A Synopsis of Sardinian Studies: Why Is it Important to Work on Island Orchids?

Abstract

<jats:p>Biological and ecological investigations of islands are crucial to explain ecosystem functioning. Many studies on island biodiversity are carried out on oceanic islands. In contrast, information on continental islands, such as those in the Mediterranean Sea, is very often fragmented in space and time. Here, a synopsis of the Orchidaceae of Sardinia is presented based on literature surveys and recent botanical field studies. Our final list comprises of 64 species and 14 genera: thirteen species and subspecies were recognized as endemic and four new species were recorded for the flora of the island: Anacamptis palustris (Jacq.) R.M. Bateman, Pridgeon &amp; M.W. Chase; Himantoglossum hircinum (L.) Spreng; Orchis italica Poir.; and Platanthera kuenkelei subsp. kuenkelei var. sardoa R.Lorenz, Akhalk., H.Baumann, Cortis, Cogoni &amp; Scrugli. This orchid richness reflects the geological history of the island that was linked to the mainland several times, facing long periods of isolation. We also discuss a critical point-of-view of the biodiversity shortfalls still problematic for insular orchids. Indeed, within the Mediterranean Basin, the greatest amount of endemism occurs mainly on large islands, and, despite a long history of botanical exploration in European countries, many of them are scarcely investigated. This annotated synopsis shows the potential of continental islands to understand trends in ecology and evolution. Further studies are required to complete our knowledge of the orchid diversity on continental islands in order to propose scientific-based conservation programs to preserve these unique taxa.</jats:p>

From Island Biogeography to Conservation: A Multi-Taxon and Multi-Taxonomic Rank Approach in the Tuscan Archipelago

“…Orchidaceae showed a particularly strong insularity in full accordance with what was reported in Lussu et al [70], where area resulted a better predictor of species richness in comparison to elevation in Mediterranean islands, although Gentili et al [71] highlighted the highest levels of speciation and diversity in Mediterranean mountains. These plants are commonly present at low population densities in a variety of habitats and this feature makes Orchidaceae particularly susceptible to island size and explains their insularity found worldwide [72].…”

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

“…Among others, many inquirenda are those cryptic and doubtful taxa belonging to the genera Limonium, Ophrys and several Asteraceae -especially those from the Cichorieae tribe -such as the ones of the genera Hieracium and Taraxacum. All these groups were already outlined as problematic, due to their phylogenetic complexity and instability [e.g., [57][58][59]. As elsewhere in the world [60], most taxa, even several includenda, were described on the basis of morphological characters and then never confirmed by molecular evidence.…”

Epipactis tremolsii Seed Diversity in Two Close but Extremely Different Populations: Just a Case of Intraspecific Variability?

“…In Sardinia, the genus Epipactis is represented by six entities among species and subspecies [ 45 ]. We refer to [ 46 ], which considers the study species as E. tremolsii . E. tremolsii is a perennial (rhizomatous) herbaceous plant, producing 1 to 6 aerial stems up to 60 cm tall [ 18 ].…”