Research Seminar: Mollie Yacano
October 22 @ 12:00 pm - 1:00 pm
A research seminar from UNC at Chapel Hill Department of Marine Sciences graduate student, Mollie Yacano. Presented by the UNC-CH Department of Marine Sciences and UNC’s Institute of Marine Sciences (IMS). The main location of this event will be in seminar room 222 at IMS in Morehead City, NC. The seminar will be streamed live to room G201 on the ground floor of Murray Hall on UNC-CH campus in Chapel Hill, NC. This event will be held on Monday, October 22nd, at 12:00pm.
Seminar Title: Impacts of invasive Phragmites australis on nitrogen processing in the Albemarle-Pamlico System
Abstract: Marshes are a buffer zone at the land-sea interface and play a key role in global nitrogen (N) cycling. Invasive species pose a threat to marsh habitats globally. One of the most prominent invasive plant species in marshes across the United States (US) is the aggressive European haplotype of Phragmites australis, which has spread throughout the US over the past several centuries. This invasion has nearly completely excluded its native counterpart, due to the European haplotype of P. australis’ ability to thrive in relatively high nutrient conditions. Although P. australis is often considered an undesirable species and can play a role in decreasing biodiversity, recent studies show it performs very closely to native marsh plant counterparts in terms of greenhouse gas emissions and provision of ecosystems services such as carbon storage and shoreline stabilization. We hypothesized that P. australis also plays a prominent role in marsh N cycling. In this study, we are conducting seasonal nutrient flux experiments at three sites within the Albemarle-Pamlico Region of the central Atlantic Coast of North Carolina, USA (Currituck Banks Reserve, Kitty Hawk Woods Reserve, and the Rachel Carson Reserve), focusing on invasive P. australis, naturally occurring Spartina alterniflora or Juncus roemerianus, and unvegetated mudflat. Flow though incubations were conducted using a membrane inlet mass spectrometer. During the spring incubation, P. australis sediments at Kitty Hawks Woods and Rachel Carson showed net denitrification over the course of our flux experiments (20.3 – 65.86 µmol N m-2 hr-1). When spiked with 20 μmol nitrate, to simulate a pulse of storm delivered nutrients, rates of net denitrification in P. australis (36.37 – 226.76 µmol N m-2 hr-1) were significantly higher than (<0.05) than S. alterniflora (27.57-71.02 µmol N m-2 hr-1). These results indicate P. australis could have an equal or higher potential than the native marsh plants to alter N processing, which may have larger implications for the adjacent estuarine waters.