**4. Results**

### *4.1. The Current Plant Landscape*

The natural vegetation of this area is composed of remnant forest patches, shrublands and extensive grasslands which are stages of degradation of pre-existing forest due to anthropic activities. Five different woods have been identified according to the environmental characteristics (bioclimate belts and substrate). The main forests formation are holm oak woods (*Ampelodesmo mauritanici-Quercetum ilicis* and *Sorbo torminalis-Quercetum ilicis*) and downy oak woods (*Oleo oleaster-Quercetum virgilianae* and *Sorbo torminalis-Quercetum virgilianae*) (Figure 4). Along the rivers also grow hygrophilous forests with poplars and willows (*Ulmo canescentis-Salicetum pedicellatae*). Shrublands of thorny bushes of Rosaceae and other evergreen Mediterranean bushes are the result of wood degradation due to cutting or fire. Grazing and fire normally lead to the establishment of *Ampelodesmos mauritanicus* grassland. These natural and seminatural vegetation patches are embedded in a matrix of agricultural land uses characterized by cereals, grapevines and olive trees, "the Mediterranean triad" [65].

The syn-phytosociological analysis allowed us to characterize the associations from a floristic and structural point of view (Table 1) and to define the dynamic relationships among seral stages (Figure 4). Four climatophilous vegetation series and one edapho-hygrophilous vegetation series, which together define the forest landscape of this area of the Sicani Mountains, were identified.

For each of them, the association head of series, the main seral stages and the ecological and geographical distribution in the region are described below.

### 4.1.1. Mesomediterranean Series of Holm Oak (*Ampelodesmo mauritanici-Querco ilicis* Sigmetum)

*Ampelodesmo mauritanici-Quercetum ilicis* Gianguzzi, Cuttonaro, Cusimano & Romano 2016 is a woody vegetation whose tree layer is clearly dominated by *Quercus ilex* and sometimes associated with *Quercus virgiliana* and *Fraxinus ornus* (Column 1 in Table 1). From the floristic point of view, this community is characterized by the occurrence of *Ampelodesmos mauritanicus*, *Hippocrepis emerus* subsp. *emeroides* and *Lonicera implexa*. In addition to the typical aspect, the subass. *viburnetosum tini* Gianguzzi et al. 2016 was surveyed in the more humid and cool stands.

This association represents the most evolved stage of an edapho-climatophilous series that includes various secondary communities derived from the degradation of woodlands. In particular, on quite sloped and sunny stands, it is often replaced by a low shrubby vegetation characterized by *Euphorbia characias* and *Anagyris foetida*, referable to *Euphorbio characiae-Anagyridetum phoetidis* Gianguzzi, Cuttonaro, Cusimano & Romano 2016, while a further community, named *Euphorbio characiae-Prunetum spinosae* Gianguzzi, Cuttonaro, Cusimano & Romano 2016, is linked to very eroded and less inclined surfaces (Column 5 in Table 1). The degradation of these communities favors the settlement of the dry grasslands belonging to *Helictotricho convolute-Ampelodesmetum mauritanici* Minissale 1994.

This vegetation occurs in the mesomediterranean belt with an upper subhumid ombrotype, generally at an altitude from 450 to 1000 m. It prefers the most inclined slopes with northern exposure, colonizing calcareous lithosols with a significant detrital component derived from erosion and landslides. Currently, this series is known only from the Sicani mountains [52].

#### 4.1.2. Supramediterranean Series of Holm Oak (*Sorbo torminalis-Querco ilicis* Sigmetum)

The head series is represented by mesophilous holm oak woods with a closed structure, referable to the *Sorbo torminalis-Quercetum ilicis* Gianguzzi, Cuttonaro, Cusimano & Romano 2016. From the floristic point of view, the association is characterized by the occurrence of some nemoral species with mesic requirements, such as *Daphne laureola*, *Paeonia mascula* subsp. *russoi* and *Euphorbia amygdaloides* subsp. *arbuscula*, etc. (Column 2 in Table 1).

In addition to *Sorbo torminalis-Quercetum ilicis*, this series is constituted by some secondary stages, which are often very frequent due to the strong anthropization of the investigated area; this vegetation should be represented only in the higher altitudes of the Barraù mountain. *Roso siculae-Prunetum spinosae* Gianguzzi, Cuttonaro, Cusimano & Romano 2016 (Column 6 in Table 1) is an orophilous shrubby community that replaces the woods on very shallow soils, forming a very dense and closed vegetation with *Rosa sicula* and some species belonging to *Berberido aetnensis–Crataegion laciniatae* Gianguzzi et al. 2011, such as *Crataegus rhipidophylla* and *Rubus canescens*. A further degradation of the woody vegetation leads to the establishment of dry grasslands belonging to *Helictotricho convolute-Ampelodesmetum mauritanici* Minissale 1994.

