Reflections on invasion biology

September 9, 2014

Invasion biology has been a remarkably active branch of the life sciences in the past two decades.  My itinerary first crossed this field when I noticed, at the time of my move to Melbourne, that the ‘precious’ mimosas (acacias, wattles) of the Madagascar highlands were called ‘green cancer’ in South Africa, and in both cases were introduced from Australia.  It was quite surprising to discover that this shrubby tree, so appreciated by Malagasy farmers (as a resource) and environmental managers (as ‘regreening’ barren lands), was seen so negatively across the Mozambique Channel.  This observation led to a research program that (1) opened a window for me to learn about and consider the field of invasion biology, and (2), serendipitously, to collaboration with ecologist Jacques Tassin at the French research institute Cirad.  I comment on some of the recent fruits of both in this blog.

The South African approach to alien plants.  Cartoon from environmental education material collected in 2006 (thanks to Rémy Kinna).
The South African approach to alien plants. Cartoon from environmental education material collected in 2006 (thanks to Rémy Kinna).

In a just-published viewpoint in the journal Land Use Policy [free official pdf until Oct. 6 pdflink], Jacques and I argue that Read the rest of this entry »


Field trip report Madagascar 2014

July 17, 2014

I recently returned from my 11th trip to Madagascar in 22 years. My main goal was to scope out potential field sites for an ARC-supported research project entitled “A weed by any other name? Comparing local knowledge and uses of environmental weeds around the Indian Ocean” (with collaborators Priya Rangan, Charlie Shackleton, and Nitin Rai). I took two week-long trips from the capital, first south to my old highland stomping grounds around Antsirabe and Ambositra, and second east to the rice bread-basket of Lake Alaotra, the rainforest escarpment at Andasibe and Beforona, and the coastal plains and hills around Vatomandry. It was also a good opportunity to renew personal and professional connections, including at the University of Antananarivo’s forestry school (ESSA-Forêts), where I was invited to give a presentation. What did I find?

Neo-Australian landscapes along RN11a in eastern Madagascar:  Grevillea, Eucalyptus, Acacia...

Neo-Australian landscapes along RN11a in eastern Madagascar: Grevillea, Eucalyptus, Acacia…

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Field trip: indigenous perspectives on weeds in the Kimberley

September 25, 2013

The team of our current ARC-funded project on local knowledge and uses of environmental weeds recently assembled in Kununurra, far northwest Australia.  The project will compare local people’s views of “weeds” across four case studies in four countries around the Indian Ocean – India, South Africa, Madagascar, and Australia.  My Monash colleague Priya Rangan and I are collaborating with Charlie Shackleton (Rhodes University, South Africa) and Ramesh Kannan (ATREE, India), supported by Tom Bach (doctoral student on our previous ARC grant) and Pat Lowe (Kimberley-based author and environmentalist). Read the rest of this entry »


The Third Wattle War: environment versus development?

December 12, 2012

Are Australian acacias planted overseas miracle plants for rural development, or are they the worst kind of environmental weeds?  The battle lines appear rather stark at times.  At least when one reads environmentalist Tim Low’s rebuttal to a critique that Jacques Tassin and I wrote of his views.  We thought our statement to be tempered and tried to build a reasonable case for responsible use of exotic agroforestry trees (see also previous blog).  But Low calls us “in denial about dangerous aid”, flogs a misplaced example about mesquite in an argument about acacia, all the time preaching his argument to the converted in the journal Biological Invasions.   Read the rest of this entry »


Do plants need passports?

August 7, 2012

The landscapes that characterize different places on the earth, and from which many people earn their livelihoods and their sense of place, and which support diverse flora and fauna, are often built with a mix of local and introduced plants.  Sometimes, introduced plants succeed so wildly in their new home that people come to see them as weeds or pests, crowding out crops or native species, changing soil conditions, altering fire regimes, or affecting the water table.  The field of invasion biology emerged over the past few decades seeking to document, understand, and stop such “alien invasions”.   But the fervour of this effort has at times crashed head-on with alternative worldviews.  One of South Africa’s top weeds, for example, is the Australian native silver wattle, also naturalized in France where it is celebrated for its winter flowers and as an ingredient for Chanel No. 5 and other perfumes [1][2].  Such conflicting outlooks were on stark display at a workshop I attended in October 2010 at Stellenbosch, South Africa, on Australian acacias as a global experiment in biogeography.

