Corresponding author: Salvatore Pasta ( salvatore.pasta@ibbr.cnr.it ) Academic editor: Simonetta Bagella
© 2021 Alfonso La Rosa, Lorenzo Gianguzzi, Giuseppe Salluzzo, Leonardo Scuderi, Salvatore Pasta.
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:
La Rosa A, Gianguzzi L, Salluzzo G, Scuderi L, Pasta S (2021) Last tesserae of a fading mosaic: floristic census and forest vegetation survey at Parche di Bilello (south-western Sicily, Italy), a site needing urgent protection measures. Plant Sociology 58(1): 55-74. https://doi.org/10.3897/pls2020581/04
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This paper illustrates the botanic heritage of Parche di Bilello, a site located in the municipality of Castelvetrano. The study area hosts several woodland fragments dominated by Olea europaea var. sylvestris, Quercus suber and Quercus ilex, respectively. According to historical data, these nuclei represent the last remnants of an open forestland which covered a much wider coastal area between Mazara del Vallo and Sciacca until the end of Middle Age. Phytosociological relevés were focused on these forest nuclei, probably the most representative of south-western Sicily, which correspond to three habitats included in the 92/43 EEC Directive (9320, 9330 and 9340, respectively) and represent the final stage of three different edaphic series. Wild olive forests probably dominated on sandy calcareous soils, holm oaks prevailed on steep calcareous and N-exposed slopes. In contrast, cork oaks mostly occurred on sandy subacid soils issuing from pedogenetic processes on palaeodunes. Moreover, field surveys allowed to list 331 vascular plant taxa. Among them, Linaria multicaulis subsp. humilis, Orobanche balsensis and Serapias orientalis subsp. siciliensis are new to Trapani Province. Detailed information on the current distribution and the synecology of several plant taxa of high biogeographic and conservation interest is also provided. The study site also hosts one habitat of priority interest (6220, i.e. xerophilous Mediterranean perennial grasslands and annual swards) and two species protected by international laws, i.e. the orchid Ophrys lunulata and the lichen Teloschistes chrysophthalmus. Considering the high value of its natural heritage, this territory deserves the adoption of more effective protection measures. For this reason the authors recommend its inclusion as a new Site of Community Interest within the Sicilian Natura 2000 network.
endangered plant species, floristic inventories, forest vegetation, landscape history, nature conservation
Italy and Sicily have a long history of nature protection. They host hundreds of protected areas, sites of interest according to 92/43 EEC Directive and important plant areas (
In this framework, field research remains the main tool to deepen basic knowledge about the biological heritage of fragile and poorly investigated areas where endangered plants and habitats may co-occur. Moreover, the correct identification and the standardised description of rare vegetation units may play a key role in protecting locally endangered plant communities and preserving all the steps of local vegetation series. These actions improve the survival and the natural dynamics between and within the patches of natural and semi-natural habitats rare at the national (
This paper presents the results from a research focused on the vascular flora and the forest vegetation of the locality ‘Parche di Bilello’. This site is located between the localities ‘Bresciana’ and ‘Madonna di Trapani’ (South), ‘Guardiola’ (West), ‘Atria’ (East) and ‘Canalotto’ (North) and belongs to the municipality of Castelvetrano (Province of Trapani, south-western Sicily) (Figs
The study area (Figs
The origin of toponym ‘Parche di Bilello’ remains unclear. On an old map printed by the Istituto Topografico Militare Italiano (
The almost flat coastal landscapes between Sciacca and Marsala are usually called Sciare, a vernacular term which seems to derive from the Arab word ‘sha’raa’ (= sterile and uncultivated area). Agricultural activities are difficult here due to poor soil availability. The term ‘Sciare’ has been broadly used to indicate local karst flatlands, characterized by a mosaic of outcropping calcareous rocks and sandy-loamy shallow lithosols supporting a mosaic-like patchwork of thermo-xerophilous vegetation including therophytic swards, perennial dry grasslands, garrigues and low maquis. The Sciare also host several small temporary ponds and rock pools rich in hygrophilous and aquatic communities. Until mid 1900s the local complex network of humid areas was fed by a rich and shallow aquifer, whose level was progessively lowered by more than 20 m during the last decades due to indiscriminate (and often illegal) water uptake (
According to
Basing on the available thermo-pluviometric data from the stations of Castelvetrano, Mazara del Vallo and Sciacca, according to Rivas-Martínez bioclimatic classification (
