the new Pinus nigra subsp. nigra natural communities, due to the pine colonisation of the abandoned grasslands by seed from pine plantations. This is a common phenomenon in the Apennines (e.g., Piermattei et al. 2014), as a consequence of the actual time of climate change and abandonment of the marginal mountain areas.
Erico-Pinetea Horvat 1959
JUNIPERO COMMUNIS-PINETALIA NigraE Biondi et Allegrezza 2020
Junipero hemisphaericae-Pinion nigrae Biondi et Allegrezza 2020
Orthilio secundae-Pinetum nigrae ass. nov.
subass. typicum
saniculetosum europaeae subass. nov.
amelanchieretosum ovalis subass. nov.
Digitalidi micranthae-Pinetum nigrae ass. nov.
Aremonio agrimonioidis-Fagion sylvaticae (Horvat 1938) Torok, Podani & Borhidi 1989; Carpinion orientalis Horvat 1958; Cytiso-Quercenion pubescentis Ubaldi 1995; Junipero-Pinetea sylvestris Rivas-Martınez 1965 nom. inv. propos.
Table S1 - Rel. 1: Crataegus monogyna Jacq. +; rel. 2: Helleborus foetidus L. +; rel. 3: Hepatica nobilis Schreb. 1. Neottia ovata 1; rel. 4: Pimpinella tragium Vill. +, Hippocrepis glauca +, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Thymus striatus subsp. acicularis +, Drymochloa sylvatica 1, Plantago lanceolata L. +, Poterium sanguisorba L. subsp. balearicum (Bourg. ex Nyman) Stace +; rel. 5: Pimpinella tragium Vill. +, Lotus corniculatus L. +, Centaurea ceratophylla Ten. 1, Hippocrepis glauca Ten. +, Pilosella officinarum Vaill. 1; Thymus striatus subsp. acicularis 1, Anthericum liliago L. +; Koeleria splendens Presl +; Dianthus longicaulis +, Leontodon crispus Vill. 1, Linum tenuifolium 1; rel. 6: Pimpinella tragium Vill. 1, Prunus mahaleb L. +, Centaurea ceratophylla 1, Drymochloa sylvatica 1, Ononis pusilla L. +; rel. 7: Laburnum anagyroides Medik. +, Limodorum abortivum (L.) Sw. +, Viola reichenbachiana Jord. ex Boreau +, Viola reichenbachiana Jord. ex Boreau +, Peucedanum verticillare (L.) Mert. et W.D.J. Koch +; rel. 8: Prunus mahaleb L. +, Festuca circummediterranea Patzke +, Viola riviniana Rchb. +, Hedera helix L. +, Asplenium adiantum-nigrum L. +; rel. 9: Laburnum anagyroides Medik. +, Dactylis glomerata L. +, Festuca circummediterranea Patzke +, Pilosella officinarum Vaill. +, Hedera helix L. +, Anthericum liliago L. +, Carlina vulgaris L. +, Helleborus foetidus L. +, Koeleria splendens Presl +, Teucrium montanum L. +, Anthyllis vulneraria L. (s.l.) +, Carlina acaulis L. subsp. caulescens (Lam.) Schübl. & G. Martens +, Centaurea rupestris L. +, Scabiosa columbaria L. (s.l.) +, Pimpinella saxifraga L. +; rel. 10: Laburnum anagyroides Medik. +, Viola reichenbachiana Jord. ex Boreau 2, Festuca circummediterranea Patzke +, Pilosella officinarum Vaill. +, Pimpinella saxifraga L. +, Arabis hirsuta (L.) Scop. +, Pyrus communis L. subsp. pyraster (L.) Ehrh. +, Hieracium villosum Jacq. (group) +, Viola eugeniae Parl. +; rel. 11: Pimpinella tragium Vill. +, Limodorum abortivum (L.) Sw. +, Emerus majus Mill. +, Teucrium montanum L. +, Seseli tommasinii +; rel. 12: Laburnum anagyroides Medik. 