Picture 1: Do plants need passports? Who should control plant movements, and on what basis? Silver wattle (Acacia dealbata), native to Australia, invasive and assimilated as mimosa in the Côte d’Azur, France.

Picture 2: Do Australian acacias need passports? Australian passports specify “free passage without let or hindrance”…

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Science, sentiment and territorial chauvinism in the acacia name change debate

January 27, 2012

Hot off the press:  a paper that Priya Rangan and I wrote on the acrimonious battle over which continent’s trees should keep the latin name “Acacia“.  It is a topic on which we wrote several blogs last year in the run-up to the Melbourne IBC conference (1, 2, 3).  We review the acacia battles as a manifestation of long-standing struggles in science between between folk- or place-based classification systems and universal, scientific approaches.  As a bonus, the paper quotes both Shakespeare (on names) and a rather politically incorrect Monty Python episode (on wattles as an Australian emblem)…

Kull, C.A. & H. Rangan (2012)  Science, sentiment and territorial chauvinism in the acacia name change debate. 197-219 in S.G. Haberle & B.David (eds), Peopled Landscapes. Terra Australis 34.  Canberra: ANU E-Press. pdf


Homo taxonomicus, Rrrr…racosperma, and Acacia thingummy

June 15, 2011

A guest blog by my colleague Priya Rangan on the acacia name issue.  Taxonomists be warned, you’ll either laugh or cry at this engaged, humorous, but deadly serious satire of the history of botanical nomenclature, the science of taxonomy, and the current wattle wars.  The solutions Priya proposes are important and novel.

Priya writes:  “The views, discussions, and comments regarding the Acacia name are fascinating.  I am glad to see that finally the cards are on the table: the name change issue has little to do with so-called scientific objectivity and rules of nomenclature, and everything to do with the feelings and tastes of concerned taxonomists.  Although I’m mangling the quote here, “Oh, what a tangled web we weave,” when we use science to deceptively conceal our personal likes and dislikes.

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More on the Acacia name change: go to Melbourne and vote!

May 30, 2011

The upcoming confrontation about the scientific name Acacia continues to inspire frustration, passion, and grumbling on all sides.  It is rarely about the science behind it (which is pretty widely accepted), but about institutional rules, about perceived injustices, about egos, and, of course (where my interest comes in), about symbolism, sentiment, national rivalry, and geopolitics.

Here I post some email correspondence, from two key participants in the debates, to which I was party in offline conversations after my initial posting on the topic.  Dick Brummitt defends his compromise proposal, despite voicing agreement with the original ‘keep Acacia for Australia’ decision.  Bruce Maslin encourages anybody who is interested and affected by the decision to attend the Melbourne meeting (paying one day’s IBC registration suffices for the right to vote at the Nomenclature sessions).  He obviously hopes for votes in favour of the original decision, and not having to use Racosperma as the moniker for Australia’s wattles.  I also present a chart that summarizes some of the different options on the table.

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The Acacia name change – botany and emotion

May 10, 2011

Botanists from around the world are sharpening their battle axes for another fight over the Latin name of the group of yellow-flowered, pod producing plants known as wattles, mimosas, thorn trees, and acacias.  Australians and their friends want to keep the name Acacia for their most common plant genus, and not to have to rename their wattles Racosperma.  Others (particularly South Africans – who for example constitute 13 of 69 authors on a recent position paper) want to keep the name Acacia for the fever trees, umbrella thorns, and other emblematic trees of the savanna (as opposed to calling them Vachellia and Senegalia).  Battle is expected in late July at the International Botanical Congress in Melbourne, and given the emotions involved, the atmosphere could be as charged as when the Wallabies and Springboks meet on the rugby pitch.

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Acacia farnesiana in Australia and Fiji

March 25, 2011

One of the key questions of our current research project is how, when, and why the ‘mimosa bush’ or ‘cassie’ tree got to Australia.  Acacia farnesiana, also known as Vachellia farnesiana (if you agree with the splitting of the acacia genus) is presumed by many botanists to be native to a broad swath of the Americas, from Bolivia north to Texas.  Yet it exists all around the tropical and subtropical world.  The first British explorers of interior Australia found it growing all over the interior northern part of the continent.  How did it get there, then?  How long has it been there?  The answer matters, because environmental managers these days want to know if a plant is ‘native’ or ‘alien’, as this has repercussions (for better or worse) on how they approach it.

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