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Session 6 – 10.18.2010 Divergent vs. convergent development models (Speaker: Ivette Perfecto)

The provision of environmental services from landscapes necessarily encompasses trade-offs, poignantly exemplified by the food crisis. Agricultural production for human wellbeing, on the one-hand, may come at the expense of protection of biodiversity, on the other. This session explores alternative models for agricultural production and biodiversity conservation, harnessing ecological principles of patch dynamics and metacommunity theory. The DIVERGENT MODEL is characterized by intensive agriculture in some areas and conservation in others. This is presented by Perfecto and Vandermeer as LANDSPARING/AGRICULTURAL INTENSIFICATION model. The CONVERGENT MODEL is characterized by spatial coincidence of agriculture and conservation. This is presented by Perfecto and Vandermeer as the AGROECOLOGICAL MATRIX MODEL.

Speaker Bio: Ivette Perfecto
Ivette Perfecto is professor of Ecology and Natural Resources at the University of Michigan. Her research focuses on biodiversity in agricultural landscapes, primarily in the tropics. She also works on spatial ecology of the coffee agroecosystem and is interested more broadly on the links between small-scale sustainable agriculture, biodiversity and food sovereignty. She teaches General Ecology, Our Common Future (a course on globalization), Food Land and Society and Field Ecology. Her most recent book is Nature’s Matrix: The Link between Agriculture, Conservation and Food Sovereignty. Dr. Perfecto received her Ph.D. in Natural Resources (1989) and an M.S. in Ecology (1982) at the University of Michigan and a B.S. in Biology (1977) at the Universidad Sagrado Corazon in Puerto Rico.
Ivette Perfecto's web page
You can learn more about the speaker at this link.
Required reading- Perfecto and Vandermeer 2010
Among the myriad complications involved in the current food crisis, the relationship between agriculture and the rest of nature is one of the most important yet remains only incompletely analyzed. Particularly in tropical areas, agriculture is frequently seen as the antithesis of the natural world, where the problem is framed as one of minimizing land devoted to agriculture so as to devote more to conservation of biodiversity and other ecosystem services. In particular, the “forest transition model” projects an overly optimistic vision of a future where increased agricultural intensification (to produce more per hectare) and/or increased rural-to-urban migration (to reduce the rural population that cuts forest for agriculture) suggests a near future of much tropical aforestation and higher agricultural production. Reviewing recent developments in ecological theory (showing the importance of migration between fragments and local extinction rates) coupled with empirical evidence, the authors argue that there is little to suggest that the forest transition model is useful for tropical areas, at least under current sociopolitical structures. A model that incorporates the agricultural matrix as an integral component of conservation programs is proposed. Furthermore, the authors suggest that this model will be most successful within a framework of small-scale agroecological production.
Supplemental readings from moderator/discussant Jeannine Cavender-Bares, Univ of Minnesota
1) Polasky et al 2008: Where to put things? Spatial land management to sustain biodiversity and economic returns; 2) Excerpt from Perfecto et al (2009) Nature's Matrix: Chapters 1 and 2; 3) Perfecto & Vandermeer 2008, Biodiversity Conservation in Tropical Agroecosystems: A New Conservation Paradigm
Supplemental readings from Universidad Nacional Autonoma de Mexico students
1- García-Barrios et al. 2009- This manuscript describes the divergent and convergent models and then analyzes the range of social and ecological drivers that underlie tropical forest conservation, management and recovery with respect to those favouring agriculture intensification. This manuscript provides then a framework of the drivers that could contribute to an agroecological matrix model (convergent) or a land sparing/agricultural intensification (divergent) one, developped by Perfecto & Vandermeer 2- Moguel and Toledo 1999- This highly cited paper describes how diverse shade coffee plantations can fit into the agroecological matrix model, by providing key agricultural products and at the same time allowing for conservation of biodiversity. 3- Grau and Aidee 2008. These manuscript presents the different ways in which demand for food and other services and biodiversity conservation can be met. It describes agricultural and forest transitions in Latin America
Video Recording: Divergent and Convergent Development Models
Speaker Presentations
Ivette Perfecto, speaker; Jeannine Cavender-Bares moderator; CIEco-UNAM student group
Summary of session 6 UNAM-CIECO student group
A summary of presentations and discussion of the sesion 6 prepared by UNAM-CIECO student group: Mariana Zarazua, Adriana Aguilar, Lizzette Luna, Rosa Miki, Juan Carlos Hernández, Mariano Torres & Martín Cadena.