Science in the National Parks

We were so encouraged by our reader’s report about the conference of the California Native Plant Society (CNPS) that we decided to attend the conference of the National Park Service (NPS), “Science for Parks, Parks for Science” at UC Berkeley, March 26-27, 2015.  As we have reported many times, the National Park Service is heavily engaged in native plant “restorations.”  Their projects are some of the most aggressive in the Bay Area and some of the most successful, because they seem to have greater resources than other local managers of public land.  Therefore, we were curious about their assessment of those efforts.  Are they starting to have doubts, as expressed by some of the presentations at the CNPS conference?  This is a brief summary of what we learned.

The angry old guard

The keynote speaker was E.O. Wilson, the granddaddy of “biodiversity.”  He spoke of his desire to safeguard biodiversity by preserving one-half of the Earth as “protected areas” and the closely related goal to connect all protected areas. This lofty goal should be compared to the current figure of 13% of the earth which is presently protected and the internationally agreed-upon goal of 17%, according to the second speaker, Ernesto Enkerlin, Chair of the IUCN World Commission on Protected Areas.

The moderator, Steven Beissinger, Professor of Conservation Biology at UC Berkeley, asked Professor Wilson a few pointed questions:

  • “Can working landscapes play a role in conservation?” Professor Wilson said. “That is a stupid, dangerous way of looking at conservation.  Parks cannot be evaluated in terms of their value to humanity.  The natural world is valuable in its own right.  Emma Marris and Peter Kareiva of the Nature Conservancy are pushing this; they have the least experience with studying the natural world.  This dangerous thinking must be countered immediately.”  Granted, Emma Marris is a science journalist, but Peter Kareiva was an academic scientist at University of Washington for decades before becoming Chief Scientist at the Nature Conservancy.
  • “Must protected areas be devoid of people?” Professor Wilson said “Of course not.  Indigenous people might be included.”  In fact, indigenous people have been evicted from many protected areas around the globe.  Furthermore, virtually the entire population of the US is not indigenous.  Where does that leave us?
  • “Given the challenges faced by conservation, is triage necessary to prioritize projects to focus on the most important and threatened species?” Professor Wilson said with some feeling, “That’s ridiculous!  We CAN bring them all back, we must SAVE THEM ALL!”

Professor Daniel Simberloff, the well-known invasion biologist, was another speaker who believes it is necessary and possible to eradicate all non-native plants and animals in our public lands.  He also called out by name Marris, Kareiva and others for their criticism of invasion biology.  Frankly, we think these personal attacks are unseemly in the context of what should be considered a scientific debate about the most effective methods of conservation.  The moderator, Professor Holly Doremus (UC Berkeley, Boalt Hall), asked Professor Simberloff a few tough questions as well:

Most other speakers at the conference had a less sanguine view of our ability to “save every species” and “eradicate every non-native species.”  The need for “triage” was repeated in many presentations and descriptions of past and present projects were often pessimistic about the prospects of success.  Climate change and its impact on the environment was the dominant theme of the conference.

All loss, no gain

Mission Blue butterfly.  Wikimedia Commons
Mission Blue butterfly. Wikimedia Commons

The endangered Mission Blue butterfly exists only in a few locations in the San Francisco Bay Area:  Twin Peaks, San Bruno Mountain, Milagro Ridge in San Mateo County, and the headlands of Marin County.  We recently reported that the 32-year effort to restore butterfly habitat on San Bruno Mountain has been plagued by natural succession to native coyote brush that competes with the butterfly’s host plant, 3 species of lupine.  The status of the butterfly population on San Bruno Mountain is unknown because of inadequate monitoring.  Save Mount Sutro Forest has reported that the butterfly population on Twin Peaks remains very small despite repeated attempts to move butterflies from San Bruno Mountain.  We learned at the NPS science conference that the effort to restore butterfly habitat in the Marin Headlands in order to increase the butterfly population there has experienced its own difficulties.

The restoration of butterfly habitat to the Marin Headlands was controversial because about 500 Monterey pines were destroyed to make way for the lupine scrub required by the butterflies.  The pines had been planted by the military over 100 years ago.  They were heavily used by raptors during their annual fall migration through the Bay Area.  The Marin chapter of the Audubon Society was therefore opposed to their destruction.  As usual, this opposition was ignored by the National Park Service, which manages that property, and the trees were destroyed in about 2009.

