The Role of Photobionts as Drivers of Diversification in an Island Radiation of Lichen-Forming Fungi

Speciation in oceanic islands has attracted the interest of scientists since the 19th century. One of the most striking evolutionary phenomena that can be studied in islands is adaptive radiation, that is, when a lineage gives rise to different species by means of ecological speciation. Some of the best-known examples of adaptive radiation are charismatic organisms like the Darwin finches of the Galapagos and the cichlid fishes of the great African lakes. In these and many other examples, a segregation of the trophic niche has been shown to be an important diversification driver. Radiations are known in other groups of organisms, such as lichen-forming fungi. However, very few studies have investigated their adaptive nature, and none have focused on the trophic niche. In this study, we explore the role of the trophic niche in a putative radiation of endemic species from the Macaronesian Region, the Ramalina decipiens group. The photobiont diversity was studied by Illumina MiSeq sequencing of the ITS2 region of 197 specimens spanning the phylogenetic breadth and geographic range of the group. A total of 66 amplicon sequence variants belonging to the four main clades of the algal genus Trebouxia were found. Approximately half of the examined thalli showed algal coexistence, but in most of them, a single main photobiont amounted to more than 90% of the reads. However, there were no significant differences in photobiont identity and in the abundance of ITS2 reads across the species of the group. We conclude that a segregation of the trophic niche has not occurred in the R. decipiens radiation.

Inland and Island Tourism, Contrasting Geographies Touching Each Other

Despite being opposite geographic regions, inland territories and small islands have very much in common in terms of economic and social constraints. Based on the case study of the Azores archipelago, the limitations and opportunities for tourism development in the small oceanic islands are analysed. This study is supported by empirical research involving the application of questionnaires to the main tourism stakeholders in the archipelago. The results lead to the conclusion that in the case of the group of small temperate islands, tourism has progressively asserted itself as strategic for the local economy, but the application of a sustainable development model must be considered as these territories are generally highly vulnerable, both environmentally and socially.

Maritime Climate in the Canary Islands and its Implications for the Construction of Coastal Infrastructures

Islands are isolated systems that depend on maritime trade for their subsistence. Efficient, durable and structurally reliable port infrastructures are essential for the economic and social development of islands. However, not all port infrastructures are designed in the same way. They can vary, depending on whether they are built on continental land, built on non-volcanic islands or built on volcanic oceanic islands (such as the Canary Islands, Spain). The latter islands are the subject of this study due to their specific features, construction difficulties and the importance of sound maritime infrastructures. The maritime climate of an area consists of the wave and storm regimes that affect it and, from these, the coastal dynamics and coastal formations of that area can be studied. For this reason, historical data were collated on significant directional wave heights from 1958 to 2015 from several WANA-SIMAR points in the virtual buoy network of State Ports of Spain located near the Canary Islands. These data have been studied to obtain the maximum directional wave heights (Hs) at each point. With this analysis, we have obtained useful summary tables to calculate wave height by a graphic method that transforms the distribution function into a line drawn on probabilistic paper, using reduced variables. This enables adjustments to be made by linear regression and minimum square methods to facilitate planning and design of maritime infrastructures in a reliable way. Doi: 10.28991/CEJ-2022-08-01-02 Full Text: PDF

Distribution and abundance of planktonic mollusks along a longitudinal gradient in the Southeastern Pacific off Chile

The objectives of this research were to estimate the abundance of the main groups of planktonic mollusks (meroplanktonic larvae, holoplanktonic gastropods and cephalopod paralarvae), and relate these groups to the physical-chemical water properties along a longitudinal gradient between Caldera, on the coast of mainland Chile, and the Easter Island ecoregion (Rapa Nui Island and Salas y Gómez Island), in the Southeast Pacific Ocean. Plankton samples were collected over the course of the CIMAR 21-Islas Cruise, from October to November 2015, at 33 oceanographic stations via vertical hauls of a WP2 net (180-µm mesh size) from a maximum depth of 300 m to the sea surface. Mollusks were sorted, counted and initially assigned to Class rank, later being identified to lower taxonomic ranks. Planktonic mollusks were obtained at all stations, and were composed of 92.7% of Gastropoda and 7.3% of Bivalvia. The total abundance of mollusks varied between 55 and 4,922 individuals 100 m-3.Euthecosomate gastropods exhibited the highest occurrence within the oceanic area. Meanwhile, no paralarvae were captured. Differences in the composition of planktonic mollusks between the continental and oceanic zones were evident. Bivalve larvae increased their abundance in warmer, salty and vertically mixed waters. These results are the first record of meroplanktonic mollusks in waters near the Chilean oceanic islands, and suggest that planktonic mollusks display spatial variation at the scale of the South Pacific Basin, which could be related to the hydrographic conditions and the water column structure.