Main climatic data obtained from the nearest climatic stations (from
A | ||||||||||||||
Station | J | F | M | A | M | J | J | A | S | O | N | D | Year | Nb. rainy days |
Campobello di Mazara | 71.0 | 76.4 | 49.6 | 53.9 | 27.7 | 3.0 | 1.3 | 8.8 | 29.1 | 81.4 | 80.9 | 73.5 | 556.6 | 67 |
B | ||||||||||||||
Station | AV of the warmest month | AV of the coldest month | Annual AV | Range between the AV of the warmest and coldest month | Absolute max. value | Absolute min. value | ||||||||
Mazara del Vallo | 22.3 | 13.8 | 18.0 | 8.5 | 48.8 | -0.1 |
The pollen analysis from cores carried out along the south-western coasts of Sicily not far from our study site at Gorgo Basso and Lago Preola (municipality of Mazara del Vallo) allowed to trace the main phases of the evolution of local landscape over last 10,500 years (
The study site falls within the wider territory of Birribaida. This toponym, still reported in the already mentioned
Indeed, between 13th and 15th centuries local forest cover underwent substantial reduction and fragmentation. Several notarial documents confirm this; for instance, Bresc-Gautier (1983) reports that already in 1239 the farmers of Sciacca complained with Emperor Frederic II Hohenstaufen for the shortage of wood needed to build ploughs, and
During the XVI century, the noble family Aragona Tagliavia, counts (and since 1564 princes) of Castelvetrano implemented a policy aiming at promoting local agricultural activities by means of mid- to long-term ground leasing contracts (emphyteusis); consequently local farmers could act as temporary land owners and gradually expanded cereal crop fields, vineyards, olive groves to the detriment of local woodland nuclei, and intensified the exploitation of local water for mills and to irrigate sugar cane plantations, rice fields and vegetable gardens (Scalisi 2012). The wide area still hosted some fragments of forest-maquis until the XVIII–XIX centuries AD (Noto 1732; Amico Statella 1759;
The coastal area between Mazara del Vallo and Menfi during the Middle Ages (from
The first records concerning the vascular plants growing in the so-called ‘Sciare’ of Marsala and Mazara date back to
Lichens identification was carried out by using the analytical keys proposed by
The taxonomic identity, the chorotypes and the life forms of the observed vascular plants follow the second edition of ‘Flora d’Italia’ (
The syntaxonomy of the high rank syntaxa (i.e. alliances, orders and classes) follows the schemes proposed by
Forest vegetation was investigated applying the Zurich-Montpellier method (
Moreover, the evaluation of the biogeographic and conservation interest of local vascular flora was supported by the most updated red-list (
Some dry specimens of the vascular plants and lichens collected in the study area are stored in the personal herbaria of A. La Rosa, L. Gianguzzi, while many exsiccata of L. Scuderi are deposited in the herbarium of the University of Catania (CAT).
Field investigations aiming to list all the lichens occurring in the study area are still going on, and the final results will hopefully be published soon in a separate paper. During these surveys, around 50 individuals of an extremely rare lichen, Teloschistes chrysophthalmus (L.) Th. Fr. (Fig.
A, Teloschistes chrysophthalmus (L.) Th.Fr. (photo: A. La Rosa, February 24, 2013); B, Linaria multicaulis (L.) Mill. subsp. humilis (Guss.) De Leon., Giardina & Zizza (photo: A. La Rosa, March 31, 2013); C, Orobanche balsensis (J.A.Guim.) Carlón, M.Laínz, Moreno Mor. & O.Sánchez (photo: A. La Rosa, May 5, 2013); D, Serapias orientalis (Greuter) H.Baumann & Künkele subsp. siciliensis Bartolo & Pulv. (photo: A. La Rosa, April 28 , 2013); E, Acis autumnalis (L.) Sweet (photo: L. Gianguzzi, October 13, 2019); F, Desmazeria sicula (Jacq.) Dumort. (photo: A. La Rosa, April 20, 2013); G, Ophrys lunulata Parl. (photo: A. La Rosa, March 31, 2013).
As much as 331 infrageneric taxa were observed during the field surveys (see Suppl. material
As for life-forms, the study site is characterized by a strong prevalence of annual (T = 170 taxa) and perennial (H = 72; G = 41) herbs and grasses, representing about 85% of total vascular flora. Woody plant list includes 27 phanerophytes, whilst chamaephytes and nano-phanerophytes are both represented by 11 taxa.
The exotic (cultivated, naturalised and invasive) taxa are 13, corresponding to only 3.9% of all the observed vascular plants.
Linaria multicaulis (L.) Mill. subsp. humilis (Guss.) De Leon., Giardina & Zizza
This taxon (Fig.
Local population counts few individuals observed growing in local fallow fields (79 m a.s.l., exposition East, 31.03.2013. A. La Rosa).
Orobanche balsensis (J.A.Guim.) Carlón, M.Laínz, Moreno Mor. & O.Sánchez
This taxon (Fig.
Serapias orientalis (Greuter) H. Baumann & Künkele subsp. siciliensis Bartolo & Pulv.
