Conservation biology of threatened Mediterranean chasmophytes: The case of Asperula naufraga endemic to Zakynthos island (Ionian islands, Greece)

PLoS One. 2021 Feb 19;16(2):e0246706. doi: 10.1371/journal.pone.0246706. eCollection 2021.

Abstract

Asperula naufraga is a rare and threatened obligate chasmophyte, endemic to Zakynthos island (Ionian islands, Greece). In this study, we provide a combined approach (including monitoring of demographic and reproductive parameters and study of genetic diversity) to assess the current conservation status of the species and to estimate its future extinction risk. The five subpopulations of A. naufraga were monitored for five years (2014-2018). Population size markedly fluctuated between 68-130 mature individuals during the monitoring period. The extent of occurrence (EOO) was estimated at 28.7 km2 and the area of occupancy (AOO) was 8 km2. Stage-structure recordings were similar for all subpopulations, characterized by high proportions of adult and senescent individuals, following a common pattern, which has been observed in other cliff-dwelling plants. Preliminary genetic analysis with SSRs markers revealed low heterozygosity within subpopulations and significant departure from H-W equilibrium, which combined with small population size suggest increased threat of genetic diversity loss. Our results indicate that the species should be placed in the Critically Endangered (CR) IUCN threat category, while according to Population Viability Analysis results its extinction risk increases to 47.8% in the next 50 years. The small population size combined with large fluctuations in its size, low recruitment and low genetic diversity, indicate the need of undertaking effective in situ and ex situ conservation measures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Conservation of Natural Resources / methods*
  • Endangered Species
  • Extinction, Biological
  • Genetic Variation / genetics
  • Genetics, Population / methods
  • Greece
  • Islands
  • Microsatellite Repeats / genetics*
  • Plants / genetics
  • Plants / metabolism
  • Rubiaceae / genetics*
  • Rubiaceae / metabolism

Grants and funding

This study was supported by grants from the General Secretariat for Research and Technology (GSRT) and the Hellenic Foundation for Research and Innovation (HFRI) (grant number 1585 to Valli A.T.). We acknowledge support part of this work by the project “PlantUP” (MIS 5002803) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme "Competitiveness, Entrepreneurship and Innovation" (NSRF 2014–2020) and co-fnanced by Greece and the European Union (European Regional Development Fund). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.