There is now a forest “fire deficit in the Western United States. Human activities and ecological and climate changes have combined to

National Oceanic and Atmospheric Administration Image

contribute to this deficit. This is according to a recent study published in the Proceedings of the National Academy of Sciences: Long-Term Perspective on Wildfires in the Western USA.   (Free access to full article.)  The study was undertaken by an international twelve-member team.

The article observes that “fire regimes are primarily a product of climate, vegetation, topography, and human activities.”  These factors interact in a variety of ways.  One of these is the introduction of invasive plant species.

President Obama proposed to put 20,000 veterans to work over the next five years with a Veterans Job Corps conservation program.  The initiative would put up to 20,000 veterans back to work over the next five years "protecting and rebuilding America."  Specifically, as stated in a White House press release:  ”veterans will restore our great outdoors by providing visitor programs, restoring habitat, protecting cultural resources, eradicating invasive species, and operating facilities. Additionally, our veterans will help make a significant dent in the deferred maintenance of our Federal, State, local, and tribal lands including jobs that will repair and rehabilitate trails, roads, levees, recreation facilities and other assets. The program will serve all veterans, but will have a particular focus on post-9/11 veterans.”

This program harkens back of course to the Works Progress Adminstration (WPA) which spent about $40 million in the late 1930s and 1940s on work in the National Parks (about $650 million in 2012 dollars).

I will keep you posted on the progress of the Veterans Job Corp.

There are several recent articles and publications on the effects of fire on invasive plants.  Fire figures into ecosytem and invasive plant species management in two big ways. 

Wildland Fire

First, invasive plants can change the way an ecosystem responds to fire.  The September 2011 issue of the Journal of Rangeland Ecology & Management has six papers on the interplay between fire and invasive weeds in the cold desert regions of the western United States. One paper, for example, focuses on the Great Basin region and the spread of invasive cheatgrass among sagebrush sites.  Cheatgrass has invaded this area.  Because cheatgrass is fine-textured and matures early, fires have become more frequent.

Second, invasive plants can change the way an ecosystem is managed with fire.  Several publications have addressed the strategies behind using prescribed burns to control invasive plants.  See  Use of Fire as a Tool for Controlling Invasive Plants by Joseph M. DiTomaso, Matthew L. Brooks, Edith B. Allen, and Ralph Minnich Edited by Joseph M. DiTomaso and Douglas W. Johnson 2006 from the California Invasive Plant Council; Wildland Fire in Ecosystems: Fire and Nonnative Invasive Plants 2008; United States Fish and Wildlife Service, Fire Management and Invasive Plants: a Handbook 2011.

Dave may not be your stereotypical tree-hugger.  He doesn’t drive a Prius or sport a pony-tail.  He drives a Chevy pick-up and often wears deer hunter orange.  He worked a union job as a mechanic and

The pond at Southwood Nature Preserve

machinist at a car dealership and raised a family with his wife Donna. He served in the army during the Vietnam War.  He grew up in rural Minnesota putting himself through trade school while working at Hugo Feed

One acre oak savanna at Southwood Nature Preserve won a LEAP award for sound ecological management practicesEarth Day Volunteers on the old viewing platform at Southwood Nature Preserve

Mill.  Now in retirement, he’s a driving force behind a community effort to create one of the most successful nature preserves in the Twin Cities metro area – Southwood Nature Preserve in North St. Paul.  Dave and his family have a life-long love of nature and Southwood Nature Preserve is an expression of that love.

 In 2007 Dave and his daughter Carrie, a field biologist with U.S. Fisher and Wildlife, walked through what was then Southwood Park.  Buckthorn dominated the forest understory.  Giant knotweed and reed canary grass choked the pond.  A confusing web of unofficial trails burdened the ecosystem.   However, Carrie told her Dad that Southwood was a potential “gold mine.”  From that point on, Dave started mining.

 Four years later Southwood is transformed.  A one acre oak savanna with wildflowers replaced an old dump site for a roofing company.  A spacious viewing platform overlooks the pond with blue wing teal, green herons, great herons egrets, mallards and occasionally a bald eagle.  Great horned owls, bluebirds, Wood ducks and bats use their newly constructed homes.  Deer and wild turkeys wander through.  New signs are up and will soon provide wildlife education.

 Southwood also draws people: classes from Cowern elementary school across the street; cross-country runners and skiers, dog walkers who get free doggie

Volunteers on Earth Day 2009 on the old viewing platform

bags and who must keep their dogs on leash.  Steve Johnson a retired teacher holds classes on bird watching for the Audubon Society along with bug classes from time to time.

