New spatial records of vascular plants in the Azores Archipelago: the PRIBES project and the Azorean Biodiversity Portal (ABP) initiatives - II. Pico island

Pico is the second largest and youngest island of the archipelago and hosts the highest elevation in Portugal (2351 m a.s.l.), resulting in pronounced altitudinal gradients. Its geomorphology is shaped by recent volcanic activity and complex volcano-tectonic structures, while soils are generally young, poorly developed and of limited agricultural suitability, contributing to low land-use intensity and relatively well-preserved natural habitats.

The climate is temperate oceanic, characterized by mild temperatures, high humidity and persistent cloud cover, with precipitation increasing markedly with elevation and exceeding 4000 mm annually in higher areas. Strong environmental gradients drive a well-defined altitudinal zonation of vegetation, ranging from coastal woodlands to alpine scrublands. Pico is unique within the Azores in preserving nearly the full sequence of vegetation belts, resulting in high ecological heterogeneity and the highest plant diversity in the archipelago.