Battle Lost with Lantana? Critique of a Recent Study by Two Experts on Invasive Plant Species Control

Conservationists are “fighting a losing battle” against invasive plant species such as Lantana (Lantana camara L.).  That is the conclusion of  a team of researchers

Lantana camara Forest & Kim Starr, U.S. Geological Survey, Bugwood.org

from the University of Oxford and the University of Bergen in their article entitled: “A Battle Lost?  Report on Two Centuries of Invasion and Management of Lantana camara L. in Australia, India and South Africa.”  According to the authors this means the “established paradigm” of eradication of invasive species must be abandoned in favor of “adaptive management.”

I discussed the article with two people who have been working for years on invasive plant species in Australia and Africa.  Rod Randall and Arne Witt.  Rod Randall works for the Department of Agriculture and Food, Western Australia.  Arne Witt works for CABI based in Nairobi, Kenya.  (See biographies below.) 

The very first thing that Randall and Witt questioned about the Lantana article was the existence of any “established paradigm of eradication” for entrenched invasive species such as Lantana.  As Randall observes, “it shows a certain naivety on the part of the authors that anyone would consider control attempts in Australia, India or South Africa as eradication efforts.”  Lantana first invaded in the 19th century.  Back then, control efforts only occurred after invasive plants had become massive problems.  It is now so well established that eradication of an established invasive such as Lantana is out-of-the-question – at least with current means.

Both Randall and Witt argue that control is the key with well-established invasives like lantana.  And both agree that control is not a lost cause.  Interestingly, they contend the problem is not so much the invasive species as it is the people in charge.  As Witt says, “a wise man once told me that the problem is not managing invasive species but managing people to manage invasive species. This is so true if you look at past efforts that have been made to manage infestations around the world.”  

As Witt relates, “I was personally involved in a project in Zambia where the government made $450,000 (U.S. dollars) available to clear Mimosa pigra from a floodplain in a National Park.” The national implementing agencies had no real structured plan or strategy for follow-up activities, but the government promised to make more funding available when current funds were depleted, so, as Witt notes, “nobody was too concerned.”  After more than 900 ha. of a 3,000 ha. infestation were cleared, funds dried up and the area is being re-invaded.  “Without knowing the details someone may say that the management of Mimosa pigra in Zambia has been an absolute failure,” and “the weed is impossible to control.”  According to Witt, however, “this is far from the truth – it was a failure of management/people, but important lessons have been learned in this process.  There are many examples where we can effectively control weeds if we develop long-term control strategies coupled to long-term sustainable funding – it is not a lost cause.”

Randall describes just such a success: involving Kochia (Bassia scoparia (L.) A.J.Scott).  This effort worked “because the critical people, the landholders . . . were right behind the program and worked well with our agency to remove Kochia from over 2700 acres and hundreds of widespread sites.” (Note this eradication program cost less than $500,000 (Australian dollars) and was deemed successful after 10 years of monitoring with no finds.) 

In short, there really is no “established paradigm” of eradication according to Witt and Randall for established invasives like lantana.  It is a straw man that distracts and discourages decision-makers such as government agencies.

And what do the Oxford and Bergen researchers mean by “adaptive management” of invasive plant species?  In a future article, Invasive Plant News will address this topic.

Arne Witt: Arne has been working on the management of invasive plants, particularly biocontrol, for the past 18 years. He has worked for CSIRO (Australia), Queensland Department of Natural Resources and Mines (now Biosecurity Queensland), the Plant Protection Research Institute of the Agricultural Research Council (South Africa), and is currently the Regional Coordinator (Africa and Asia) for IAS for CABI. He has been the International Project Coordinator and/or Technical Advisor for GEF-UNEP IAS Projects in Africa, SE Asia and the Caribbean assisting in the strengthening/development of IAS policy, creating awareness, building IAS capacity and the development and implementation of control programmes for IAS.

Rod RandallA biologist by training, Rod started his career with the Western Australian Agriculture Protection Board in 1985 moving to the Department of Agriculture’s Weed Science group in 1987.  In 2002 he published A Global Compendium of Weeds the most comprehensive document on the status of the worlds weed flora.  Rod has worked extensively on weed biology and ecology for a quarter century and for the past 16 years has assessed all plant introductions into Western Australia for their weed potential.  In that time he has assessed over 10,000 species and extensively reviewed the weed status of many hundreds of others.

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6 Comments »

  1. Randy westbrooks said

    Excellent response by Rod Randall and Arne Witt…. Early Detection and Rapid Response (EDRR) is clearly the management strategy of choice for addressing new and emerging invasive species – within a designated geographical area…. The USDA Witchweed Eradication Program and the Kochia Eradication Program in Western Australia are good examples of this management strategy at it’s best. But, it is NOT practical at all to totally eradicate widespread IVS such as Kudzu in the southeastern USA…. Except on a very localized basis…. We want people to effectively manage IVS on the lands they own, or that they manage…. Whether it us a country, a state, a county, a city, a park, a farm…. Or Their own backyard…. So Randall and Arne are right…. In the big scheme of things, there a definitely a place for IVS eradication…. When used in the appropriate situation. RGW

  2. I too agree with Arne and Randall. The authors assume there is an intent to eradicate. This is not and never has been the case. A process of “adaptive” management has always been followed albeit not as formally as it is currently practiced – people have done the best they could to deal with it under the circumstances. The alternative of “doing nothing” will end up with landscapes that are pure Lantana deserts.

  3. […] discussion going on about the realities of invasive species management thanks to the article in Invasive plant News which involved one of our regional Coordinators for Invasives Arne Witt from our CABI Africa […]

  4. theherpdude said

    A tiresome argument that won’t go away (reminds me of another scientific “controversy”). Adaptive management has been applied in Florida over the past two decades, at the least. It merely means using all the tools at your disposal and pursuing and adapting current control technologies. Rather than rehash the argument, I will cross-post the comment I left at the PLoS site for the original article. ###

    “Biologists, ecologists and conservationists disagree on the best way to respond to invasive species.”

    No, they do not. Integrated weed management has been around for at least two decades. The response to any invasive species (plant or animal) is five-fold: (1) Prevention; (2) Early Detection and Rapid Response (EDRR) [the only segment that has eradication as its goal]; (3) Management (Control); (4) Research, Inventory, and Monitoring; and, (5) Education and Outreach.

    The authors mistake a contrarian opinion (Davis, et al; their first reference) as a serious basis for “debate,” when no such debate exists. Very few credentialed invasion biologists would argue that there is a “paradigm of eradication” or that invasive species management is a failure. Instead, you have philosophers, historians, and others making that argument.

    There have been successful attempts at eradication, when incipient populations were targeted through EDRR. This is entirely different from managing a species that has been established for over 100 years. The authors muddle two separate, although related, principles to reach their conclusion.

    This discussion has been previously and better covered in the article “We need to strengthen, not weaken, the struggle against harmful invasive species,” which is available from the ISSG [http://www.issg.org/pdf/r…].

  5. R A Criley said

    While the wild forms of lantana earn a high degree of invasiveness rating, plant breeders have been developing sterile or almost sterile forms for amentiy horticulture. These should not be tarred with the same brush.

  6. Good discussion. It is a huge issue around where I live in Nairobi, has big impact of replanting and allowing indigenous trees to regenerate in Karura Forest, also is being associated with the sleeping sickness spread in eastern Uganda, where the northern and southern variety of sleeping sickness are about to meet in Teso.

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