This taxon is new to Trapani province and to western Sicily (Fig.
Local population counts about 20 individuals, colonizing a grassland patch occupying a gap of local shrubland, dominated by Cytisus infestus, referred to the association Pyro amygdaliformis-Calicotometum infestae (79 m a.s.l., exposition North, 28.04.2013, A. La Rosa).
Acis autumnalis (L.) Sweet
The earliest records of this species (Fig.
Local population counts few individuals concentrated in semi-shaded surface along a path with one of the forest nuclei referred to Pistacio lentisci-Quercetum ilicis (80 m a.s.l., exposition North-East, 14.10.2012, A. La Rosa).
Desmazeria sicula (Jacq.) Dumort.
Within Trapani Province, this plant (Fig.
Local population counts few individuals growing along the borders of the road that takes to the local ‘baglio’ (= rural house) (80 m a.s.l., exposition North, 20.04.2013, A. La Rosa).
Ophioglossum lusitanicum L.
This small fern grows in the annual swards on nutrient-poor sandy soils (Helianthemion guttati Br.-Bl in Br.-Bl. & Wagner 1940) or in temporary ponds or seasonally wet rock pools referred to Cicendion (Rivas Goday in Rivas Goday & Borja 1961) Br.-Bl. 1967. In the province of Trapani it was first noticed by
More in detail, the population found at Parche di Bilello counts few individuals growing within a bryophytic community colonising a clearing within one of the main forest nuclei (80 m a.s.l., exposition East, 03.02.2013, A. La Rosa).
Ophrys lunulata Parl.
Included in the Appendix I of Washington Convention and in the Appendix II of the 92/43 EU ‘Habitats’ Directive, this Sicilian endemic occurs almost everywhere in the pasturelands (garrigues, perennial grasslands, open shrubland, thermophilous forest edges) throughout the Sicilian territory, albeit it usually forms small or very small populations. As for its distribution in the Province of Trapani (Fig.
Only three individuals were observed growing in a xeric grasslands along the main road (80 m a.s.l., exposition East, 31.03.2013, A. La Rosa).
Oxalis pes-caprae dominates the winter facies of the weed communities referred to the alliance Diplotaxion erucoidis Br.-Bl. in Br.-Bl., Gajewski, Wraber & Walas 1936 (
The local occurrence of Galinsoga parviflora confirms its establishment and spread during last decades. This ruderal thermophilous plant native to North America is listed among the characteristic species of the order Eragrostietalia J. Tx. ex Poli 1996 (
This paragraph provides a brief description of the main features of the local landscape (Table
The main disturbance factors recorded in the study area are wildfires, which frequently affect local vegetation, and the use of non-organic fertilisers and pesticides in the olive groves, citrus orchards and vineyards in the surroundings.
As for the semi-natural plant communities, particular attention has been paid to forest vegetation. Vegetation relevés (see Tables
Several patches of local evergreen sclerophyllous vegetation are dominated by wild olive trees, localised on calcareous sandstone outcrops. These nuclei shall be framed into the Chamaeropo humilis-Oleetum sylvestris acanthetosum mollis (Gianguzzi and Bazan 2019; Fig.
Local wild olive forest fragments, referred as habitat 9320 of the 92/43 ‘Habitats’ Directive, are among the best preserved in the entire Sicilian territory (
Few patches of Quercus ilex forest are localized on north-facing slopes; these woodland fragments (Fig.
Soil cover units, phytosociological units and habitats (* = priority) according to 92/43 EU Directive of the study area and the nearby territory.
Soil cover units | Association(s) | Habitats |
Climatophilous vegetation of semi-natural areas | ||
Holm oakwood nuclei | Pistacio lentisci-Quercetum ilicis | 9340 |
Cork oakwood nuclei | Stipo bromoidis-Quercetum suberis (impoverished) | 9330 |
Dwarf palm-wild olive maquis | Chamaeropo humilis-Oleetum sylvestris acanthetosum mollis | 9320 |
Rock-rose garrigues | Rosmarino-Thymetum capitati | - |
Perennial grasslands | Hyparrhenietum hirto-pubescentis | 6220* |
Annual swards | Ononido breviflorae-Stipetum capensis, Thero-Sedetum caerulei | 6220* |
Hygrophilous vegetation occurring in the watercourses of the nearby territory | ||
Riparian forests | Salicetum albo-pedicellatae | 92A0 |
Scrub of the seasonally dry Mediterranean riverbeds | Tamarix africana-dominated community | 92D0 |
Reed meadows | Phragmitetum communis | - |
Dwarf Palm-Wild Olive evergreen sclerophyllous maquis (Chamaeropo humilis-Oleetum sylvestris acanthetosum mollis). Relevés 1–5 (L. Gianguzzi, 24.04.2005, in Gianguzzi & Bazan 2019a, Tab. S4 n. 74 and 82–85); relevés 6–9 (L. Gianguzzi, 9.05.2007, in Gianguzzi & Bazan 2019a, Tab. S4 n. 77–78 and 88–87); relevés 10-14 (L. Gianguzzi, 12.05.2014, unpubl.).
