In January 2015, the California Native Plant Society (CNPS) celebrated its 50th anniversary by holding a gigantic conference. About 700-1,000 people attended. There were several hundred short presentations and many posters describing research and “restoration” projects. The abstracts of these presentations are available on the CNPS website. We are publishing a brief description of a few of the presentations sent to us by one of our readers who attended the conference. We publish with permission but without attribution, on request. We have added a few edits in brackets and italics as well as a few links to relevant articles on Million Trees.
I was very impressed with the quality of the presentations at the CNPS conference. Some were given by academic scientists or their graduate students. Many were given by land managers and managers of “restoration” projects. There were about 225 presentations in 5 simultaneous sessions, so it was possible to hear only about 45 of them. There were also many short “lightning” presentations and nearly 50 posters. Please consider this an impression of the conference, rather than a comprehensive report.
Michael Soulé was the opening speaker. You might recognize his name as one of the proponents of invasion biology who is angry about growing acceptance of “novel ecosystems” and the ecological functions they perform. [Million Trees has posted articles about this debate among academic scientists. Soulé is one of the invasion biologists who demanded that the Nature Conservancy abandon their support for novel ecosystems.] His objection to any acceptance of non-native plants was the main focus of his presentation. He closed by saying that he “cannot live” without wild nature. Since his definition of “nature” seems to exclude non-native plants, one wonders how he will manage to survive. Perhaps he lives in an alternate universe populated solely by native plants.
Jared Farmer was the speaker at the conference dinner. His subject was the history of eucalyptus in California. His presentation was similar to his treatment of the subject in his book, Trees in Paradise. [Million Trees has posted articles about Farmer’s book.] Like his book, his presentation was even-handed in its treatment of eucalyptus. That enraged the audience, which booed every time he said something positive about eucalyptus. One wonders why he was invited to speak to this audience. Were the organizers of the conference interested in promoting a more balanced view of eucalyptus? Or did they just want a provocative speaker to wake up a sleepy audience after hours of a fund-raising auction?
Many of the presentations were surprisingly frank about the difficulties experienced by “restoration” projects. CNPS deserves credit for inviting speakers who described some stunning failures of their effort to “restore” native landscapes. I’ll describe just a few of the themes of speakers I heard.
San Francisco’s Public Utilities Commission
I was surprised to learn that San Francisco’s Public Utilities Commission (PUC) is heavily engaged in native plant “restorations.” The PUC is responsible for managing thousands of acres of open space in the watershed that supplies San Francisco’s drinking water. Common sense suggests that the PUC’s top priority would be the purity and safety of the water supply. The PUC presentations at the conference suggest otherwise. The PUC’s commitment to native plant “restorations” seems to trump the goal of clean water.
The PUC attempted to “restore” 100 acres of wetland and riparian habitat in San Mateo, Alameda, and Santa Clara counties by planting over 500,000 native plants, obtained from several different nurseries. They claim to have followed a strict protocol which theoretically should have prevented the introduction of diseased plants. Their protocol obviously failed. The fact that many of the plants were infected with Phytophthora was not discovered until they were planted in the ground. Phytophthora is the pathogen that is causing Sudden Oak Death. The PUC is now faced with the difficult—if not impossible—task of trying to contain the spread of a fatal pathogen for which there is no known cure.
This project was funded by a “mitigation” grant for capital projects elsewhere in San Francisco. Environmental laws require the builders of new development to “mitigate” for the impact they have on the environment by funding projects elsewhere, which are considered beneficial to the environment. This often looks like legalized extortion to me. It also increases the cost of infrastructure improvements, which limits the number of improvements we can make. In this case, there clearly was no benefit to the environment. It was both money down the drain and a poke in the environment’s eye.
As pointless as that project seemed, the other project presented by the PUC seemed even more pointless. They presented a poster describing an experiment intended to determine the most effective application method and type of herbicide to eradicate coyote brush. They used several different methods and types of herbicide, including Garlon (triclopyr) [which is known to be very toxic to aquatic life] and Milestone (aminopyralid) [which is banned in the State of New York because it is persistent and very mobile in the soil].
