Late-glacial and Holocene climate dynamics at the steppe/forest ecotone in southernmost Patagonia, Argentina: the pollen record from a fen near Brazo Sur, Lago Argentino.

<div class="Abstract"><a name="Abs1"></a><span class="AbstractHeading">Abstract  </span>We present a pollen record from a fen at the eastern shore of Brazo Sur south of Lago Argentino, Argentina (core BRS 1/06, 50°34′54″S, 72°54′52″W, 198 m a.s.l.). The coring site is located in the transition zone from humid grass steppe to Andean Nothofagus forest. With the exception of a mid-Holocene sand layer, the record covers the interval between 13,350 and 1,700 cal <span style="font-variant:small-caps">b.p.</span>, indicating that there could have been no recurrence of Late-glacial conditions in Brazo Sur, as has been suggested in the literature as having been contemporary with the Younger Dryas interval in the northern hemisphere. The Late-glacial and early Holocene periods at Brazo Sur are characterized by fluctuations between humid grass-dominated steppe associations and drier ones dominated by Asteraceae and Ericaceae. At the start of the Holocene, the pollen influx increased. Nothofagus dominance began by 7,700 cal <span style="font-variant:small-caps">b.p.</span> probably due to increasing moisture. Present-day closed Nothofagus forest developed around 2,500 cal <span style="font-variant:small-caps">b.p.</span>, related to a further increase in moisture. </div> [ABSTRACT FROM AUTHOR]