Interpopulation Plasticity in a Darkling Beetle Life-History along a Whole Oceanic Island Altitudinal Gradient

Insects show remarkable phenotypic plasticity in response to changing environmental conditions. The abiotic factors that determine their phenotypes often vary in time and space, and oceanic islands harbour ideal environments for testing predictions on this matter. The ubiquitous beetle Pimelia laevigata costipennis Wollaston, 1864 (Tenebrionidae) is distributed over the entire altitudinal gradient of the island El Hierro (Canary archipelago), from 0 to 1501 m above sea level. Here, we examine how environmental factors (i.e., rainfall and temperature), associated with the altitudinal gradient, affect the body size, reproductive phenology, clutch size and egg volume, and population dynamics of this ectothermic flightless insect. Pimelia l. costipennis populations inhabiting upland localities, typified by lower temperatures, and greater precipitation and vegetation cover, were larger in body size and laid larger clutches with smaller eggs than those in the lowlands. Moreover, reproduction occurred earlier in the year at lower sites and later at higher sites, whereas activity density was highest in the uplands where it increases with temperature. This study first explores the changes in life history patterns along a whole insular altitudinal gradient, and finds interpopulation plasticity. It confirms that environmental factors associated with species spatial distribution act additively as drivers of phenological and phenotypic expression.

Revision of the European species of the genus Hincksina Norman, 1903 (Bryozoa, Cheilostomatida, Flustridae)

Four Atlantic species of the flustrid genus Hincksina Norman, 1903, which were introduced during the 19th and early 20th century, are redescribed and imaged: Hincksina flustroides (Hincks, 1877) from Great Britain, Hincksina sceletos (Busk, 1858) from Madeira as well as Hincksina neptuni (Jullien in Jullien & Calvet, 1903) n. comb. and Hincksina alice (Jullien in Jullien & Calvet, 1903) n. comb. from the Azores, the latter two of which were hitherto placed in the cribrilinid genus Membraniporella Smitt, 1873. Lectotypes are designated for all species. A new species, Hincksina synchysia n. sp., is introduced for the Mediterranean taxon previously referred to as Hincksina flustroides f. crassispinata Gautier, 1962. In contrast to species from the continental shelf, which have simple cylindrical or flattened spines, some of the species from the oceanic islands of Madeira and the Azores are particularly characterised by falciform and variably formed palmicorn spines. Moreover, whilst most Hincksina species have avicularia with a relatively short, (sub)rounded rostrum and mandible, the two Azorean species have elongated, curved and pointed avicularia. The relationship between Gregarinidra Barroso, 1949, which also has pointed avicularia, and Hincksina is commented upon. Based on several shared diagnostic characters, the genus Cribralaria Silén, 1941 is here transferred from the Cribrilinidae Hincks, 1879 to the Flustridae Fleming, 1828.

Mosses diversity from Simeulue Island, Sumatera, Indonesia

Simeulue is an oceanic islands located in the western coast of Sumatera, just offshore of the southwestern coast of Aceh Province, Indonesia. The diversity of mosses in the island was unknown. Unfortunately, the island was largely devastated by the 2004 tsunami, which also affected the flora of the island, including the moss flora. In order to conserve the present day mosses flora, the current study is conducted covering several types of habitats. 83 samples of mosses from 41 species have been collected and identified. Three species are apparently new records to both Simeulue and Sumatera; Hyophila javanica (Nees) Brid., Taxithelium kerianum (Broth.) M. Fleisch., and Taxithelium ramicola Broth. Neckeropsis gracilenta (Sande Lac.) M. Fleisch. is the dominant species.

