|Scientific Name:||Isoetes delilei Rothm.|
Isoetes setacea Lam.
Isoëtes delilei Rothm.
|Taxonomic Source(s):||Greuter, W. and Troìa, A. 2015. Disentangling Isoetes setacea and removing threats to Isoetes echinospora. Taxon 64(4): 811-815.|
|Taxonomic Notes:||The name Isoetes setacea Lam. has historically been applied to two different taxa. It is most frequently used for a lowland species with an amphibious habit (i.e. growing in shallow temporary ponds drying up in late spring) in the western Mediterranean, particularly in southern France.
It has alternatively been applied to an aquatic species growing in temperate-montane permanent lakes, a species usually known as I. echinospora Durieu. Some authors have rejected the name I. setacea on that account even though it would have nomenclatural priority over both names, yet its most frequent use is not compatible with its original description. The pragmatic designation of an epitype has placed the name I. setacea in synonymy under I. lacustris L., so that the correct name for the amphibious Mediterranean species becomes I. delilei Rothm. (Greuter and Troia 2015).
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer(s):||Grillas, P., Ali, M.M., de Bélair, G., Alves, P., Temple, H. (IUCN Species Programme) & Muller, S.D.|
This is an amended version of the 2007 assessment, updating the scientific name of this taxon from Isoetes setacea to the correct name: Isoetes delilei.
This species has only a small area of occupancy (less than 2,000 km2) and it is experiencing a decline in population size, but it is not severely fragmented and occurs at more than 10 locations. It is classified as Near Threatened owing to its fragile habitat, temporary pools, that is under much pressure from agricultural and infrastructure development as well as land abandonment.
|Previously published Red List assessments:|
|Range Description:||This is a west Mediterranean species. It is found in France (Hérault, Orientals Pyrenees), Spain (centre and west of the country and in Catalonia), the Balearic Islands (Minorca) and Portugal (centre and south). |
In North Africa, it is limited to Morocco where it has been recently discovered in only one locality (Benslimane) with an area of occupancy smaller than 1 km². In the Mediterranean region, the extent of occurrence is 530,000 km². The area of occupancy has not been quantified but may be less than 2,000 km² as the species is restricted to a particular type of habitat.
Native:France (Corsica, France (mainland)); Morocco; Portugal (Portugal (mainland)); Spain (Baleares, Spain (mainland))
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The populations are known to be declining due to the deterioration of the habitat. In France, the species is present in about one hundred ponds in the Natural Reserve of Roque-Haute, one pond in the plain of Béziers, one in Torremila, several ponds and ditches at Rodés plateau (Fenouillèdes). A more or less slow regression of populations of this species has been reported as a result of the disappearance of the species in the ponds of Saint Estève (Oriental Pyrenees), Grammont (Hérault) and Redessan (Gard). The species is present in the centre and the west of the Iberian Peninsula, as well as in Catalonia and on the island of Minorca (13 provinces in Spain and six in Portugal). In Morocco, the species is very rare with populations that are reduced to only one locality.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||A perennial Hydrophyte (Geophyte), characteristic for temporary humid zones and can support water levels of up to 50 cm. The species is restricted to temporary pools on quaternary basalt. It is found in Mediterranean aquatic quillwort swards, communities with Isoetes spp. in fluctuating water bodies (Corine biotope 22.3412). The vegetative growth generally takes place in winter while the maturation of the spores takes place in spring.|
|Major Threat(s):||Big constructions (rental, roadwork, etc.), the drainage of pools or their infilling, the extraction of sediment, and permanent retaining of water, constitute serious threats for the populations of this species. However, in France, besides these threats, the restriction of its environment followed by the abandonment of land uses favours the colonisation by competitive perennial plants of large size (woody, big Helophytes) and the accumulation of their litter that affects the populations negatively (heliophile species, sensitive to competition). The quality of the habitats of the species is deteriorating resulting from land and therefore grazing abandonment which increases the sediments and the shade.|
In France, the habitats are monitored in several locations (ligneous species and clonal plants dynamic, water level), the species is under national protection and included in the red list. The site of Roque-Haute is designated under a Natural Reserve statute since 1975 (but without any management plan).
In the Balearic Islands, the species is classified as Vulnerable.
In Morocco, there are no conservation measures in place but the following actions are recommended:
- Legal protection of the species in Morocco (List of protected species in Morocco).
- Surveillance of the existing areas and search for new sites.
- Monitoring of the population dynamics.
- Raising awareness of the general public.
- Creation of protected perimeters where pastoral activities are maintained.
- To avoid the permanency of water in the pools.
- To reintroduce sheep grazing in Helophyte polls and in ligneous pools (after cutting).
- To eliminate litter in the pool.
- To evaluate the vegetation dynamic after sheep grazing introduction and all new managements.
|Citation:||Rhazi, L. 2016. Isoetes delilei. The IUCN Red List of Threatened Species 2016: e.T163983A104174654.Downloaded on 17 March 2018.|
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