Recent changes in snow cover and evolution of supratimberline vegetation in the Puerto de los Neveros, Guadarrama Mountains (Spain)

Abstract

The purpose of this study is to add more insight to the relationship between recent climate change and modifications in plant cover in supratimberline areas of Spain's Central Mountain Range. A 118 hectare study site was chosen at Puerto de los Neveros pass (2100 m) located on the ridge Peñalara (Montes Carpetanos), and between the high basins of the Lozoya and Eresma rivers. Historically, the pass is associated with the most abundant and long lasting snow accumulations in the Guadarrama Mountains, and with frequent use of the snow by local populations. A collection of sequenced aerial photographs of the plant cover was used to interpret the vegetation's spatial dynamics in relation to the evolution of thermal and snow depth variables recorded for the period 1951-2006 at the weather station at Puerto de Navacerrada. The significant value of the resulting coefficients confirms that plant cover at Puerto de los Neveros has been greatly affected by climate change, particularly by warmer winters, less snowfall and shorter snow duration, which have contributed to the shrinking surface area of snow hollows, high meadows and open shrublands and to the expansion of dense bush.