A High-Resolution, Mutiproxy Record of Climate, Vegetation, and Fire History at the Southern Limit of the Temperate Tallgrass Prairie, USA
Abstract
Many researchers have explored the complex interplay between early interglacial climate and the dispersal of a broad range of taxa across the North American midcontinent at the close of the last glacial maximum (LGM). The southern limit of the temperate tallgrass prairie in south-central Missouri is one of the least studied areas in the midcontinent, yet this region represents a major ecological and climatic boundary between the Great Plains of the north and warm temperate forests of the south. Furthermore, there is substantial evidence that the Midwestern United States served as a particularly important migration corridor as the climate shifted after the LGM. We recovered a soil core containing the full soil profile near the southern limit of the temperate tallgrass prairie in southwest Missouri in order to improve spatiotemporal coverage of climate records in this region. We present a high-resolution multiproxy record of vegetation, derived from phytoliths (taxonomically significant silica microfossils produced by many plants); climate inferred from the C3 to C4 ratio, derived from soil carbon isotopes; and fire dynamics, derived from macroscopic charcoal (a proxy for local fire) from Golden Prairie, Golden City, Missouri, USA, covering the LGM to present. Preliminary results suggest that fire activity was low and intermittent from the base of the record until the mid-Holocene, when fire frequency increased sharply. Modern decreases in fire are attributed to human activity following European settlement. Isotope results generally agree with others in the region, indicating stable glacial conditions from the base of the record to approximately 19 kya, followed by a transitional period in which the community oscillated between C3 and C4 dominance. The community was predominantly C4 during the mid-Holocene climate optimum. Vegetation shifted toward a mixed C3/C4 community following the transition to modern climate. Modern declines in d13C are attributed to the Suess Effect.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP31D1666C
- Keywords:
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- 1616 Climate variability;
- GLOBAL CHANGE;
- 4943 Paleolimnology;
- LIMNOLOGY;
- 4914 Continental climate records;
- PALEOCEANOGRAPHY;
- 4954 Sea surface temperature;
- PALEOCEANOGRAPHY