Relevé (n°) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Altitude (m) | 80 | 80 | 86 | 84 | 80 | 76 | 70 | 67 | 65 | 78 | 79 | 81 | 81 | 86 |
Slope (°) | 20 | 30 | 15 | 15 | 15 | 20 | 30 | 25 | 25 | 15 | 5 | 5 | 5 | 7 |
Aspect | SW | S | E | S | N | E | E | SE | S | E | E | E | E | N |
Area (m2) | 120 | 150 | 150 | 150 | 150 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
Total cover (%) | 100 | 100 | 100 | 95 | 95 | 100 | 100 | 90 | 100 | 100 | 100 | 100 | 100 | 100 |
Tree cover (%) | 100 | 100 | 100 | 90 | 90 | 100 | 100 | 20 | 100 | 100 | 95 | 100 | 100 | 40 |
Shrub cover (%) | 100 | 100 | 100 | 90 | 90 | 100 | 100 | 80 | 100 | 100 | 95 | 100 | 100 | 70 |
Herbaceous cover (%) | 40 | 40 | 40 | 40 | 40 | 40 | 40 | 30 | 20 | 30 | 25 | 20 | 20 | 15 |
Average heigth of the dominant layer (m) | 6 | 6 | 5 | 3,5 | 4 | 5 | 7 | 3,5 | 5 | 6 | 6 | 5 | 5 | 7 |
Species per relevé | 17 | 17 | 18 | 20 | 17 | 21 | 23 | 22 | 21 | 20 | 22 | 22 | 19 | 21 |
Char. and diff. of association and subassociation | ||||||||||||||
Olea europaea L. var. sylvestris (Mill.) Lehr | 5 | 5 | 4 | 5 | 4 | 5 | 5 | 5 | 5 | 5 | 5 | 5 | 4 | 5 |
Acanthus mollis L. subsp. mollis | 2 | 3 | 2 | 1 | + | 3 | 3 | 1 | 2 | 1 | + | 1 | 1 | 1 |
Chamaerops humilis L. | + | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | . | . | 1 | 1 | + |
Rhamnus alaternus L. subsp. alaternus | . | . | 1 | . | + | . | . | . | 1 | + | 1 | 2 | 2 | . |
Char. of alliance and order | ||||||||||||||
Pistacia lentiscus L. | 2 | 2 | 3 | 3 | 3 | 3 | 3 | 2 | 2 | 3 | 3 | 2 | 3 | 3 |
Stachys major (L.) Bartolucci & Peruzzi | + | + | 1 | 1 | 2 | 1 | + | 1 | 1 | . | 1 | + | 1 | 1 |
Allium subhirsutum L. subsp. subhirsutum | 1 | 1 | 1 | 1 | . | 1 | 1 | + | . | + | + | . | 1 | . |
Asparagus albus L. | 1 | 1 | + | . | 1 | . | . | 1 | 1 | 1 | 1 | + | + | . |
Clematis cirrhosa L. | 2 | 1 | 1 | + | + | . | + | . | . | + | . | . | . | . |
Anagyris foetida L. | . | . | 1 | 1 | . | 2 | . | 2 | . | . | . | 1 | 2 | 1 |
Cytisus infestus (C.Presl) Guss. subsp. infestus | . | . | 1 | . | . | + | . | 1 | . | . | 1 | + | 1 | 1 |
Teucrium fruticans L. subsp. fruticans | . | . | . | 1 | 2 | . | . | . | . | + | 2 | . | . | . |
Myrtus communis L. | . | . | . | 1 | . | . | . | . | . | . | . | . | . | . |
Ceratonia siliqua L. | . | . | . | . | . | . | . | . | . | . | . | 1 | . | . |
Rhamnus lycioides subsp. oleoides (L.) Jahand. & Maire | . | . | . | . | . | . | . | . | . | . | . | . | . | 1 |
Char. of class Quercetea ilicis | ||||||||||||||
Smilax aspera L. | 2 | 2 | 3 | + | 1 | 3 | 3 | + | 2 | 1 | 1 | 3 | 2 | 1 |
Asparagus acutifolius L. | 1 | 1 | 1 | 1 | + | 1 | 1 | 1 | 1 | 1 | 1 | 1 | . | + |
Rubia peregrina L. | 1 | 1 | 1 | 1 | 1 | . | + | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Arisarum vulgare O.Targ.Tozz. subsp. vulgare | + | 1 | 1 | 1 | + | 1 | . | + | 1 | + | + | . | 1 | + |
