Late-Holocene environmental dynamics and climate variability in a Mediterranean high mountain environment (Sierra Nevada,Spain) inferred from lake sediments and historical sources

Abstract

Landscape dynamics in the periglacial belt of a high mountain Mediterranean environment is a process of rapid evolution but complex reconstruction. Following this purpose, in this paper we discuss data from two sources concerning the past evolution of the present-day periglacial environment in the Sierra Nevada (southern Iberian Peninsula): mountain lake sediments and documentary sources. La Mosca lake sedimentary record provides information about the palaeocological evolution in the Mulhacén cirque over the last three millennia, while documentary sources enable us to reconstruct the landscape evolution in the high lands of this massif over the last eight centuries. During the late Holocene cold and wet phases have favoured the activity of geomorphic processes, with ephemeral development of glaciers in the highest northern cirques, abundance of late-lying snow patches and a decrease of the vegetation cover in the highest catchments. By contrast, warm periods have been more conducive to geomorphic stability, with an extension of the vegetation grass cover, but without glaciers and with a lower density of snow patches in summer. The comparison of the palaeocological evolution and associated palaeoclimatic conditions in the Sierra Nevada with other regional proxies shows evidence of the moderate sensitivity of the geomorphological processes occurring in the massif during the late Holocene with respect to the climate variability prevailing in the Iberian Peninsula and neighbouring areas. According to lake sedimentary records, the ‘Little Ice Age’ has been the coldest period during the late Holocene. Historical sources suggest a temperature increase of 0.93°C since the middle of the 19th century.