NPS has been engaged in the effort to restore the habitat needed by the Mission Blue since the trees were removed.  Those engaged in that effort presented a poster at the NPS science conference which reported:

  • In 2010, NPS and its collaborators attempted to promote the growth of the 3 species of lupine required by the Mission Blue by removing all vegetation mechanically and with prescribed burns, then seeding with lupine.
  • Neither burn nor mechanical treatments resulted in increased lupine species cover after one or three years. In fact, both mechanical and burn treatment resulted in increased cover of non-native forbs and grasses after three years.

In other words, 500 trees were destroyed, which were heavily used by migrating raptors, but Mission Blue butterflies did not benefit from the destruction of these trees because efforts to restore the habitat they require have been completely unsuccessful.  This is a familiar scenario:  all loss and no gain.

Karner blue butterfly - USFWS
Karner blue butterfly – USFWS

We also heard a presentation about a 20-year effort to “restore” the habitat required by an endangered butterfly (Karner blue) at Indiana Dunes National Lakeshore.  The complete failure of that effort is attributed to changes in the climate, considered “abnormal:”

Despite advances in our understanding of habitat needs of the Karner blue, and extensive management to meet those needs, Karner numbers at Indiana Dunes have fallen more than 99% over the past fifteen years, with precipitous declines associated with historically abnormal weather in 2012. We have documented a role phenological [seasonal] mismatching between the butterfly and its host plant plays in this population decline and the sensitivity of this species to habitat fragmentation.”

One wonders what “abnormal” weather means during a time of extreme changes in the climate, which are not expected to return to “normal.”  The speaker predicted that the likely outcome for the Karner blue at Indiana Dunes is its complete disappearance and probable replacement with a different butterfly species which is better adapted to the new climate.

Reality Check

Doug Johnson, Executive Director of the California Invasive Plant Council, made a presentation about new digital tools to identify populations of plants considered “invasive:”  CalWeedMapper and WHIPPET.  These tools will enable land managers to set priorities for attempts to eradicate these plants.  Using  a thistle species as an example, he showed a map that indicated this “invasive” plant is present everywhere in northern California, but there are isolated pockets of it south of there.  These small, isolated populations represent potential opportunities to prevent its spread before it is so widespread that eradication is impossible.  This is an example of triage, which was the dominant theme of the conference. 

Oxalis in Glen Canyon Park, San Francisco
Oxalis in Glen Canyon Park, San Francisco

Mr. Johnson was recently interviewed by Bay Nature about a non-native species of oxalis, which San Francisco’s so-called Natural Areas Program has been attempting to eradicate for many years by spraying it with Garlon.  Garlon is the most hazardous pesticide used by the Natural Areas Program.  Mr. Johnson expressed his opinion to Bay Nature that it is futile to attempt to eradicate oxalis: “‘It’s not a target for landscape-level eradication because it’s way too widespread.’”

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 overall rating itself is an improvement.  We are grateful to our readers who sent comments to Cal-IPC on its deeply flawed first draft of the reassessment.

In other words, the California Invasive Plant Council seems to have entered a new era of realistic expectations.  This looks like a BIG step forward to us, because if that viewpoint is adopted by land managers it should mean less destruction and less use of pesticides.

The Take Away

The old guard is unprepared to compromise their firm belief that it is possible to save every species of native plant and animal and that every non-native plant and animal must be killed to achieve that lofty goal. They defend their indefensible opinion by attacking those who are looking for a more realistic approach to conservation. However, climate change is bringing more and more converts to this viewpoint, which was best expressed by one of the plenary speakers, Hugh Possingham, Professor of Mathematics and Ecology, University of Queensland in Australia.  He was asked how his model of “ecological parks” fits with the mission of the National Park Service to preserve the parks “unimpaired.”  We paraphrase Professor Possingham’s answer:

“The Australian conservation ethic is similar to the United States’.  We yearn for pre-invasion days.  When I grew up in Adelaide we had 7.5 hectares of pristine vegetation for the entire city, which had 750 species at one time and now there are 500 species left.  It’s a museum.  It isn’t a functioning ecosystem.  So, we have got to embrace the creation of ecosystems that are not particularly natural.  However, I’ve learned that the birds don’t care where the plants come from.  Where weeds have been ripped out, bird diversity has plummeted.  I have been converted to the European viewpoint of disturbed landscapes: that is, these new plants have value.  Australia is completely over-run with non-native plants and animals.  Australians would be willing to shoot all the feral cats, but the fact is it’s not possible because we don’t have the resources to attempt it, let alone succeed at it.”

Thank you, Professor Possingham, for your frank acknowledgement of the value of new species to wildlife and your acceptance of more realistic goals for conservation in the 21st Century.


Videos of the plenary speakers are available on the conference website, as well as abstracts of posters and presentations.

