Three millennia of vegetation and environmental
dynamics in the Lagunas de Mojanda region,
northern Ecuador
1 1 | Herbario QCA, Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador,
P.O. Box: 17-01-2184, Quito, Ecuador |
2 | University of Göttingen, Department of Palynology and Climate Dynamics, Untere Karspüle 2,
37073 Göttingen, Germany |
Online publication date: 2017-12-19
Publication date: 2017-12-19
Acta Palaeobotanica 2017; 57(2): 407–421
ABSTRACT
The pollen record from Lagunas de Mojanda, located at 3748 m a.s.l. (northern Ecuadorian Andes)
reflects the vegetation and climate dynamics for the last ca 3400 cal yr BP. Páramo vegetation has been the main
vegetation type since the beginning of the record. At Lagunas de Mojanda, from the last ca 3400 to 2200 cal yr BP,
grass páramo was well represented mainly by Poaceae (40%) and the occurrence of Valeriana (5%), while montane
forest taxa were poorly represented and subpáramo taxa were rare. The vegetation composition suggests cool and
humid conditions. Between ca 2200 and ca 1300 cal yr BP, montane rainforest and subpáramo taxa had a higher
presence but páramo taxa remained the main vegetation type in the study area, suggesting cool climatic conditions.
From ca 1300 to ca 500 cal yr BP, páramo vegetation remained stable, with higher presence of Phlegmariurus and
Isoetes, suggesting cool and humid conditions. The last ca 500 cal yr BP generally show lower frequency of montane
rainforest and subpáramo taxa. Páramo vegetation reached the highest share, with the presence of Poaceae, Plantago
and Ranunculus suggesting a trend of peat bog drying. Fires were present during the whole record, perhaps
human-caused, but the study area does not show great disturbance except from ca 1300 to 500 cal yr BP, a period
of an evident higher influx of charcoal particles coincidentally with nearby ancient human occupation.