1, Lotus corniculatus L. +, Centaurea ceratophylla +, Hippocrepis glauca +, Thymus striatus subsp. acicularis +; rel. 13: Emerus majus Mill. 1, Epipactis microphylla +, Arabis sp. +; rel. 14: Hippocrepis glauca +, Emerus majus Mill. +, Silene italica (L.) Pers. +; rel. 15: Lotus corniculatus L. +, Prunus mahaleb L. +, Centaurea ceratophylla +, Festuca circummediterranea Patzke +, Limodorum abortivum (L.) Sw. +, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Cotoneaster pyrenaicus +, Polygala nicaeensis +; rel. 16: Pimpinella tragium Vill. +, Lotus corniculatus L. 1, Cerastium tomentosum +; rel. 17: Galium corrudifolium Vill. +, Hepatica nobilis Schreb. +, Pimpinella tragium Vill. +, Prunus mahaleb L. +, Corylus avellana L. 2, Pilosella officinarum Vaill. +, Viola riviniana Rchb. +, Daphne oleoides Schreb. +; rel. 18: Galium corrudifolium Vill. +, Arabis turrita L. +, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Quercus ilex L. +, Daphne oleoides Schreb. +, Helianthemum nummularium (L.) Mill. subsp. obscurum (Celak.) Holub +, Arctostaphylos uva-ursi (L.) Spreng. +, Gentiana dinarica Beck +, Sorbus aucuparia L. +, Thymus serpyllum (s.l.) +; rel. 19: Galium corrudifolium Vill. +, Medik. +, Cephalanthera damasonium (Mill.) Druce +, Knautia calycina +, Limodorum abortivum (L.) Sw. +, Primula vulgaris Huds.+, Hypericum perforatum L. +, Quercus ilex L. +, Campanula micrantha Bertol. +, Epipactis muelleri Godfery +, Peucedanum oreoselinum (L.) Moench +, Pyrus communis L. subsp. pyraster (L.) Ehrh. +, Leontodon hispidus L. (s.l.) +, Luzula sylvatica (Huds.) Gaudin +, Potentilla rigoana Th. Wolf +, Poterium sanguisorba L. subsp. balearicum (Bourg. ex Nyman) Stace +, Senecio inaequidens DC. +, Silene ciliata Pourr. subsp. graefferi (Guss.) Nyman +, Silene vulgaris (Moench) Garcke subsp. tenoreana (Colla) Soldano & F. Conti +; rel. 20: Cephalanthera damasonium (Mill.) Druce +, Dactylis glomerata L. +, Knautia calycina +, Hypericum perforatum L. +, Cotoneaster pyrenaicus +, Hieracium racemosum Waldst. & Kit. ex Willd. (s.l.) +, Vicia cracca L. +, Leucanthemum heterophyllum (Willd.) DC. +, Prunella laciniata (L.) L. +, Sorbus domestica L. +; rel. 21: Hepatica nobilis L., +, Dactylis glomerata L. +, Knautia calycina +, Hypericum perforatum L. +, Pimpinella saxifraga L. +, Carlina vulgaris L. +, Pilosella piloselloides (Vill.) Soják +, Rosa arvensis Huds. +, Acer platanoides L. +, Fraxinus excelsior L. 1, Globularia bisnagarica L. +, Salvia pratensis L. 1; rel. 22: Knautia calycina +, Luzula sylvatica (Huds.) Gaudin subsp. sieberi (Tausch) K. Richt. +, Prunus avium L. +, Helianthemum nummularium (L.) Mill. subsp. obscurum (Celak.) Holub +, Sesleria juncifolia Wulfen ex Suffren +, Hieracium sp. +; rel. 23: Viola reichenbachiana Jord. ex Boreau +, Viola riviniana Rchb. +, Luzula sylvatica (Huds.) Gaudin subsp. sieberi (Tausch) K. Richt. +, Prunus avium L. +, Arabis hirsuta (L.) Scop. +, Rosa arvensis Huds. +, Sesleria juncifolia Wulfen ex Suffren +, Campanula scheuchzeri Vill. +, Galium verum L. +, Hieracium pseudogrovesianum Gottschl. 