Secondary mat-grass swards on nutrient-poor soils at low and mid-altitudes of the temperate, boreal and subarctic regions of Europe
Nardetea strictae Rivas Goday et Borja Carbonell in Rivas Goday et Mayor López 1966 nom. conserv. propos.
Nardetea strictae Rivas Goday et Borja Carbonell in Rivas Goday et Mayor López 1966 nom. conserv. propos.
nar01 | De Foucault (1994, 2012) presented synoptic tables featuring the Nardetalia alongside the 'Festucetalia spadiceae', Saginetalia piliferi, Trifolietalia parnassi and Udo-Nardetalia to be classified within the 'Nardetea'. This approach has been also followed in some other European surveys (e.g. Kliment & Valachovič 2007). The synoptic tables in de Foucault's paper actually support the opposite view − one that has been adopted in our paper. We prefer to place the secondary oligotrophic pastures of the Nardetalia (the nomenclature type of the Nardetea) into the Nardetea as defined originally by Rivas Goday & Rivas-Martínez (1963), while the primary oligotrophic pastures/grasslands occurring at high altitudes and showing high level of regional and local endemism are classified within the Juncetea trifidi. The secondary low-altitude Nardetalia pastures are replacing various woods on nutrient-poor substrates (e.g. Quercetea robori-petraeae), degraded heaths of the Calluno-Ulicetea and drained oligotropic wetlands. It is obvious that the historical and evolutionary (hence biogeographic) drivers in the secondary and primary oligotrophic grasslands are of different nature, steering the community assemblage in different ways. Mechanistic placement of the above-mentioned oligotrophic grassland units all under one broad umbrella on the basis of occurrence of a very broadly distributed group of species into the broadly conceived class 'Nardetea' (as interpreted by de Foucault (l.c.) defies the logic of an informative syntaxonomic system. Some vegetation surveys prefer a physiognomically heterogeneous concept of a broader class − the Calluno-Ulicetea sensu lato (incl. both heath and oligotrophic grasslands) arguing for poor floristic difference between the Nardetea and the Calluno-Ulicetea s.str., yet neglecting vegetation-structural characteristics. (L. Mucina) For the detailed argumentation underpinnig the proposal to conserve the name Nardetea strictae Rivas Goday et Borja Carbonell in Rivas Goday et Mayor López 1966 against the name Nardo-Callunetea Preising 1950 see Di Pietro et al. (2015). (J.-P. Theurillat).