 Southwood has been a lot of hard work.  Dave, Donna, city workers, and volunteers galore have done one project after another.  It started with a major buckthorn pull for which Dave designed and welded eight buckthorn wrenches.  North Haven Church, Boy Scout troop 188 and North St. Paul High Jr. ROTC pitched in.  The City, at Dave’s urging, even hired a crew from the local workhouse. 

Dave Nelson handing a buckthorn gavel to Congresswoman Betty McCollum with a buckthorn gavel - a gift for President Obama for signing a bill strengthening the Endangered Species Act.

After the buckthorn removal, garlic mustard took off.   When the garlic mustard was almost ready to go to seed, Dave recruited an “emergency crew” from the North St. Paul chapter of the Jr. ROTC to pull garlic mustard on a rainy Saturday. Seven people including Dave and Donna have done “capstone” projects for their certification as Minnesota Master Naturalists. (Now, Dave is president of the North Metro Chapter of the Minnesota Master Naturalists.) Park Commissioner Dave Andren helped design and construct the viewing platform along with other volunteers).  Two scouts provided many hours of labor to the nature preserve earning their Eagle Scout badge.

Dave has also sought broader community and political support for the preserve and for stronger environmental protection more generally.  He has gone door-to-door recruiting volunteers and donors.  He handcrafted more than seventeen gavels made from buckthorn.  The buckthorn gavels can only be earned with a $200 contribution to a Southwood Preserve fund or as recognition for significant work for the environment.

If you go to Southwood Nature Preserve on a spring, summer, or fall day

Volunteers working at the new viewing platform at Southwood

you likely will find Dave and Donna working on something. If you do, be sure to interrupt them. There is only one thing Dave likes better than working at Southwood and that’s talking to visitors about Southwood.

common teasel - dispsacus fullonum - photo by Steve Dewey

I attended the Invasive Plant Symposium 2011 in Milwaukee, Wisconsin, on December 14 and 15.  The event was co-hosted by the North Central Weed Science Society.   I tried to take a step back and look at some of the overarching topics discussed in the talks:

Mapping – critical for early detection and management of invasive species.  EDDMapS, for example, is a nationwide effort to map invasive species distrubution. 

Invasion Vectors – roads, railroads, waterways, powerlines are all routes for the spread of invasive plants. 

Prevention (e.g., cleaning off seeds and propagules from equipment), detection, and early control can limit the spred. 

Cooperative Weed Management Areas – neighbors banding together to prevent, detect, and control invasive plants. 

Protecting Gems – native prairies, wetlands, and other ecosystems can’t just be islands.  Buffer zones around these areas are critical.

Urban Area Management – some of these sites are highly disturbed and altered.  But at every conference I have been to, someone talks about rare and endangered plants that exist right in cities like Milwaukee.

Best Practices – Guidelines for organizations (forestry, construction, utilities, etc.) on detecting and preventing the spread of invasive plants.

The symposium had a lot of energy and was not doom and gloom.  Groups like MIPN and IPAW operate on very tight budgets.  It was an impressive effort.

I have spent several great sessions working with a volunteer at a park just north of St. Paul treating Japanese knotweed (Fallopia japonica, syn. Polygonum cuspidatum, Reynoutria japonica).  This is an amazingly invasive plant.  It’s not surprising given it’s a pioneer species on the volcanic desert formed on the southeast slope of Mount Fuji.  Here is striking video from the BBC showing the superweed grew more than 1m-tall (3ft) in just three weeks.

Ken Moore wrote this article about controlling broom in California.  French broom (Genista monspessulana), Spanish broom (Spartia junceum) and Scotch broom (Cytisus scoparius) are invasive plants throughout California.  However, the article offers advice for the long-term control of a variety of invasive species.  Ken originally wrote this article for the California Invasive Plant Council Newsletter.  We reprint it here with permission.

Ken started working on invasive species control in 1963!  He started the Wildlands Restoration Team in 1990.  Go to the website for some great articles on invasive species control techniques.  Also, here is a video of a short interview with Ken Moore.  G

In analytic geometry, an

Fig. 1 Deer Herbivory

asymptote of a curve is a line such that the distance between the curve and the line continually approaches closer to, but never quite achieves zero as they tend to infinity. 

