Faculty Mentor
Dr. Rebecca Brown
Presentation Type
Poster
Primary Discipline of Presentation
Biology
Abstract
Following the historic dam removal along the Elwha River in Olympic National Park, we are evaluating the impact of seeding in the former Lake Mills reservoir by examining the soil seed bank composition. The Elwha River had the largest dam removal project in history, and the second largest ecological restoration project in National Parks Service history. Active restoration (seeding and planting) took place in terraces and valley walls, the two dominant landform types found in the former reservoir. While the plant community in the former dam reservoirs is well documented, the soil seed bank remains unexplored.
My objective is to determine the long-term effectiveness of seeding post-dam removal in the former Lake Mills. Examining the composition would determine if seeding had any long-term effect on the species found in the reservior. I hypothesized that seeded plots had greater diversity and species richness than unseeded plots, and that seeding had a greater effect in terraces than in valley walls. I also hypothesized that seed bank species richness would differ from the observations from the 2023 revegetation survey. In the summer of 2023, I collected soil seed bank samples from 40 plots stratified across 2 landforms within the former Lake Mills; half of the plots in each landform were seeded. Samples were grown in flats in the EWU greenhouse from December of 2023 to April of 2024. Analysis demonstrated that landform had a significant effect on species richness, but seeding did not. These results can be used to inform future management decisions.
Recommended Citation
Tabino, Makenna and Brown, Rebecca, "Determining the Long-Term Effectiveness of Seeding Post-Dam Removal in the Elwha River, WA, Through Soil Seed Bank Analysis" (2024). 2024 Symposium. 20.
https://dc.ewu.edu/srcw_2024/works_2024/works_2024/20
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
Determining the Long-Term Effectiveness of Seeding Post-Dam Removal in the Elwha River, WA, Through Soil Seed Bank Analysis
Following the historic dam removal along the Elwha River in Olympic National Park, we are evaluating the impact of seeding in the former Lake Mills reservoir by examining the soil seed bank composition. The Elwha River had the largest dam removal project in history, and the second largest ecological restoration project in National Parks Service history. Active restoration (seeding and planting) took place in terraces and valley walls, the two dominant landform types found in the former reservoir. While the plant community in the former dam reservoirs is well documented, the soil seed bank remains unexplored.
My objective is to determine the long-term effectiveness of seeding post-dam removal in the former Lake Mills. Examining the composition would determine if seeding had any long-term effect on the species found in the reservior. I hypothesized that seeded plots had greater diversity and species richness than unseeded plots, and that seeding had a greater effect in terraces than in valley walls. I also hypothesized that seed bank species richness would differ from the observations from the 2023 revegetation survey. In the summer of 2023, I collected soil seed bank samples from 40 plots stratified across 2 landforms within the former Lake Mills; half of the plots in each landform were seeded. Samples were grown in flats in the EWU greenhouse from December of 2023 to April of 2024. Analysis demonstrated that landform had a significant effect on species richness, but seeding did not. These results can be used to inform future management decisions.