This series is linked to stands with eroded calcareous soils, above 1000 m a.s.l., which are characterized by a meso or supramediterranean bioclimate with an upper subhumid ombrotype. It was surveyed only in the Sicani mountains, representing a geographical vicariant of *Acer campestri-Querco ilicis* sigmetum from the Madonie area. In the investigated area, only small, floristically impoverished relicts of this vegetation remain.

### 4.1.3. Thermo-Mesomediterranean Series of Downy Oak (*Oleo oleaster-Querco virgilianae* Sigmetum)

The *Oleo oleaster-Quercetum virgilianae* Brullo 1984 represents the most evolved stage of this series, as a woody vegetation dominated by *Quercus virgiliana* (Ten.) Ten. and *Quercus amplifolia* Guss. (Column 3 in Table 1). It is a deciduous woodland with a rich xeric-thermophilous component belonging to *Quercetalia calliprini* Zohary 1955, represented by *Olea europaea* L. var. *sylvestris* Brot., *Pistacia lentiscus*, *Teucrium fruticans* L., *Prasium majus*, etc. Moreover, *Quercetalia ilicis* Br.-Bl. ex Molinier 1934 is well represented by several species, such as *Quercus ilex*, *Rubia peregrina* subsp. *longifolia*, *Carex distachya* Desf., *Osyris alba*, *Asparagus acutifolius*, *Smilax aspera*, *Calicotome infesta*, *Arisarum vulgare*, *Lonicera implexa*, *Ruscus aculeatus*, etc.

The secondary stages of *Oleo sylvestris-Quercetum virgilianae* include the garrigues of the Cisto eriocephali–Ericion multiflorae Biondi 1997 and the deciduous shrubs of Crataego-Prunetea Tx. 1962, such as *Roso corymbiferae-Rubetum-Rubetum ulmifolii* Gianguzzi, Cuttonaro, Cusimano & Romano 2016 in the investigated area (Column 7 in Table 1). The degradation of these shrubby communities, mainly due to fires, leads to the establishment of dry grasslands belonging to *Avenulo cincinnatae-Ampelodesmion mauritanici* Minissale 1995. The further degradation of the soil due to erosive phenomena determines the establishment of ephemeral communities of *Trachynion distachyae* Rivas-Martinez 1978.

This series occurs on more or less deep and evolved soils, developing on various kinds of substrates (limestone, dolomite, marl, clay, basalt, sandstones, schist, etc.). Generally, its potential area coincides with the places which are most suitable for agricultural activities; for this reason, it is

currently fairly localized and covers only small surfaces. From the bioclimatic perspective, it falls within the thermo-mediterranean belt, with some penetrations in the subhumid mesomediterranean belt. Its distribution range includes Sicily and southern Italy [66].

### 4.1.4. Supramediterranean Series of Downy Oak (*Sorbo torminalis-Querco virgilianae* Sigmetum)

*Sorbo torminalis–Quercetum virgilianae* Gianguzzi, Cuttonaro, Cusimano & Romano 2016 is a woodland dominated by *Quercus virgiliana*, whose mesic character is emphasized by the occurrence of *Sorbus torminalis* and a rich herbaceous component characterized by some rare umbellifers, among them *Physospermum verticillatum* (Waldst. & Kit.) Vis., *Geocaryum cynapioides* (Guss.) Engstrand. and *Cnidium silaifolium* (Jacq.) Simonk. (Column 4 in Table 1).

This association has completely disappeared from the area in which it could potentially be present, such as the summit plains of Monte Barraù. It has been replaced by the *Crataegetum laciniatae* Brullo & Marcenò 1984, an orophilous scrub dominated by *Crataegus rhipidophylla*, which is sometimes associated with *Pyrus spinosa* and scattered shrubby specimens of *Acer campestre* (Column 8 in Table 1). However, larger surfaces are covered by a mosaic of mesophilous meadows belonging to *Cynosuro-Leontodontetum siculi* Brullo & Grillo 1978 and *Cachyretum ferulaceae* Raimondo 1980, while the most eroded surfaces and the rocky outcrops are characterized by the prostrate chamaephytic vegetation of *Carduncello pinnati-Thymetum spinulosi* Brullo & Marcenò in Brullo 1984.

