Taxonomic Notes
Rorippa valdes-bermejoi is a wild relative of Watercress, Nasturtium officinale W.T. Aiton and N. microphyllum Boenn. ex Rchb.
It is possible that this species is conspecific with R. africana Maire, but but there are differences in the leaves and fruits between the species. Further research is needed to clarify this.
Justification
R. valdes-bermejoi is endemic to southwestern Spain. It was lost in the past from its type locality, Almonte Camino de la Algaida, the site from which it was originally described. The only known extant locality is in the Doñana National Park in Huelva, where it persists in one population that occupies an area of less than 100 m2, with an area of occupancy (AOO) and extent of occurrence (AOO) of 4 km2. The species occurs in one location, with the primary threat being potential changes to the hydrological regime; over-abstraction of groundwater is affecting all waterbodies within the Doñana National Park. The current population size is estimated at 13 individuals. The species therefore qualifies as Critically Endangered [CR B1ab(iii,v)+2ab(iii,v); C2a(i,ii); D].
Geographic Range Information
This species is endemic to the Parque Nacional de Doñana in southwestern Spain (Huelva). Only one population is known, that occupies an area of less than 100 m². It has disappeared from Almonte, the site that it was originally described from.
In 2011, four groups of plants were planted in Arroyo de la Rocina, two with fences and two without fences. Currently, we know that three groups remain, two fenced and one unfenced, which we visit several times a year, and we do not have recent data on the fourth unfenced population because the area was too difficult to access because the vegetation had grown a lot. The fenced reintroductions are growing successfully, each occupying an area of 4 square meters. The unfenced area occupies approx. 30 square meters (Last visit May 1st, 2021). Plant growing successfully. Finally, the group planted in 2004 in the Doñana Palace (Biological Reserve) in an area of approx. 10 square meters also persist (fenced), however, the group planted in 2004 in El Martinazo have been lost.
Population Information
This species was originally described in 1986 from Almonte (Huelva) from where it has now been lost due to degradation of its habitat which was related to the logging of Eucalyptus trees and the subsequent silting of its habitat with sandy sediments.
A new population was discovered in Palacio del Acebrón, in the Rocina stream in the Doñana National Park, but its situation is critical. In 2002, it had only four stands with 84 aerial stems of which less than 15% developed accessory fruit. There was insufficient seed production to maintain the population by sexual reproduction but only by vegetative reproduction. In 2004 several introductions were conducted in the Doñana National Park from seeds or stolons collected from the natural population. Seeds from the new cultivations were collected in 2009. In 2011, 15 individuals were reintroduced in the Arroyo de la Rocina population, and fenced to avoid herbivory. As a clonal species, estimating the number of mature individuals is difficult, but 13 separate stands (individuals) are estimated.
All natural populations and many reintroduced populations are declining in size and vigour, representing a continuing decline in the number of mature individuals.
Habitat and Ecology Information
This clonal species grows in a shady grove in peat dust over limestone. The forest where the population occurs is very dense with deciduous trees and tall tussock helophytes with a fringe of cork oaks and vines. It is accompanied by the following taxa: Fraxinus angustifolius, Frangula alnus, Vitis vinifera, Salix atrocinerea, Carex panicea, C. otrubae, C. paniculata subsp. lusitanica, Hydrocotyle vulgaris, Thelypteris palustris and Samolus valerandi.
Threats Information
The hope that the only known population maintains stable in situ is minimal due to the small number of individuals and the low sexual reproductive success. In addition, an alteration of the hydrological regime of the Rocina stream, together with competition with the natural vegetation, could quickly lead this species to extinction. The logging of Eucalyptus trees and the subsequent silting of its habitat with sandy sediments led to the extinction of the type population.
Use and Trade Information
The species is not known to be utilised.
Conservation Actions Information
The genus Rorippa is listed in Annex I of the International Treaty on Plant Genetic Resources for Food and Agriculture as part of the brassica complex. The extant population is within the Parque Nacional de Doñana, a well-protected area and its site is currently fenced off. The plant has been successfully cultivated from seeds in glasshouses but a reintroduction of plants in 2002 was not successful. No germplasm accessions of R. valdes-bermejoi are reported by EURISCO to be held in European genebanks (EURISCO Catalogue 2010). In 2009 seeds were collected by Red Andaluza de Jardines Botánicos and currently are stored at Banco de Germoplasma Vegetal Andaluz (BGVA) belonging to the Spanish germplasm bank (REDBAG). Seeds are stored at -5ºC and -20ºC.
Ex situ actions
Seeds have been germinated successfully under controlled conditions; the percentage of germination is over 60%, and the establishment of seedlings is high, flowering and fruiting in a few months. Additionally, 100% of the cuttings obtained from the cultivated plants have roots.
In situ actions
Monitoring the reinforcement activities in Arroyo de la Rocina. In 2011, 15 individuals were reintroduced in the Arroyo de la Rocina population, and fenced to avoid herbivory.
A positive development has been confirmed inside the protection boundaries. Additionally, a number of individuals have been incorporated to the Botanical Garden Dunas del Odiel (Huelva) to guarantee the conservation of plant material.
Germplasm collection and duplicated ex situ storage is a priority for this species. It is furthermore recommended to continue the reintroduction efforts, to monitor the population, and to ensure maintenance of the water regime of the Rocina stream.
In 2011, four groups of plants were planted in Arroyo de la Rocina, two with fences and two without fences. Currently, we know that three groups remain, two fenced and one unfenced, which we visit several times a year, and we do not have recent data on the fourth unfenced population because the area was too difficult to access because the vegetation had grown a lot. The fenced reintroductions are growing successfully, each occupying an area of 4 square meters. The unfenced area occupies approx. 30 square meters (Last visit May 1st, 2021). Plant growing successfully. Finally, the group planted in 2004 in the Doñana Palace (Biological Reserve) in an area of approx. 10 square meters also persist (fenced), however, the group planted in 2004 in El Martinazo have been lost.
The species was assessed as Critically Endangered (A2acde, B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v);C1+2a(ii)b) in the Spanish Red List (Moreno 2008) and on the Red List of Andalucia (Cabezudo et al. 2005).
