Vegetation trends over eleven years on mountain summits in NW Argentina

As global climate change leads to warmer and dryer conditions in the central Andes, alpine plant communities are forced to upward displacements following their climatic niche. Species range shifts are predicted to have major impacts on alpine communities by reshuffling species composition and abundances. Using a standardized protocol, we surveyed alpine plant communities in permanent plots on four high Andean summits in NW Argentina, which range from 4040 to 4740 m a.s.l. After a baseline survey in 2006-2008, we re-surveyed the same plots in 2012, and again in 2017. We found a significant decrease in plant cover, species richness and diversity across the elevation gradient in the three censuses, and a strongly decrease in soil temperature along the elevation gradient. We found a high plant community turnover (37-49%) among censuses, differentiating according to summits and aspects; major changes of community turnover were observed in the lowest summit (49%) and on the northern (47%) and...