Long-Term Changes in Mountain Passerine Bird Communities in the Sierra Nevada (Southern Spain): A 30-Year Case Study

摘要: Shifts in composition and abundance of bird communities were studied along an elevational gradient the Sierra Nevada (S. Spain), comparing censuses made at same locations 1980s during 2008–2012. Censuses three representative ecosystems: 1) Pyrenean oak woodland, 2) high-mountain juniper scrubland, 3) summits. In a global change context, avian-community dynamics are related mainly to changes two following drivers: climate land-use occurring over past 30 years. Our results show continuous turnover community, with overall 27% species composition, ecological setting that has changed little, especially scrubland summit areas. We detected increase diversity relative 1980s, mostly woodland. Moreover, our also sharp decrease density 30-year study period, chiefly affecting dominant forest scrubland. high-summit ecosystems, decline alpine paralleled uphill expansion some mediterranean ones. The outcome these processes is community flux, both abundance, where interannual variability similar interdecadal variability. conclude showing strong spatial temporal now accelerating, perhaps because warming.