Jean Werner 2018
Quelques associations de bryophytes sur rochers de grès acides et bois pourrissant au Luxembourg
Ferrantia 80, Musée national d’histoire naturelle, Luxembourg, 54 p.
publication date: 28 december 2018
price: 15 €
More than thirty bryophyte associations or communities of acid sandstone or decaying wood are dealt with in this paper, which is based on 139 phytosociological records, drafted between 1984 and 2016 within the sandstone area of Gutland (Bon Pays, Lorraine district, Luxembourg), especially so in the Petite Suisse Luxembourgeoise. In this region, due to the special rocky topography, one can observe rare microclimates and special ecologies regarding temperature, available light and the moistness of the surrounding air.
Some recent remarkable floristic records made during the preparatory work for this paper are reported. The associations and communities observed are briefly commented, especially from an ecological and floristic point of view. A new sub-association with Harpanthus scutatus is described, as belonging to the Lepidozio reptantis-Mnietum horni Bardat 1993 (Tetraphidion alliance). An ill-known community, dominated by the liverwort Liochlaena lanceolata is examined in more detail, taking into account the author’s surveys and those from the sparse literature; a new association – Liochlaenetum lanceolati (Rodi, Hennecke & Haas 1976) Werner ass. nov – is formally described.
These cryptogamic communities are then examined together, with respect to their site micro-ecology; an approximate classification shows the importance of temperature, light availability and the moistness of the surrounding air. With respect to phytogeography, a great number of mountainous communities are encountered here at low altitudes, while sub-oceanic influences are also much perceivable. Typical succession patterns – both on short and long term – are briefly commented. This paper stresses also the patrimonial value of many of these associations, a great number of which are threatened at various degrees, among others by human influence and climatic change; thus, a Red List is proposed for the most significant associations, which is roughly drafted along IUCN criteria.