The Vegetation of S'Ena Arrubia lagoon (centre-western Sardinia)

This study describes the vegetation of S'Ena Arrubia lagoon, in the Gulf of Oristano, in the centre-western coast of Sardinia. This lagoon is classified as: Special Protection Zone (S.P.Z.) according to EEC Directive 79/409, community importance site according to EEC Directive 92/43, I.B.A. (Important Birds Area) site and fixed oasis of fauna protection and natural reserve. Throughout the years it was subject to several alterations. The most important ones were carried out in the Seventies and allowed the marine water upwelling and the fast removal of freshwater coming from the watershed. Before the fulfilment of these interventions, lagoon waters had a low salinity, as demonstrated by previous vegetation studies that showed the presence of freshwater communities and, only to a smaller extent, of halo-tolerant and halophile ones. This phytosociologic study led to the identification of several associations that are showed in the groups of merely halophile vegetation, in the freshwater and subhalophile lagoon vegetation and in the merely anthropogen vegetation typologies. The location of the considered typologies is represented with distributive patterns, which synthesise the current state of vegetation referring to the salinity. Two new associations, the Inulo crithmoidis-Paspaletum vaginati and the Astero tripolii-Bolboschoenetum maritimi, are here described. The first is dominated by the presence of Paspalum vaginatum Swartz, recorded for the second time in Italy and for the first time in Sardinia. It is recorded near the inlet, where it forms mosaics together with Salicornietum emerci association and it is also present, as bolboschoenetosum maritimi subassociation, in more inland and less salty zones. The latter new association includes the subhalophile reedswamps that are present in the areas floodcd by salty waters for a long time, where it replaces the Scirpetum compacto-littoralis, a less halophile association present in several siles of the Mediterranean and also in Sardinia. In addition, it is necessary to point out the recovery of Salicornietum venetae association, characterised by the presence of Salicornia veneta Pign. et Lausi, which was believed endemic in the North Adriatic lagoons. Finally, the significance of environmental changes fulfilled in the basin, which are the reason for some vegetation modifications and are detected by comparison between current associations and those at the beginning of the Seventies, is pointed out

Cartography and diachronic analysis of the vegetation of S'Ena Arrubia Lagoon (Centre-Western Sardinia)

The vegetation map of S'Ena Arrubia Lagoon in centre-western Sardinia (1: 2,500 scale) is presented and some diachronic remarks are made by referring to historical data available. The main object of this cartography, after a research on the biotope vegetation, is to allow the biomonitoring of an extremely important site for the biodiversity conservation (Protected Area: S.I.C., Z.P.S., I.B.A.), which is to use for an ecologically aware management

Phytosociological study of the shrub and pre-forest communities of the effusive substrata of NW Sardinia

The trachybasalt biogeographic sub-district of the NW Sardinian district, included in the coastal and hilly sub-sector of the Sardinian biogeographic sector, is characterised by two large effusive complexes: that of the rhyolites, andesites and dikes of the Oligo-Miocene alkaline volcanic cycle (14-32 Ma) and alkaline basalts, rhyolites, rhyodacites and dikes of the volcanic cycle with alkaline, transitional and sub-alkaline affinity of the Pliocene-Pleistocene (0.14-5.3 Ma). Between 2000 and 2004, 156 surveys were carried out on shrub communities in order to improve knowledge of their phytosociology. Vegetation analysis led to the identification of 11 associations and 13 subassociations, referring to 3 syntaxonomic classes. Of these, 5 new associations are hereby described for the first time: Clematido vitalbae-Maletum pumilae, Crataego monogynae-Aceretum monspessulani, Lavatero olbiae-Rubetum ulmifolii, Genisto desoleanae-Ericetum arboreae and Telino monspessulanae-Cytisetum villosi

Issues related to the classification of Mediterranean temporary wet habitats according with the European Union Habitats Directive

From a biological and biogeographic point of view, Mediterranean temporary wet habitats are recognised to be amongst the most interesting habitats in the Mediterranean bioclimatic region. They are considered to be habitats of Community Interest and are included in the “standing water group”. Due to an overlap in the plant species and syntaxa indicated as characteristic, the assignment of the plant communities to the habitats 3120, 3130 and 3170* is far from straightforward. We propose that the Isoetion communities be assigned to habitat 3170*, the Preslion cervinae, Cicendio-Solenopsion and Agrostion pourretii communities to habitat 3120, and the Cyperetalia fusci and Littorelletea uniflorae communities to habitat 3130

<i>Anchusa sardoa</i> (Illario) Selvi <i>et</i> Bigazzi

Descrizione della specie Anchusa sardoa (Illario) Selvi et Bigazzi

Halophilous vegetation of Olbia pond system (NE-Sardinia)

