Regresar

Mid- and late Holocene vegetation and environmental dynamics in the Llanganates National Park, Anteojos Valley, central Ecuadorian Andes

Abstract:

The last ca. 4100 cal yr BP of palaeoenviromental conditions in the Llanganates National Park, central Ecuadorian Andes, has been reconstructed from the pollen record 'Anteojos Valley' (3984 m elevation). The pollen record, dated with four radiocarbon dates, indicates that the local páramo vegetation was relatively stable with only minor fluctuations since the mid-Holocene. The páramo vegetation was characterised mainly by Asteraceae, Cyperaceae and Poaceae. The regional lower mountain rainforest vegetation is mainly represented by Moraceae/Urticaceae, and the upper mountain rainforest by Melastomataceae, Polylepis and Weinmannia. Between ca. 4100 to 2100 cal yr BP, páramo was the main vegetation type with a low presence of mountain rainforest, probably reflecting cool conditions. Between ca. 2100 cal yr BP and the present, the proportion of páramo vegetation increased with a decreased occurrence of mountain rainforest, suggesting cooler and moister conditions. Low frequencies of fires were evidenced since the mid-Holocene. However, there is a slight increase of regional fire between ca. 4100 and 3100 cal yr BP. The low abundance of larger carbonised particles since the beginning of the record suggests a low occurrence of local fire in the study area.