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In light of the hypothesis that different authors, who have access to the same information and tools, can give different interpretations of the same reality, namely the vascular plants, existing within a determinate geographic boundary, this research aims to verify how and to what extent these differences can affect a checklist, and what critical issues and positive effects may arise in them. To this purpose, we compared two different checklists which were developed approximately in the same period for the same geographic area, the island of Sardinia (Italy). The results show that checklists of the same area can differ in quantitative terms, establishing a different value of floristic richness. Moreover, they can differ in qualitative terms due to the different approach adopted by the authors concerning nomenclature, taxonomy, and interpretation, delimitation, and circumscription of taxa. These discrepancies may have positive side effects as they offer insights for critical reviews and further investigation.

Spinescence refers to the presence of sharp appendages of various origins with ecological, evolutionary or biogeographic significance. This research was conducted to explore patterns and adaptive p...

Italy is among the European countries with the greatest plant diversity due to both a great environmental heterogeneity and a long history of man–environment interactions. Trait-based approaches to ecological studies have developed greatly over recent decades worldwide, although several issues concerning the relationships between plant functional traits and the environment still lack sufficient empirical evaluation. To draw insights on the association between plant functional traits and direct and indirect human and natural pressures on the environmental drivers, this article summarizes the existing knowledge on this topic by reviewing the results of studies performed in Italy adopting a functional trait approach on vascular plants, bryophytes and lichens. Although we recorded trait measurements for 1418 taxa, our review highlighted some major gaps in plant traits knowledge: Mediterranean ecosystems are poorly represented; traits related to belowground organs are still overlooked; traits measurements for bryophytes and lichens are lacking. Finally, intraspecific variation has been little studied at community level so far. We conclude by highlighting the need for approaches evaluating trait–environment relationship at large spatial and temporal scales and the need of a more effective contribution to online databases to tie more firmly Italian researchers to international scientific networks on plant traits.

Depensation in a population growth rate, well-known as Allee effect , has dramatic implications for the dynamics and conservation of small or sparse populations, as it can drive low-density populations to extinction when their demographic size is below a critical threshold. Although rarely detected, depensation effects are believed to be common in nature. Here we present experimental evidence for Allee effect in one Mediterranean endemic plant: Anchusa sardoa . Depensation in the population growth rate is demonstrated through a density-based approach by showing the fingerprinting relationship which ties the population density to its per capita growth rate ( pgr ) during specific stages of the plant life-cycle. The pgr –density plots derived from observational data qualitatively compare with a general 2nd order polynomial function which features one of the peculiar trends underlying an Allee mechanism. We found strong evidence for depensation in the seedling and sapling classes, whereas no-depensation effect could be clearly observed in the adult classes. We also point out a characteristic demographic structure of A. sardoa (i.e. number of juveniles > number of adults) which reflects a not common life strategy with respect to Mediterranean endemic plants. By combining dynamical and demographic information, the results of this study suggest a possible scenario by which A. sardoa population could go extinct, and are discussed in the context of the increasing mass tourism in Mediterranean coastal environments.

With the consensus that human activities are leading to dangerous interference in Earth’s climate, there has been growing policy pressure for clear quantification and attribution of the resulting biological impacts. Despite the exceptional diversity in the Mediterranean biome, largely due to the number of rare and endemic plant species, the effect of future climate change on present Mediterranean plant species has only been examined in a few studies. In this study we presented an analysis of the potential effects of climate change on 22 plant species whose range is restricted to central-northern Mediterranean region. We used species distribution modelling to test whether projected climate change may affect the current suitability of species’ habitat; to evaluate possible future threats due to climate change; and to test any relationship between extinction risk and ecological and life-history predictors. The studied species were predicted to lose some 50% of their current range by 2020. Similarly, the probability of occurrence in known localities was predicted to drop drastically by 2020. Our results support a relationship between biological characteristics and range contractions. Although the Mediterranean species were projected to lose a lower amount of habitat than Alpine ones, species with restricted geographic range seem to be more prone to climate change effects than widespread ones. Our results emphasize the need for immediate monitoring and conservation actions and suggest that rare species might be useful for monitoring the conservation status of habitat in relationship to the effects of global warming in the Mediterranean region.

