Estuaries and Coasts

, Volume 33, Issue 5, pp 1237–1246

Responses of Uniola paniculata L. (Poaceae), an Essential Dune-Building Grass, to Complex Changing Environmental Gradients on the Coastal Dunes

Article

DOI: 10.1007/s12237-010-9269-2

Cite this article as:
Gormally, C.L. & Donovan, L.A. Estuaries and Coasts (2010) 33: 1237. doi:10.1007/s12237-010-9269-2

Abstract

Coastal dunes are well known for plant species zonation but less is known about species-specific responses to underlying environmental gradients. We investigated variation in morphological traits and tissue nutrient concentration in Uniola paniculata, along a shoreline-to-landward gradient (transects spanning from the dunes directly behind the high tide mark to 40–100 m inland) in the southeast USA. Several environmental factors decreased with distance from the shoreline (soil B, K, Mg, Na; salinity, pH, and sand accretion), and differences were most pronounced between the 10 m closest to the shoreline and the remainder of the transect. In the 10 m closest to the shoreline, 94% more sand accumulated, which was 31% more saline. Additionally, plants here were taller, contained higher aboveground tissue N and K, and a higher percentage tended to flower. This contrasts with patterns found in salt marshes and saline desert dunes, where plant size is often negatively correlated with salinity. During the 2 years following the planned study, storms washed out ≤25 m of the transects. Resampling of the remaining sites demonstrated that even after erosion of the dune profile, a higher percentage of the plants in the 10 m closest to the shoreline plants tended to flower, relative to populations located further from the shore. Our findings suggested that the environment and plant response in the shoreward 10 m can re-establish relatively quickly.

Keywords

Environmental gradients Intraspecific variation Phenotypic plasticity Coastal sand dunes Sand accretion and erosion Salinity Nutrients Uniola paniculata 

Copyright information

© Coastal and Estuarine Research Federation 2010

Authors and Affiliations

  1. 1.Department of Plant BiologyUniversity of GeorgiaAthensUSA