Land-use dynamics in the Asturian mountains (NW Iberian Peninsula): Evidence from pollen and non-pollen palynomorphs

Palynological investigation carried out at El Pozu'l Ḷḷau/Pozo del Chao pond (Principality of Asturias, northwest Spain) provided insight into vegetation dynamics and the role played by different past management practices (grazing, in particular) on local environmental changes during the last millennium. NPP data offered complementary information to pollen and macroscopic charcoal records, allowing a finer-scale spatial resolution and demonstrating their value for obtaining more comprehensive palaeoecological reconstructions. During the Medieval Warm Period, the landscape surrounding the sampled site is characterised by scattered oak woodlands, abundant heathlands (probably promoted by local fire disturbance), meadows and grazing areas. In the Little Ice Age, the intensification of pastoral and agricultural activities, together with a reduction of heathlands and woodlands lead to more open landscape conditions. Clearance burning practices for the benefit of agricultural areas and meadows, and a local reduction of grazing areas shape the landscape during the Modern Warming Period. Since the XXI century onwards, the abandonment of management practices has contributed to the spread of heathlands and woodlands, and to the consequent reduction of crops (in particular) and grasslands around the investigated pond. The close linkage between palynological richness patterns and human activities – that lead to a more heterogeneous landscape mosaic – is underlined by our results, stressing the importance of long-term knowledge to better understand main vegetation diversity processes for successful conservation and management measures.