| Livestock Exclusion Effectiveness Monitoring |
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The Oregon Watershed Enhancement Board (OWEB) and the Washington Salmon Recovery Funding Board (SRFB) are currently working cooperatively to monitor livestock exclusion projects in both states as part of a "project-scale" effectiveness monitoring program for watershed and salmon habitat restoration projects. Livestock exclusion has been identified as an important action for restoring fragile riparian areas. Livestock exclusion includes building and maintaining fences along riparian areas. Project data and results is shared between the states. This coordinated approach represents a successful effort to collect comparable and compatible data across jurisdictional boundaries.
Project Summary
The used a Before-After-Control-Impact (BACI) design. A BACI design means that data is collected "Before" and "After" an action, in this case the action is fence building. A "Control" and "Impact" reach are also established. The "Control" reach is established in an area not expected to change during the project. The "Impact" reach is where the action will occur; in this case the "Impact" is the fence building. This specialized design helps to isolate changes in the "Impact" reach by comparing the "Impact" and "Control" reaches over the life of the study. This project is collecting data addressing livestock presence in the exclusion, bank erosion, and riparian vegetation structure at each project site. Monitoring takes place one, three, five and ten years after fence installation.
OWEB and SRFB contracted with Tetra Tech EC, Inc. to monitor the effectiveness of twelve livestock exclusion projects. The final report for baseline sampling (Year 0), first year after fencing (Year 1), and third year after fencing (Year 3) are posted below.
Preliminary Outcomes
When data from Oregon and Washington are combined, preliminary results from the latest monitoring year (Year 3) indicate that:
- 10 of 12 fencing projects (83%), were effective in keeping livestock from riparian areas.
- A major reduction in bank erosion occurred.
- No changes in riparian vegetation height have been detected thus far.
- No changes in riparian vegetation cover have been detected thus far.
These results are promising and begin to shape the understanding of the importance of livestock exclusion as a restoration action that improves stream quality.
A few lessons learned from the projects are:
- Riparian planting may also be needed at the time of fencing is installed to advance riparian diversity.
- Invasive species control in the exclusion may also be necessary to allow native species to mature.
Next steps for livestock exclusion effectiveness monitoring could include:
- How do livestock exclusions affect fish populations and growth at a larger scale.
- How do livestock exclusions affect the influx of sediments, nutrients and pesticides.
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