Phytolith and microalgae records of Late Pleistocene and Holocene climate-driven landscape shifts in the Canary Islands

Rapid climatic changes at the end of glacial cycles have shaped landscapes and biodiversity globally, yet their influence on the landscapes of the islands of Macaronesia remains poorly understood. Here we discuss how three microfossil records from the islands of Tenerife, Gran Canaria and La Gomera can shed light on landscape transformations linked to climatic changes after the Late Glacial Maximum. Phytoliths as proxy data from vegetation change and microalgae (diatoms and chrysophytes) as proxies of hydrological dynamics are analysed alongside sedimentological and geochemical data to understand the multiple aspects of landscape change linked to climatic variability. Our data show the occurrence of significant vegetation changes linked to deglaciation, after 16,000 cal yr BP in Gran Canaria and Tenerife based on increases in palm (Phoenix canariensis) phytolith and shifts in grassland composition. Records from Tenerife and La Gomera show a decrease in palms and changes in microalgae communities after the end of the African Humid Period linked to the aridization of the Sahara (c. 5000 cal yr BP-present day). Multi-proxy and inter-island record comparison reveals significant variability dependent on mesoclimates and local vegetation dynamics, showing the complexity of understanding the influence of climatic changes in the landscapes of this archipelago.