USC Dana and David Dornsife College of Letters, Arts & Sciences > Blog

July 28, 2012

On the Trail

Filed under: Uncategorized — Tags: , , , , — judithfo @ 8:48 pm

Last Thursday, we were able to make significant progress on our Deer Valley Trail projects. We finally got our hands on the necessary supplies, including cement and flags for our plots. We were able to dig almost all the holes for the informative trail signs. The interns from last year had written and designed them, but getting them in the ground proved to be a challenge for us, as the soil was incredibly solid and we lacked the proper tools. However, we were able to use heavy metal rod to create holes deep enough for the signs. The first one was successfully mounted into the ground using cement.

The same day, we also accomplished a lot for our fennel project. After obtaining and processing the soil samples the day before, we began the fennel treatments. To ensure the plots were random we picked papers out of a hat for the three treatments (full removal, mowing, and a control). The different treatments are designated by a different color flag in the middle of each of the plots. For the full removal, we used shovels and grubbers to break the fennel at its taproot, which will prevent it from growing back. This is the primary method used by the Catalina Island Conservancy. Full removal is the most effective method but can result in soil disturbance and requires intense manual labor. Because of this, we are also looking at the effectiveness of mowing. To mow the fennel, we used pruners to cut the fennel stalk as low to the ground as possible without disturbing the taproot. Mowing will almost always result in fennel re-growth, but we are looking to see if mowing continuously once a year will eventually kill the plant. We did not touch the control plots. We had two of each treatment at each site, totaling to four plots per treatment type. We also decided to take additional soil samples from under native plants so that we can already have a comparison in nitrogen levels before the summer ends.

We felt a sense of accomplishment in finishing one of the major steps in our project. After this, we will be taking soil samples once a quarter to monitor the soil nutrient levels and observe any changes. Most likely, next year’s summer interns will resume the project and continue with the annual mowing.

Top: Judy Fong mows a plot using pruners. Photo credit: Dawnielle Tellez. Bottom: Dawnielle performs full removal of fennel. Photo credit: Judy Fong


We hope to not only unlock interesting answers regarding how different fennel treatments affect soil nutrient levels, but also to provide a consistent project for future Environmental Studies interns to build upon. The trail will serve as a field lab for classes and groups. The class ENST 320A: Water and Soil Sustainability will be utilizing the trail as a platform to perform soil samples in the future. For example, one of the ENST 320A field trips to Catalina could process the soil samples for that quarter and contribute to our data. In addition, the restoration project should provide experience removing fennel and other invasive grasses, watering, taking more soil samples, and potentially some seed or root collection. We hope that our work with the fennel project and restoration project will help allow for learning opportunities and hands-on experience for students. We expect that this trail will be getting more and more use as time goes on. Whether it be through the informative signage or the restoration site, we hope that our efforts will make a lasting impact on whoever uses the trail in the future.


Editor’s note: The ENST Catalina Island Internship at USC Dornsife is offered as part of a summer internship program offered to undergraduate students in theUSC Dana and David Dornsife College of Letters, Arts and Sciences. This course takes place on location at the USC Wrigley Marine Science Center on Catalina Island. Students investigate important environmental issues such as ecological restoration, protected-area planning and assessment, and invasive species management. During the course of the internship, students will work closely with USC faculty and staff scientists from the Catalina Island Conservancy to support ongoing conservation and management programs being implemented on the island. Instructors for the course include David Ginsburg, Assistant Professor of Environmental Studies, Lisa Collins, Lecturer in Environmental Studies, and Tony Summers, Invasive Plant Program Supervisor from the Catalina Island Conservancy.