Overview of habitat history in subtropical oceanic island summit ecosystems

Summit ecosystems of oceanic islands constitute one of the most ephemeral and isolated ecosystems existing, harboring specific features that confer on their biota an outstanding distinctness. Summits are short-lived entities, being the last ecosystems to be constructed during the growth of the new oceanic island, and the first to vanish due either to island subsidence, island erosion, or both. Whereas their geological emergence/disappearance is controlled by the volcanic/erosion activity, Pleistocene glaciations in the past million years, by forcing the altitudinal shift of the timberline, have also likely created or destroyed summit ecosystems, enabling the appearance of alpine ecosystems during glacial maxima where they were not present in interglacial periods and vice versa. On the other hand, summit ecosystems constitute islands within islands, being more isolated from climatically similar ecosystems than the coastlines of the islands containing them. Thus summit biota, frequently displaying a high endemicity, may originate either through dispersal from other close summit ecosystems during peak periods, or from the colonization of the summits and later evolution to the new conditions from mid-altitude species of the same island. Conversely, if peak periods are absent, the disappearance of summit ecosystems implies the extinction or extirpation of their constitutive species. Current summit species have likely occupied a much larger area during glacial periods. Thus the summits may be classified as climatic refuges. This is especially the case if glacial periods were associated with much drier conditions on oceanic islands as is the case on continents

The rediscovery of silene guicciardii (Caryophyllaceae) on Mt. Parnassos (Greece) after 160 years: Taxonomic re-evaluation and conservation

Silene guicciardii (Caryophyllaceae) was rediscovered after field surveys carried out on Mt. Parnassos (Sterea Ellas, Greece), 160 years after the type collection made by J.B. Samaritani and J. Guicciardi in 1857. Since its first collection, it has been considered either as a distinct species, a variety or a mere synonym of the SW-Asiatic S. marschallii. We provide a revised description of the species and we re-evaluate its taxonomic position and that of the related species. We propose to treat the taxon guicciardii at the subspecific rank of S. marschallii. A color plate of S. marshallii subsp. guicciardii and a distribution map for all subspecies of S. marschallii are also provided. The name Silene guicciardii was lectotypified on a specimen preserved at G-BOIS, while isolectotypes are at G-BOIS, B, BR, C, GOET, JE, K and WU. © 2017 Magnolia Press

Two new Allium (A. Sect. Cupanioscordum, Amaryllidaceae) species from Greece

Allium iatrouinum from Evvia Island (W Aegean, Greece) and A. pycnotrichum from Mt. Parnon (SE Peloponnisos, Greece) are described and illustrated. They belong to A. sect. Cupanioscordum, which includes ca. 24 species so far, mainly distributed in the Mediterranean region. Both species are diploid/dysploid (2n = 2x = 14), related to each other and also related to other dysploid members of the A. cupanii group, especially A. hirtovaginatum (W Turkey) and A. maghrebinum (Tunisia, Algeria). The new species grow in rocky habitats and occur in restricted mountain areas, where they flower in summer, mostly from July to August. © 2017 Magnolia Press

Allium orestis sp. nov. (Amaryllidaceae) from Parnon and Taigetos mountains, south Peloponnisos, Greece

Allium orestis Kalpoutzakis, Trigas & Constantinidis sp. nov. (Amaryllidaceae) from Parnon and Taigetos mountains (south Peloponnisos, Greece) is described and illustrated. It belongs to A. sect. Codonoprasum, and its closest relatives are A. rausii, a local endemic species of Ossa and Pilion mountains (east-central Greece) and A. anzalonei, another localized species from west-central Italy. The new species grows in the understorey of Castanea sativa forests and is currently known from three areas on Mt Parnon and one locality on Mt Taigetos. The chromosome number of A. orestis, 2n =2x =16, is reported and a metaphase plate is illustrated. © 2012 The Authors. Nordic Journal of Botany © 2012 Nordic Society Oikos

Multivariate morphometric analysis of Petrorhagia subsect. Saxifragae (Caryophyllaceae) in Greece, with a new species from SE Peloponnisos: P. laconica

The intra-generic relationships within the intriguing genus Petrorhagia are currently debated, as the genus is underrepresented in recent taxonomic studies. In this study, we investigate the relationships among the species of Petrorhagia [sect. Petrorhagia] subsect. Saxifragae occurring in Greece. Based on a combination of ordination methods and discriminant analyses of 36 macromorphological characters, five species are recognized in Greece. The analyses showed that all currently known species from Greece (P. fasciculata, P. graminea, P. phthiotica and P. saxifraga) represent distinct taxonomic entities. According to our results, two recently collected populations from SE Peloponnisos represent a fifth, new Petrorhagia species, which is first described and illustrated here as P. laconica. It is related to the widespread P. saxifraga and the Greek endemic P. graminea, but clearly distinct from both species by a combination of morphological characters, including indumentum, inflorescence, calyx, capsule and seed characters. © 2018 The Authors ·