1, Lilium bulbiferum L. subsp. croceum (Chaix) Jan +, Monotropa hypopitys L. +, Rhamnus saxatilis Jacq. +; rel. 24: Galium corrudifolium Vill. +, Viola reichenbachiana Jord. ex Boreau +, Dactylis glomerata L. +, Primula vulgaris Huds. +, Viola riviniana Rchb. +, Luzula sylvatica (Huds.) Gaudin subsp. sieberi (Tausch) K. Richt. 1, Epipactis muelleri Godfery +, Hieracium racemosum Waldst. & Kit. ex Willd. (s.l.) +, Vicia cracca L. +, Bupleurum falcatum L. subsp. cernuum (Ten.) Arcang. +; rel. 25: Lotus corniculatus L. +, Digitalis micrantha Roth ex Schweigg. +, Pilosella piloselloides (Vill.) Soják +, Festuca heterophylla Lam. +, Medicago lupulina L. +; rel. 26: Galium corrudifolium Vill. +, Cephalanthera damasonium (Mill.) Druce +, Digitalis micrantha Roth ex Schweigg.+, Vicia dasycarpa Ten. +, Cirsium morisianum Rchb. +, Cnidium silaifolium (Jacq.) Simonk. +, Dactylorhiza maculata L. (s.l.) +, Heracleum sphondylium L. subsp. pyrenaicum (Lam.) Bonnier & Layens +, Myosotis sylvatica Hoffm. +, Picris hieracioides L. (s.l.) +, Platanthera bifolia (L.) Rchb. +, Trifolium ochroleucum Huds. +; rel. 27: Galium corrudifolium Vill. +, Cephalanthera damasonium (Mill.) Druce +, Digitalis micrantha Roth ex Schweigg. +, Arabis turrita L. +, Silene italica (L.) Pers. +, Vicia dasycarpa Ten. +, Clinopodium alpinum (L.) Merino +, Galium mollugo L. subsp. erectum Syme +, Hieracium cymosum L. +, Poa nemoralis L. +, Trifolium alpestre L. +, Trifolium pratense L. +; rel. 28: Hepatica nobilis Schreb. +, Viola reichenbachiana Jord. ex Boreau 1, Primula vulgaris Huds. 1, Prunus avium L. +, Abies alba Mill. +, Campanula micrantha Bertol. +, Daphne laureola L. +, Cardamine bulbifera (L.) Crantz +, Prunella vulgaris L. +, Taxus baccata L. +; rel. 29: Viola reichenbachiana Jord. ex Boreau +, Corylus avellana L. +, Abies alba Mill. +, Melittis melissophyllum L. +, Pteridium aquilinum (L.) Kuhn +, Rubus hirtus (group) +; rel. 30: Hepatica nobilis Schreb. +, Corylus avellana L. +, Peucedanum oreoselinum (L.) Moench +, Fraxinus angustifolia Vahl subsp. oxycarpa (Willd.) Franco & Rocha Afonso +, Lilium martagon L. +, Populus tremula L. +, Trifolium montanum L. subsp. rupestre (Ten.) Nyman +; rel. 31: Laburnum anagyroides Medik. +, Corylus avellana L. +, Arabis turrita L. +, Melittis melissophyllum L. +; rel. 32: Primula vulgaris Huds. +, Silene italica (L.) Pers. +, Daphne laureola L. +, Equisetum arvense L. +, Galium aparine L. +, Lathyrus pratensis L. +, Orchis purpurea Huds. +, Stellaria media (L.) Vill. +, Veronica hederifolia L.+.
