Abstract We studied the recovery of the woody vegetation in a segment of the Rayas River, which drains the Chaitén Volcano, in southern Chile. Data collection in the river corridor was performed to assess the regeneration rates of the colonizing vegetation within the river corridor, to investigate the site-specific regeneration modes (i.e. with respect to the different morphological units), to determine the species composition and to observe potential similarities with the regeneration process on hillslopes (i.e. outside the river corridor). We first performed a sampling of the shrub and tree vegetation regenerating in the Forest adjacent to the study segment. Further sampling efforts were executed on Islands, High bars, the Floodplain, and in association with Wood jams. Results show that 9 years after the volcano's last eruption, pre-eruption remnant Islands and the Floodplain exhibited abundant regeneration, with the highest density of recruits and species richness. In addition, a clear difference was observed between the river corridor and the forest, both in the characteristics of the plants that were regenerating as well as in the species composition. Finally, the vegetation that has re-established after the eruption has not yet acquired the capacity to play a stabilizing role in the fluvial corridor. New insights are provided on reforestation patterns at sites impacted by large infrequent disturbances.

ABSTRACT Sedimentary records were analyzed from three lakes in the Ruby Mountains and East Humboldt Range of northeastern Nevada. Lakes are rare in the arid Great Basin, and these represent the highest-elevation lacustrine records from this region. The three cores cover overlapping time intervals: One, from a lake located just beyond a moraine, is interpreted to represent the Last Glacial Maximum, extending back to 26 cal ka; another extends to deglaciation ca. 14 cal ka; and the third extends to deposition of the Mazama ash, ca. 7.7 cal ka. Multiproxy analysis focused on measurements of bulk density, organic matter content, C:N ratio, biogenic silica abundance, and grain-size distribution. Depth-age models were developed using optically stimulated luminescence (OSL) dating, along with accelerator mass spectrometry (AMS) 14 C dating of terrestrial macrofossils (wood and conifer needles), charcoal, and pollen concentrates (for deep sediment in one lake). Collectively, the three lakes record a series of discrete intervals spanning an unusually long stretch of time. These include the local Last Glacial Maximum (26.0–18.5 cal ka), local deglaciation (18.5–13.8 cal ka), the onset of biologic productivity (13.8–11.3 cal ka), early Holocene aridity (11.3–7.8 cal ka), deposition and reworking of the Mazama ash (7.8–5.5 cal ka), a neopluvial interval (5.5–3.8 cal ka), a variable late Holocene climate (3.8–0.25 cal ka), and a latest Holocene productivity spike (250 yr B.P. to the present) that may be anthropogenic. Data from all three lakes are presented, and the collective record of climate and environmental change for the Ruby Mountains and East Humboldt Range is compared with other paleorecords from the Great Basin.