COS-JAM2018 - Agenda

01:00 - 01:45
Room: Jordan Hall Galleria
Poster session
Through time and space: mapping ​Schoenoplectus americanus​ population change in the salt marshes of the Chesapeake Bay
Erin Nguyen
McLachlan Lab, University of Notre Dame, Notre Dame

Recent studies have demonstrated that the common salt marsh sedge, Schoenoplectus americanus, possesses seeds that can be resurrected after a century-long dormancy by germinating seeds collected in sediment cores. Thus, sampled sediment cores can be used to understand  population shifts across decadal scales. The objective of this study was to investigate changing S. americanus populations using seed abundance as a proxy for population estimates of S. americanus in the Chesapeake Bay. We propose that S. americanus populations would decline with sediment depth due to decomposition. The preliminary data suggests this is not the case, instead revealing the surprisingly heterogenous character of these core samples, across both temporal and spatial scales. For example, in one sediment core, the top, or most modern, layer had an abundance of 6 seeds but the bottom, or most ancestral, had 226 seeds. Compare this to yet another core with a top layer  abundance of 143 seeds and a bottom layer abundance of 0 seeds. The lack of a trend in population abundance may be reflective of various environmental factors from the marsh such as a nutrient or salinity gradient or distance inland Currently we are determining germination rates of these old and modern seeds as a proxy for decomposition rates. These decomposition rates may help determine which environmental factors are most critical in determining how abundant S. americanus will be in a particular region in future studies.

 


Session:
Poster session 1
Presenter/s:
Erin Nguyen
Presentation type:
Poster
Room:
Jordan Hall Galleria
Date:
Friday, May 4th, 2018
Time:
01:00 - 01:45
Session times:
01:00 - 01:45