Daphne gnidium L. | + | . | 1 | . | + | . | + | . | . | . | + | + | . | + |
Ampelodesmos mauritanicus (Poir.) T.Durand & Schinz | . | . | + | 1 | . | + | 1 | + | . | . | . | . | + | . |
Rosa sempervirens L. | . | . | . | . | . | + | 2 | + | + | + | . | . | . | . |
Quercus suber L. | . | . | . | . | . | . | . | . | 1 | 1 | 1 | . | . | . |
Osyris alba L. | . | . | . | . | . | . | . | . | . | 1 | . | + | . | + |
Celtis australis L. subsp. australis | 1 | 1 | . | . | . | . | . | . | . | . | . | . | . | . |
Pyrus spinosa Forssk. | . | . | . | . | . | + | 1 | . | . | . | . | . | . | . |
Phillyrea latifolia L. | . | . | . | . | . | . | . | . | . | . | + | . | . | . |
Other species | ||||||||||||||
Oxalis pes-caprae L. | 3 | 2 | 2 | 3 | 3 | 2 | + | 1 | + | 2 | + | + | 1 | . |
Oloptum miliaceum (L.) Röser & H.R.Hamasha | + | . | . | 1 | . | + | + | 1 | + | + | + | + | . | + |
Geranium purpureum L. | . | + | . | + | 2 | + | . | . | . | . | 2 | 1 | 1 | + |
Hyparrhenia hirta (L.) Stapf subsp. hirta | + | + | . | . | . | . | + | 1 | + | . | + | . | . | . |
Capparis spinosa L. | . | + | . | + | 1 | . | . | + | . | . | . | . | + | + |
Asphodelus ramosus L. subsp. ramosus | . | + | . | + | . | . | . | . | + | + | . | + | . | + |
Mercurialis annua L. | + | . | . | . | . | + | . | . | + | . | 1 | + | . | . |
Ferula communis L. subsp. communis | . | . | . | . | . | . | + | 1 | . | 1 | . | . | . | + |
Charybdis pancration (Steinh.) Speta | . | . | . | . | . | . | . | + | . | . | + | + | + | . |
Smyrnium olusatrum L. | . | . | + | 1 | . | . | . | . | + | . | . | . | . | . |
Brachypodium retusum (Pers.) P.Beauv. | . | . | . | . | + | + | + | . | . | . | . | . | . | . |
Silene latifolia Poir. | . | . | . | . | . | + | + | . | 1 | . | . | . | . | . |
Rubus ulmifolius Schott | . | . | . | . | . | 1 | 1 | . | . | . | . | . | . | . |
Kundmannia sicula (L.) DC. | . | . | . | . | . | . | + | + | . | . | . | . | . | . |
Umbilicus horizontalis (Guss.) DC. | . | . | . | . | . | . | + | . | + | . | . | . | . | . |
Magydaris pastinacea (Lam.) Paol. | . | . | . | . | . | . | . | . | . | + | . | . | + | . |
Cistus creticus subsp. creticus | . | . | . | . | . | . | . | . | . | . | . | + | . | 1 |
Bituminaria bituminosa (L.) E.H.Stirt. | . | . | . | . | . | + | . | . | . | . | . | . | . | . |
Crataegus monogyna Jacq. | . | . | . | . | . | . | 1 | . | . | . | . | . | . | . |
A, Evegreen maquis-forest nucleus referred to the Chamaeropo humilis-Oleetum sylvestris acanthetosum mollis (Habitat 9320) (photo: L. Gianguzzi, May 9, 2007); B, Forest nucleus dominated by Quercus ilex (Habitat 9340) (photo: L. Gianguzzi, May 9, 2007); C, Century-old tree of Quercus suber (photo: L. Gianguzzi, May 9, 2007); D, Forest strip dominated by Quercus suber (Habitat 9330) (photo: L. Gianguzzi, May 9, 2007).
Holm oak wood stands (Pistacio lentisci-Quercetum ilicis). Relevés 1–2 (L. Gianguzzi, 9.05.2007, unpubl.).
