Arbres voyageurs et plantes invasives dans les pays du Sud

October 17, 2016

FGSE Unil ouverture des cours 2016-2017 Last month I gave the ceremonial first lecture of the academic year for our Faculty.  The video is now online (see below).  The presentation dips into a number of research projects I’ve contributed to in recent years in order to make a number of observations about the relationship between plants and people, notably with iconic ‘natural’ plants and problematic ‘invasive’ weeds.  These observations include: Read the rest of this entry »


Approaching invasive species in Madagascar

March 13, 2015

While a number of plants, animals, and insects in Madagascar have been called ’invasive’, the topic of invasive species has until recently received less attention here than in other island contexts. Some species, often alien to Madagascar and introduced by humans, have expanded their range rapidly and have had both negative and positive effects on landscapes, on native biodiversity, and on livelihoods. Examples include the prickly pear (raketa), the silver wattle (mimosa), and, recently, the Asian common toad (radaka boka). Building on a conceptual approach, my recent paper (link; pdf) in the journal Madagascar Conservation and Development emphasizes the importance of inclusive and deliberative site- and population- specific management of invasive species. The paper analyses three separate concepts commonly used in definitions of invasion: the origin, behaviour, and effects of particular species.

The three components often used in defining invasive species. Different definitions emphasise different components.  Source:  Kull et al. 2014 (supplementary online material)

The three components often used in defining invasive species. Different definitions emphasise different components. Source: Kull et al. 2014 (supplementary online material)

It places these concepts in their broader social and ecological context, with particular attention to local perspectives on invasive species. My co-authors and I illustrate these concepts with numerous Malagasy examples from the literature and our own experiences. Read the rest of this entry »


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 »