Authors: Jared Crain*, Berry College, Zachary P. Taylor, Berry College
Topics: Paleoenvironmental Change, Biogeography, Physical Geography
Keywords: paleoenvironmental reconstruction, fire, lake sediments, charcoal, Colorado, Gunnison Sage Grouse
Session Type: Poster
Start / End Time: 3:05 PM / 4:45 PM
Room: Lincoln 2, Marriott, Exhibition Level
Presentation File: No File Uploaded
The Gunnison Sage Grouse (Centrocercus minimus), a federally-designated threatened species, is dependent on a fire-maintained sagebrush ecosystem for food and cover. Here, we use a 2.58 m sediment core from Big Alkali Lake, Colorado (38°45'7.89"N, 106°55'39.40"W, 3,164 m) to reconstruct past fire dynamics and environmental history. Our radiocarbon chronology dates the formation of the lake to 1500 BP. From 1500 to 1100 BP, bulk density is relatively high and organic content is low. Macroscopic charcoal reaches a very large peak around 1200 BP. Most of these particles are woody charcoal, suggesting a major fire event. From 1100 to 900 BP, there is a smaller peak in bulk density, organic content, and charcoal. From 900 BP to present, organic content, bulk density, and charcoal are low. Excluding the major fire event, the majority of the charcoal is herbaceous in origin, indicating low intensity burning of the sagebrush habitat. Particle size analysis identified changes in stratigraphy throughout the core, with coarser silts prior to 1100 BP and finer material thereafter. Our record will be helpful to develop management efforts in the fire-dependent habitat of the Gunnison Sage Grouse.