Distribution, floristic and ecological characterization of Sardinian Gymnospermae communities

A complete analysis of the distribution, ecology and floristic composition of the natural pine woods of Sardinia, belonging to Pinus halepensis Mill., P. pinaster Ait. subsp. pinaster and P. pinea L., was for the first time produced in Sardinia by means of aerial photographs, literature, Local Ecological Knowledge (LEK) and phytosociological surveys carried out within the areas where the three pine species are considered native or putative native. The phytosociological work allowed the description of two new associations for P. halepensis woods, located in the south-western coastal area, as well as the confirmation of a previously described one on the island of San Pietro, which is currently in a more mature stage than its original description. A new association related to P. pinaster subsp. pinaster woods was described in north-eastern Sardinia, with two new sub-associations. Finally, a new association for P. pinea woods on coastal dunes of the south-western Sardinia. The diachronic study of pine woods’ decrease and subsequent recovery represents an important step in the analysis of how human impact and land use change can influence the vegetation dynamics of pioneer species with restricted distribution ranges in insular contexts. In this respect, the help of local people and toponymy was crucial for trying a reconstruction of the loss happened in recent times. The method here applied can be an example for further research on rare and declining species. We improved the knowledge of the distribution, ecology and threats of Taxus baccata L. populations in Sardinia as well, by analysing climatic factors, to define yew’s ecological niche and the species potential distribution in the island. In this study, we found 234 different localities were T. baccata grows or was known in recent times, then confirming how the potential distribution is similar to the real one. On the other hand, we highlighted that in many localities the presence of the species is today related to isolated to scattered old individuals. Many factors are driving this species to become more and more rare in the Mediterranean environments. We selected 40 sites, a part of which are characterised by the presence of T. baccata old-growth woods, then compared these woods with others where human impact and mean dimensions of the samples identify them as younger formations. This comparison was useful to understand which of the structural features are significantly differentiating old-growth stands with yew from younger ones, and can therefore have a methodological value. The places where the species still thrives today are subject to a long pressure by overgrazing and are often the remnants of wider populations reduced by practices such as wildfires, cuttings, and subsequent reforestations. This work increases the knowledge in relation to the health of the species and its distribution in Sardinia. Moreover, it represents a crucial point for its conservation since it shows how future conservation measures seem to be necessary to preserve the most endangered populations. In managed forests, silvicultural systems should be able to maintain, restore or develop structural attributes useful to a reprise of yews free of competition of alien naturalised taxa. Moreover, the application of protection protocols can represent an effective tool for the characterisation of the old growth stands with yews, in order to plan better management and conservation measures

Notulae alla checklist della flora vascolare italiana 4: 1413-1417

1413. Marsilea strigosa Willd. (Marsileaceae) 1414. Hypericum androsaemum L. (Hypericaceae) 1415. Anthriscus caucalis M. Bieb. (Apiaceae) 1416. Deschampsia flexuosa (L.) Trin. (Poaceae) 1417. Leersia oryzoides (L.) Sw. (Poaceae

The Endemic Vascular Flora of Sardinia: A Dynamic Checklist with an Overview of Biogeography and Conservation Status

The vascular flora of Sardinia has been investigated for more than 250 years, with particular attention to the endemic component due to their phylogeographic and conservation interest. However, continuous changes in the floristic composition through natural processes, anthropogenic drivers or modified taxonomical attributions require constant updating. We checked all available literature, web sources, field, and unpublished data from the authors and acknowledged external experts to compile an updated checklist of vascular plants endemic to Sardinia. Life and chorological forms as well as the conservation status of the updated taxa list were reported. Sardinia hosts 341 taxa (15% of the total native flora) endemic to the Tyrrhenian Islands and other limited continental territories; 195 of these (8% of the total native flora) are exclusive to Sardinia. Asteraceae (50 taxa) and Plumbaginaceae (42 taxa) are the most representative families, while the most frequent life forms are hemicryptophytes (118 taxa) and chamaephytes (106 taxa). The global conservation status, available for 201 taxa, indicates that most endemics are under the ‘Critically Endangered’ (25 taxa), ‘Endangered’ (31 taxa), or ‘Least Concern’ (90 taxa) IUCN categories. This research provides an updated basis for future biosystematics, taxonomic, biogeographical, and ecological studies and in supporting more integrated and efficient policy tools

Structural heterogeneity and old-growthness: A first regional-scale assessment of Sardinian forests

