Let's cultivate biodiversity - Growing resilience

Source Agritrop Cirad (https://agritrop.cirad.fr/600243/)

International audience

anglais. First, I will share with you some background elements on biodiversity in agriculture, Second, I will develop some examples considering different levels and dimensions for biodiversity. Biodiversity considers the diversity of organisms but also the interactions between them and with their environment. Even if the CBD is centered on the four main dimensions, genetic, specific, ecosystemic and cultural diversity, the concept of sustainable development based on social, economic and ecological issues is very important for understanding relationships across sectors. Passing from biodiversity to agrobiodiversity, we can see that all different levels depends on a strong cultural component: -Pools of genes from the wild for crop adaptability, -Diversification in cropping systems considering multiple uses, -Ecosystem services like soil and water conservation, or pollination -Local practices and knowledge Agrobiodiversity is broader that only plant and animal genetic resources for food and agriculture. Agrobiodiversity considers all biodiversity that interacts with agriculture and food production. Human activities have increasingly destroyed and degraded forests as mentioned in the last IPBES global assessment in 2019 : Three quarters of the Earth's environment has been significantly modified by human action. More than one-third of the world's land surface, and nearly 75% of freshwater resources, are now used for agriculture or livestock production. Considering livestock in animal biomass, we can see that the planet is dominated by cattle in biomass (graphic on the left), and by poultry in number of individuals (graphic on the right). Today, the total number of farmed is close to the total number of wild birds, all species combined. I will present you some examples of agricultural biodiversity at the three levels. The history of our agriculture, for more than 10,000 years, is associated with a decline of genetic diversity. If 5,000 plants participate in our diet, only 20 plants provide the majority of the world's food (cereal, root & tuber, legume). It is associated with a depletion of genetic diversity in cultivated plants compared to their wild relatives. Despite this low genetic diversity, the diffusion of domesticated plants has created a high level of agrobiodiversity through diversification and flows. BUT the development of commercial varieties (during the last 70 years) has greatly reduced the diversity cultivated. Cultivated diversity and diversity of crop wild relatives allow adaptation to climate change. The spread of maize, rice, millet and apple cultivation (....) is associated with gene exchanges between cultivated and wild forms. The varietal genetic diversity of pearl millet is a key factor in its adaptation in West Africa for local farmers. BUT, these wild relatives today are at risk of extinction today. AND, let's cultivate diversity alone will not be enough to adapt to global changes, given the magnitude of the phenomena. Specific diversity is a central axis of agroecology for the diversification of cropping systems in order to take advantage of the complementarities and synergies between varieties/species. It may be applied at different spatial scales from plot to landscape. Co-culture of species in association is different from diversification across space and time in the rotation. Going more in depth with different species at the same time in the plot valorizes the complementarity between species, that can provide at the same time higher yields and maintain less weeds. Landscape approaches are key for understanding the mobility of pests and auxiliaries. Simple landscapes host fewer auxiliaries and are most susceptible to infestations. Cultivated diversity and cultural diversity are interrelated, it is why an agro-ecosystemic approach with local stakeholders is essential for considering that social organizations influence the dynamics of cultivated biodiversity. This example of an Andean agroecosystem shows the spatial organization of the activities and their potential interaction, with a closed linked between agriculture and livestock, a distribution of plots and species according to altitude, but also specific places for festive or ritual activities. Participatory mapping with local communities aims at understanding their representation of cultivated and wild relatives for developing conservation programs with them. This example of the distribution of 7 species of wild relatives of quinoa cultivated in Peru is very interesting because local communities classify wild species with possible intercrossing with quinoa as Mother grains and they manage the around cultivated fields for collecting grains or leaves. Categories used by local populations are directly related to the uses, the spoken languages, and the organizations. This example of agricultural biodiversity in West Africa shows that the richness (of cultivated species) varies greatly depending on the latitude, the languages spoken in the village, the age of the villages and whether or not the farmer is a member of a farmer organization. Some key messages to take home in conclusion. The spatial organization of agrarian societies defines a diversity of agro-ecosystems that reflect not only an adaptation to the environment but also particular social rules. The agricultures of the South do not compartmentalize living organisms according to our western wild/cultivated components, but consider them in a continuum of which they perceive the flows [of genes] and integrate them into their agricultural practices. The new forms of biodiversity governance at different scales must take into account local rules and customs, in order to respect farmers' rights and facilitate dialogue between actors with multiple interests. The multiple dimensions of biodiversity make it a biological, social and political object at the same time, which requires a real dialogue between the different parties for its conservation. This representation of life defines a particular relationship with nature that we must understand in order to build on it and better support the adaptation of family farms to the global changes underway. The FAO Strategy on biodiversity will be key for addressing it across agricultural sectors.