Coastal habitats are particularly vulnerable to recreational impacts because these environments are highly dynamic and continually change in response to biotic and abiotic factors. Sand dune communities are worldwide characterized by high levels of biodiversity, but are often affected by human-induced impacts as those caused by tourist trampling. To understand the effects of human frequentation, trampling, and other human-induced impacts, fencing experiments have been traditionally carried out on coastal dunes. Since in touristic areas dune systems are subjected to different intensities of human frequentations rather than to opening or fencing, in this study we explore the effects of accessibility on vascular plants cover. This study tests the hypothesis that human frequentation on beaches affects spatio-temporal variability of vascular plant abundance on dunes by comparing the plant assemblages of high and low accessible sites in North-East Sardinia (Italy). Our results show that accessibility plays a cr...

11 páginas, 1 tabla, 5 figuras. The final publication is available at www.springerlink.com, [EN] The introduction of alien ungulates is a major threat for the survival of endangered plants, especially in island ecosystems. However, very few studies have investigated the potential damage of large herbivores on plant diversity in Mediterranean protected areas. In this study, we describe the population structure and the long-term dynamics of the main populations of the Sardinian narrow endemic Centaurea horrida Bad. (Asteraceae), by means of permanent plots where individual plants were tagged and monitored through 6 years (2004–2009). We monitored this endangered plant at three sites: two were protected areas where introduced and feral ungulates are present, and the other one was a non-protected site without introduced ungulates. We found that adults and saplings were more abundant at the non-protected site. Through matrix models, we also highlighted that the non-protected population showed the highest population growth rate. Finally, by means of an exclusion experiment for ungulates at one protected site, we demonstrated that herbivores had a negative effect on the survival of seedlings and adult plants, and reduced the stochastic population growth rate. An LTRE analysis showed that differences in the survival, especially of adult individuals, had the highest responsibility in explaining the higher population growth rate when herbivores are excluded. Our study constitutes a clear example on how the protection of alien large herbivores can have opposite effects on the conservation of an endangered plant. Some management options are proposed, and the urgent need of manipulative experiments on species-specific interactions between protected plants and alien herbivore species is invoked., This study was supported by the Regione Autonoma della Sardegna, LR 7/2007–PO Sardegna FSE 2007–2013, with the Grant No. CRP2_474 for RF and EF, and no. CRP3_188 for SP. MBG also got support from a Spanish National Park project (OAPN, REF. 430/211). We thank the Ente Foreste della Sardegna, the Parco Nazionale dell’Asinara and the Parco Regionale di Porto Conte for the technical aid received.

Spatial variability in the structure of a population and in the reproductive traits of the narrow endemic coastal plant thorny knapweed (Centaurea horrida; Asteraceae) was estimated. Variations in the distribution of individuals and reproductive effort were described and quantified at the per-site scale (3 sites, less than 30 kilometers apart) for two habitats (cliff face and cliff plateau) to provide a basis for further investigations of the factors affecting C. horrida performance and to provide information necessary for an effective conservation of this species. Centaurea horrida was considerably more abundant at one site, especially in the cliff plateau, in the contribution of adults. Estimates of spatial variance for each life stage at both habitats revealed that, on the cliff plateau, a much greater variability was found at the per-site scale for classes of saplings and adults of middle size, whereas in the cliff face local (among replicates), spatial variance was higher for all comparisons...

When assessing the conservation status of narrow endemic plants, life history traits must be taken into account, since endemics combine small population ranges and sizes, and long persistence with limited reproductive and dispersal ability. In this paper, we present the global assessment of the conservation status of a narrow endemic plant from the Sardinian‐Corsican biogeographic province, by applying IUCN criteria and categories, together with an evaluation of some reproductive traits. Centaurea horrida Badaro (Asteraceae) is an endemic species of northern Sardinia (Italy). It is protected by the Bern Convention (Appendix I) and listed as priority species by the “Habitat” Directive (92/43/EEC, Annex II). The species appears in the 1997 IUCN Red List as “Vulnerable” (VU). With the aim of evaluating the risk of extinction and of providing management tools for the network of protected areas in which this species is present, some reproductive traits have been evaluated, and the distribution, size a...

