|Scientific Name:||Arenaria nevadensis Boiss. & Reuter|
|Red List Category & Criteria:||Critically Endangered B1ac(iii,iv)+2ac(iii,iv) ver 3.1|
|Assessor(s):||Gutiérrez, L. & Blanca, G.|
|Reviewer(s):||de Montmollin, B., Bilz, M. & Peraza Zurita, M.D.|
|Contributor(s):||Peraza Zurita, M.D.|
Arenaria nevadensis is listed as Critically Endangered because its extent of occurrence and area of occupancy do not exceed 2 km² and the species has a very scarce and specific habitat which is declining due to livestock and climate change. It is known only from one subpopulation, which undergoes extreme fluctuations, and does occupy an actual area of less than 1 km².
|Previously published Red List assessments:|
|Range Description:||This species is endemic to the Sierra Nevada mountain range in Spain, where it can be found in one single location. Its area of occupancy and extent of occurrence is 2 km² (Gutiérrez and Blanca 2004). It is confirmed that the species does not occur in the Almirez (Almeria's part of Sierra Nevada).|
Native:Spain (Spain (mainland))
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||There is a single population, comprising 2,533 individuals, with five nuclei populations who respond to the presence of water from melting snow. Because of its status as an annual plant, there are significant variations annually in the number of individuals.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This annual herb grows at the most elevated summits, at altitudes between 2,950 and 3,300 m. It grows on earthy sites between pebbles with certain mobility and in sandy level stretch with oligotrophic water supply from melting of the permanent snow of the most elevated summits.|
The domain corresponds to the series de Festuca clementei (Erigeronto frigidi-Festuceto clementei S.). Although the community has very low coverage, it can be found in the vicinity of Linaria glacialis, Viola crassiuscula, Galium rosellum, Hormathophylla spinosa, Festuca clementei, Arenaria tetraquetra ssp. amabilis, Jasione crispa ssp. amethystina, Saxifraga nevadensis, Coincya monensis ssp. nevadensis, Crepis oporinoides, Holcus caespitosus, and so on.
All individuals flourish at the end of the period of growth. Each flower produces ten seeds, of which between 40-60% fail in pre-fertilization. It is estimated that 69% of the flowers produce viable seeds.
The fact that it is a therophyte is quite exceptional since in the peaks of the Sierra Nevada it is almost exclusively chamaephytes and hemicryptophytes. Its development is in summer, with its growing season vegetation less than 30 days. It is pollinated by insects (mainly Hymenoptera and Diptera), the maximum Anthesis occurs in early August, although it can often overlap between different stages of phenology. The dispersal of seeds is passive and often falls in the vicinity of the mother plant, caught between the stones. It doesn't reproduce vegetatively and plagues or diseases of consideration have not been detected.
The principal threats are of natural origin; the fragility of the habitat, the fluctuations of the population due to climate conditions. It is threatened by its strict water supply requirements which make it sensitive to climate changes. Secondly it is threatened by the displacement of soil caused by the possible impact of wild herbivores and livestock and hikers.
This taxon is listed as priority species on Annex II of the EU Habitats Directive and under Appendix I of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). It is included as species "En peligro de extinción" in the Spanish national catalogue of threatened species. It is listed Critically Endangered (CR) B1ac(iii,iv)+2ac(iii,iv) in the Spanish Red List 2008 (Moreno 2008).
It occurs within the protected area Parque Nacional de Sierra Nevada (SCI). A recovery plan has been drafted and some of its activities are already underway. There are also some seeds stored in the germplasm bank of Sierra Nevada.
|Citation:||Gutiérrez, L. & Blanca, G. 2011. Arenaria nevadensis. The IUCN Red List of Threatened Species 2011: e.T61634A12530058.Downloaded on 14 December 2017.|