Mediterranean forests have been altered by several human activities. Consequently, relatively intact forests that have been unmodified by humans for a relatively long time (i.e., old-growth forests) are often reduced to isolated and fragmented stands. However, despite their high conservation value, little is known about their features and even presence several Mediterranean areas. First steps of their investigation are based on the identification of old-growth features such as amount of large‐size and old trees, tree species composition, canopy heterogeneity, occurrence and amount of deadwood. The Structural Heterogeneity Index (SHI) is commonly used to summarise features of old-growthness in one single value. Here, the SHI was derived for 68 plots included in 45 forest stands within the 4,297 km2 of territory that is covered by forests in Sardinia. SHI values were affected by variables that are likely to be related to forest age and structural complexity, such as presence of cerambycids, canopy cover, forest layers, location and three old-growthness classes. Results confirm a high structural variability among forests with old-growth features, determined by the presence, or lack, of given living and deadwood features. Our findings identified, for the first time, most of the forest stands that need special protection in Sardinia for the presence of old-growth features. In this sense, the SHI was confirmed useful for improving their management and conservation, although more specific and deeper studies are necessary for better understanding their species composition and dynamics

Chemical-physical agents and biodeteriogens in the alteration of limestones used in coastal historical fortifications

The alteration of rocks is usually due to the chemical-physical processes that are initially established on the outer surface of the stone and gradually proceed towards the inner matrix. The chemical alteration generated by the interaction with atmospheric agents (weathering) involves the transformation of the mineral phases constituting the rock that are less stable in the current climatic conditions. That often leads to the formation of new secondary phases more stable with respect to the alteration. However, among these phases are often present some very soluble and hygroscopic phases (i.e., soluble salts, clay minerals) that cause inner degradation of the rock, due to their physical-mechanical actions (inner crystallization pressure, hydration dilation). In the case of carbonate rocks (limestone, sandstone with carbonate cement, etc.), the dissolution is the more frequent process, especially when the monuments were located within the cities, due to the acid meteoric precipitations (with H2CO3, H2SO4) that lead to the sulfation of carbonate matrix with formation of gypsum, very harmful to the stone. When the rock (e.g., clay-arenaceous limestones) naturally contains hygroscopic phases inside the matrix (i.e., marine salts, phyllosilicates) and they are also porous (> 20%), the physical degradation is accelerated, with decohesion of the mineralogical matrix (between the crystalline granules) and consequent disintegration of the stone. In the rock-atmosphere interaction often occurs the presence of biodeteriogens (plants, fungi, lichens, micro- organisms, etc.), which negatively participate and in various ways in the processes of rock alteration. The research aims to define the chemical-physical alteration factors on the limestones exposed to different bioclimatic and biogeographic contexts (Mediterranean and Atlantic), taking two study-case monuments located in the Italian and in the Portuguese coasts. In the study presented in this paper the preliminary results of the case-study of Cagliari fortifications have been discussed. In the study the different vascular plants present on stone surface and crevices and their different role in the degradation of limestone rocks have been also studied

Global and Regional IUCN Red List Assessments: 2

In this contribution the conservation status assessment of six plant species according to IUCN categories and criteria are presented. It includes the assessment at global level of Charybdis glaucophylla Bacch., Brullo, D’Emerico, Pontec. & Salmeri, Euphorbia nicaeensis All. subsp. japygica (Ten.) Arcang., Hieracium australe Fr. subsp. australe, Limonium multiforme Pignatti, Onosma helvetica Boiss. em. Teppner subsp. lucana (Lacaita) Peruzzi, Aquaro & Cesca and the assessment at national level (Italy) of Lathyrus laxiflorus (Desf.) Kuntze subsp. laxiflorus

Notulae to the Italian native vascular flora: 5.

In this contribution, new data concerning the distribution of native vascular flora in Italy are presented. It includes new records and confirmations to the Italian administrative regions for taxa in the genera Allium, Arabis, Campanula, Centaurea, Chaerophyllum, Crocus, Dactylis, Dianthus, Festuca, Galanthus, Helianthemum, Lysimachia, Milium, Pteris, and Quercus. Nomenclature and distribution updates, published elsewhere, and corrections are provided as supplementary material

Notulae to the Italian alien vascular flora 6

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions of taxa in the genera Acalypha, Acer, Canna, Cardamine, Cedrus, Chlorophytum, Citrus, Cyperus, Epilobium, Eucalyptus, Euphorbia, Gamochaeta, Hesperocyparis, Heteranthera, Lemna, Ligustrum, Lycium, Nassella, Nothoscordum, Oenothera, Osteospermum, Paspalum, Pontederia, Romulea, Rudbeckia, Salvia, Sesbania, Setaria, Sicyos, Styphnolobium, Symphyotrichum, and Tradescantia. Nomenclature and distribution updates, published elsewhere, and corrigenda are provided as supplementary material

Notulae to the Italian alien vascular flora: 12

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1