Relevé (n°) | 1 | 2 |
Altitude (m) | 73 | 75 |
Slope (°) | 20 | 15 |
Aspect | N | N |
Area (m2) | 100 | 100 |
Total cover (%) | 100 | 80 |
Tree cover (%) | 100 | 100 |
Scrub cover (%) | 30 | 60 |
Herbaceous cover (%) | 20 | 5 |
Average heigth of the dominant layer (m) | 7.5 | 7.0 |
Species per relevé | 26 | 21 |
Char. association | ||
Quercus ilex L. | 5 | 5 |
Pistacia lentiscus L. | 3 | 4 |
Chamaerops humilis L. | + | 1 |
Asparagus albus L. | + | . |
Char. alliance (Fraxino-Quercion ilicis), order (Quercetalia ilicis) and class Quercetea ilicis | ||
Smilax aspera L. | 2 | 3 |
Olea europaea L. var. sylvestris (Mill.) Lehr | 2 | 1 |
Phillyrea latifolia L. | 2 | 1 |
Clematis cirrhosa L. | 2 | 1 |
Rhamnus alaternus L. subsp. alaternus | 1 | 2 |
Arisarum vulgare O.Targ.Tozz. subsp. vulgare | 1 | 2 |
Rubia peregrina L. | 1 | 2 |
Quercus suber L. | 1 | 2 |
Pistacia lentiscus L. | 1 | 1 |
Asparagus acutifolius L. | 1 | 1 |
Allium subhirsutum L. subsp. subhirsutum | 1 | + |
Stachys major (L.) Bartolucci & Peruzzi | + | . |
Osyris alba L. | + | . |
Daphne gnidium L. | + | . |
Ampelodesmos mauritanicus (Poir.) T.Durand & Schinz | + | . |
Teucrium fruticans L. subsp. fruticans | . | + |
Other species | ||
Acanthus mollis L. subsp. mollis | 2 | 3 |
Smyrnium olusatrum L. | 2 | + |
Oxalis pes-caprae L. | 1 | 1 |
Crataegus monogyna Jacq. | 1 | + |
Oloptum miliaceum (L.) Röser & H.R.Hamasha | 1 | + |
Asphodelus ramosus L. subsp. ramosus | + | + |
Stellaria neglecta Weihe subsp. cupaniana (Jord. & Fourr.) Gutermann | + | . |
Silene latifolia Poir. | + | . |
Degraded cork oak stands (Stipo bromoidis-Quercetum suberis) of Parche di Bilello (Relevés 1–2: L. Gianguzzi, 9.05.2007, unpubl.) and adjacent areas (Relevé 3: L. Scuderi, Locality Bresciana, municipality of Castelvetrano, 7.06.2005; cf. Scuderi, 2006).
Relevé (n°) | 1 | 2 | 3 |
Altitude (m) | 77 | 80 | 48 |
Slope (°) | 5 | 2 | 2 |
Aspect | N | N | S |
Area (m2) | 100 | 100 | 200 |
Total cover (%) | 100 | 90 | 80 |
Tree cover (%) | 95 | 90 | 80 |
Scrub cover (%) | 70 | 60 | 60 |
Herbaceous cover (%) | 40 | 45 | 40 |
Average heigth of the dominant layer (m) | 7.5 | 8.0 | 7.0 |
Species per relevé | 19 | 15 | 19 |
Char. of association and alliance Erico arboreae-Quercion ilicis | |||
Quercus suber L. | 5 | 5 | 4 |
Myrtus communis L. | . | . | 1 |
Aristella bromoides (L.) Bertol. | . | . | + |
Char. order Quercetalia ilicis and class Quercetea ilicis | |||
Smilax aspera L. | 3 | 2 | 2 |
Pistacia lentiscus L. | 2 | 2 | 2 |
Rosa sempervirens L. | 1 | 2 | 2 |
Olea europaea L. var. sylvestris (Mill.) Lehr | 2 | 1 | 1 |
Rubia peregrina L. | 2 | 1 | 1 |
Allium subhirsutum L. subsp. subhirsutum | 1 | + | 1 |
Stachys major (L.) Bartolucci & Peruzzi | 1 | + | + |
Asparagus acutifolius L. | 1 | 2 | + |
Arisarum vulgare O.Targ.Tozz. subsp. vulgare | + | 1 | . |
Rhamnus alaternus L. subsp. alaternus | 1 | . | . |
Asparagus albus L. | 1 | . | . |
Quercus ilex L. | + | . | . |
Chamaerops humilis L. | . | + | . |
Carex divulsa Stokes | . | . | + |
Other species | |||
Acanthus mollis L. subsp. mollis | 2 | 1 | . |
Geranium purpureum L. | + | + | . |
Euphorbia ceratocarpa Ten. | 1 | . | 1 |
Hyparrhenia hirta (L.) Stapf subsp. hirta | 1 | . | 1 |
Oloptum miliaceum (L.) Röser & H.R.Hamasha | + | . | 2 |
Rubus ulmifolius Schott | . | 1 | 1 |
Silene latifolia Poir. | + | . | . |
Smyrnium olusatrum L. | . | + | . |
Crataegus monogyna Jacq. | . | . | 1 |
Cistus creticus L. subsp. eriocephalus (Viv.) Greuter & Burdet | . | . | + |
Solanum villosum Mill. | . | . | + |
Although severely degraded and floristically impoverished, some cork oak wood nuclei still survive in the study area, forming linear features along dry stone walls and hedges which probably correspond to the past borders of the fief. These forest fragments host some majestic (more than 1 m of diameter at breast height: Fig.
