Creating new populations of Apium bermejoi (Apiaceae), a critically endangered endemic plant on Menorca (Balearic Islands)

Abstract

Apium bermejoi is a stoloniferous plant endemic to the island of Menorca (Balearic Islands). It is found only at one locality, and it is listed as Critically Endangered (according to the IUCN criteria). We describe the main results of population restoration actions undertaken under the Recovery Plan for this species, including the following: 1) introduction at two new localities (2008), 2) reinforcement of the original wild and the introduced populations, and 3) a programme for monitoring population dynamics (including both wild and introduced populations) spanning four years (2006-2010). The plant material for the introduction and reinforcement projects was generated from seeds gathered in the wild. We carried out a monthly census of all of the individuals/patches and emerged seedlings, from which we assessed their survival at 3-4months. The survival rates of the planted individuals in the two new localities after three months were found to be 59.0% and 56.3%, and more than 80% of the surviving plants produced fruits. A seasonal pattern was observed based on the minimum cover values recorded in the censuses taken at the end of summer, with an increase detected during autumn, and maximal cover values recorded during May/June. The A. bermejoi populations showed large inter-annual fluctuations in both the number of patches and area of occupancy. The number of seedlings varied across the study years, and their survival was linked to specific meteorological events, such as severe storms and dry and hot spells during autumn. The initial phase of introduction for this species has been overall successful, but a final evaluation can only be made on a longterm basis.

Keywords

• conservation biology
• reintroduction
• threatened species
• population dynamics
• seedling survival
• mediterranean flora