Salt marsh plant community ecology


Photo: Salt marsh creek at low tide in Georgia.

Photo: Striking plant zonation pattern in Georgia.

Photo: Striking plant zonation pattern in Alabama.

Photo: Weeding plots studying plant interactions in Alabama.

I am interested in the factors that structure plant communities in salt marshes.  Salt marshes are attractive to community ecologists because they are relatively simple systems that contain strong gradients in physical stress (notably waterlogging of soils and soil salinity).  The plants that occur in salt marshes are also relatively easy to transplant.  As a result, salt marshes are ideal systems for experimentally studying how physical stress and biological interactions (competition and facilitation) combine to create pattern in plant communities.


Salt marshes are a major habitat type on the East and Gulf coasts of the United States, and also occur as small patches along the West coast.  In different geographic regions, similar plant communities experience different climates and different tidal regimes.  Climate and tidal regimes may also vary among years within a single location.


As part of the Georgia Coastal Ecosystems LTER program (see link), I am currently examining spatial and annual variation in plant community composition and production in Georgia marshes, with the goal of linking this variation to variation in climate and tidal regimes.  As part of this work, I am conducting some  comparative studies of plant community ecology in Gulf coast salt marshes, with sites in Alabama and Texas.


In Texas, my lab is also examining the mechanisms and consequences of the geographic expansion of mangroves into wetland habitats previously dominated by salt marsh plants (see separate tab).




Some recent publications about plant community ecology:

Peng, D., L. Chen, S. C. Pennings, Y. Zhang. 2018. Using a marsh organ to predict future plant communities in a Chinese estuary invaded by an exotic grass and mangrove. Limnology & Oceanography 63:2595-2605. Doi: 10.1002/lno.10962.


Liu, Wenwen, D. R. Strong, S. C. Pennings, Y. Zhang. 2017. Provenance-by-environment interaction of reproductive traits in the invasion of Spartina alterniflora in China. Ecology 98(6):1591-1599.


Liu, W., Maung-Douglass, K., Strong, D.R., Pennings, S.C. and Zhang, Y. 2016. Geographical variation in vegetative growth and sexual reproduction of the invasive Spartina alterniflora in China. Journal of Ecology 104:173-181.


Guo, H., K. Więski, Z. Lan and S. C. Pennings. 2014. Relative influence of deterministic processes on structuring marsh plant communities varies across an abiotic gradient. Oikos 123:173-178.


Więski, K. and S. C. Pennings. 2013. Climate drivers of Spartina alterniflora saltmarsh production in Georgia, USA. Ecosystems. DOI: 10.1007/s10021-013-9732-6.


Guo, H. and S. C. Pennings. 2012. Post-mortem ecosystem engineering by oysters creates habitat for a rare marsh plant. Oecologia 170:789-798.


Guo, H. and S. C. Pennings.  2012.  Mechanisms mediating plant distributions across estuarine landscapes in a low-latitude tidal estuary.  Ecology 93(1):90-100.


Więski, K., H. Guo, C. B. Craft and S. C. Pennings.  2010.  Ecosystem functions of tidal fresh, brackish, and salt marshes on the Georgia Coast.  Estuaries and Coasts 33:161-169.


Updated 1/2019