title: Changes in the high-mountain vegetation of the Central Iberian Peninsula as a probable sign of global warming.
abstract: Aerial images of the high summits of the Spanish Central Range reveal significant changes in vegetation over the period 1957 to 1991. These changes include the replacement of high-mountain grassland communities dominated by Festuca aragonensis, typical of the Cryoro-Mediterranean belt, by shrub patches of Juniperus communis ssp. alpina and Cytisus oromediterraneus from lower altitudes (Oro-Mediterranean belt). Climatic data indicate a shift towards warmer conditions in this mountainous region since the 1940s, with the shift being particularly marked from 1960. Changes include significantly higher minimum and maximum temperatures, fewer days with snow cover and a redistribution of monthly rainfall. Total yearly precipitation showed no significant variation. There were no marked changes in land use during the time frame considered, although there were minor changes in grazing species in the 19th century. It is hypothesized that the advance of woody species into higher altitudes is probably related to climate change, which could have acted in conjunction with discrete variations in landscape management. The pronounced changes observed in the plant communities of the area reflect the susceptibility of high-mountain Mediterranean species to environmental change.
authors.affiliation: Departamento de Producción Vegetal: Botánica, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica, Ciudad Universitaria s/n, E-28040 Madrid, Spain. msanzelorza@segovia.catastro.minhac.es
authors.forename: Mario
authors.initials: M
authors.lastname: Sanz-Elorza
authors.forename: Elías D
authors.initials: ED
authors.lastname: Dana
authors.forename: Alberto
authors.initials: A
authors.lastname: González
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sobrino
mesh_terms: D017753:Ecosystem; D017752:Greenhouse Effect; D063245:Plant Development; D011157:Population Dynamics; D011891:Rain; D013030:Spain