Formidable odds against reintroduction of Mission Blue butterfly

Mission Blue butterfly. Wikimedia Commons

The Mission Blue butterfly is a federal endangered species which existed historically on Twin Peaks in San Francisco.  San Francisco’s Natural Areas Program has been trying to reintroduce the Mission Blue to Twin Peaks for several years, so far with limited success.  Visit the Save Sutro website for a detailed description of these efforts which began in 2009.

The “Recovery Action Plan for the Mission Blue Butterfly at Twin Peaks Natural Area” acknowledges the difficulty of this undertaking.  It cites a study of 226 attempts to reintroduce butterflies where they have been extirpated (locally extinct).  These attempts lasted an average of 15 years.  Only 29 of the attempts were ultimately successful.  So what are the odds of success on Twin Peaks?

Identified obstacles to success

The federal Endangered Species Act requires that a recovery plan be written for each endangered species.  These recovery plans are a valuable source of information about each endangered species, the factors that resulted in their endangered status, and the plans to promote the recovery of the population.  From the recovery plan for the Mission Blue, we learn of several issues that make its reintroduction problematic at best:

  • The Mission Blue is dependent upon just 3 species of lupine for its development.  Two of these exist on Twin Peaks, but the predominant species is infected with a fungal pathogen which flares up during warmer, wetter weather.  The small population of Mission Blues on Twin Peaks crashed in 1998 when the fungal pathogen killed many of the lupines. 
  • The lupine is crowded out by scrub species if natural disturbances such as fire do not prevent natural succession from grassland to scrub such as native coyote brush.
  • Non-native species of plants are also competitors of the native lupines and their growth is encouraged by higher levels of nitrogen in the soil found in urban environments as a result of the burning of fossil fuels. 

The Natural Areas Program cannot control these factors:

  • There is no known cure for the fungal pathogen that is killing lupine.  In wetter years, it is likely to kill some of the lupine on Twin Peaks again, as it has in the past.
  • The Draft Environmental Impact Report for the Natural Areas Programs says that prescribed burns will not be conducted in the “natural areas.”  Prescribed burns are conducted by the State parks department periodically on San Bruno Mountain, where a viable population of Mission Blue butterflies exists.  This method of preventing natural succession to scrub in order to maintain a population of the butterfly’s host plant will not be an option on Twin Peaks. 
  • We should probably assume that existing automobile traffic in San Francisco will continue to contribute to nitrogen in the soil for the foreseeable future.  Higher levels of nitrogen will promote the growth of the non-native vegetation that competes with the native lupine upon which the Mission Blue depends.

Unidentified obstacles to success

Pesticide Application Notice, Twin Peaks

In addition to the issues that have been identified by federal and local recovery plans, the Natural Areas Program has introduced a new threat to the Mission Blue.  Herbicides are being used on Twin Peaks to control non-native vegetation.  Twin Peaks was sprayed with herbicides 16 times in 2010 and 19 times in 2011.  Are these herbicides a factor in the limited reproductive success of the Mission Blues that have been reintroduced to Twin Peaks?

A recently published study reports that the reproductive success of the Behr’s metalmark butterfly was significantly reduced (24-36%) by herbicides used to control non-native vegetation.  Two of those pesticides are used on Twin Peaks, imazapyr and triclopyr.  Triclopyr was used most often on Twin Peaks in 2010 and imazapyr in 2011.

The study does not explain how this harm occurs.  It observes that the three herbicides that were studied work in different ways.  It therefore speculates that the harm to the butterfly larva may be from the inactive ingredients of the pesticides which they have in common, or that the harm comes to the larva from the plant which is altered in some way by the herbicide application.  Either theory is potentially applicable to the herbicides used on Twin Peaks and consequently harmful to the Mission Blue.

Native plant advocates would like us to believe that the herbicides used to eradicate non-native plants are not harmful to animals, including humans. In fact, they don’t know that. The truth is that no one knows if herbicides are harmful to animals because there is almost no research that would answer this question.  The tests required by law by the Environmental Protection Agency to put new chemicals on the market are very limited.  The honeybee is the only insect on which the EPA is required to test chemicals before they are put on the market.  No tests are required for butterflies or any other insect. 

US Fish & Wildlife funded the research on the Behr’s metalmark butterfly which suggests that herbicides are harmful to butterflies.  US Fish & Wildlife is also the co-sponsor and co-funder of the reintroduction of the Mission Blue butterfly on Twin Peaks.  Will US Fish & Wildlife advise the Natural Areas Program that herbicide use on Twin Peaks should be stopped? 

In a more perfect world we would have the wisdom to stop using pesticides until we had some scientific evidence that they are not harmful to us and the animals with which we share the planet.