Patterns of terrestrial and limnologic development in the northern Greater Yellowstone Ecosystem (USA) during the late-glacial/early-Holocene transition

Abstract

A high-resolution record of pollen, charcoal, diatom, and lithologic data from Dailey Lake in southwestern Montana describes postglacial terrestrial and limnologic development from ice retreat ca. 16,000 cal yr BP through the early Holocene. Following deglaciation, the landscape surrounding Dailey Lake was sparsely vegetated, and erosional input into the lake was high. As summer insolation increased and ice recessional processes subsided, Picea parkland developed and diatoms established in the lake at 13,300 cal yr BP. Closed subalpine forests of Picea, Abies, and Pinus established at 12,300 cal yr BP followed by the development of open Pinus and Pseudotsuga forests at 10,200 cal yr BP. Increased planktic diatom abundance indicates a step-like warming at 13,100 cal yr BP, and alternations between planktic and tychoplankic taxa suggest changes in lake thermal structure between K

Climatic and non‐climatic controls shaping early postglacial conifer history in the northern Greater Yellowstone Ecosystem, USA

“…The early intermittent spikes in Pseudotsuga pollen accumulation rates at all sites suggest the presence of small populations of Douglas‐fir, given that the genus is a very poor pollen producer and its pollen does not travel far from the source (Gugger and Sugita, ). Following the expansion of Pinus , pollen assemblages in northern Yellowstone were dominated by conifer pollen, including undifferentiated Pinus , which we did not examine in this study (Krause and Whitlock, ; Krause, ; Krause et al , ).…”

“…Results from previously published records, Dailey Lake (Krause et al , ), Blacktail Pond (Huerta et al , ; Krause and Whitlock, ) and Slough Creek Pond (charcoal record; Millspaugh et al, ) are only described briefly.…”

“…Solid black lines indicate weighted averages of all possible chronologies and is bounded by a dotted‐line confidence interval (95%); and top left inset shows the iteration history, the middle inset shows the prior (lines) and posterior densities (area fill) for the mean sediment accumulation rate, and the right inset shows the prior (line) and posterior (fill) of the memory (1‐cm autocorrelation strength). For age determinations at Dailey Lake and Blacktail Pond, see Krause et al () and Krause and Whitlock (), and Table for age determinations at Slough Creek Pond.…”

“…Alternatively, the Abies peak may be an artifact of an undetected change in sediment accumulation rates, which in turn would have affected the calculation of pollen accumulation rates. At all sites, shrubs, particularly Artemisia , and forbs were also an important component of the Lateglacial vegetation (Krause and Whitlock, ; Krause, ; Krause et al , ).…”

“…To complement existing high‐resolution paleorecords in the northern GYE from Dailey Lake (Krause et al , ) and Blacktail Pond (Huerta et al , ; Krause and Whitlock, ), a new sediment core from Slough Creek Pond was collected for pollen and stratigraphical analyses using a modified Livingstone square‐rod piston sampler (Wright et al , ). In September 2011, a 4.76‐m‐long core was retrieved from a floating platform at a water depth of 8.05 m at Slough Creek Pond.…”