Genetic data from the extinct giant rat from Tenerife (Canary Islands) points to a recent divergence from mainland relatives

Evolution of vertebrate endemics in oceanic islands follows a predictable pattern, known as the island rule, according to which gigantism arises in originally small-sized species and dwarfism in large ones. Species of extinct insular giant rodents are known from all over the world. In the Canary Islands, two examples of giant rats, † Canariomys bravoi and † Canariomys tamarani , endemic to Tenerife and Gran Canaria, respectively, disappeared soon after human settlement. The highly derived morphological features of these insular endemic rodents hamper the reconstruction of their evolutionary histories. We have retrieved partial nuclear and mitochondrial data from † C. bravoi and used this information to explore its evolutionary affinities. The resulting dated phylogeny confidently places † C. bravoi within the African grass rat clade ( Arvicanthis niloticus ). The estimated divergence time, 650 000 years ago (95% higher posterior densities: 373 000–944 000), points toward an island colonization during the Günz–Mindel interglacial stage. † Canariomys bravoi ancestors would have reached the island via passive rafting and then underwent a yearly increase of mean body mass calculated between 0.0015 g and 0.0023 g; this corresponds to fast evolutionary rates (in darwins (d), ranging from 7.09 d to 2.78 d) that are well above those observed for non-insular mammals.

Block level weather forecast using direct model output from NWP models during monsoon season in India

The forecast for 655 districts and 6500 blocks had been prepared and implemented on 1st June, 2014. The procedure for getting forecast for the districts and blocks in India including altitude corrections is based upon regular (0.25 × 0.25) grid output from the T-574 Model and output from 9 km WRF model. A verification study for rainfall forecast at 0.25 × 0.25 degree grid for Indian Window (0-40° N and 60-100° N) is also conducted, which had indicated that skill of the rainfall forecast is good for all parts of the country except oceanic islands and high terrain regions and one can down scale to any level, down to the blocks, the skill scores will not differ much. A detailed verification study for the skill of the forecast at block level for all the eight weather parameters for which the forecast was issued is conducted. The skill of the rainfall forecast is obtained for categorical forecast and as well as for yes/no forecast. The skill scores for rainfall had indicated that highest value of Hanssen and Kuiper (HK) score is 0.44, Hanssen and Kuiper score for quantitative rainfall (HKQ) is 0.18, Ratio score for yes/no forecast is 90 percent and Hit rate (HR) is 0.83. The detailed verification study for the block level weather forecast for monsoon 2014 is presented in the paper and the skill found is good. The study indicates that model forecast has the potential to be used for the block level forecast after making the quick value additions for which hints are given in the conclusion part.

A Taxonomic Revision of the Genus Dracophyllum Labill. (Ericaceae)

<p>In recent years the New Zealand biogeographic paradigm has shifted from 'Moa's Ark' (Bellamy et al. 1990) to the view that most biota has dispersed here in the lastà à ± 10 My (Fleming 1975, Pole 1994, McGlone et al. 2001). Large and widely distributed genera on island archipelagos and oceanic islands are important elements for the investigation of evolutionary processes such as dispersal from continents to islands and back, adaptive radiation and in some cases extinction. The genus Dracophyllum (Ericaceae: Richeeae) occurs on the Australian continent and the New Zealand archipelago as well as on many oceanic islands in the region. With its wide distribution, ecological importance and apparent taxonomic complexity, a monograph and phylogenetic study of Dracophyllum will make a valuable contribution towards the understanding of the above- mentioned processes. There is still uncertainty about generic limits within tribe Richeeae (Dracophyllum Labill., Richea R. Br. and Sphenotoma R. Br. ex Sweet). Sphenotoma is geographically isolated (southwest Western Australia), monophyletic and forms a distinct evolutionary lineage that diverged early from Dracophyllum and Richea (Powell et al. 1996, Kron et al. 2002). The generic limits between Dracophyllum and Richea still need to be addressed, preferably by making use of DNA sequence data. There are two fundamental aims of systematics: a) to discover, describe and name all species and b) to document the changes on the branches that have occurred during evolution and to transform these into a predictive classification system that reflects evolution (Systematics 18 Agenda 2000). Systematics is therefore the study of the biological diversity that exists on earth today and its evolutionary history (Judd et al. 1999). Taxonomic revisions, especially of large groups, need to focus on groups that are monophyletic (i.e. comprising an ancestor and all of its descendents) and not constrained by geography. Generic delimitation can become problematic when the flora of a specific region is studied in isolation. Many important aspects of genotypic and phenotypic variation are then not taken into consideration, resulting in a skewed and unrealistic representation of the genus as a whole. The long list of synonyms in the southern hemisphere for the genus Veronica L. is a reflection of this situation: Paederota L., Hebe Comm. ex Juss., Derwentia Raf., Pygmaea Hook.f., Detzneria Schltr. ex Diels, Parahebe W.R.B.Oliv., Chionohebe B.G.Briggs & Ehrend., Leonohebe Heads, Heliohebe Garn.-Jones and Hebejeebie Heads.</p>