Salta al contingut principal

Population genetics and conservation priorities for the critically endangered island endemic Delphinium pentagynum subsp. formenteranum (Ranunculaceae)



Abstract. Isozyme electrophoresis was used to evaluate levels of genetic diversity and population genetic
structure of the critically endangered (CR) perennial larkspur, Delphinium pentagynum subsp. formenteranum (Ranunculaceae), endemic to the island of Formentera (Balearic Islands, Spain). There is only one known population for this taxon, containing only 480 individuals. Moderate values of diversity were detected (P 5 40.7%, A 5 1.6 and H 5 0.180), within the range observed in other surveyed larkspurs, e but higher than most island endemics. Moderate levels of inbreeding were detected, probably as a consequence of the population’s genetic structuring (biparental inbreeding). Threats to this taxon are mainly anthropogenic (fires, grazing, pathway works, and building pressures), although given that only one population exists, stochastic risks cannot be ignored. Conservation of D. pentagynum subsp. formenteranum requires in situ strategies, such as implementing a monitoring program and establishing a ‘botanical reserve’, and ex situ strategies, such as collection and long-term storage of seeds

Key words: Allozyme diversity, Balearic islands, Conservation, Critically endangered, Delphinium
pentagynum subsp. formenteranum, Formentera, Island endemic, Population structure, Ranunculaceae


JORDI LOPEZ-PUJOL , MARIA BOSCH, JOAN SIMON and CESAR BLANCHE (2003) Biodiversity and Conservation 12

Etiquetes de comentaris:

Comentaris

Publica un comentari a l'entrada

Entrades populars d'aquest blog

Lizards as pollinators and seed dispersers: an island phenomenon

Although it is well established that many insects, birds and mammals serve as important pollinators and seed dispersers of flowering plants, the role of lizards in these processes has traditionally been considered as rare and less important. However, recent work shows both that their role as mutualistic agents has been underestimated and also reveals a striking pattern – that pollination and seed dispersal by lizards is most common on islands. We argue that this island phenomenon occurs because island lizards reach very high densities (density compensation) and experience a lower predation risk than do those on the mainland and, consequently, can expand their diet to include nectar, pollen and fruit. Although further empirical evidence is needed to confirm this explanation, such relationships could be ideal systems with which to study fundamental ecological problems, such as niche shifts, ecological release and competition. Jens M. Olesen a...
Publica un comentari a l'entrada
Més informació

Implications of Extreme Life Span in Clonal Organisms: Millenary Clones in Meadows of the Threatened Seagrass Posidonia oceanica

The maximum size and age that clonal organisms can reach remains poorly known, although we do know that the largest natural clones can extend over hundreds or thousands of metres and potentially live for centuries. We made a review of findings to date, which reveal that the maximum clone age and size estimates reported in the literature are typically limited by the scale of sampling, and may grossly underestimate the maximum age and size of clonal organisms. A case study presented here shows the occurrence of clones of slow-growing marine angiosperm  Posidonia oceanica  at spatial scales ranging from metres to hundreds of kilometres, using microsatellites on 1544 sampling units from a total of 40 locations across the Mediterranean Sea. This analysis revealed the presence, with a prevalence of 3.5 to 8.9%, of very large clones spreading over one to several (up to 15) kilometres at the different locations. Using estimates from field studies and models of the clonal growth of...
Publica un comentari a l'entrada
Més informació

An analysis of habitat distribution and associations in theOdonata of theBalearic Islands, Spain

 Spatial structure of the odon. community is analysed. The different abundance of the spp. and their most characteristic habitats in the islands are indicated. The reproduction of 19 spp. on the Balearic Islands is confirmed. Coenagrion scitulum is recorded for the first time from the archipelago. The associations of spp. existing on each of the islands were established by meansof factoranalysis (correspondence analysis); a total of9 associations are defined. This study has been made on larvae exclusively. Sympetrum striolatum is the most abundant sp. in the Balearic Islands. Previous records are discussed. García-Aviles, J,   Puig, M.A,  Soler, A.G. & Ferreras-Romero, M. (1995)  Odonalologica 24(3)
Publica un comentari a l'entrada
Més informació