Genetic Approach on Sanionia uncinata (Hedw.) Loeske to Evaluate Representativeness of in situ Conservation Areas Among Protected and Neighboring Free Access Areas in Maritime Antarctica and Southern Patagonia

The Antarctic Specially Protected Areas (ASPAs) are zones with restricted access to protect outstanding environmental, scientific, historic, aesthetic, or wilderness values adopted inside the Antarctic Treaty System. Meanwhile, in southern Patagonia, conservation initiatives are implemented by the state of Chile and private entities. However, both are considered unrepresentative. Our work evaluates the representativeness of the in situ conservation through a genetic approach of the moss Sanionia uncinata (Hedw.) Loeske among protected and neighboring free access areas in Maritime Antarctica and southern Patagonia. We discuss observed presence with both current and reconstructed past potential niche distributions (11 and 6 ka BP) in the Fildes Peninsula on King George Island. Results showed occurrence of several spatially genetic subpopulations distributed inside and among ASPA and free access sites. Some free access sites showed a higher amount of polymorphism compared with ASPA, having ancestry in populations developed in those places since 6 ka BP. The different spatial and temporal hierarchies in the analysis suggest that places for conservation of this species in Maritime Antarctica are not well-represented, and that some free access areas should be considered. This work represents a powerful multidisciplinary approach and a great challenge for decision-makers to improve the management plans and the sustainable development in Antarctica.

Le Lescuraeetum mutabilis Greter ex Wilm. 1962 dans le Massif central

Le Lescuraeetum mutabilis Greter ex Wilm. 1962 (Neckeretea complanatae Marst. 1986) est une association corticole acidiphile colonisant la base des troncs tortueux des vieux hêtres, à l’étage subalpin, ou au montagnard supérieur, au sein de communautés trachéophytiques relevant respectivement de l’Acerion pseudoplatani (Oberdorfer 1957) Rameau in Rameau, Mansion & Dumé 1993 nom. nud., du Fagion sylvaticae Luquet 1926 (pour les communautés neutrophiles) ou du Luzulo luzuloidis-Fagion sylvaticae Lohmeyer & Tüxen in Tüxen 1954 (pour les communautés acidiphiles). Cette association substratohygroclinophile, psychrophile, strictement inféodée aux forêts alticoles, est caractérisée dans le Massif central par la présence de 4 espèces : Lescuraea saviana, L. mutabilis, Sciuro-hypnum reflexum et Sanionia uncinata. La haute fréquence de Lescuraea saviana est une originalité régionale de l’association, considérée comme insuffisante pour définir une sous-association, mais permettant cependant l’individualisation d’une race géographique méridionale de cette association largement répandue dans les massifs montagneux du domaine tempéré européen. Cette association cryophile présente certainement une grande sensibilité vis-à-vis de l’augmentation des températures et des modifications du régime de précipitation et possède un fort enjeu conservatoire.

Experimental warming of bryophytes increases the population density of the nematode Plectus belgicae in maritime Antarctica

Despite nematodes routinely being the most frequent soil- and bryophyte-associated animals in maritime Antarctica, there is a lack of clarity about the influence of warming on their populations in the region. Here, we report the results of a field experiment on Adelaide Island that tested the effects of warming with open-top chambers (OTCs) for 37 months on nematodes associated with the bryophytes Cephaloziella varians and Sanionia uncinata. Over the experiment's duration, OTCs increased the population density of the nematode Plectus belgicae in mats of both bryophytes by six-fold, with four- to seven-fold increases in the abundances of male, female and juvenile P. belgicae in warmed mats, and with the largest effects on the abundances of juveniles. Despite C. varians, which is black in colour, warming to a greater extent than S. uncinata during summer, no interactive effects of OTCs and bryophyte species were recorded on the population density of P. belgicae. Our results corroborate a previous study showing that warming increases Plectus population densities in maritime Antarctic soils, with implications for the region's terrestrial food webs.

Do new records of macrofungi indicate warming of their habitats in terrestrial Antarctic ecosystems?

Relatively few macrofungi have been historically described from terrestrial environments of the Antarctic Peninsula and its associated archipelagos which are characterized by a moss-dominated vegetation, most of them preferentially or obligatorily associated with bryophytes. During the study of the influence of penguin rockeries to moss communities on the South Shetland Islands, the bryophilous basidiomycetes Rimbachia bryophila and Arrhenia cf. lilacinicolor were found for the first time on King George Island, growing on carpets of Sanionia uncinata. Other bryophilous fungi previously recorded in the same region are Arrhenia antarctica, Omphalina pyxidata and the rare Simocybe antarctica. The detection of the supposedly parasitic R. bryophila, together with other new observations of macrofungi on different hosts in the Antarctic bryoflora could indicate increased sexual reproduction. The likely increase of reproduction as an effect of warming on the terrestrial antarctic tundra should be proven by follow up field studies.

Evaluation of the acute toxicity, phototoxicity and embryotoxicity of a residual aqueous fraction from extract of the Antarctic moss Sanionia uncinata

Background Ultraviolet (UV) radiation is the main exogenous inductor of skin damage and so photoprotection is important to control skin disorders. The Antarctic moss Sanionia uncinata is an important source of antioxidants and the photoprotective activity of its organic extracts has been investigated. This study aimed to evaluate the potential photoprotection, cytotoxicity and embryotoxicity of residual aqueous fraction (AF) from the moss S. uncinata. Methods UV-visible spectrum and SPF (sun protection factor) were determined by spectrophotometry. Embryotoxicity potential was evaluated by Fish embryo-larval toxicity test using zebrafish (Danio rerio) as organism model. Cell death assays by water-soluble tetrazolium salt (WST-1) and lactate dehydrogenase (LDH) were investigated using HaCaT keratinocyte cell line cultured in monolayers and three dimensions (3D). Phototoxicity and association with UV-filters were performed by 3T3 neutral red uptake test. Results The AF showed sharp absorption bands in the UV region and less pronounced in the visible region. The SPF was low (2.5 ± 0.3), but the SPF values of benzophenone-3 and octyl-methoxycinnamate increased ~ 3 and 4 times more, respectively, in association with AF. The AF did not induce significant lethal and sublethal effects on zebrafish early-life stages. In monolayers, the HaCaT cell viability, evaluated by WST-1, was above 70% by ≤0.4 mg AF/mL after 48 and 72-h exposure, whereas ≤1 mg AF/mL after 24-h exposure. The LDH assay showed that the cell viability was above 70% by ≤0.4 mg AF/mL even after 72-h exposure, but ≤1 mg/mL after 24 and 48-h exposure. In 3D cell culture, an increased cell resistance to toxicity was observed, because cell viability of HaCaT cell by WST-1 and LDH was above ~ 90% when using ≤1 and 4 mg AF/mL, respectively. The AF demonstrated values of photo irritation factor < 2 and of photo effect < 0.1, even though in association with UV-filters. Conclusions The residual AF absorbs UV-vis spectrum, increased SPF values of BP-3 and OMC and does not induce embryotoxicity to zebrafish early life-stage. The cell death assays allowed establishing non-toxic doses of AF and phototoxicity was not detected. AF of S. uncinata presents a good potential for skin photoprotection against UV-radiation.