Conservation genetics of four critically endangered greek endemic plants: A preliminary assessment

The Mediterranean basin constitutes one of the largest global biodiversity hotspots, hosting more than 11,000 endemic plants, and it is recognised as an area with a high proportion of threatened taxa. Nevertheless, only a tiny fraction of the threatened Mediterranean endemics have their genetic diversity assessed, and we are unaware if and how climate change might impact their conservation status. This is even more pronounced in Eastern Mediterranean countries with a rich endemic flora, such as Greece, which hosts a large portion of the plant taxa assessed at the European level under the IUCN criteria. Using inter simple sequence repeats (ISSR) markers and species distribution models, we analysed the genetic diversity and investigated the impacts of climate change on four critically endangered and extremely narrow and rare Greek island endemic plants, namely Aethionema retsina, Allium iatrouinum, Convolvulus argyrothamnos, and Saponaria jagelii. All four species are facing intense anthropogenic threats and display moderate genetic diversity (uHe: 0.254–0.322), while climate change is expected to have a profound impact on their range size during the coming decades. A combination of in-and ex-situ measures, such as population reinforcement and seed bank conservation, are urgently needed in order to preserve these highly threatened and rare Greek endemics. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Genetic Variation in Three Closely Related Minuartia (Caryophyllaceae) Species Endemic to Greece: Implications for Conservation Management

The genus Minuartia is highly diverse in the Mediterranean region and includes several endemic and locally restricted species. The genetic variation of three Minuartia species (M. dirphya, M. parnonia, M. wettsteinii) which are endemic to Greece was investigated, aiming to also develop effective conservation plans for their protection. Minuartia dirphya and M. wettsteinii are known to occur only at their type localities, each forming a small population, while M. parnonia is more widespread with seven populations located in the south-east Peloponnese. Genetic diversity was estimated using ten chloroplast microsatellite and five REMAP markers. The chloroplast microsatellite markers exhibited limited polymorphism among species only, while REMAP revealed a significant amount of genetic variation at the population and species level. All the analyses performed (dendrograms, PCoA, STRUCTURE) showed clear differentiation among species, highlighting M. wettsteinii as the most genetically distant. As shown by AMOVA, a degree of differentiation was detected within M. parnonia, where 41 % of the total variation was partitioned among populations and 59 % to the individuals within them. At the species level, the highest genetic diversity (PPB = 75.86 %, Hj = 0.2728, I = 0.3509) was observed in M. parnonia, followed by M. dirphya (PPB = 55.17 %, Hj = 0.2350, I = 0.2767), while the lowest was observed in M. wettsteinii (PPB = 28.74 %, Hj = 0.1449, I = 0.1498). Scarce gene flow (Nm = 0.5451) was observed among M. parnonia populations. The current study is important for developing conservation management plans for the three threatened Minuartia species. © 2014, Institute of Botany, Academy of Sciences of the Czech Republic

Spatial phylogenetics, biogeographical patterns and conservation implications of the endemic flora of Crete (Aegean, Greece) under climate change scenarios

Human-induced biodiversity loss has been accelerating since the industrial revolution. The climate change impacts will severely alter the biodiversity and biogeographical patterns at all scales, leading to biotic homogenization. Due to underfunding, a climate smart, conservation-prioritization scheme is needed to optimize species protection. Spatial phylogenetics enable the identification of endemism centers and provide valuable insights regarding the eco-evolutionary and conservation value, as well as the biogeographical origin of a given area. Many studies exist regarding the conservation prioritization of mainland areas, yet none has assessed how climate change might alter the biodiversity and biogeographical patterns of an island biodiversity hotspot. Thus, we conducted a phylogenetically informed, conservation prioritization study dealing with the effects of climate change on Crete’s plant diversity and biogeographical patterns. Using several macroecological analyses, we identified the current and future endemism centers and assessed the impact of climate change on the biogeographical patterns in Crete. The highlands of Cretan mountains have served as both diversity cradles and museums, due to their stable climate and high topographical heterogeneity, providing important ecosystem services. Historical processes seem to have driven diversification and endemic species distribution in Crete. Due to the changing climate and the subsequent biotic homogenization, Crete’s unique bioregionalization, which strongly reminiscent the spatial configuration of the Pliocene/Pleistocene Cretan paleo-islands, will drastically change. The emergence of the ‘Anthropocene’ era calls for the prioritization of biodiversity-rich areas, serving as mixed-endemism centers, with high overlaps among protected areas and climatic refugia. © 2020 by the authors. Licensee MDPI, Basel, Switzerland