Evaluation and monitoring of populations of Swertia perennis in the Ayllón mountain range, Spain

Resumen

Swertia perennis L. (Gentianaceae) is a boreoalpine species whose most southerly populations in the Iberian Peninsula are found in the Central and Iberian mountain ranges. It is very scarce in these mountains, with relictual populations in the Ayllón range (province of Segovia, Autonomous Community of Castilla y León) and in the Albarracín range (province of Teruel, Autonomous Community of Aragón). In Spain, this species is protected under different regional protection categories: in Castilla y León, as a taxon of Preferential Attention and in the Foral Community of Navarra as Endangered. The aim of this study is to assess the viability and conservation status of its populations located on the northern slopes of the Ayllón range, the easternmost of the Central System. For this purpose, some of these populations have been monitored by installing permanent monitoring plots, marking individuals and monitoring them throughout the growing season. Variables that provide information on their evolution from a vegetative, phenological and reproductive point of view have been measured, applying chorological and demographic work methodology proposed in the project Atlas of Endangered Vascular Flora of Spain. In order to assess the viability of current populations, seed germination trials have been carried out, the results of which have been compared with previous data to determine the chorological and demographic trend of these populations. In addition, a preliminary study has been carried out to determine the phylogenetic relationships of this population nucleus with the rest of the known and characterised European populations, which are located from the Pyrenees to the north of Europe.