Spatial distribution and environmental analysis of vascular flora of the Pyrenees

Abstract

the recent "on line" edition of the Atlas of vascular flora of the Pyrenees, allow us now to delimit the floristic diversity and to analyze the spatial distribution and some environmental features to contribute to their ecological study and conservation. the native vascular flora of the Pyrenees consists in 3,652 species and subspecies of vascular plants. this fgure places the Pyrenees as the second most important point of Europe plant diversity, after the Alps. Considering 6 geographical sectors, the central-south (76%) and both the easterns (75%) shelter the highest plant abundance. In the altitudinal gradient, the montane belt holds the highest plant richness (87% of the total). With respect to chorology, 32% of plants are eurosiberians and 29% mediterraneans, whereas alpine orophytes and boreoalpines account for 12.6% and 5% are endemisms. Concerning life-forms, hemicryptophytes (44%) and therophytes (20.4%) predominate, although the later decrease with altitude, while chamaephytes increase. Looking at the edafc affnity, 35% of plants are calcicolus and 21% silicicolus. Distribution according to habitats shows that near 30% of the flora occur in grasslands, 16% in wetlands, and a similar percentage (around 12-13%) in rocks, forest, shrublands and anthropic plant communities. Finally, taking into account the habitat naturalness, 47% of plants occur in high or very high preserved habitats, although almost a quarter of plants live in the most disturbed ones.