Leaving a Lasting Impact: Riparian Zone Restoration

Leaving a Lasting Impact: Riparian Zone Restoration

Since coming to Point Reyes, I’ve spent a lot of time in creeks. Many people (myself included) may focus on the contents of the creek; what species are swimming around under rock shelves, what is the quality of the water? However, a very important aspect of these ecosystems is the vegetation surrounding it, which is called the riparian zone! The riparian zone is essential to the health of freshwater streams, as it filters runoff before it enters the creek and performs other essential functions such as erosion control. A healthy riparian zone is characterized by dense cover of native vegetation. Unfortunately, in many situations, this riparian cover is removed in favor of human development, perhaps for agricultural or aesthetic reasons. This unfortunately has been the case for many sections of freshwater creeks in Point Reyes, and restoration projects have taken place in the past to attempt to rectify these changes and re-establish healthy riparian cover.

The "before" image of one of the restoration sites; this photo was taken in 2012 right after the project was completed. The most prominent part of the photo are the erosion control structures that were installed at the top and bottom of the slope.
The "after" image of this same site! This photo is taken from almost the same angle, but the growth is so drastic the area is almost unrecognizable. The plant cover is almost entirely native and erosion has signifigantly decreased, showing the project has been successful!

My project is to survey the progress of these restoration sites and provide recommendations based on these observations. In order to do this, we have to read reports of previous restoration sites to determine their location, the goals of the project, and what actions were taken to achieve these goals. These actions include invasive plant removal, native plantings, implementation of erosion control structure, and infrastructure to prevent grazing, such as browsing guards and cattle-exclusion fences. Site evaluations are necessary to determine the effectiveness of these efforts. After finding information from each site, we went to the project location and rated the cover of native vs. non-native plants, the amount of erosion at the site, and the state of whatever infrastructure was installed. Afterwards, we provided individual recommendations based on what we observed at the site. Most of the sites we observed showed an increase in native plant cover and a decrease in erosion. If a site did not have a good percentage of native cover, we would recommend ways to rectify this such as more invasive removal and native plantings. We also participated in this type of action ourselves! We spent some time removing invasive French Broom, as well as watered and removed browning guards from various other sites.

Our team pulling French Broom at a new restoration site. French Broom is highly invasive and highly flammable, making it less than ideal for the California landscape.

This type of monitoring is important to ensure the success of restoration efforts. For the best results, monitoring a site for ten years or more is best to determine any issues that may arise from the initial project. Restoration efforts are long-term, and it’s worth the work to make sure they succeed!

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