Table S2 - Rel. 1: Scabiosa columbaria L. (s.l.) +, Sorbus domestica L. +, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Globularia meridionalis (Podp.) O. Schwarz +, Festuca circummediterranea Patzke +, Arabis hirsuta (L.) Scop. +, Ononis pusilla L. +, Ajuga reptans L. +, Asperula aristata L. f. subsp. oreophila (Briq.) Hayek +, Asperula cynanchica L.+, Pilosella piloselloides (Vill.) Soják +, Hieracium sp. +, Juglans regia L. +, Leontodon crispus Vill. +, Pimpinella tragium Vill. +, Prunella laciniata (L.) L. +, Saxifraga paniculata Mill. +, Thymus longicaulis C. Presl +: rel. 2: Rubus caesius L. +, Inula conyzae (Griess.) Meikle +, Poterium sanguisorba L. subsp. balearicum (Bourg. ex Nyman) Stace +, Hieracium murorum L. (s.l.) +, Eryngium amethystinum L. +, Festuca heterophylla Lam. +, Hypericum perforatum L. +, Solidago virgaurea L. +, Campanula glomerata L. 1, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Leontodon hispidus L. (s.l.) +, Clinopodium alpinum (L.) Merino +, Carex digitata L. +, Coronilla minima L. +, Trifolium ochroleucum Huds. +, Bellis perennis L. +, Carex flacca Schreb. +, Crepis leontodontoides All. +, Goodyera repens (L.) R. Br. +, Onosma echioides (L.) L. +, Picea abies (L.) H. Karst. +, Silene vulgaris (Moench) Garcke subsp. tenoreana (Colla) Soldano & F. Conti +; rel. 3: Listera ovata (L.) R. Br. +, Rubus caesius L. +, Inula conyzae (Griess.) Meikle +, Poterium sanguisorba subsp. balearicum (Bourg. ex Nyman) Stace +, Scabiosa columbaria L. (s.l.) +, Hieracium murorum L. (s.l.) +, Eryngium amethystinum L. +, Festuca heterophylla Lam. +, Hypericum perforatum L. +, Solidago virgaurea L. +, Abies alba Mill. +, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Globularia bisnagarica L. +, Leontodon hispidus L. (s.l.) +, Robinia pseudoacacia L. +, Clinopodium alpinum (L.) Merino +, Carlina utzka Hacq. +, Geranium lucidum L. +, Genista tinctoria L. +, Stachys recta L. (s.l.) +; rel. 4: Listera ovata (L.) R. Br. +, Fragaria vesca L. +, Inula conyzae (Griess.) Meikle +, Poterium sanguisorba L. subsp. balearicum (Bourg. ex Nyman) Stace +, Scabiosa columbaria L. (s.l.) +, Acer pseudoplatanus L. +, Hieracium murorum L. (s.l.) 1, Eryngium amethystinum L. +, Festuca heterophylla Lam. +, Pilosella officinarum Vaill. +, Globularia bisnagarica L. +, Leontodon hispidus L. (s.l.) +, Robinia pseudoacacia L. +, Carex digitata L. +, Coronilla minima L. +, Ononis pusilla L. +, Trifolium ochroleucum Huds. +, Achillea millefolium L. +, Crepis lacera Ten. +; rel. 5: Cephalanthera damasonium (Mill.) Druce +, Arabis turrita L. +, Inula conyzae (Griess.) Meikle +, Scabiosa columbaria L. (s.l.) +, Festuca heterophylla Lam. 1, Senecio inaequidens DC. +, Silene italica (L.) Pers. subsp. italica +, Carex halleriana Asso +, Festuca inops De Not. +, Limodorum abortivum (L.) Sw. +; rel. 6: Inula conyzae (Griess.) Meikle +, Scabiosa columbaria L. (s.l.) +, Pilosella officinarum Vaill. +, Senecio inaequidens DC. +, Silene italica (L.) Pers. +, Abies cephalonica Loud. +, Globularia meridionalis (Podp.) O. Schwarz +, Cedrus deodara (D. Don) G. Don. +, Festuca circummediterranea Patzke +, Arabis collina Ten. +, Astragalus aquilanus Anzal. +, Carex divulsa Stokes +, Erysimum pseudorhaeticum Polatschek +, Picris hieracioides L. (s.l.) +, Pimpinella major (L.) Huds. +; rel. 7: Rubus ulmifolius Schott +, Hypericum perforatum L. +, Pilosella officinarum Vaill. +, Senecio inaequidens DC. +, Silene italica (L.) Pers. +, Abies cephalonica Loud. +, Globularia meridionalis (Podp.) O. Schwarz +, Cedrus deodara (D. Don) G. Don. +, Ferula communis L. +, Helianthemum oelandicum (L.) Dum. Cours. subsp. incanum (Willk.) G. López +, Hieracium grovesianum Arv.