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Hugonnot V.,Conservatoire Botanique National du Massif Central | Celle J.,Conservatoire Botanique National du Massif Central
Nova Hedwigia | Year: 2015

Helodium blandowii is reported as new to France in the oriental part of the Pyrenean range and the Massif Central. The plant communities are described and associated bryophytes are listed. Issues relating to conservation are discussed. © 2015 J. Cramer in Gebr. Borntraeger Verlagsbuchhandlung, Stuttgart, Germany.


Hugonnot V.,Conservatoire Botanique National du Massif Central
Phytotaxa | Year: 2015

Riccia melitensis was considered to be an andemic species of the Maltese Archipelago and has never been relocated in the field since its discovery in 1913. The type specimen of Riccia melitensis Mass. has been examined and its taxonomic morphological characters re-evaluated. As a result, R. melitensis is considered to be a synonym of R. ciliifera Lindenb. © 2015 Magnolia Press.


Hugonnot V.,Conservatoire Botanique National du Massif Central | Hedenas L.,Swedish Museum of Natural History
Journal of Bryology | Year: 2015

Arvernella microclada Hugonnot & Hedenäs is described from several localities in the Massif Central of France (Auvergne). This diminutive, autoicous, pleurocarpous moss has strongly prorate distal ends of the leaf lamina cells and straight and erect inner perichaetial leaves. It bears a superficial resemblance to small Heterocladium Bruch & Schimp. species, especially H. flaccidum (Schimp.) A.J.E.Sm. or weak phenotypes of H. wulfsbergii I.Hagen. Other small confervoid species, like Platydictya jungermannioides (Brid.) H.A.Crum or Serpoleskea confervoides (Brid.) Loeske differ in several respects, most notably in the absence of abaxial leaf lamina cell prorations, but also in rhizoid topography (Platydictya) and leaf orientation and leaf margin denticulation (Serpoleskea). Arvernella microclada grows in subalpine tall-herb communities and Fagus sylvatica L. mountain woods on small lava blocks on cold, unstable, and steep scree slopes. The restricted known geographical distribution may be of conservation concern. © British Bryological Society 2015.


Hugonnot V.,Conservatoire Botanique National du Massif Central | Chavoutier L.,Les Hesperides
Cryptogamie, Bryologie | Year: 2015

Aloina bifrons (De Not.) Delgad. is recorded for the first time in France in the Limagne, Puy-de-Dôme department, Auvergne region. This is a significant northward extension of the species' known range. It grows there on sunny marlaceous lime with gypsum traces on a south-facing steep slope. The French habitat differs significantly from the situation recorded in other parts of the Mediterranean and Irano-Turanic areas, where Aloina bifrons is a typical inhabitant of gypsum soils with a rich assemblage of Xeropottioid elements. © 2015 Adac. Tous droits réservés.


Poncet R.,Conservatoire Botanique National du Massif Central | Hugonnot V.,Conservatoire Botanique National du Massif Central | Vergne T.,Conservatoire Botanique National du Massif Central
Cryptogamie, Bryologie | Year: 2015

The conservation of rare and endangered species like Orthotrichum rogeri Brid. requires a precise knowledge of their ecology and distribution. However, the scarcity of financial resources and the inadequacy of chorological data difficult the design of efficient conservation policies. In this context, species distribution models (SDM) can provide useful information to apply conservation measures over large areas like Auvergne region, France (26,000 km2). Unfortunately, the use of SDM to assist the introduction of conservation measures is uncommon in bryology. O. rogeri is a rare and poorly known moss at the national scale which is well represented in Auvergne. The European Union through the "Habitats and Species Directive" made its protection compulsory. The aim of this work is to use SDM to improve our current knowledge on O. rogeri distribution in order to provide guidance for designing conservation measures. To do so, we first designed a survey to gather presence/absence data and then fit logistic regression model. Model accuracy was assessed using previous knowledge on species occurrences (which have not been used in SDM). The output of the SDM leads us to an improved understanding of the chorology of O. rogeri. Our results showed that this species is clearly too scarcely represented in the Natura 2000 regional network and pointed to the need of targeted surveys. Natura 2000 sites are either too severely fragmented and/or too small to allow efficient conservation of O. rogeri and the suite of related remarkable epiphytes. We suggest that slight modifications of current outline of Natura 2000 sites to allow the integration of several known populations. O. rogeri shows some paradoxical habitat requirements, in some areas it is strongly linked to anthropogenic habitats while in others it is linked to ancient woodlands without anthropogenic activities. Disturbance regime is identified as of prime relevance for the conservation of appropriate habitats. Due to the contrasted requirements of the species diverging conservation strategies could be adopted. Besides, taking into account the various scenarios offers the possibility to anticipate environmental changes caused by global warming and its likely effect for the successful implementation of conservation measures. © 2015 Adac.


