Investigating dune‐building feedback at the plant level: Insights from a multispecies field experiment. Issue 9 (9th May 2019)

• Record Type: Journal Article
• Authors: Mullins, Elsemarie; Moore, Laura J.; Goldstein, Evan B.; Jass, Theo; Bruno, John; Durán Vinent, Orencio
• Is Part Of: Earth surface processes and landforms. Volume 44:Issue 9(2019)
• Page Start: 1734
• Page End: 1747
• Publication Date: 2019-05-09
• Subjects: Coastal foredunes -- Dune Grasses -- Ammophila breviligulata -- Uniola paniculata -- Spartina patens; Geomorphology -- Periodicals; 551.4
• DOI: 10.1002/esp.4607
• Languages: English
• ISSNs: 0197-9337

Abstract

Abstract: Coastal foredunes provide the first line of defense against rising sea levels and storm surge and for this reason there is increasing interest in understanding and modeling foredune formation and post‐storm recovery. However, there is limited observational data available to provide empirical guidance for the development of model parameterizations. To provide guidance for improved representation of dune grass growth in models, we conducted a two‐year multi‐species transplant experiment on Hog Island, VA, U.S.A. and measured the dependence of plant growth on elevation and distance from the shoreline, as well as the relationship between plant growth and sand accumulation. We tracked total leaf growth (length) and aboveground leaf length and found that Ammophila breviligulata (American beachgrass) and Uniola paniculata (sea oats) grew more than Spartina patens (saltmeadow cordgrass) by a factor of 15% (though not statistically significant) and 45%, respectively. Our results also suggest a range of basal/frontal area ratios (an important model parameter) from 0.5‐1 and a strong correlation between transplant growth and total sand deposition for all species at the scale of two years, but not over shorter temporal scales. Distance from the shoreline and elevation had no effect on transplant growth rate but did have an effect on survival. Based on transplant survival, the seaward limit of vegetation at the end of the experiment was approximately 30 m from the MHWL and at an elevation of 1.43 m, corresponding to inundation less than 7.5% of the time according to total water level calculations. Results from this experiment provide evidence for the dune‐building capacity of all three species, suggesting S. patens is not a maintainer species, as previously thought, but rather a moderate dune builder even though its growth is less stimulated by sand deposition than A. breviligulata and U. paniculata . © 2019 John Wiley & Sons, Ltd. Abstract : An experiment reveals that Ammophila breviligulata and Uniola paniculata are more stimulated by burial than Spartina patens and that transplant growth and total sand deposition are correlated at the scale of two years but not shorter. Distance from the shoreline and elevation did not affect growth rate but affected survival – the seaward vegetation limit corresponded to an elevation inundated only 8.7% of the time. Results suggest that S. patens is not a maintainer species, but rather a moderate dune builder.