RECONSTRUCTING MESO AND MICRO SCALE CLIMATE PATTERNS FROM HOLOCENE BURIED SOILS (Invited Presentation)

Soil variation across landscapes results from a number of interacting processes whose drivers and effects vary over space and time. Because the response time of soil properties to changes in environmental factors varies, some soil properties (such as organic matter) more faithfully record relatively short-term conditions, while others (such as clay accumulation or mineral weathering) record longer-term conditions. Addressing human interactions with the environment necessitates a focus on paleosol properties that may record landscape-scale and century- to millennial-scale environmental change. Carbon-isotope studies of soil organic matter, when combined with standard morphological and micromorphological analyses of paleosols formed in episodically aggrading landscape positions, can provide insights at these meso and micro scales.

Carbon-isotope records from paleosols formed in Holocene alluvial and colluvial sequences in the Upper Midwest USA provide proxy vegetation and climate records at regional to sub-landform scales. Information at this scale informs us about factors that may have influenced past human use of landscapes and allows us to frame questions about how climate, geomorphic processes and prehistoric human activity may have affected vegetation and soil patterns. These records are not without uncertainties, however, and several factors that may affect their integrity must be addressed to ensure accurate reconstructions.