It is a universally relevant principle, with applications in such diverse fields as quantum mechanics, particle theory, hierarchical resemblance; even philosophy. As you approach infinity (completion, perfection, etc.) each further step becomes disproportionally more difficult.  

Examples abound: Sharpening weed tools is easy. But to obtain the edge a surgeons’ scalpel requires honing with successively finer stones, followed by polishing with successively finer rouges. However, even that mirror edge looks rough under a microscope, because the finest abrasives still cannot produce the theoretically perfect, sharpest edge.

In weed work where eradication is the goal, infinity = zero presence. This is always challenging, but broom, more than anything else I’ve tackled, epitomizes the asymptote principle.  Broom control has three distinct phases:

PHASE 1 is removal of standing broom. Everything from hands to heavy equipment is employed at this stage. While this appears to be the hardest step, it’s actually the easiest, even though it’s the most work! People love the satisfaction they get from visible results.

PHASE 2  Broom removal has triggered the seedbank, and you’re faced with a sea of seedlings. Now the real difficulty of controlling broom becomes apparent. People don’t relish pulling endless seedlings. Where they can be used, flaming and foliar spray are the major methods employed on larger sites. But after a few years, native plant growth on most sites will preclude using either of these methods.  You’ve entered…

PHASE 3. Native plants have achieved sufficient size and density so that broom is getting harder to see each year. Hand pulling or stem treatments are required now, and even seasoned pullers are missing broom. You’re close to finishing, yet it’s harder to prevent seed set. The asymptote principle!  Paul Simon put it succinctly: “The nearer your destination, the more you slip-sliding away.”

However, there are forces gathering out there which have taken me 25 years to fully appreciate. Their effects are only beginning to become visibly apparent, and are therefore under-valued by many land managers.

Broom cannot tolerate heavy shade. It usually established following logging or other activities that removed tree canopy. Now that these areas are recovering, broom is increasingly shaded out. And where we’re boosting native re-growth by removing broom, the effect is dramatic. Check seed pods in shady areas. They may still form, but not reach maturity.

Evolution is also helping. Yep, even on broom sites! When broom initially established here, browsers

Fig. 2 Cambium Gnawing

probably ignored it. But sooner or later, one gets curious: “Hmmm, not bad.”  The word gets around!

Deer, rabbits, squirrels, gophers, wood rats, mice, and voles have all benefitted from our removing many of their predators. There are more hungry mouths to feed out there, especially herbivores: Being nature’s larder on the hoof, they multiply copiously!

Not only are there more mouths, there’s less native forage available to them. As we “convert” natural areas and invasive species displace natives, those mouths will increasingly turn to non-native plants to survive.

But evolution doesn’t manifest itself overnight, so it’s no wonder that early signs of adaptation to broom by browsers go unnoticed. On sites where broom removal is not underway, it’s easy to miss.  But look closely and you’ll see it, even there.

 Where broom is being controlled, the effects of browsing escalate. As fewer plants remain, they get hammered even harder. This is particularly helpful in Phase 3, when plants are harder to find. And those hungry mouths are out there, 24/7!  

Here’s what to look for: Check smaller broom around the edges of infestations. Deer nip off the tender ends of young plants, making a sharp angled cut.  Fig. 1. Further in, wood rats, rabbits, mice, and voles gnaw the tender cambium layer, eventually girdling the stem.  Fig. 2. Gophers and ground squirrels work mostly underground. They will completely sever the roots of large broom.   I’ve seen entire stands of broom die in this way.  Fig. 3.

Compounding all of this, there are many more of us out there, as well! Some 150 people attended our

Fig. 3 Root Herbivory

initial gathering in 1992, and I clearly remember we all wondered if we could ever assemble that number again.  CalIPC is now 1,000 strong, and counting!

Still feeling these factors aren’t significant? Think longer term, when escalation of these combined processes has kicked in! Browsers may not eradicate broom alone, but they aren’t alone! Seeing them closing ranks behind us is empowering to me.  The best ally we could ever have is the very one we’re working to save.

The horticultural industry may sell cultivars of invasive plants that produce fewer seeds. These are billed as non-invasive cultivars. According to new research, however, many of these non-invasive cultivars are still invasive. Tiffany M. Knight of Washington University and co-authors from the Chicago Botanic Garden conducted population modeling and found that even a 95 percent reduction in viable seed production of an invasive plant still can result in invasion. Moreover, the offspring of cultivars do not usually “breed true” especially if they cross with plants from feral populations. The results of their study are published in the October 2011 issue of BioScience.

