Biophysical dynamics and wave attenuation in a constructed saltmarsh: Insights from laboratory and remote sensing data

Successful establishment and growth of constructed saltmarshes can be evaluated through consistent monitoring of plant biophysical parameters, such as aboveground biomass and leaf area index. Monitoring during the early establishment stage is vital for ensuring the long-term effectiveness of constructed saltmarshes in delivering anticipated ecosystem services, including wave energy dissipation, which strongly depends on vegetation biophysical characteristics. Efficient, low-disturbance methods are needed for the successful adoption of such monitoring plans. This study combines laboratory measurements and remote sensing observations to evaluate the performance of vegetation indices in capturing changes in aboveground biomass, leaf area index, and wave energy dissipation in a constructed saltmarsh. Allometric equations were also investigated to predict aboveground biomass from non-destructive plant traits. Results showed acceptable correlations between vegetation indices, measured biophysical parameters and wave energy dissipation characteristics. All species performed better with NIR-R-based indices for leaf area index, while aboveground biomass predictions varied, with both NIR-R- and G-R-based indices performing best depending on species. Wave energy dissipation also correlated with vegetation indices, aligning closely with the best predictors of aboveground biomass, particularly when vegetation was submerged. These findings indicate that remote sensing combined with allometric equations offers a promising method for monitoring newly established marshes and estimating their biophysical parameters, which serve as key indicators of successful establishment and initial wave energy dissipation.