Lichens, Vascular plants and habitat types of high biogeographic/conservation interest occurring at Parche di Bilello. Since 1995 all the European Orchids are included within the Appendix I of CITES. * = species listed in the Appendixes or habitat of priority interest according to 92/43 EU Directive.
Taxon | Endemic | Narrow Range | Protected/ Red-Listed | Other Criteria |
Acis autumnalis | x | |||
Allium obtusiflorum | x | |||
Ambrosina bassii | x | |||
Anacamptis papilionacea subsp. grandiflora | x | |||
Barlia robertiana | x | |||
Carlina sicula subsp. sicula | x | |||
Desmazeria sicula | x | |||
Echium italicum subsp. siculum | x | |||
Euphorbia ceratocarpa. | x | |||
Linaria multicaulis subsp. humilis | x | x | ||
Ophioglossum lusitanicum | x | x | ||
Ophrys apifera | x | |||
Ophrys lunulata | x | * | x | |
Ophrys lutea subsp. lutea | x | |||
Ophrys sicula | x | |||
Ophrys speculum | x | |||
Ophrys tenthredinifera subsp. grandiflora | x | x | ||
Orobanche balsensis | x | |||
Pimpinella anisoides | x | |||
Serapias orientalis subsp. siciliensis | x | x | x | |
Tragopogon cupanii | x | |||
Habitats of the 92/43 EU Directive occurring in the study area | Endemic | Narrow Range | Protected/ Red-Listed | Other Criteria |
6220 | * | |||
9320 | x | x | ||
9330 | x | x | ||
9340 | x | |||
Habitats of the 92/43 EU Directive occurring in the nearby territory | Endemic | Narrow Range | Protected/ Red-Listed | Other Criteria |
92A0 | x | |||
92D0 | x |
Local fragments of Quercus suber woods probably represented the final stage on local well-drained and mostly sandy-loamy soils on palaeodunes. This head of serieshas been wiped out little by little to give room to vineyards and olive groves over wide areas of the surrounding territory. The degradation of cork oakwoods usually leads to the spread of a patchy landscape made of broom-dominated shrublands referred to Pyro amygdaliformis-Calicotometum infestae – locally very rare due to the century-lasting removal of fuelwood – and garrigues (Rosmarino-Thymetum capitati) intermingled with perennial grasslands (Hyparrhenietum hirto-pubescentis) and annual therophytic swards belonging to Helianthemetea guttati Rivas Goday & Rivas-Mart. 1963). Like in the Erei territory (e.g., Niscemi, Caltagirone), on the deeper soils of the innermost part of southwestern Sicily such cork oak forests might have occurred in close contact with thermophilous woodlands dominated by Quercus pubescens s.l.. Downy oaks have completely disappeared from the whole territory, with the only exception of few remarkable isolated individuals growing in the bottom of the canyon of Castello di Pietra (
With regards to the taxonomic value of Q. virgiliana as well as of various other taxa belonging to the collective group of Q. pubescens Willd., widely reported for Sicily and southern Italy in the last decades, a lively scientific debate is still going on (see Wellstein & Spada 2015;
Ancient floras suggest that until few centuries ago Q. pubescens s.l. was more common than today in the lowlands and near the coastline, while the few avaialable data on vegetation dynamics after the abandonment of cork production (
At present, very few data were available on the occurrence of cork oak in the north-western and western Sicily (
Although south-western Sicily is correctly included in both the potential (
Additionally, small stands and isolated trees of Q. suber still occur along the roadsides of the ancient Feudo (= fiefdom) of Dimina between Castelvetrano and Partanna (
The discovery of Linaria multicaulis subsp. humilis and Serapias orientalis subsp. siciliensis, discussed in the present paper, together with the recent finding of Retama raetam (Forssk.) Webb subsp. gussonei (Webb) W. Greuter (
As already highlighted by
On this purpose, we should underline that our study area is not far from the River Modione. This watercourse which still hosts several fragments of riparian forest referred to Salicetum albo-pedicellatae (Salicion albae). Moreover, several spots of thermo-hygrophilous scrub (Tamarix africana-dominated community) occur on the seasonally dry beds and the riversides of this river, while reed meadows (Phragmitetum communis) colonize its thalweg (data not shown). All these data suggest to promote a more comprehensive investigation of the size, importance and distribution of other patches of semi-natural habitats testifying for the previous extension of local woodlands and riparian forests. For instance, taking into account a wider portion of the territory may allow to produce a more articulated proposal for the institution of a new site of Community interest or to create the ecological corridors needed to connect the site of Parche di Bilello with an already existing hub of the Sicilian Natura 2000 network, i.e. ITA010005 ‘Laghetti di Preola e Gorghi Tondi e Sciare di Mazara’, located within a 15 km radius from our study area.
