Cartografía diacrónica: estabilidad y cambios en la vegetación de Rasos de Peguera (Prepirineos Orientales), 1956-2014. Actas XI Coloquio de Botánica pirenaicocantábrica

Abstract

We analyse here the changes occurring in the vegetation of Rasos de Peguera Massif (2,057 m a.s.l., Eastern Pyrenees) in the period 1956-2014, by means of diachronic cartography. Our study includes a protected area (the Space of Natural Interest of Rasos de Peguera, 1.008 ha), the ski resort of Rasos de Peguera and the surroundings of the abandoned village of Peguera (295 ha). Physiognomic maps for 1956 and 2014 were elaborated with ArcMap. Seven vegetation units were considered: forests, shrublands, pastures, wetlands, crops, rocks and scree, and small villages. The 1956 map was produced by photointerpretation, while the 2014 map was derived from a Corine habitats map made the same year. Both were combined to generate transition maps, as well as to quantify surface changes. The comparison of the coverages of 1956 and 2014 shows a preponderance of stable areas (63%). Progressive successional changes (increase of vegetation complexity) affect 35% of the territory, and only 2% undergo regressive changes. The transitions the most widespread are pastures in forests (310.9 ha), and those related to the crops abandonment, which become mainly pastures (49.1 ha). The regressive changes the most relevant are related to logging (25.1 ha). In addition, significant differences are detected among unprotected and protected areas, which have greater proportion of stable surfaces (65% vs. 56.2%). Such dynamics are analogous to those observed in Pyrenean areas similar in altitude and physiography.