HIGH-RESOLUTION PALEOECOLOGICAL ANALYSIS OF RECENT DISTURBANCE IN A SOUTHERN CHILEAN NOTHOFAGUS FOREST

A 1600 year paleoecological record of environmental change is develope d from a small lake in the Nothofagus forest of southern Chile (45.5 d egrees S, 72 degrees W). High resolution fossil pollen, charcoal, sedi mentological, and chrysophycean stomatocyst analyses are used to inves tigate the impacts of natural and anthropogenic disturbances on terres trial and lacustrine environments. Chronological control is based on a combination of Pb-210 and C-14 dating. Temporal resolution during the past 150-200 yr is ca. 8 yr/sample. The macroscopic charcoal record c orrelates very closely with historical and dendroecological records of 20th century anthropogenic burning in this region. The chrysophyte st ratigraphy indicates that this burning had immediate impacts on the la ke itself, while the pollen record provides evidence for a succession of vegetation changes lagging slightly behind the disturbance. These p alynological changes are very similar to the pollen signal of European disturbance in northeastern North America. Pre-European shifts in chr ysophyte assemblages may be due to the influence of earthquake activit y on the lake, though there is no corroborative evidence in the pollen or charcoal records. This study demonstrates that high resolution pal eoecological methods can be used to help bridge the temporal gap betwe en traditional ecological and paleoecological studies of environmental change in the temperate forests of southern South America.