Authors: Camryn Soehnlein*, Stetson University, Benjamin Tanner, Stetson University , Jason Evans, Stetson University
Topics: Coastal and Marine, Soils, Anthropocene
Keywords: Salt Marsh, Mangroves, Soil, Soil Deposits, Migration, Climate
Session Type: Poster
Start / End Time: 10:00 AM / 11:40 AM
Room: Napoleon Foyer/Common St. Corridor, Sheraton, 3rd Floor
Presentation File: No File Uploaded
As our climate grows warmer, our continuously evolving shoreline is changing with it. Ponce Inlet, Florida (~29 degrees N Latitude), has historically been perceived as an ecotonal boundary between cold-tolerant saltmarsh intertidal communities to the north and more tropical mangrove intertidal communities to the south. Over recent years, there has been increasing evidence of mangroves rapidly migrating northward and invading into saltmarsh communities. It is generally hypothesized that this recent northward mangrove expansion is being caused by decreased winter freezing associated with modern anthropogenic warming. However, there is interest in evaluating the paleo-record to better characterize whether recent northward mangrove expansion may have analogues in Holocene sediments, or if the current migration of mangroves is clearly anomalous. As a first phase of such an evaluation, this project is characterizing differences between mangrove and saltmarsh soil. Using thirty surface soil samples each from both mangrove and salt marsh communities near Ponce Inlet, we analyzed several proxy indicators that included plant remains, soil color, bulk density, water content, loss on ignition, bulk carbon and nitrogen, and carbon isotopic composition. Our research shows that mangrove deposits have more woody debris, lower organic carbon, lower δ13C values, lower water content, and higher bulk density than salt marsh deposits. The results of this research facilitate interpretation of different community types within the paleo-record.