Disponibilità idrica e cambiamenti nella composizione floristica osservati in alcune piccole isole della Sardegna

Modifications to climate, occurring frequently and over increasingly short periods, lead to changes in the flora of specific territories. The changes in the composition of several florae originally surveyed in different periods highlight the fact that reduction in the availability of water leads to an increase in therophytes and to a drastic reduction of hemicryptophytes. This phenomenon has been observed on some of the small Sardinian islands which, when compared with studies carried out there in previous years, now show evidence of significant alteration in their floristic composition

Variazioni della flora e del manto vegetale osservate sull'isola di Santo Stefano (Sardegna NE)

Le ricerche floristiche su quest'isola sono state intraprese da diversi studiosi sin dal secolo scorso e negli anni sessanta viene analizzata la vegetazione su basi fisionomiche. Recentemente, nel corso di uno studio realizzato con il contributo della Comunità Europea, è stato riscontrato un notevole cambiamento della componente floristica indicata negli inventari floristici precedenti e in particolare è stato osservato il mancato ritrovamento di 30 specie

Variazione di alcuni indici fitoclimatici osservati a Cagliari dal 1892 al 2002

Analyzing the thermopluviometric data of Cagliari from 1892 to 2002, have been processed the most important phytoclimatic indices reported both to whole time and to five equivalent periods. The achieved results, confirmed by the all calculated indices, point out a shifting towards conditions of greater dryness, more obvious in the last years, determining in the local floras an increase of annual species

Modificazioni e strategie competitive osservate nella flora dell’isola Rossa di Teulada (Sardegna sud occidentale)

The authors report on the results of their survey on the Isola Rossa near Teulada (South-western Sardinia). The flora found on the island, which consisted of 206 entities, grouped in 59 families and distributed in 157 genera, differs notably from the flora surveyed 50 years ago. In particular, 81 new species have been found, while 44 species listed in the earlier survey have not been confirmed. Comparison of typically mediterranean biological spectra showed an increase in terophytes and a sharp decrease in hemicriptophytes. The application of Grime’s triangular system to this survey and the earlier one showed that floral changes are characterised by a decrease in stress-resistant species and an increase in ruderal species. The vegetation cover has also undergone major changes. The colonising capacity of Brassica insularis is particularly interesting in this regard: this plant, which was previously found only on the northern side of the island, is now scattered throughout the island. All these changes have also been confirmed by the turnover ratio, which is in excess of 60%, and highlights the occurrence of deep environmental changes

Riferimenti bibliografici sulla flora vascolare sarda riportati nell'Informatore Botanico Italiano dal 1969 al 2004

The authors have been referring to works about Sardinian flora published in Informatore Botanico Italiano. The works date back to establishment of review to 2004. A flora list has been drown up on a database where there is a lot of information on every single entity: the places where they have been found, the relative bibliographical references and when it is necessary the nomenclatural updating. 1334 records which were studied in 136 works have been analysed. There are totally 610 entities of Sardinian flora like the list shows

Flora vascolare del Capo di Monte Santu (Sardegna centro orientale)

The vascular flora of Capo di Monte Santu (Central-Eastern Sardinia) – The Authors present their study on the flora of Capo di Monte Santu, a calcareous area forming the southern tip of the Gulf of Orosei. Investigation allowed us to identify 381 taxa, belonging to 62 families and comprising 228 genera. Data regarding the biological spectrum show a prevalence of therophytes (49.2%), typical of the regions of the Mediterranean area, followed by hemicryptophytes (21.8%) and geophytes (10.8%). An overview of the chorological spectrum of the flora highlights dominance of the Mediterranean component (78.5%). Amongst the Mediterranean species s.s. (47.2%) we noted greater presence of entities of the Steno-Mediterranean distribution area (25.7%), followed by endemics which with 43 entities constitute 11.3% of total flora. From the chorological point of view, the prevailing element amongst the endemics is the Sardinian (11 taxa) including 5 taxa which are exclusive to the calcareous massif of central-eastern Sardinia. The analysis of rarities, performed by applying Rabinowitz’ categories, shows as being most numerous (86 taxa) species spread over the territory with a restricted ecology and scarce, non-dominant populations (WRS), whereas the least consistent (9 taxa) is that of the species with limited spread over the territory, a wide ecology and scarce and non dominant populations (NBS). Those entities considered worthy of protection based on the IUCN red lists are four in number (Lactuca longidentata, Orchis brancifortii, Polygala saxatilis and Sedum villosum subsp. glandulosum), one entity (Ruscus aculeatus) is listed in Annex V of the Habitat Directive while Annex II of CITES includes all the Orchidaceae (10) and Cyclamen repandum subsp. repandum

Research on the changes in the flora and vegetation cover on "Isola Rossa" of Trinità D'Agultu (Central-Northern Sardinia)

The Authors report the results of their survey carried out on the Isola Rossa of Trinità d'Agultu (Central Northern Sardinia). This survey covered a two-year period and shows that 13 species previously reported do not seem to occur in the island any longer where as 23 new records have been added. The flora, consisting of 40 entities, included numerous invasive and ruderal species which have to a large extent modified the composition, floristic distribution and vegetation cover of the island, the species which has played a major role in this modification being without doubt Lavatera arborea L. Details are also provided on the main plani formations on the island, in comparison with those previously reported

L'esplorazione botanica nei territori del Sarrabus-Gerrei(Sardegna Sud Orientale)

The authors report on thè history of botanical exploration in the Sarrabus-Gerrei area through analysis of the bibliography and o/exiccata available in various publications. Botanical research in southern Sardinia was conditioned by the poor quality of means of communication which were not upgraded as a restili of limited interest in this sector ofthe island. The areas addressed by several botanists during the I9h century are situated along the main communication routes ofthe perìod and only in the second half of thè 20th century do we fìnd significant increase in research initiatives

FEA testing the pre-flight Ariel primary mirror

Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is an ESA M class mission aimed at the study of exoplanets. The satellite will orbit in the lagrangian point L2 and will survey a sample of 1000 exoplanets simultaneously in visible and infrared wavelengths. The challenging scientific goal of Ariel implies unprecedented engineering efforts to satisfy the severe requirements coming from the science in terms of accuracy. The most important specification – an all-Aluminum telescope – requires very accurate design of the primary mirror (M1), a novel, off-set paraboloid honeycomb mirror with ribs, edge, and reflective surface. To validate such a mirror, some tests were carried out on a prototype – namely Pathfinder Telescope Mirror (PTM) – built specifically for this purpose. These tests, carried out at the Centre Spatial de Liège in Belgium – revealed an unexpected deformation of the reflecting surface exceeding a peek-to-valley of 1µm. Consequently, the test had to be re-run, to identify systematic errors and correct the setting for future tests on the final prototype M1. To avoid the very expensive procedure of developing a new prototype and testing it both at room and cryogenic temperatures, it was decided to carry out some numerical simulations. These analyses allowed first to recognize and understand the reasoning behind the faults occurred during the testing phase, and later to apply the obtained knowledge to a new M1 design to set a defined guideline for future testing campaigns