As you know, coyote brush is a native plant, so one wonders why it was necessary to eradicate it. According to PUC’s poster, it’s another example of trying to prevent natural succession from grassland to scrub. You might ask why the PUC is obligated to maintain grassland? You might also ask how the PUC can justify using toxic herbicides in our watershed? I can’t answer those questions. It doesn’t make sense to me.
San Bruno Mountain
There was also a discouraging presentation by the folks who have been engaged in the effort to “restore” San Bruno Mountain in order to preserve and maintain a population of several species of rare butterflies, including the endangered Mission Blue butterfly. This project officially began 32 years ago when the Habitat Conservation Plan was created by federal environmental protection laws. The goal was to restore native grassland required by the rare butterflies. The speaker said this goal remains largely unfulfilled. As for the butterflies, their current status is largely unknown because monitoring efforts are not sufficient to determine the size of the population.
While non-native plants considered “invasive” are a part of the problem in achieving the goal of this project, the biggest problem is, in fact, a native plant. Once again, natural succession from grassland to native scrub, dominated by coyote brush, is the main reason why grassland continues to shrink on San Bruno Mountain:
“Although the last mapping effort in 2004 reported 1296 acres of grassland, we believe that many of these areas are in imminent threat of scrub encroachment and could be converted to scrub after a good coyote brush recruitment year. Large patches of contiguous grassland with less than 2% scrub cover are quickly vanishing…Baccharis pilularis (coyote brush) accounts for the majority of the scrub encroachment observed on San Bruno. It seems to follow the well documented pattern of episodic establishment in wet seasons when roots can more quickly tap into needed soil water. Once seedlings have survived the first critical year, mortality drops quickly and full establishment plays out over the next 5-7 years (Williams et al. 1987). During this process of establishment, grassland resources decline and eventually disappear. Soil changes such as increased nitrogen and allelopathic compounds often follow scrub encroachment (Zavaleta and Kettley 2006, Weidenhamer and Callaway 2010) reducing the ability of grasslands to successfully re-establish without an intermediate disturbance such as a fire or intensive browsing (Hobbs and Mooney 1986).” (1)
It’s seems almost comic that when all is said and done, the main threat to native grassland “restoration” is apparently a native plant that is just doing what comes naturally…”invading” grassland in the absence of fire or grazing.
Hybridization: Friend or foe?
I also attended the presentation of a native plant advocate from Mammoth Lake, on the eastern side of the Sierras. She is engaged in a futile crusade to prevent the hybridization of a new plant, which she considers non-native, with a closely related native plant. When this new plant arrived in her neighborhood, she recognized that it was different, but she was unable to identify it. It wasn’t easy to find someone who could identify it. Eventually, she found a botanist in Wyoming (where it is native) who was able to tell her that the new plant is a variety of a plant that is native at Mammoth Lake. These plants are in the aster family. The native is Dieteria canescens. The new plant considered a non-native invader is Dieteria canescens var. canescens. In other words, they are the same species!
From a horticultural standpoint, the new plant is superior to the native in every way: it is a bigger plant with more flowers; the flowers are bigger with more rays; the flowers are a deeper color. So, why must it be eradicated? Because native plant advocates fear that it will hybridize with the native aster and “swamp” it genetically, i.e., wipe it out. Would that be such a terrible thing? That is a matter of opinion.
One person in the audience asked why the new plant was not being accepted as an adaptation to climate change that would probably increase the likelihood of the survival of the species. The speaker’s answer was that she could not accept the loss of the variety she considers native. Another person in the audience asked this rhetorical question: “What is our narrative here? How can we expect the public to understand that it is necessary to eradicate a plant that is the same species?” The speaker agreed that it is not an easy sell. I was encouraged by these questions. They seem to be a glimmer of common sense. I hope they are prophetic of the future of the native plant movement.
On that happy note, I close with an invitation to visit the CNPS website to read the abstracts of the hundreds of posters and presentations at this excellent conference.
- “Assessment of the past 30 years of habitat management and covered species monitoring efforts associated with the San Bruno Mountain Habitat Conservation Plan (Draft),” Creekside Science, October 21, 2014.