The study area worths to be protected and valorized for the high symbolic value of the last remnant nuclei of forest vegetation, especially considering that the Parche di Bilello host the best conserved nuclei of wild olive forests occurring in the entire province of Trapani and the last fragments of cork oak woods referred to Stipo bromoidis-Quercetum suberis, completely wiped out from the whole south-western Sicily. Since 2014 the management of the study area is under the responsibility of the ONG ‘Cooperativa Sociale Onlus Rita Atria-Libera Terra’, aiming at promoting legality and traditional extensive agricultural practices. A best practice could be to assign to this ONG the role of guardian of this area, representing a precious tile survived to the destruction of the past coastal woodland/shrubland/grassland mosaic.
The presence of bifacial pebble tools, probably dating back to Mesolithic and testifying for the long-lasting history of local human presence, has been reported for the study area (
QUERCETEA ILICIS Br.-Bl. ex A. Bolòs et O. de Bolòs in A. Bolòs y Vayreda 1950
QUERCETALIA ILICIS Br.-Bl. ex Molinier 1934
Fraxino orni-Quercion ilicis Biondi, Casavecchia et Gigante in Biondi et al. 2013
Pistacio lentisci-Quercetum ilicis Brullo et Marcenò 1985
Erico arboreae-Quercion ilicis S. Brullo, De Martino et Marcenò 1977
Stipo bromoidis-Quercetum suberis Barbagallo 1983
PISTACIO LENTISCI-RHAMNETALIA ALATERNI Rivas-Martínez 1975
Oleo sylvestris-Ceratonion siliquae Br.-Bl. 1936 em. Rivas-Martínez 1975
Pistacio lentisci-Chamaeropetum humilis Brullo et Marcenò 1985
Chamaeropo humilis-Oleetum sylvestris acanthetosum mollis Gianguzzi et Bazan 2019
Pyro amygdaliformis-Calicotometum infestae Gianguzzi et La Mantia 2008
ONONIDO-ROSMARINETEA Br.-Bl. in A. Bolos y Vayreda 1950
ROSMARINETALIA OFFICIALIS Br.-Bl. ex Molinier 1934
Cisto eriocephali-Ericion multiflorae Biondi 2000
Rosmarino officinalis-Thymetum capitati Furnari 1965
LYGEO SPARTI-STIPETEA TENACISSIMAE Rivas-Martínez 1978
CYMBOPOGONO-BRACHYPODIETALIA RAMOSI Horvatic1963
Hyparrhenion hirtae Br.-Bl., P. Silva et Rozeira 1956
Hyparrhenietum hirto-pubescentis A.et O. de Bolòs et Br.-Bl. in A. et O.Bolòs 1950
STIPO-TRACHYNIETEA DISTACHYAE Brullo in Brullo, Scelsi et Spampinato 2001
BRACHYPODIETALIA DISTACHYI Rivas-Martínez 1978
Trachynion distachyae Rivas-Martínez 1978
Sedetum caerulei Brullo 1975
STIPO-BUPLEURETALIA SEMICOMPOSITI Brullo in Brullo, Scelsi et Spampinato 2001
Plantagini-Catapodion marini
Ononido breviflorae-Stipetum capensis Brullo, Guarino et Ronsisvalle 1998
SALICETEA PURPUREAE Moor 1958
SALICETALIA PURPUREAE Moor 1958
Salicion albae Soo 1951
Salicetum albo-pedicellatae Brullo et Spampinato 1991
NERIO-TAMARICETEA Br.-Bl. et O. de Bolòs 1958
TAMARICETALIA AFRICANAE Br.-Bl. et O. de Bolòs 1958
Tamaricion africanae Br.-Bl. et O. de Bolòs 1958
Tamarix africana-dominated community
PHRAGMITO-MAGNOCARICETEA Klika in Klika et V. Novák 1941
PHRAGMITETALIA KOCH 1926
Phragmition communis Koch 1926
Phragmitetum communis Koch 1926
Ammophiletea Br.-Bl. & Tx. ex Westhoff, Dijk & Passchier 1946; Chenopodietea Br.-Bl. in Br.-Bl. et al. 1952; Crithmo-Staticetea Br.-Bl. in Br.-Bl., Roussine & Nègre 1952; Diplotaxion erucoidis Br.-Bl. in Br.-Bl., Gajewski, Wraber & Walas 1936; Eragrostietalia J. Tx. ex Poli 1966
We are indebted to Angelo Troia (Dept. STEBICEF, University of Palermo) for sharing unpublished personal data. We also thank two anonymous reviewers and the editorial board of Plant Sociology, whose critical comments and suggestions significantly improved the quality of the manuscript.