-Touv. ex Belli (s.l.) +, Knautia calycina +, Pimpinella saxifraga L. +; rel. 8: Poterium sanguisorba L. subsp. balearicum (Bourg. ex Nyman) Stace +, Sorbus domestica L. +, Campanula glomerata L. +, Rosa arvensis Huds. +, Securigera varia (L.) Lassen +; rel. 9: Sorbus domestica L. 1, Lonicera caprifolium L. +, Cyanus triumfetti (All.) Dostál ex Á. & D. Löve +, Arabis hirsuta (L.) Scop. +, Crataegus laevigata (Poir.) DC. 1, Emerus majus Mill. +; rel. 10: Corylus avellana L. 1, Arabis turrita L. +, Fragaria vesca L. +, Inula conyzae (Griess.) Meikle +, Campanula trachelium L. +, Cornus sanguinea L. (s.l.) +, Viola reichenbachiana Jord. ex Boreau +, Euphorbia cyparissias L. +, Robinia pseudoacacia L. +, Euonymus latifolius (L.) Mill. +, Saponaria ocymoides L. +, Alyssoides utriculata (L.) Medik. +, Doronicum columnae Ten. +, Poa nemoralis L. +, Rhamnus saxatilis Jacq. +, Thalictrum aquilegiifolium L. +; rel. 11: Corylus avellana L. +, Arabis turrita L. +, Rubus ulmifolius Schott +, Cornus sanguinea L. (s.l.) +, Hypericum perforatum L. +, Viola reichenbachiana Jord. ex Boreau +, Euphorbia cyparissias L. +, Tamus communis L. +, Berberis vulgaris L. +, Euonymus latifolius (L.) Mill. +, Medicago lupulina L. +, Saponaria ocymoides L. +, Acer monspessulanum L. +, Cirsium erisithales (Jacq.) Scop. +, Potentilla micrantha Ramond ex DC. +, Oreoherzogia fallax +, Rhamnus cathartica L. +; rel. 12: Corylus avellana L. Campanula trachelium L. +, Lonicera caprifolium L. +, Prunus avium L. +, Vicia cracca L. +, Berberis vulgaris L. +, Pinus sylvestris L. 1, Sonchus oleraceus L. +, Melittis melissophyllum L. +; rel. 13: Corylus avellana L. +, Arabis turrita L. +, Hieracium murorum L. (s.l.) +, Campanula trachelium L. +, Senecio inaequidens DC. +, Viola reichenbachiana Jord. ex Boreau +, Vicia cracca L. +, Pinus sylvestris L. +, Sonchus oleraceus L. +, Geranium lucidum L. +, Lathyrus apacha L. +, Sedum rupestre L. +; rel. 14: Cephalanthera damasonium (Mill.) Druce +, Scabiosa columbaria L. (s.l.) +, Cornus mas L. +, Pilosella officinarum Vaill. +, Clematis recta +, Osyris alba L. 2, Vincetoxicum hirundinaria Medik. +; rel. 15: Cornus mas L. +, Aremonia agrimonoides (L.) DC. +, Clematis recta +; rel. 16: Fragaria vesca L. +, Hieracium murorum L. (s.l.) +, Rubus ulmifolius Schott +, Eryngium amethystinum L. +, Carex flacca Schreb. +, Cotinus coggygria Scop. +, Pteridium aquilinum (L.) Kuhn +, Clinopodium vulgare L. +; rel. 17: Cephalanthera damasonium (Mill.) Druce +, Fragaria vesca L. +, Rubus ulmifolius Schott 1, Sorbus domestica L. +, Cotinus coggygria Scop. +, Buglossoides purpurocaerulea (L.) I.M. Johnst. +; rel. 18: Aremonia agrimonoides (L.) DC. +, Viburnum lantana L. +; rel. 19: Cornus sanguinea L. (s.l.) 1, Rosa arvensis Huds. +, Euonymus europaeus L. +; rel. 20: Campanula trachelium L. +, Cornus sanguinea L. (s.l.) +, Tamus communis L. +, Medicago lupulina L. +; rel. 21: Listera ovata (L.) R. Br. +, +, Acer pseudoplatanus L. 1, Lonicera caprifolium L. 1, Abies alba Mill. +, Lathyrus sylvestris L. +, Orchis purpurea Huds. +, Tamus