In short, don’t buy cultivars of Japanese barberry, buckthorn, burning bush, etc.!

Weeds are defined as any plant that is out of place. This is a large part of the problem. The following is an interview with Bob Flasher, who has worked on vegetation management crews in regional parks and in weed control programs in the national parks for more than 20 years. His education is in
cultural anthropology, which will explain some of his interesting and controversial insights into how we define a “good” or “bad” plant.

Bob hugging a native tree - the Pacific madrone

Invasive Plant News: You have been accused of being a weed-loving tree-hugger and have actually been seen hugging eucalyptus trees.  Is there any truth to these accusations?

Bob: I am not now, nor have I ever been a weed-loving tree-hugger. I do cop to loving plants though. The issue is that what plants seem out of place depends almost entirely on someone’s perspective. The National Parks captures this distinction by referring to invasive non-California plants as “plants out of place.”  This is to assure us that just because a plant is from another country on our planet, it isn’t necessarily a bad plant, just out of place here.

Invasive Plant News: Are you then recommending that we turn a blind eye to weeds?

Bob: I’m recommending that we tolerate plants we may have considered weeds in the past and focus instead on ones that have never learned how to play well with others.  There are many good reasons for doing so.  One is that it can save a load of money on weed control.  Another reason is that by focusing our efforts on plants that are the most invasive–not every non-native in sight–there is a chance that we will control them.  Yet another reason is that it is better karma to tolerate, accept, or even appreciate differences.  Martin Luther King Jr. reminded us that “We will either learn to live together as brothers or perish together as fools.”  This may apply to plants from different countries as well.

Invasive Plant News: You’ve got to be kidding, right?

Bob: Not really. Here’s one example. The California Native Plant Society defines native plants based on plant communities that have existed in California since the last ice age. But during the ice age, the only native plants in most of California were much more tolerant of cold.  As the planet warmed, other warmer-climate-loving plants invaded and are now the ones we call natives.  As the ice melted and sea level rose over 200 feet, many of the native plants at that time were overrun by seaweed, kelp, etc.  Does this make these marine aquatic plants weeds?  So where exactly to we draw the line on what is native and what is exotic?  And isn’t that line based more on a climatic or geological time frame than on what has adapted well and supports local wildlife without unduly impairing “native” plant communities?

Invasive Plant News:  What about the plants that were introduced by humans and didn’t invade on their own?  For example, do you consider eucalyptus “plants out of place” or weeds?

Bob: It depends on your perspective.  If a eucalyptus sprouts in the middle of your native grassland or native succulent bed, you would consider it a weed and remove it.  If it sprouts on the edge of an existing eucalyptus forest, you might ignore it instead.  It’s not as if these trees spread like broom, poison hemlock, pampas grass or yellow star thistle.  Except for a few adventurous trees, they are homebodies that stay put where they were originally planted.  They provide nectar to hummers during the winter, when other nectar-providing plants are harder to find. They provide habitat for bats that literally hang out under their peeling bark during the daytime.  They also provide us firewood, and will continue to re-sprout with more firewood forever. If the sprouts are cut in a timely fashion, we don’t need to split them, just buck them up, let them cure for a year, and light ‘em up in our fireplace on a cold winter night. In addition, eucalyptus draw a lot of water and mulch the ground heavily, preventing a lot of weed species from growing below them. In places like Tilden Regional Park, where fog provides many additional inches of rain every summer, native shrubs grow throughout these forests.

Invasive Plant News:  So you’re suggesting that we see the positive side of plant invasions, whether natural or human-induced?  Do all plants have a positive side?

Bob: All plants have positive and negative impacts.  For example, native plants fight with each other for sunlight and water.  This benefits some while hurting others.  But all plants, whether we consider them wonderful or weeds, produce oxygen, cool the earth through their evapotranspiration, add organic material to the soil, and provide shelter for local wildlife.  What has us all freaked out about weeds is their pushiness.  They don’t share well and tend to overrun other plant species more effectively than do other exotics or natives. If this was a case of an American business growing way faster than its competitors, we would point to that as a great success.  But we are much more judgmental when we are thinking about plants that do the same.

Invasive Plant News:  Can you find a creative rationalization to justify respecting every plant regardless of its harm to others?