Hugonnot V.,Conservatoire Botanique National du Massif Central
Flora Mediterranea | Year: 2014

The bryoflora of the Gorges de l'Ardèche has been bryoflostically investigated. The previously published records, corresponding to 27 taxa, have been taken into account. Today, 216 bryophyte taxa are confidently recorded in the Gorges de l'Ardèche site. It is considered as a local hot-spot of bryological diversity in a south-eastern France context. Several genera are of special ecological interest: Didymodon, Orthotrichum, Bryum, Fissidens and Riccia. More than 20 remarkable species are additionally recorded: Acaulon triquetrum, Aleniella besseri, Barbula bolleana, Bryum canariense, Cheilothela chloropus, Cinclidotus danubicus, Didymodon nicholsonii, Ephemerum recurvifolium, Fissidens fontanus, Grimmia tergestina, Homalia lusitanica, Homalothecium aureum, Mannia californica, Marchantia paleacea, Orthotrichum philibertii, Orthotrichum sprucei, R. trabutiana, Radula lindenbergiana, Riccia cavernosa, Scorpiurium sendtneri, Timmiella anomala and Tortella inflexa. A significant number of species is largely dependant upon the natural functioning of the Ardèche river, with an intense alluvial activity and remodelling of river banks. Most forest stands are young ones, originating from forest recolonization of ancient pastoral areas. The conservation of the bryophyte communities is very simple and shall be based upon the principle of minimum intervention. An improvement of the waste water disposal systems of many campsites is needed.


Hugonnot V.,Conservatoire Botanique National du Massif Central
Journal of Bryology | Year: 2016

The invasive Campylopus introflexus (Hedw.) Brid. is suspected to outcompete native bryophytes but we know very little about the mechanisms involved in its success. We used extensive mixed-stands of Campylopus introflexus and the indigenous C. pilifer Brid. in a French Nature Reserve to study comparative ecological niches, growth rates, density and reproduction between the two mosses. A re-evaluation of the discriminant morphological characters was first undertaken to allow a straightforward separation of both species in the field. Sporophytes were never encountered on Campylopus pilifer, whereas they are produced in great profusion by C. introflexus, implying a massive sporal investment. In contrast, Campylopus pilifer can produce deciduous shoot-tips in mature colonies whereas C. introflexus is apparently unable to do so, the propagules being restricted to immature developmental stages. Campylopus pilifer does not occupy exactly the same niche as C. introflexus. Only Campylopus pilifer occupies the harsher microhabitats whereas only C. introflexus occurs in moister ones. The mixed-stands are restricted to medium-dry environments. The success of the alien Campylopus introflexus may be largely attributed to its growth response which is, on average across habitats, about twice that of C. pilifer. The combination of faster growth and higher branch frequency contribute to the competitive advantage of Campylopus introflexus, which is able to aggressively overtop and laterally penetrate adjacent cushions of Campylopus pilifer. Removal of trees as soon as their crown begins to cast some shade and soil scraping should be tested in order to lower the negative impacts of Campylopus introflexus in the study site. © British Bryological Society 2016


Pepin F.,Conservatoire Botanique National du Massif Central | Hugonnot V.,Conservatoire Botanique National du Massif Central | Celle J.,Conservatoire Botanique National du Massif Central
Journal of Bryology | Year: 2013

For obscure reasons, sporophytes of the dioicous Hamatocaulis vernicosus are currently unknown in France. With the aim of understanding this failure of sporophyte production we investigated (1) sexual phenology, (2) sex ratio pattern at different spatial scales, (3) limitation of sporophyte formation by the availability of only one sex, (4) limitation of sporophyte formation caused by the distance between male and female, (5) location of sporophytes and (6) the consevation implications of this failure of sporophyte production. Principal results show that phenology cannot explain the failure of sporophyte production. At the regional scale, sporophyte formation is prevented by the fact that several mountain ranges have singlesex populations. The production of spore capsules relies on a strict combination of factors at the local scale: occurrence of sexually expressed mixed-sex colonies, a short distance between male and female individuals and favourable environmental factors (light grazing, high water table). In the Massif Central of France spore production is unlikely because of current unfavourable conditions. Fertility patterns appeared useful in a conservation context. © British Bryological Society 2013.


Hugonnot V.,Conservatoire Botanique National du Massif Central | Celle J.,Conservatoire Botanique National du Massif Central | Vergne T.,Conservatoire Botanique National du Massif Central
Cryptogamie, Bryologie | Year: 2013

Aphanolejeunea microscopica, Breutelia chrysocoma, Harpalejeunea molleri, Jubula hutchinsiae subsp. hutchinsiae, Lejeunea patens, Plagiochila bifaria, P. exigua are seven hyperoceanic bryophytes which have been recently observed in western Massif Central. The French distribution of each of these species is updated. The ecological requirements of these forest rocks dwelling species are summarized. The examination of their reproductive and demographic characteristics highlights their precarious situation and their strong vulnerability. The conservation of this remarkable element requires adopting constraining measures. © 2013 Adac. Tous droits réservés.


Philippe M.,9 boulevard Joffre | Hugonnot V.,Conservatoire Botanique National du Massif Central
Bulletin Mensuel de la Societe Linneenne de Lyon | Year: 2016

Two moss species are reported for the first time for the Ain department, north-eastern France, Seligeria patula (Lindb.) Lindb. and Seligeria carniolica (Breidl. & Beck) Nyholm. The latter, a European endemic moss, rare at continental scale, was represented by what might be the largest known population. Both species having been observed on marly limestone, the peculiarities of this substrate are briefly discussed.

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