It colonizes deep calcareous soils, preferring the fresh and shady northern slopes at altitudes between 800 and 1400 m a.s.l. From the bioclimatic viewpoint, it is localized from the mesomediterranean to the supramediterranean belt with an upper subhumid ombrotype. This series is restricted to the higher belt of the Sicani area [52].

### 4.1.5. Thermo-Mesomediterranean Edapho-Hygrophilous Series of Mediterranean Willow (*Ulmo canescentis-Salico pedicellatae* Sigmetum)

The riparian forest dominated by *Salix pedicellata* should be referred to the *Ulmo canescentis-Salicetum pedicellatae* Brullo & Spampinato 1990 (Column 9 in Table 1). The canopy of this vegetation, which can reach a height of 10–15 m. is characterized by the occurrence of *Salix alba*, *Populus alba*, *P. nigra* and *Ulmus canescens*. The *Alno-Populetea* P. Fukarek & Fabijani´c 1968 class is represented by many species, such as *Carex pendula*, *Equisetum telmateia*, *Hypericum hircinum* subsp. *majus* and *Arum italicum* subsp. *italicum*.

This association is the most mature stage of an edapho-hygrophilous series. The degradation stages are mainly represented by shrubby communities belonging to *Pyro spinosae–Rubetalia ulmifolii* Biondi, Blasi & Casavecchia in Biondi et al. 2014 (*Crataego-Prunetea* class), such as *Rubo ulmifolii–Tametum communis* R. Tx. in R. Tx. & Oberd. 1958 or *Roso sempervirentis–Rubetum ulmifolii* Blasi, Di Pietro & Fortini 2000.

This azonal vegetation has its optimal conditions at altitudes between 300 and 800 m, within the thermo and mesomediterranean belts. Its geographical distribution includes several rivers and streams of northern and central Sicily [67], including the Giardinello watercourse within the investigated area.

The analysis of the woody components of current plant communities considered 56 taxa among the phanerophytes and nanophanerophytes of the nine forest and preforest associations recognized in the area (Table 2).

The analysis of the frequency of taxa, based on presence–absence data, highlights the ubiquitous nature of many species that are not exclusive to one association. Among the dominant trees, *Quercus ilex* (with a frequency equal to 1.00 in Holm Oak woods) has a frequency value of 0.40 and 0.67 in Downy Oak woods (*Oleo oleaster-Quercetum virgilianae* and *Sorbo torminali-Quercetum virgilianae*).




**Table 2.** *Cont*.

In contrast, *Quercus virgiliana* (with a frequency equal to 1.00 in Downy Oak woods) has a frequency value of 0.70 in *Ampelodesmo-Quercetum ilicis* and a value of 0.39 in *Sorbo-Quercetum ilicis*. *Fraxinus ornus* is a species which is always present in the forest formations, except in the riparian forest, while *Sorbus torminalis* grows only in forests with a meso-supramediterranean bioclimate (Figure 4). *Acer campestre*, in the same bioclimatic belt, is quite common both in forest and in secondary shrublands, such as *Roso siculae-Prunetum spinosae* and *Crataegetum laciniatae*. In contrast, species such as *Smilax aspera*, *Prunus spinosa* and *Rosa canina* are present in all climatophilous associations.

The mean coverage of woody plants, phanerophytes and nanophanerophytes (Table 2 and Figure 5) is the information that allowed us to statistically determine the probability of finding (and therefore collecting) a species in a community. The mean coverage of *Quercus ilex* is 77.58% and 73.66% in *Ampelodesmo-Quercetum ilicis* and in *Sorbo-Quercetum ilicis,* respectively, and the value dramatically drops to 0.62% in *Oleo-Quercetum virgilianae* and 4.85% and in *Sorbo torminalis-Quercetum virgilianae*.

In contrast, Downy Oak (*Quercus virgiliana*) shows mean coverages of 73.72% and 70.79% in *Oleo-Quercetum virgilianae* and in *Sorbo-Quercetum virgilianae*, respectively, becoming less significant in *Ampelodesmo-Quercetum ilicis* (6.20%) and in *Sorbo torminalis-ilicis* (6.60%).

In the forest associations, in addition to the oaks, which are the most abundant species, *Hippocrepis emerus* subsp. *emeroides* (16.41% in *Oleo-Quercetum virgilianae*) and *Viburnum tinus* (19.43% in *Ampelodesmo-Quercetum ilicis*) show higher values of coverage. In the secondary shrubland, species such as *Crataegetum laciniatae*, *Crataegus rhipidophylla* (47.46%), *Acer campestre* (33.98%), *Pyrus spinosa* (3.92%) and *Hedera helix* subsp. *helix* (12.30%) are dominant.

