SOIL SALINITY AND THE OCCURRENCE OF INVASIVE PHRAGMITES AUSTRALIS IN SCARBOROUGH MARSH
Anthony J. DeVecchis and Dr. Joseph K. Staples Abstract
Background Importance of tidal marshes like Scarborough Marsh Phragmites australis as an invasive species Previous research Methods and Results Analysis of soil salinity, temperature, and moisture Plant community characteristics Connection between soil salinity and P. australis Significance Insight and management – locally and beyond Background
Functions of tidal marsh ecosystems Productivity Coastal Buffer Key Habitat Significance of Scarborough Marsh Maine Natural Areas Program Invasive Phragmites australis
Spread in New England (Fussell et al., 2015)
Tolerance (Vasquez et al., 2005)
Changes to salinities in salt marshes (Fussell et al., 2015; Warren et al, 2001) Methods and Materials
Analysis of Soil Moisture, Salinity, and Temperature Paired Transects to upland edge (Morgan and Adams, 2018; Warren et al, 2001) Upper tidal reaches Conductivity as proxy for salinity (Yang et al. 2019) Relationship of conductivity to plant species Analysis and Results
Conversion of conductivity to specific conductance Simple t-tests comparing Spartina and Phragmites data Significant differences in soil specific conductance were observed along each transect Specific conductance
1400 1400 t-test P < 0.001 t-test P < 0.05 a t-test P < 0.02 1200 1200 a 1000 1000 ) µs/cm b b ) µs/cm 800 800
600 600
400 400 Specific Conductance ( Conductance Specific ( Conductance Specific 200 200
0 0 Spartina Spartina Spartina Spartina Phragmites Phragmites Phragmites Phragmites Libby River 1 Libby River 2 Nonesuch River 1 Nonesuch River 2 Significance
Results yielding similar results to previous research (Fussell et al., 2015; Warren et al., 2001)
Indication of freshwater input
Fairly rapid, easily repeatable method
Information for conservation efforts Complications
Slow progress sampling in winter Impact of ice on conductivity Native vs. Invasive Influences of road salting Inability to access the Dunstan River Details Conclusions
Reliability of data Future Research Acknowledgements
Environmental Science and Policy Faculty at USM Dr. Joseph Staples and Dr. Karen Wilson Friends of Scarborough Marsh Steve Pinette Maine Department of Inland Fisheries and Wildlife Brad Zitske Field Data Collection Help Sam Whitted References
Fussell, S. B., Dionne, M. L., & Theodose, T. A. (2015). Expansion rates of Phragmites australis patches in a partially restored Maine salt marsh. Wetlands, 35(3), 557-565. https://doi.org/10.1007/s13157-015-0645-3 Maine Natural Areas Program. (2013). Focus Areas of Ecological Significance: Scarborough Marsh. https://www.maine.gov/dacf/mnap/focusarea/scarborough_marsh_focus_area.pdf Morgan, P. A., & Adams, M. D. O. (2018). Tidal marshes in the Saco river estuary, Maine: A study of plant diversity and possible effects of shoreline development. Rhodora, 119(980), 304- 331. https://doi.org/10.3119/16-19 Vasquez, E. A., Glenn, E. P., Brown, J. J., Guntenspergen, G. R., & Nelson, S. G. (2005). Salt tolerance underlies the cryptic invasion of North American salt marshes by an introduced haplotype of the common reed Phragmites australis (poaceae). Marine Ecology. Progress Series (Halstenbek), 298, 1-8. https://doi.org/10.3354/meps298001 Warren, R. S., Fell, P. E., Grimsby, J. L., Buck, E. L., Rilling, G. C., & Fertik, R. A. (2001). Rates, patterns, and impacts of Phragmites australis expansion and effects of experimental Phragmites control on vegetation, macroinvertebrates, and fish within tidelands of the lower Connecticut River. Estuaries, 24(1), 90-107. https://doi.org/10.2307/1352816 Yang, S., Liu, F., Song, X., Lu, Y., Li, D., Zhao, Y., & Zhang, G. (2019). Mapping topsoil electrical conductivity by a mixed geographically weighted regression kriging: A case study in the heihe river basin, northwest china. Ecological Indicators, 102, 252-264. https://doi.org/10.1016/j.ecolind.2019.02.038