Authors report some results about a phytosociological study concerning the wetlands to the south of Olbia (Gallura, north-eastern Sardinia). Vegetation analysis allowed to detect 21 associations, among them two are new and denominated Halimionio portulacoidis-Limoniastretum monopetali ass. nova and Ephedro fragilis-Pistacietum lentisci ass. nova. Among them, the association Halimiono portulacoidis-Limoniastretum monopetali shows a particular phytogeographical interest, because it sets the Limoniastrum monopetalum vegetation in the only Sardinian station of this shrubby Plumbaginacea. From a syntaxonomic point of view, described syntaxa are included in 9 vegetation classes. Plant landscape of the area was reconstructed by the study of chain contacts among different communities, placed in space according to humidity and salinity gradients, determined by substratum texture and micromorphology. On the basis of phytocoenotic diversity stressed by this research, this study area is believed to be deserving of protection aiming at conserving and managing its populations and plant communities

A Phytosociological study of the deciduous oak woods of Sardinia (Italy)

We present here the results from a phytosociological and synchorological study of the deciduous oak woods of Sardinia. This vegetation analysis has allowed the individuation of three new associations: Lonicero implexae-Quercetum virgilianae, Ornithogalo pyrenaici-Quercetum ichnusae and Glechomo sardoae-Quercetum congestae. The Lonicero implexae-Quercetum virgilianae association includes the woods on calcareous substrata spread throughout Northern Sardinia, which can occasionally be found in southern areas; the first of these are rich in mesophilous species and are attributed to the subassociation cyclaminetosum repandi, while the others are referred to quercetosum virgilianae. The Ornithogalo pyrenaici-Quercetum ichnusae association, more widely distributed in Central-Northern Sardinia, includes the climatophilous deciduous woods that are found on lithological substrata of a non-carbonatic nature, and in particular, on andesites, trachytes and metarenites. The typical aspect is referred to the subassociation cytisetosum villosi, while the subassociation ilicetosum aquifolii includes the more mesophilous woods on basaltic substrata. The Glechomo sardoae- Quercetum congestae association always includes the woods found on the non-carbonatic substrata in the higher altitude areas with an oceanic pluviseasonal temperate bioclimate. Of this, the subassociation quercetosum congestae, on the granite areas, and oenanthetosum pimpinelloidis, on those metamorphic and of basalt, are proposed. At the higher hierarchical levels, the association Lonicero implexae-Quercetum virgilianae is referred to the endemic Sardinian-Corsican suballiance Clematido cirrhosae-Quercenion ilicis, of the alliance Fraxino orni-Quercion ilicis, while for the other associations the new suballiance Paeonio morisii-Quercenion ichnusae, (holotypus: Glechoma sardoae-Quercetum congestae ass. nova) particular to the Sardinian biogeographic subprovince, is proposed, of the alliance Pino calabricae-Quercion congestae, the order Quercetalia pubescentipetraeae, and the class Querco roboris-Fagetea sylvatica

Caratterizzazione fitosociologica dell’habitat prioritario 6220*-“Percorsi substeppici di graminacee e piante annue dei <i>Thero-Brachypodietea</i>”: caso di studio della Sardegna settentrionale

In this paper we aimed at characterizing phytosociologically the priority habitat 6220* in Northern Sardinia. In the study area this habitat is identified on the field by the presence of 18 plant associations, referred to the following syntaxonomic classes: Helianthemetea guttati, Poetea bulbosae, Artemisietea vulgaris and Lygeo-Stipetea. Within the Brachypodio ramosi-Dactyletalia hispanicae order of the Artemisietea vulgaris class, three new associations are here described for the first time: Ophrydo praecocis-Dactyletum hispanicae, Orchido longicorni-Dactyletum hispanicae and Orchido collinae-Dactyletum hispanicae which are all referred to the Leontodo tuberosi-Bellidion sylvestris alliance. The wide structural and functional heterogeneity, that prevent from outlineing common management strategies to all the 4 vegetation classes included in the habitat, suggests the need of a clarification of the Habitats Directive and its revision on the basis of the recent phytosociologic findings

Analisi del paesaggio vegetale delle aree olivetate della Sardegna nord-occidentale

The olive grove traditional production maintenance is linked to biodiversity and the knowledge of plant landscape and vegetation dynamics is at the bottom of this process. In this context the hierarchical analysis of the landscape of the olive grove area of North Western Sardinia and the geobotanical analysis of vegetation, according to the phytosociological method, were carried out. Two landscape units with the same geopedologic, bioclimatic and vegetational characteristics were identified: the low mesomediterranean unit of the calcareous-marley substrata and the dry thermomediterranean unit of the alluvial plains. Inside these units five main vegetation series were recognized and described: Asparago acutifolii-Oleo sylvestris, Prasio majoris-Querco ilicis, Pyro amygdaliformis- Querco ilicis, Lonicero implexae-Querco virgilianae and Allio triquetri-Ulmo minoris sigmeta. These dynamic models represent an effective management tool. Furthermore a high conservation value of these systems was detected: accordig to the “Habitats” Directive (92/43/EEC) five habitats of community interest were identified in the studied area: 5220, 5330, 92A0, 9320, 9340. These results, which have pointed out the high conservation value of the olive groves of the studied area, should be taken into account in the management projects as well as socio-economical data