More generally, thorny Rosaceae are the species that shape the physiognomy of secondary shrub communities. *Rubus ulmifolius* (44.69%) and *Crataegus monogyna* var. *monogyna* (31.32%) are abundant in *Roso corymbiferae-Rubetum ulmifolii; Prunus spinosa* is common in *Roso siculae-Prunetum spinosae* and *Euphorbio characiae-Prunetum spinosae*(with mean cover values equal to 74.19% and 71.84%, respectively). In this latter association, *Rosa canina* shows a significant mean cover equal to 15.50%.

In the riparian forest dominated by *Salix pedicellata* (mean cover = 49.98%), *Populus nigra* is the second most abundant species in the association.


**Table 3.** Frequency of taxa per chronological phase: Phase 1, late 8th–9th century AD; Phase 2, 10th–11th century AD. Each column shows the indication of the absolute number of wood charcoals, their volumes inmm<sup>3</sup> andtheirincidenceasapercentageofthe totalperphase.

**Figure 5.** Mean coverage curves of the associations of Sicani Mountain forests and shrubs. The same color indicates associations belonging to the same vegetation series. The points show the incidence of identified taxa in the total volume of medieval wood charcoals (Phase 1: late 8th–9th century AD; Phase 2: 10th–11th century AD). In the x axis, the numbers indicate the taxa of Table 2 (phytosociological record) and the names are related to the taxa of Table 3 (archaeobotanical record).

### *4.2. Medieval Landscape: Anthracology and Wood Species*

The preservation of the samples is quite good. Wood charcoals are from 1 mm<sup>3</sup> to about 1.5 cm<sup>3</sup> but on average quite small (3–4 mm3). The volume of each stratigraphic unit in relation to the density of identified wood charcoals is quite similar (therefore the density is on average the same for all soils), with the exception of a burnt layer connected to the fuel of the kilns (US 43) in which the density is strongly higher, some stratigraphic units (US 12, 13, 49, 52 and 61) in which it is higher and other stratigraphic units in which the density is clearly lower (US 36, 37, 1 and 2).

From the comparison with modern vegetation, nine species were identified (Quercus ilex, Quercus cfr. pubescens Willd., Pistacia terebinthus, Rhamnus alaternus, Fraxinus ornus, Ulmus minor, Acer campestre, Ostrya carpinifolia, Populus nigra); the identification rate reached the detail of genus or subfamily in four cases (Phillyrea sp., Sorbus sp., Prunus sp., cfr. Rosaceae, Pyrus sp., cfr. Fabaceae Hippocrepis emerus subsp. emeroides/Anagyris foetida). The arboreal vegetation is therefore represented by evergreen oaks, semi and deciduous oaks, maples, ash, and it is associated with riparian species such as elm, poplar and hornbeam and with shrubby species such as alatern, terebinth, rowan, plum.

In the phase of the late 8th–9th centuries AD, Holm Oak prevailed with 35% of the samples and, together with the other oaks, it made up 48% of the total. The terebinth followed with 9% and all other species exhibited between 1% and 5% of representativeness. In the furnace, many wood charcoals were mixed with ash concentrations at various densities; some of these fragments bore traces of strong distortion due to combustion processes. It is also interesting that, in this context, most of the species represented were Holm Oak and terebinth, with a very low percentage of other species.

In the second medieval phase (10th–11th centuries AD), the variability seemed to be slightly wider with 11 species/genera but with a clear preponderance in the representativeness of Holm Oak, which in terms of volume represented 49% of the total, followed by lower percentages of unidentified oaks, terebinth, poplar, elm and a leguminous plant perhaps identifiable as *Anagyris foetida*.

The relative frequencies were calculated by excluding the data on the unidentified samples and on those oaks that were not better identified (that is, they were not recognized either as deciduous or evergreen) and which therefore could not be placed more precisely within the series. The frequencies are quite similar in both phases, with a slight deviation in the incidence of Holm Oak (which increased in phase 2) and the absence of deciduous oaks in the more recent phase (Table 3).

The frequencies in the anthracological record were overlapped to the mean coverage of taxa (Figure 5). This overlapping has shown the correspondence between the species recorded in archaeobotanical samples with forest or preforest associations detected in the current area.
