Stepping it Up on Sudden Oak Death, Part II - Some Answers From An Expert

So I passed my previous post, in which I bemoaned the lack of action being taken to prevent and control the spread of Sudden Oak Death (SOD) (especially the lack of public education that I have observed), on to eminent UC Davis expert, Dave Rizzo. Since I am an expert in the spread of invasive (rapidly spreading) non-native weeds, but SOD is an invasive pathogen (as was the infamous Chestnut blight, which decimated the magnificent American Chestnut, the Redwoods of the east), I was curious to hear his thoughts about how my concerns as an expert in invasive plants translated to this rapidly spreading pathogen.

My comments were inspired by a rather dire article that I had read on the subject, combined with my observations that little is being done to prevent hikers and vehicles from spreading SOD (something that they've been shown to do - particularly in the spring rainy months), even in highly visited areas that are highly infested with the disease, like Muir Woods National Monument. This has frustrated me since I first learned that symptom levels are greater with increasing human activity, such as hiking, in an area.

Dr. Rizzo has been both a pioneer and a leader of efforts to solve the mystery of not just how the disease spreads and what to do about it, but also exactly what it is (the pathogen wasn't even identified until around 2000!).

Here are his comments on the current status of efforts to control the disease and educate the public about how we can all help avoid spreading it (special thanks to Dr. Rizzo for granting permission to share them with you).

Hi Jon,

Thanks for the message and pointing toward your blog.

I agree with you about the importance of public education - I've written about it in a number of review articles and in most of my talks. And I agree about the small signs at Muir Woods. I have been somewhat disappointed about the response of the Muir Woods folks and (other) parks about posting information. (One exception is Hendy Woods State Park in Mendocino County). We (California Oak Mortality Task Force - COMTF) have mentioned this many times and have had discussions on foot washes and even made up posters, but with little success. However....

I have found it is very easy to talk about public education, but much, much harder to implement it. You can put up large posters - getting people to actually read them is a different story. The COMTF has made a huge effort in public education. I have given dozens of talks to local groups, others have given even more talks, thousands of brochures have been sent, dozens of training sessions have been held for professionals and the general public. I have participated in making several documentaries including at least 2 that have been shown on PBS in the Bay Area. I have given hundreds (I lost count at 500) of print, radio and TV interviews. There are six million people in the Bay Area- not counting, as you mentioned, all of the tourists. How do we reach them? Any suggestions? (I mean that sincerely)

Management of this disease occurs at three non-exclusive levels - individual trees, the landscape and regional to international. For the individual tree, there is now a preventative fungicide (phosphates) that has extremely low toxicity. This is considered a green product, but I'm not sure if it is "officially" certified organic.

The regional to international level is where the regulations come in to play. Right now all plants leaving CA, OR and WA must be inspected regardless if they are known hosts for P. ramorum (Editor's note: the genus and species of SOD is Phytopthera ramorum - the same genus as the Irish Potato Famine!). Inspection and detection is easier said than done. If if we had billions to spend it would still be a difficult task with such a cryptic organism. The best bet would be simply not to move plants further than locally. We could make regulations to that end, but in my mind this is as much a cultural issue as a political one. Unfortunately, people like planting non-native exotic plants in their yards. All the regulations in the world may not change that. This is not to say we should just give up, only that it is a difficult task. (Editor's note: perhaps a little environmental psychology might help...)

The landscape, I think, is the most difficult scale for management. While cleaning shoes, etc. is important, it is still a very low probability pathway for pathogen movement (although certainly not zero). Unfortunately, this pathogen spreads quite nicely on its own. The other way the pathogen is probably most often spread is through ornamental plants planted in the urban-wildland interface (see above).

It would have been great to stop this pathogen at an early stage. Unfortunately by the time we figured out the cause, the pathogen already covered large areas of California. Based on our work, Oregon was able to detect the pathogen. But they are finding it very difficult to eradicate.

There are several reasons for the relative lack of landscape management. First, we had (and still have) very little information on the pathogen. What approaches could be taken? Obviously, chemical controls at very large scales are impractical at best, dangerous at worst. This leaves tree removals and fire as the remaining major management tools. How do you use these tools with little or no information and avoid making the problem worse? We now have more information and are moving in these landscape directions in Humboldt, Sonoma, Santa Cruz and Monterey counties (Big Sur). We have developed grass roots management efforts by working with local landowners (public, NGO, individual landowners).

But SOD cannot be taken out of context. The first thing I ask landowners is what would be their management goals in the absence of SOD. This is not an easy question - it is very surprising how little ecological information (fire history, successional patterns, etc.) is available for many of the these forest types. In particular, the mixed-evergreen forest has been very little studied (we have a number of collaborative projects trying to get this information). Developing large scale land management plans is not easy.

For example, in Humboldt county we are attempting an early intervention to slow the spread of the pathogen. But to implement that, the farm advisor needed to work with many different groups and in context of regulations designed to protect other species; i.e. spotted owl and marbled murrelet. In Big Sur, much of the impacted area is designated Wilderness, which requires lots of paperwork to be able to do treatments. By the time the exceptions could be granted often it will be too late for some canyons.

While I believe that it will be impossible to eradicate P. ramorum and probably to prevent its spread, I do think we can slow its spread and develop management tools to lower its impact on our forests. We are making substantial efforts to coordinate landscape management with other management needs (e.g., fire issues, other invasive plant and animal species). These projects involve many dedicated people who are working very hard to make them a success. But unfortunately these things don't happen over night.

Dave

For those of you who'd like more information, Dr. Rizzo advised that:

The best website for info on SOD is www.suddenoakdeath.org. The website is run by the California Oak Mortality Task Force (COMTF). The site includes lots of current info on outreach and research. We will be running another training session on SOD for the public in Sonoma County on July 20. There should be info and an agenda posted on the website soon.

In case you are not aware, the COMTF is a consensus group that has tried to bring together many different agencies to help recommended research, policy and outreach directions to various state and federal agencies. Most of its efforts have been toward public education. At various times, I believe something like 65 government agencies and NGOs have been involved. We have an executive board that meets a few times of year to discuss issues surrounding SOD. We also have several subcommittees (management, regulations, monitoring, etc.). On the board, currently we have representatives from the US Forest Service, CDF, CDFA, APHIS, UC, and the nursery industry. I serve as the science advisor for the group.

Sounds to me like it is a complicated issue, the kind that a "consensus group" that represents many different interests (though no conservation organization taking a lead role...) might have a difficult time agreeing on strong, decisive measures to implement (just as the diverse interests who hammered out the Kyoto Protocol ended up producing a watered down treaty that will hardly approach solving the problem of global warming).

If implementing larger-scale measures poses complex challenges and happens much slower than the disease is spreading, perhaps getting some smaller-scale measures in place, such as better public education at parks designed to minimize the risk that hikers and vehicles spread the disease, are all the more important. In the end, a lot of little steps can add up to good things. These should, ideally, be accompanied by monitoring (excellent graduate project) to determine how to maximize their effectiveness in stimulating action (perhaps the type of environmental communication research that has generated reports like this). There really is no gratifying excuse for all that can be done to not be getting done. As scientists and economists have shown, early preventative steps may be more expensive to start, but they tend to make dealing with a destructive invasive species like SOD both more effective and much cheaper in the long run.