Il Paesaggio vegetale della Nurra (Sardegna nord-occidentale)

The description of vegetation typologies that characterise the plant landscape in Nurra - according to phytosociological and sinphytosociological interpretations - is presented. Plant associations found out are here presented from areas closer to the sea towards the inner ones, grouped according to environmental and structural characteristics. The following new associations are described. Crithmo maritimi-Limonietum nymphaei, Evaco pygmaeae-Bellietum bellidioidis, Senecioni leucanthemifolii-Nanantheetum perpusillae, Spergulario salinae-Hordeetum marini, Limonietum laeti-glomerati, Brassico insularis-Seselictum praecocis, Anthyllido vulnerariae-Kundmannietum siculae, Loto cytisoidis-Dactyletum hispanicae, Dactylo hispanicae-Camphorosmetum monspeliacae, Scillo obtusifoliae-Bellidetum sylvestris, Scillo autumnalis-Bellidetum sylvestris, Hypecoo procumbentis-Silenetum nummicae, Bupleuro fontanesii-Scorpiuretum muricati, Rosmarino officinalis-Thymelaeetum tartonrairae, Dorycnio pentaphylli-Cistetum eriocephali, Pyro amygdaliformis-Quercetum ilicis, Euphorbio characiae-Juniperetum turbinatae, Pistacio lentisci-Calicotometum villosae, Crataego monogynae-Pistacietum lentisci. Furthermore, phytosociological and syntaxonomical study of the subnitrophilous hemicryptophyte communities allowed their attribution to the Artemisietea vulgaris c1ass. Within this class the new Brachypodio ramosi-Dactyletalia hispanicae order is described, together with two new alliances, Reichardio maritimae-Dactylion hispanicae and Leontodo tuberosi-Bellidion sylvestris. The order includes the perennial, hemicryptophyte and geophyte, subnitrophilous vegetation of the secondary formations, finding their optimum in the sub-humid and humid mesomediterranean macroclimate, and can also penetrate into the thermomediterranean one for edaphic compensation. Moreover, this study suggests to include in the new Brachypodio ramosi-Dactyletalia hispanicae order, the Bromo-Oryzopsion and the Thero-Brachypodion ramosi alliances. The study of associations and their dynamic relationships also allowed to reconstruct the vegetation series which integration produces the main plant landscape units present in Nurra. The coastal Tyrrhenian, basophilous, calcicole, thermomediterranean and edaphon-xerophilous series of Juniperus turbinata (Chamaeropo humilis-Junipereto turbinatae sigmetum) was reconstructed on Mesozoic limestone. Different plant associations of comophytic and chasmophytic communities integrating the coastallimestone landscape are connected to this pattern by chain relationships. Between the landscape units of the Mesozoic limestone sector and the Paleozoic metamorphic one, the coastal Tyrrhenian, neutroacidophilous, of sandstone, thermomediterranean and edaphon-xerophilous series of Juniperus turbinata with Arbutus unedo (Chamaeropo humilis-Junipereto turbinatae arbutetosum unedonis sigmetum), representing an edaphic variant of the previous one, linked to the violet quartzose sandstone on which a more clayey soil is generated, was reconstructed. The geosigmetum of Mesozoic limestone is completed by the Tyrrhenian, neutroacidophilous, calcicole, thermomediterranean c1imatophilous series of Quercus ilex (Pistacio-Querceto i1icis sigmetum). It is present on the inner hills and, of its series-head, only a few examples of Quercus ilex grove remain, which assume a particular characterisation for the presence of Chamaerops humilis. The Sardinian coastal, neutroacidophilous, of Paleozoic schist, thermomediterranean, climatophilous and edaphon-xerophilous series of Juniperetus turbinata (Euphorbio characiae-Junipereto turbinatae sigmetum) was reconstructed in the metamorphic area. The prevalently chain contact with the subhalophile garigue and the microgeosigmeta of the therophytic and chamaephytic halophile communities occurs in the coastal girdle close to the c1iff. The landscape unit of the coastal metamorphic section is completed by the Tyrrhenian, neutroacidophilous, mesomediterranean, of schist, climatophilous series of Quercus ilex (Erico arboreae-Querceto ilicis sigmetum). In the alluvial plain of Nurra, on strong clayey substrata with a mixed calcicole-silicic matrix, always in thermomediterranean climate but under a marked edaphic compensation, the Sardinian, neutroacidophilous, of plain, edaphon-mesophilous series of Quercus ilex and Quercus suber (Pyro amygdaliformis-Querceto i1icis sigmetum) is found. The geosigmetum of the alluvial plain is completed by the edaphon-hydric series of the alluvial soils in the north-western Sardinia (Allio triquetri-Ulmeto minoris sigmetum). Finally, some indications about land management are given in order to maintain the high biodiversity that currently is still present