Evaluating Sod Mats as an Alternative to Plugs in Wetland Revegetation
1Biohabitats, Denver, CO, USA; [email protected]
The City of Fort Collins (CO) Natural Areas Department used custom-grown wetland sod mats largely in place of herbaceous plugs to revegetate a newly constructed wetland at Gadwall Pond (Kingfisher Point Natural Area). Wetland sod mats are constructed from two layers of coconut fiber matting as a growth substrate for herbaceous wetland plants. The hypotheses underlying the preferential use of sod mats for revegetation at Gadwall Pond was that the mat-rooted vegetation would be more resistant to herbivory than plugs, which are easily pulled out by waterfowl, and the higher cost per unit area would be offset by more efficient installation, faster establishment from higher growth rates, and no need for protective fencing. Moreover, the City had locally collected seed that could be used for the custom grow and ensured that the mats would represent local ecotypes. Seed from graminoids and forbs was delivered, processed, and grown over the course of ~9 months. Forb mats were experimental. All mats were delivered and installed in the late summer of 2018. Within a few days of installation, it was clear that wetland sod mats cannot withstand the high herbivory pressure at Gadwall Pond. Even the coconut fiber matting was torn apart in some areas. Protective fencing was quickly installed to protect the vegetation. The sod mats have cost more than installing plugs over the same area, but advantages in establishment success and near-term biomass gains are still being evaluated.