Vegetation and climate change, fire-regime shifts and volcanic disturbance in Chiloé Continental (43°S) during the last 10,000 years

W.I. HENRÍQUEZ; P.I. MORENO; B.V. ALLOWAY; G. VILLAROSA,

QUATERNARY SCIENCE REVIEWS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2015 vol. 123 p. 158 - 167

0277-3791

Disentanglingthe roles of paleofires and explosive volcanism from climatic drivers of pastvegetation change is a subject insufficiently addressed in the paleoecologicalliterature. The coastal region of the Chiloe Continental sector of northwesternPatagonia is ideal in this regard considering its proximity to active eruptivecenters and the possibility of establishing comparisons with more distal,upwind sites where volcanic influence is minimal. Here we present afine-resolution pollen and macroscopic charcoal record from Lago Teo with theaim of documenting the local vegetation and climate history, and assessing therole of disturbance regimes as drivers of vegetation change during the last~10,000 years.The LagoTeo record shows a conspicuous warm/dry interval between ~7500 and 10,000 calyrs BP followed by a cooling trend and increase in precipitation that haspersisted until the present, in agreement with previous studies in the regionand interpretations of past southern westerly wind activity at multi-millennialscales. The presence of 26 tephras throughout the record allows examination ofthe relationship between explosive volcanism and vegetation change undercontrasting climatic states of the Holocene. We found consistent statisticallysignificant increases in Tepualia stipularis after tephra deposition over thelast 10,000 years, in Eucryphia/Caldcluvia between 7500 and 10,000 cal yrs BPand in Hydrangea over the last 7500 years. Our results indicate a primary roleof climate change as driver of long-term vegetation change and as a modulatorof vegetation responses to volcanic disturbance at multidecadal and centennialtimescales.