By Arne Johanson, Co-Chairperson Habitat Restoration Committee, CNPS-San Diego
Last month I provided an overview of our efforts. This month I will focus on just one, the San Dieguito River. While nowhere near the finish line, we have certainly accomplished much to get to this point. First, we trained and licensed volunteers who then earned the trust of USFW and the several property owners through our efforts at other sites. With our partners we obtained all of the permits to work in the river. Then we only had to obtain right of entry for some 6-10 parcels before initiating work.
Our work commenced by clearing a 20-foot wide path through 100 feet of Arundo donax. This provided the initial degree of fire safety the fire department required while also giving us a way to haul the Arundo out. With that, we proceeded to treat another dozen acres. This included cutting canes 20 or more feet tall and then hauling or chipping them all. With this accomplished, we could treat the other weeds before taking a break for bird nesting season and to let the natives fill in.
Our methods vary by type of weed. Small weeds of all types are pulled by hand wherever possible. Our approach for Arundo is to cut it and then to spray with 5%-6% glyphosate when it grows back to about three feet. Most Eucalyptus and Acacia are cut down and we treat the stump with 41% glyphosate. The Pampas Grass is sprayed with 2% glyphosate. Follow up on any of these is usually to spray with 2% glyphosate. Big palms are usually drilled and injected with small amounts of 41% glyphosate. With these approaches, directed specifically to individual weeds, we are able to achieve very good control while using far less herbicide than allowed for a given area.
The recruitment method we use is paced to the regrowth of native vegetation. This means we are providing replacement habitat as we go. Of course the native vegetation is of much higher quality so we see an increase in wildlife from year to year.
Season two began by re-treating any weeds that came back up in our initial area. This will be repeated as long as needed until we exhaust the supply of weed seed and roots, typically some three to five years. Eventually the natives will grow back and crowd out most of the weeds.
Bob Byrnes has also plowed into new areas cutting more Arundo while utilizing the rest of us as beasts of burden. Training the local gardeners is also a priority so they will know how to maintain the area once it is restored.
Yes, we have made great strides here. We have a great deal more to do. And we have plans in the works to do even more. The project area has just about doubled this season with the addition of parcels to the north.
We will get help from ACE (American Conservation Experience) workers for two weeks. And we are planting some sparse areas. If you would like to contribute to the efforts we would love to have you. We provide hands-on training at your pace and pretty much on your schedule.
Please contact Bob Byrnes or Arne Johanson with your interests and availability. We can be reached at: habitatrestoration@cnpssd.org.