communis L. +, Carex flacca Schreb. +, Galium mollugo L. subsp. erectum Syme +, Peucedanum verticillare (L.) Mert. et W.D.J. Koch 1; rel. 22: Listera ovata (L.) R. Br. +, Poterium sanguisorba L. subsp. balearicum (Bourg. ex Nyman) Stace +, Sorbus domestica L. +, Lonicera caprifolium L. +, Prunus avium L. +, Orchis purpurea Huds. +, Vicia cracca L. +, Peucedanum verticillare (L.) Mert. et W.D.J. Koch 1, Cruciata glabra (L.) Ehrend. +, Dactylorhiza maculata L. (s.l.) +; rel. 23: Cephalanthera damasonium (Mill.) Druce +, Arabis turrita L. +, Cornus mas L. +, Rubus ulmifolius Schott +, Lactuca muralis (L.) Gaertn. +, Prunus avium L. +, Abies cephalonica Loud. +, Galium odoratum (L.) Scop. +, Helleborus bocconei Ten. +, Luzula forsteri (Sm.) DC. 1, Luzula sylvatica (Huds.) Gaudin +, Ruscus aculeatus L. +; rel. 24: Cephalanthera damasonium (Mill.) Druce +, Listera ovata (L.) R. Br. +, Rubus caesius L. +, Acer pseudoplatanus L. +, Solidago virgaurea L. +, Campanula glomerata L. +, Globularia bisnagarica L. +, Lathyrus sylvestris L. +, Hieracium racemosum Waldst. & Kit. ex Willd. (s.l.) +, Lilium bulbiferum L. subsp. croceum (Chaix) Jan +; rel. 25: Listera ovata (L.) R. Br. +, Rubus caesius L. +, Cornus mas L. +, Lactuca muralis (L.) Gaertn. +, Solidago virgaurea L. +, Lathyrus sylvestris L. +, Orchis purpurea Huds. +, Mercurialis annua L. +, Sonchus asper (L.) Hill (s.l.) +, Stachys officinalis (L.) Trevis. +; rel. 26: Corylus avellana L. +, Rubus caesius L. 2, Fragaria vesca L. +, Acer pseudoplatanus L. +, Cornus mas L. 2, Lactuca muralis (L.) Gaertn. 2, Prunus avium L. +, Viola reichenbachiana Jord. ex Boreau +, Aremonia agrimonoides (L.) DC. +, Castanea sativa Mill. +, Hepatica nobilis Schreb. 1, Mercurialis perennis L. 1, Salvia glutinosa L +, Viola hirta L. +; rel. 27: Cephalanthera damasonium (Mill.) Druce +, Corylus avellana L. +, Rubus caesius L. +, Arabis turrita L. +, Fragaria vesca L. +, Acer pseudoplatanus L. +, Lactuca muralis (L.) Gaertn. 1, Silene italica (L.) Pers. +, Abies alba Mill. +, Rosa arvensis Huds. +, Galium mollugo L. subsp. erectum Syme +, Hieracium racemosum Waldst. & Kit. ex Willd. (s.l.) +, Pteridium aquilinum (L.) Kuhn +, Ceterach officinarum Willd. (s.l.) +, Geranium robertianum L. +, Hieracium bifidum Kit. ex Hornem. (s.l.) +, Ligustrum vulgare L. +, Pyrus communis L. subsp. pyraster (L.) Ehrh. +, Smirnyum olusatrum +, Sorbus aucuparia L. +.
Table S1 - Rels 1–6: 14/07/1987, Godi Mountain, Abruzzo, Lazio and Molise National Park; Rel. 7: 22/08/2016, near Villetta Barrea (AQ), Abruzzo, Lazio and Molise National Park 33T 411228m E 4625974m N; Rel. 8: 22/08/2016, near Villetta Barrea (AQ), Abruzzo, Lazio and Molise National Park, 33T 410310m E 4625680m N; Rel.: 9: 22/08/2016, near Villetta Barrea (AQ), Abruzzo, Lazio and Molise National Park, 33T 411346m E 4625577m N; Rel. 10: from
Table S2 - Rel. 1: 27/07/2015, Assergi (AQ), Gran Sasso e Monti della Laga National Park, 33T 376782m E 4695117m N.; rel. 2: from
Column 1: Junipero hemisphaericae-Pinetum nigrae Biondi et Allegrezza 2020 [(from Allegrezza & Biondi (2020), Table S1, rels 1-6)], Campo Imperatore plateau (Gran Sasso e Monti della Laga National Park, central Apennines); column 2: Orthilio secundae-Pinetum nigrae ass. nov. (present paper); column 3: Digitalidi micranthae-Pinetum nigrae ass. nov. (present paper); column 4: Genisto sericerae-Pinetum nigrae