Geological Survey

Description

This opportunity is to support research to be performed for the Greater Everglades Ecosystem restoration planning and scenario evaluation. This study focuses on analysis of carbon isotopic signatures of soil organic matter (SOM) in marl prairie sediment cores to reconstruct historic vegetation and hydrologic conditions. Objectives include measurement of carbon isotopes from an estimated 105 samples from sediment cores collected in marl prairies throughout the Greater Everglades ecosystem. Because the abundance of C3 plants is positively correlated with wetland hydroperiod, changes in ∂13C values of SOM reflects, in large part, changes in proportions of C3 and C4 species related to hydrologic shifts. Other proxies examined from these samples include pollen and charcoal, and a combination of radiocarbon dating, lead-210 and cesium-137 analysis, and pollen biostratigraphy form the basis for development of age models. Ultimately, the resulting stable isotope data will be integrated with evidence from pollen and charcoal analyses to identify intervals of vegetation change associated with development of marl-prairie plant communities.

Who can apply

• Others

Contact

FAITH GRAVES <br/>Contract Specialist <br/>Phone 703-648-7356
fgraves@usgs.gov