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ARS Home » Plains Area » Sidney, Montana » Northern Plains Agricultural Research Laboratory » Pest Management Research » Research » Publications at this Location » Publication #375808
Research Project: Biological Control and Community Restoration Strategies for Invasive Weed Control in the Northern Great Plains Rangelands

Location: Pest Management Research

Title: A 12,000 kyr paleohydroclimate record in the southeastern, U.S.A based on deuterium from bat guano

Author
item TSALICKIS, ALEXANDRA - Southern Illinois University
item WATERS, MATTHEW - Auburn University
item Campbell, Joshua

Submitted to: Environmental Earth Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2022
Publication Date: 2/22/2022
Citation: Tsalickis, A., Waters, M.N., Campbell, J.W. 2022. A 12,000 kyr paleohydroclimate record in the southeastern, U.S.A based on deuterium from bat guano. Environmental Earth Sciences. 81. Article 148. https://doi.org/10.1007/s12665-022-10234-x.
DOI: https://doi.org/10.1007/s12665-022-10234-x

Interpretive Summary: Bat guano deposits can be found in select caves in the Southeastern United States. These deposits can provide chemical and physical data that can be used to interpret past environmental conditions. We obtained a core sample of a guano deposit from Cave Springs Cave (Alabama, USA) that was carbon dated to 14,000 years old. The guano contained chemical (stable isotopes) data that revealed numerous environmental changes throughout the last 14,000 years. This record strengthens and enhances the knowledge of past climatic conditions of the entire Holocene of the Southeastern United States. Additionally, these data show the promise of utilizing bat guano as a proxy for paleoenvironmental research.

Technical Abstract: The southeastern United States endures environmental change from human population increase, climate change, and land use alterations creating the need to understand baseline conditions and environmental patterns prior to human impacts. While paleoenvironment data can be reconstructed from a variety of archives (e.g. lake sediments, tree rings, speleothems), some geographic areas (e.g. southeastern United States) contain fewer of such records. One paleoenvironmental archive capable of recording moisture regimes and other paleoenvironmental changes over millennia, but has received little attention, is bat guano deposits in cave systems. Bat guano deposits are found in many cave environments in the southeastern United States and can be used as an archive of paleoenvironmental data including precipitation, vegetation, and aspects associated with the ecology of bats. Here, we present a 14,000-year record of moisture (wet/dry) and other periods of paleoenvironmental change based on stable isotopes (d15N, • 13C, • D) in a guano core collected from Cave Springs Cave in Alabama, USA. Moisture was inferred from changes in guano dD content. d13C revealed vegetation type and d15N changes proved inconclusive. Results suggest that during the end of the deglaciation (11,151 – 13,764 Years Before Present, YBP) the southeastern United States was drier than the first six thousand years of the Holocene period (4,388 – 10,916 YBP), roughly coinciding with the Holocene Climatic Optimum (HCO) time interval (5,000 – 9,000 YBP). During the last 4,177 years, conditions in the region became drier once again in the southeastern United States region. Climate inferences based on guano dD are consistent with the role of atmospheric moisture on regional vegetation changes suggested by pollen records obtained from lake sediment cores. The d15N, • 13C composition of bat guano show variability through time that does not correlate with dD. We suggest that these proxies are controlled by other environmental factors and do not directly reflect atmospheric moisture. This study suggests that bat guano dD may be a reliable method to provide a long-term paleoclimate record.