Regeneration Ecology of the Rare Plant Species Verbascum dingleri: Implications for Species Conservation

Abstract

Verbascum dingleri Mattf and Stef. is a Greek endemic plant species belonging to the family of Scrophulariaceae that only occurs in northeastern Greece, east of the city of Kavala. Knowledge of species distribution, habitat requirements, reproduction, ecology, and population characteristics is limited in the literature. In this study, habitat characteristics, population counts, fruit and seed diversity, and germination were studied for the first time. The results indicate that the species geographical distribution is very restricted, lying in the Mediterranean floristic zone at a low altitude (100–200 m asl) and on very shallow soils. The habitat of this species is characterized by the Csa climate type, with a mean annual precipitation of 602 mm and a mean annual temperature of 14.6 °C. The species occurs in the area lying between the geographical coordinates 40°58′16.59″ N, 24°27′54.93 E, and 41°05′7.2″ N, 24° 47′17.2″ E. The species thrives in degraded shrub communities, dominated by the shrub species Paliurus spina-cristi Mill., Olea europea L. ssp. europaea, and Quercus coccifera L. Only a very small number of individuals were found (less than 200) at a density considered too small for long-term persistence of the species. The fruits of the species contained a high number (mean value 58.2) of minute seeds. The seeds exhibited high germination (up to 80.0% in laboratory and up to 30% in ambient conditions). We conclude that in situ and ex situ species conservation and habitat restoration are feasible through the introduction of seedlings produced from seeds collected from local populations.