In December 2013, one of our collaborators in the effort to save our urban forest from pointless destruction submitted a request to the California Invasive Plant Council to reconsider its evaluation of blue gum eucalyptus (Eucalyptus globulus) as “moderately invasive.”
The California Invasive Plant Council (Cal-IPC) has responded to that request with a draft reassessment which is available here: http://www.cal-ipc.org/ip/inventory/eucalyptus.php. Cal-IPC’s draft maintains the same over-all rating of blue gum as “moderately invasive.” Cal-IPC is inviting “substantive comments and questions” by July 31st to email@example.com.
Today we are publishing with permission the cover letter of a public comment that will be submitted by one of our collaborators. We hope it will inspire you to write your own public comment by the deadline of July 31, 2014.
From the perspective of humans, there are pros and cons to most species of plant and animal. E. globulus is no exception to this general rule. Cal-IPC reaches a negative conclusion regarding blue gum by exaggerating negative issues and de-emphasizing or omitting positive issues. Cal-IPC now acknowledges that blue gum has “low invasive potential” only in specific conditions and that its population in California is stable, but it has introduced new issues and intensified others so that it can maintain its overall rating of “moderately invasive.” I remind Cal-IPC that its name is Invasive Plant Council, not fire council or hydrology council.
Cal-IPC also fails to take into consideration the negative side-effects of attempting to eradicate eucalyptus. There are environmental benefits associated with leaving blue gums alone. These damaging consequences of eucalyptus removal should appear on the “asset” side of the ledger:
- When eucalypts are destroyed, repeated applications of herbicide to stumps are required to kill the roots of the trees to prevent them from resprouting multiple trunks. If the resprouts are not aggressively managed, the result will be more eucalypts than presently exist, which has been the result of some past projects.
- The herbicides used to kill the roots (usually Garlon) are known to damage mycorrhizal fungi and microbes in the soil. Therefore, the growth of whatever plant succeeds the eucalypts is hindered by the damage that is done to the soil.
- Because many of the herbicides used to kill non-native vegetation are mobile in the soil or are taken up by the roots of the plants that remain, plants and trees, which are not intended targets, are often damaged or killed.
- Existing eucalypts are often sheltering plants and trees that are considered valuable by Cal-IPC. When the eucalypts are destroyed, the plants that remain are subjected to increased light and wind, which sometimes damages or kills the remaining plants.
- Eucalypts are storing many millions of tons of carbon, which are released into the atmosphere when the trees are destroyed, contributing to the greenhouse gases causing climate change. Scientists tell us that the native ranges of plants and animals have changed in response to climate change and must continue to change. Therefore, Cal-IPC’s interest in preserving native plants in their historic ranges is not served by contributing to climate change.
It is also not in Cal-IPC’s strategic best interests to continue to advocate for the eradication of eucalyptus in California:
- As the eradication projects get progressively more destructive, the public’s negative reaction to the destruction becomes progressively more aggressive. There are now thousands of us all over the State and all over the country, working to stop this destruction and we are often effective in preventing these projects from being approved or funded. An op-ed in the New York Times in September 2013, expressed support for our opinion that the word “invasive” has become a destructive tool and is inappropriately applied to eucalyptus in California.
- The scientific community has also become progressively more critical of the attempts to eradicate eucalyptus. Last fall, Nature magazine quoted several well-known academic scientists in an article that criticized plans to destroy 30,000 eucalypts on Mount Sutro in San Francisco. In May 2014, the CEO and Chief Scientist of the Nature Conservancy expressed their opinion on TNC’s website that destroying eucalypts in California is unnecessary.
- Since blue gum eucalyptus is no longer available in nurseries in California and has not been planted for many decades, it has no long-term future in California. To the extent that eucalyptus is a problem, it is a problem that will resolve itself in time.
Cal-IPC’s continued support for these projects is no longer in the mainstream of scientific or public opinion. Removing eucalyptus from Cal-IPC’s “hit list” would significantly improve Cal-IPCs chances of success with the plants that remain on its inventory of invasive plants. The public is unlikely to expend the same amount of energy opposing the eradication of broom, for example.
Cal-IPC has an opportunity to defuse a controversy that is handicapping the success of its venture. Cal-IPC would be wise to abandon its crusade aganst blue gum eucalyptus.
Update: On March 13, 2015, the California Invasive Plant Council published its final reassessment of Blue Gum Eucalyptus (available HERE). Cal-IPC has downgraded its rating of invasiveness and ecological impact from “moderate” to “limited.” Although the detailed assessment is less than perfect, the over all rating itself is an improvement. Thanks to those who sent comments to Cal-IPC.