Biocultural Interactions

Research themes

The team "Biocultural Interactions" is structured around five major themes presented below, pursued in several geographically well defined regions, many of which are in the tropics. The team’s ambition is to conduct good research in the domains of excellence of the different members of the team (ecology, ethnoscience, geography), but above all to produce a truly interdisciplinary approach, aiming in particular to understand how social change and environmental change are interlinked. This project has found its natural niche in the CEFE, where for the past several years a scientific strategy has been pursued aiming at fruitful dialogue between biological sciences  and human and social sciences. Our work also leans upon the technical and conceptual competence of several CEFE teams in the biology of populations, communities and ecosystems, but also on that of colleagues in human and social sciences and of our local partners in the parts of the world where we conduct research.

1. Plant domestication and diversification

Our objective is to understand how actions of humans (both contemporary and in the geologically “recent” past, including the history of domestication) and the biology of each species interact to shape the distribution of diversity, particularly genetic diversity, in domesticated plants. Our approach, explicitly interdisciplinary, integrates genetics, biology, and ethnobotany. Our study models are major crop plants, emblematic and bearing strong cultural, social and economic value. These include almonds, figs, and olives in the Mediterranean region; millets and sorghum in sub-Saharan Africa, and cassava (manioc) and coconuts in other parts of the inter-tropical zone. As we deal with cultivate d plants, we pay particular attention to the notion of "landraces" or "local varieties", which are the units of selection, and of the perception of genetic diversity, as classified by the cultivators themselves.

An original aspect of our work is the analysis of the intervention of human actors in the maintenance of diversity. Manioc in Amazonia offers a striking example: the numerous independent adaptations of this plant to agriculture, and to agricultural environments—adaptations acquired during domestication—result from the interaction of natural and human selection, and are the fruit of a system that mixes clonal reproduction (exercised by cultivators) and "wild" sexual reproduction, the recombinant products of which are incorporated by cultivators as new clones. One of our objectives is to understand whether such practices, still widespread in the area of origin of a crop plant, are maintained (or are rediscovered) when a cultivated plant is introduced into new areas.

These projects should enable us to elaborate original strategies for managing genetic diversity, strategies that combine in situ and ex situ approaches and that directly apply the knowledge and practices of local people.

2. The travels of peoples and of their domesticated plants

In continuity with the preceding theme, it is important to note that on the local processes of domestication are superposed phenomena of "migration": in effect, human migrations lead to the diffusion of plants, and this will in turn influence the cultural adaptation of the human migrants and the evolutionary dynamics of their plants. The IBC team is interested in this research problem in insular agroecosystems, well known to evolutionary biologists and biogeographers as living laboratories. Insularity makes it easier to distinguish between the influence of migration and that of local adaptation. Migration phenomena may be apprehended in terms of the geographical distances covered, the experiences acquired (i.e., how migration is lived by the migrants themselves) and the biological and cultural identities of the plants that migrants transport. Research questions focus on the reasons behind human migrations, and on new practices following migration (of people or of plants) that affect the maintenance of diversity. Our studies on this theme are mostly conducted in the Pacific, and our principal models are sweet potato, breadfruit, and manioc.

