Friends,
We have a confirmed report of a new high priority invasive plant in the Big Canyon area of Upper Newport Bay.
On Tuesday OC CNPS member, Barbara Boethling, sent our invasive plant committee information and photos of a plant at Upper Newport Bay that appeared to be an unknown species of Centaurea. After some effort it was determined that it was likely Volutaria tubiliflora or Canary Island knapweed. Last evening I visited the site and confirmed it as this species.
This is a very new pest in the U.S., with an invasion in the early stages and being battled in the Anza-Borrego Desert area. The first U.S. record was at that location in 2010 when it was incorrectly identified as V. canariensis. It is now under management at that location, but success is still uncertain. This Newport Beach occurrence is the first U.S. record outside of the Anza-Borrego area.
The good news is that I only found 23 plants in one colony over an area of just a few square meters. The bad news is that the plants have already begun dispersing seed and there may also be a parent population that has not yet been found. It was quite late and the light was poor, so my photos are rather poor and I was not able to do a very extensive search of the surrounding area. I removed one plant as a voucher.
This plant is a serious threat to the bay and to native ecology. Some speculation is that it may even have the potential of a Sahara Mustard type of invasion. The California Invasive Plant Council has given the plant a Red Alert status.
The plants are located mostly on the edge of the Big Canyon Nature Trail at coordinates 33.632602, -117.882955.
Now what?
The population needs to be removed. This should be done soon and in a sanitary manner, so as not to disperse additional seed.
I am uncertain who the land manager is for this particular site and which agency should take the leadership role, CDFW, OC Parks or City of Newport Beach.
The surrounding area should be surveyed for additional plants soon.
The area should be monitored for the next few years and additional plants should be removed at a vegetative state.
Prior to removing the plants I suggest that other interested parties may quickly want to visit the site, to become familiar with the plant.
The Orange County California Native Plant Society is here to help. Through Early Detection and Rapid Response (EDRR) and the coordination of the public, land managers and other interested parties we can work collaboratively to manage these new invasive threats. Our Emergant Invasive Plant Management program is specifically focused on occurrences like this knapweed.
We would be happy to meet interested parties at the site, assist with the removal, help survey the surrounding area, etc.
In the meantime, let's get these plants removed.
Emergent Invasive Plant Program