Ecological modeling of emergent vegetation for sustaining wetlands in high wave energy coastal environments

Oregon State University, Corvallis OR

Investigators

Abstract

CBET-0828549 D. Cox, Oregon State University The purpose of this study is to conduct a set of large-scale experiments, guided by a combination of hydraulic engineering, plant ecology, and coastal wetlands restoration practices, to develop an understanding of the dynamics of wave-sediment-vegetation interaction. The project goals are to (1) model the wave characteristics of two plant types common to high energy wave environments (Schoenoplectus pungens or 'bulrush' and Spartina alteriflora or 'cord grass'), (2) compare changes in sediment volume and bed form resulting from wave action in vegetated and non-vegetated areas, (3) determine the wave thresholds of plant survivability, and (4) understand the post-storm response of plants, particularly their root structure. The first goal will parameterize the wave attenuation through an empirical drag coefficient that can be integrated into regional-scale wave models currently used in wetland restoration practice. The second goal will directly impact decisions in land use planning since the comparisons will provide quantitative information on value of existing vegetated shorelines (or proposed restoration projects) to reduce shoreline loss. This study will document the thresholds for bulrush and cord grass survival in terms of wave energy (height and period), looking at both loss of stem due to breakage and loss of the entire root system. This information can be used, for example, to determine the likelihood of plant loss for a given extreme event (e.g., hurricane). The project will integrate research and education through an established Education and Outreach program, including summer Research Experience for Undergraduates (REU) and Teacher (RET) activities, an annual open house to increase ecological engineering literacy among the general public, and weekly K-12 tours and demonstrations.