Bob:  How long do I have?  Actually, when it gets way too hard to justify loving a plant, it is a sign that it will soon show up on my weed list.  But I always think twice about what will happen if I remove weeds.  Two examples:  1. My family owns a home along a river that floods every year.  The creekbanks are overrun with ivy.  But this ivy helps hold the banks in place during floods.  The neighbors, who removed all the ivy from their property, each experienced a huge bank collapse and had to spend over $10,000 to repair the damage and armor the banks with boulders.  2. I spent many years removing eucalyptus forests that were considered a fire threat in the east bay.  Those fuelbreaks are now filled with huge, very flammable and more easily ignitable coyote brush and poison oak. 

With hindsight, it would have been more effective to remove the lower limbs of the eucs, burn the duff periodically, and maintain the forest.  The shady forest would have helped prevent the invasion of natives which have made the fuelbreaks easier to ignite.  So in this case involving public safety, it is the native plants that are the weeds.  The local parks and municipalities responsible for these fuelbreaks now have to pay goat herders around $700 per acre to keep the brush pruned down to safe levels.  The fuelbreak is 13 miles long and has been in existence for over 30 years.  Do the math.

Invasive Plant News: You seem to have a very unconventional and laissez faire attitude about weeds.  The problem as I see it is this: we generally won’t know whether a non-native “plays well with its neighbors” until it is too late.  In our neck of the woods, buckthorn may have seemed like a great shrub for hedges in the 1800s.  Now it chokes native woodlands and wetlands and causes over $1 billion a year in crop losses as the primary host of the soybean aphid.  Because of globalization, many more non-native plants will be arriving, and we have no idea how they will fit into our ecosystems.  Aren’t you advocating less vigilance precisely at the time we need more!?

Bob: I think I’m advocating more fatalism.  Due to the hospitable nature of the earth’s Mediterranean climates, I think we are stuck with a lot of plants that have found and will be finding a new home here—at least until the next ice age. In the meantime, as Rodney King pleaded, “Can’t we all just get along?” The answer, unfortunately, is “no.”  So I’d agree with you that we have to be constantly vigilant about new invasions.  For frame of reference, think about the comparison between plant invasions and human epidemics.  Epidemiologists tell us that there is so much international air travel that by the time we realize an epidemic is taking place, it will already have spread everywhere.  We can probably expect similar things to occur with plants that have yet to be introduced or invade.  This is already true in Hawaii.  That is life on earth.

The Golden Gate National Recreation Area handles this challenge by recruiting and training volunteer invasive weed spotters.  They walk the trails, forests, brushlands and grasslands, looking for plants on the “least wanted” list.  If spotted, the staff immediately eradicates them before they become a much larger problem.  So I believe that a combination between more acceptance of increasingly diverse Mediterranean ecosystems in California and quick action to eliminate the most invasive plants will probably be the most effective weed abatement techniques.

Invasive Plant News:  We’re afraid to ask another question.  Do you have any last words to add before we revoke your credentials?

Bob:  Yes. Martin Luther King Jr. pointed out, “We may have come over on different ships but we are all in the same boat now.”  This applies to local plants and ones from far away as well.  We need to adjust our attitude as much as possible so we don’t make ourselves crazy trying to control the later arrivals.  This would be similar to Americans trying to control each historic wave of human immigrants as they migrated from their home countries.  It worked for a limited time on a limited basis, but we eventually accepted all the newcomers as part of our society. The vast majority of them, including all of us, have contributed positively to our country.  So uprooting us and sending us back to our countries of origin because we are all exotics, wouldn’t make sense.  We can’t do this with plants either.  All we can do is root out the very small percentage of “plants out of place” that are the plant world’s equivalent of terrorists, bent on the destruction of all others in their path.  But we need to do this thoughtfully, paying close attention to unexpected consequences. And there are always unexpected consequences.

Humans seem to have more genetic programming to fear and hate than to love; that’s why we’re living in hell on earth.  If we ever want to live in heaven on earth, we need to become more accepting and appreciative of others.  I think this applies to plants as well.  My credentials are in the mail.

Invasive Plant News seeks articles from guest writers.  We are especially interested in articles on practical topics such as advice on identification and control. 

Write an Article for Us!

The articles can take various forms: You can write it from beginning to end.  Or, we can do an interview of you with questions and answers.  The intended audience can be laypeople or experts.  Photos and videos are desirable.  A short bio will also be included.  The total length should be approximately 250 to 500 words.

Please contact me, John Lampe (publisher, typesetter, and paperboy) at john at wowcoweb.com.