3. Adaptation of societies to global change

Our research in this theme is aimed at understanding the influence of global change on the functioning and organisation of societies, primarily naturalist societies, i.e., those which are highly (although in today’s world never exclusively) dependent upon resources furnished by local environments. We focus on strategies for managing these local resources, especially (but not solely) cultivated plants. Our scope includes all types of global change, societal (modernisation of agriculture, changes in diets), political (global environmental policies) and ecological. A central objective is to understand whether strategies of risk management of naturalist societies can help them adapt to the present context of climate change, whether erratic events that are linked to long time cycles, such as El Nino, or in contexts of rapid but continual changes related to human activities. The team is working towards an understanding of adaptive responses of such societies, by exploring the perceptions and understanding that the societies themselves have of the bioclimatic events. Studies we undertake are based on different societal responses (what types of knowledge are utilised?) and on mechanisms behind the transmission of knowledge and know-how. Four situations are being addressed. The first study explores ways by which the Punan of Borneo have adapted to a major shift from a nomadic to a more sedentary lifestyle, driven by huge pressure on their environment due to deforestation. The second case examines how cultivators of manioc (cassava) may adapt to the higher concentrations of toxic metabolites (cyanogens) in this plant that are expected with global atmospheric change (climate change, but also flooding of carbon cycles by increased atmospheric concentration of carbon dioxide). A related important question is how groups of people that adopt manioc as a new crop—often because of its ability to grow on degraded land that can no longer support other crops—learn to detoxify manioc cyanogens. Changes at two levels, in plant metabolites and in cultural choices regarding this major staple species, may lead to public health problems. The third situation is work that has been undertaken on coconut palm populations which are particularly fragile and vulnerable to climate change on Pacific islands. In the fourth case, we are studying changes in attitudes in Europe towards traditional and local products, by analysing the reconstruction of an abandoned man-made agroecosystem, the Chestnut orchard-forests in the Mediterranean hinterland areas (Cévennes and Lozère).

4. Domestication of environments and landscapes

The previous themes have been particularly aimed at understanding interactions between cultivated species and people, and how societies have organised themselves in the process of domestication or in processes of adaptation to global change. In contrast, this theme broadens our scope to focus on the coupled effects of human and ecological factors at other levels, those of communities, ecosystems, and landscapes. Our work on Ficus species in Madagascar is an illustrative example. Because Ficus species are at the centre of complex biotic interactions as a keystone resource for frugivores (which also transport the seeds of a large number of other plant species), and are also highly valued culturally, being widely planted and encouraged, they are the catalysts of recolonizing processes. They are therefore ecological and cultural keystone species that can play a major role in the restoration of communities and habitats.

The flooded savannas of the littoral areas of Guyanas represent a second emblematic case study. Indeed, the morphology and functioning of these savannas seem to have resulted from the joint work of human and natural engineers of these ecosystems.

5. Traditional ecological knowledge, policies, and environmental issues

This part of our research aims at understanding the effects of national policies (e.g., agricultural and forest policies) and of global policies mainly related to biodiversity conservation and sustainable development, on local practices and knowledge. It is based on close collaborations with social science researches from the IRD research unit "Socio-environmental dynamics and resource governance" (UR 199).

The interactions between forces at global, national and local levels are not a recent phenomenon, as many societies, in the course of their history, have had to face exogenous policies and practices (e.g., those of colonial governments) that led them to adjust their practices in dealing with local environments. However, although local practices and knowledge have long been denigrated, a large array of studies in ethnobiology have shown their importance for sustainable environmental management. Their importance has also been formalised in the Convention for Biological Diversity, thus leading to many changes in the ways these practices and knowledge are utilised locally, with, for example, the integration of local actors in local decision processes (participatory approaches), or in the commercial sector ( the promotion of locally produced resources as a commercial argument). The central question is: how do interactions between world views, knowledge and practices of different local actors produce new relationships at the society – nature interface? What effects do these interactions have on the environment at the local scale? Two approaches, each associated with different research objects, are being followed by the team: (1) the interface between protected areas and human practices (e.g., in Shey Phoksundo National Park in Nepal, in the Cevennes National Park in France, and in the forest corridor linking Ranomafana National Park and Andringitra National Park in Madagascar), 2) the interaction between policies, local practices and knowledge related to trees and rural forests in Mediterranean agroecosystems (for example, chestnut agroforests in the Cevennes and agroecosystems centred around the Argan tree in Morocco). This articulated approach between local knowledge, policies and environmental issues also relates to the management of genetic resources (policies for in situ conservation, participatory selection). It therefore links to the first research theme of the team, developed above.