Summary The Mediterranean Basin, possessing 4.3% of all plants of the world, is considered one of the biodiversity hotspots at global scale. Several forms of impact on biodiversity are currently taking place in European Mediterranean countries as a result of the abandonment of traditional extensive production systems in areas of particular value for nature conservation. In this study we investigated the effects of the cessation of agro-sylvo-pastoral activities on Centaurea horrida Badaro, a very rare sea-cliff plant, endemic to North-Western Sardinia (Italy) and listed by the IUCN as vulnerable. In a similar way to other cliff species, Centaurea horrida can expand its range when unsuitable surrounding habitats are disturbed. The analysis of aerial photos indicates that about 88.5% of a surface previously occupied by a Centaurea horrida dwarf community was replaced by juniper scrub over a 50-year period. In the juniper scrub Centaurea horrida density is at present 1/5 of that observed in the dwarf community. The spatial distribution of Centaurea horrida individuals was not random but concentrated in open microhabitats, more abundant in the dwarf community than in the juniper scrub. Juveniles were found mainly on bare soil; this being the only microhabitat where seedling emergence may occur. Furthermore, disturbance had a positive effect on the survival rates of saplings. Our data show that Centaurea horrida is a species that is linked to the initial stages of secondary succession, when patches of bare soil are available, but it is non-competitive with the late-succession species of the juniper scrub. Active management practices to maintain Centaurea horrida populations are therefore proposed and discussed.

3 p., 1 fot., Two individuals morphologically intermediate between Centaurea horrida Badarò (1824: 367) and C. filiformis Viviani (1825: 6) were collected by Charles Immanuel Forsyth Major on 26 May 1885 at Tavolara Islet, Italy (FI!): these samples were published by Fiori (1904) and later reported in Arrigoni (1972) as two different hybrids: “C. superfiliformis × horrida Levier” and “C. superhorrida × filiformis Levier”. As annotated on the label by Emile Levier, the material deposited in FI shows that the morphology of the two hybrids is very different and only the one named by Fiori as “C. superfiliformis × horrida Levier” was labelled as C. forsythiana Levier (Fig. 1). This sample is morphologically similar to the individuals of a hybrid population we discovered in the same site in the Tavolara Islet (Timone), on limestone, as reported by Fiori (1904). The hybrid named “C. superhorrida × filiformis Levier” by Fiori (1904) was collected by Forsyth Major in a different site (Bocchetta) on granite, and has never been recollected afterwards. For the matter of this note, this is not a problem since, according to Article H.4.1 of the International Code of Nomenclature (McNeill et al. 2012), all the hybrid variants originated from the same parental species, as far as considered nothotaxa (Art. H.3.1), should bear the same name., This study was supported by the Regione Autonoma della Sardegna, LR 7/2007–PO Sardegna FSE 2007–2013, with the grant no. CRP2 474 for all authors and no. CRP3 188 for SP.

Studies over the last two decades demonstrate that hybridization has played an integral role in the evolution of several sections of the genus Centaurea. Nevertheless, natural hybridization between narrow Mediterranean endemic Centaurea species has not been documented as yet. A population of fertile Centaurea individuals exhibiting intermediate morphological traits between two Sardinian narrow endemics, C. horrida and C. filiformis, was identified at the Tavolara Islet (Sardinia, Italy). Intermediate leaf length and head width characterized this population, suggesting its hybrid origin. The putative hybrid population was structured (i.e., composed of seedlings, saplings and adult individuals) and had a relatively high levels of seed production. The number of chromosomes was identical to that of the proposed progenitors (2n = 18). Genotyping at five microsatellite loci showed that the putative hybrid possessed several alleles in common with the proposed parental species and intermediate values of genetic differentiation, as indicated by both FST and RST, between C. horrida and C. filiformis. We therefore conclude that the studied intermediate population is of hybrid origin, and discuss possible mechanisms of its reproductive isolation from the parental species, potential re-introgression, and evolutionary implications of this hybridization.