Rock outcrops enhance plant diversity in Patagonian landscapes

SPEZIALE, K. L. ; EZCURRA C.

Bariloche

Congreso; VI Southern Connection Congress, Bariloche, febrero 2010.; 2010

Universidad Nacional del Comahue, Inibioma-Conicet

Rock outcrops usually support unique communities also acting as refuge for species thatcannot survive in the surroundings due to overgrazing, fire or climate change among otherdisturbs. We studied plant communities associated to 50 outcrops along a diverse longitudinalgradient from shrubland to steppe habitats in north-western Patagonia. We recorded everyplant species in each outcrop and mounted a temperature and humidity sensor (north andsouth face). We also characterized the outcrops respect to their morphological variables. Wecompared species composition and richness within outcrops (north vs. south face), betweenoutcrops and between each outcrop and its surrounding matrix. Correspondence analysisseparated shrubland, steppe and outcrop plots. Within outcrops composition of north faceswas different from those of the south face. Differences in species composition and richnesswere related to microsite variables. Our results suggest that rock outcrops could be acting asrefuges for species that cannot be found in the surrounding matrix. In this way outcrops couldbe enhancing biodiversity in northwestern Patagonia