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Delegates who attended the workshop. CIB team members Brian van Wilgen and Dave Richardson are 3rd and 4th from the left in the back row. Director of the Institute for Biological Invasions at the University of Tennessee, Professor Dan Simberloff, is 4th from the right in the back row.

Alien conifers have been widely planted in the Southern Hemisphere. Australia , New Zealand and South Africa, all with long histories of alien conifer planting, have major problems with invasive conifers (also known as “wildings”). Widespread planting of alien conifers has a much shorter history in South America, and invasions are recent but are increasing rapidly in many areas.

A workshop was convened in Argentina in May 2007 to discuss all aspects relating to the rapid emergence of problems with invasive conifers in South America. The project was a joint initiative of the C•I•B, the Universidad Nacional del Comahue, Bariloche, Argentina; and two of the C•I•B’s international partners - the Institute for Biological Invasions, University of Tennessee, USA, and the Center for Advanced Studies in Ecology & Biodiversity at the Catholic University of Chile. The C•I•B was represented by Deputy Director Prof. Dave Richardson and core-team member Dr. Brian van Wilgen.

Fifteen researchers from Argentina, Brazil, Chile, New Zealand, South Africa and the USA attended the three-day meeting on Isla Victoria near Bariloche, Argentina. The workshop brought together considerable experience on the ecology and management of conifers, as native trees, plantation crops and as invasive alien species.

The workshop had four main goals:

  1. To assess the problem of conifer invasions on the South American continent, and to look for parallels from other southern hemisphere regions that could be used to predict likely outcomes in South America.
  2. To share learning, both between practitioners and researchers from South America, as well as between South Americans and other southern hemisphere ecologists, with a view to capacity-building.
  3. To provide information on the problem, and potential solutions, for use by policy-makers and managers.
  4. To bring people working on conifer invasion throughout the Southern Hemisphere together to forge collaborations.

The workshop included formal presentations from the represented regions, followed by a series of participatory discussions aimed at generating outputs. The main areas of consensus were:

  1. That the problem is expected to increase substantially soon in many parts of the continent due to the large areas recently planted, many of them in invasion-prone ecosystems.
  2. That the problem is not widely recognized among foresters, stakeholders, policy-makers and the public.
  3. That lessons from elsewhere can be transferred.
  4. That collaboration among researchers of different regions can bring substantial benefits.

The following priority actions were identified:

  1. The need for an accurate assessment of the dimensions of the problem.
  2. The need to raise awareness of the problem.
  3. The need for a common research agenda among researchers on this topic in the Southern Hemisphere.
  4. The need to initiate management interventions.

Towards raising awareness of the problems associated with conifers invasions, the workshop produced THE BARILOCHE DECLARATION ON INVASIVE ALIEN CONIFERS IN SOUTH AMERICA. This consensus document with information on the current situation and suggestions for managing conifer invasions will be widely circulated among decision makers and other stakeholders throughout South America. Participants also agreed to work on two scientific products. The first of these (with a working title of “Biogeography and ecology of introduced conifers in South America: status, impacts and prospects for invasion”) will report on an eco-regional assessment of the extent of planting and the degree of invasion, and assess the potential impacts on key ecosystem services and processes. The second document (with a working title of “Conifer invasions in South America: Management challenges and solutions”) will build on the ecoregional assessment, and will stress the expectation that invasions will take off much sooner, and at a larger scale, than they did on other continents, and what the expected consequences would be.

Other outcomes of the workshop included the formation of the Southern Hemisphere Network on Conifer Invasions (SHNCI) which aims to promote interaction and collaboration between researchers, managers and planners involved in all aspects of conifer invasions in the southern hemisphere. The network plans to convene further workshops associated with various conferences, including Southern Connections, MEDECOS and EMAPI (Ecology and Management of Alien Plant Invasions), to promote the exchange of researchers and students, and to initiate engagement with a wide range of key stakeholders.

A more detailed report on the workshop is in press for the journal Biological Invasions and will be published in late 2007.

For further information contact Professor Dave Richardson (

Lodgepole pine invading grassland near Bariloche airport.

Extensive plantings of ponderosa pine between Bariloche and Esquel.

Ponderosa pines invading natural vegetation in foothills of the Andes.

Prolific regeneration of lodgepole pine along a Patagonian road.

Invasion of natural Austrocedrus forests by Douglas-fir.