Nibbles: BSF, GNR2020, AI, IITA, Papa, Volcani, Yu, aDNA

One Reply to “Nibbles: BSF, GNR2020, AI, IITA, Papa, Volcani, Yu, aDNA”

  1. Benefit Sharing Fund

    FAO provides three examples of ITPGRFA projects and conclude that these demonstrate:… “that the greater the diversification of crops, the more food secure a community can become and the more resilient they find themselves in the face of current threats like climate change, pests and disease.”

    I challenge this conclusion, seemingly based on the common misconception that more biodiversity per se is inevitably better. It isn’t: it depends on how the biodiversity is managed (in most cases, how it is selected).

    But in fact the three projects described do not depend on “more biodiversity is better” In two of the three projects pre-selected varieties and crops are introduced from reservoirs of crop genetic resources stored elsewhere (the classic role of international genebanks). The third project, on cassava in East Africa, depends on access to more resistant and tolerant cassava breeding lines – that is selected by breeders for the subsequent selection by farmers – again, the classic role of plant breeding (formal and farmer). Selection for quality (rather than increasing in-field biodiversity) is the key to success.

    The FAO misconception about biodiversity is worsened in one of the documents cited by the ITPGRFA report: [CL 163/11 Rev.1 FAO Council Document 2019 “FAO Strategy on Mainstreaming Biodiversity across Agricultural Sectors”]. This provides biologically-naive and dangerous generalizations about the role of biodiversity in the field, quite ignoring the essential role of selection (natural and human).

    The FAO Council Document claims (Para. 2) “Biodiversity provides regulating and supporting ecosystem services including nutrient cycling, soil formation and rehabilitation, carbon sequestration, water storage and filtration, habitat provision for wild species, biological pest control and pollination.” The simplest refutation of this is that biodiversity also provides all those pests and diseases. Where is the biological control of locust plagues?

    A more nuanced critique of the FAO depends on the recognition that all plant species are not equal. Each has evolved an adaptive strategy related to ecological stress and disturbance (https://doi.org/10.1086/283244). In natural systems increased stress and disturbance can reduce vegetation to one species (for example, Rhizophora mangroves): this is a result of intense selection (of an order of magnitude similar to selection by a plant breeder within multi-thousand genebank samples). The best species or variety wins. This is relevant for arable farming. The first farmers of our first cereals mimicked the disturbance and stress that maintained monodominant annual vegetation of cereal ancestors, maintained by large seeds, seed-burying awns and annual disturbance (probably fire – http://dx.doi.org/10.1098/rspb.2018.0277). Under strong natural selection biodiversity needed to be stripped away in the search for competitive ability (and seed production).

    For ecosystem services and grain production it would make more sense for our fields to imitate species – (very) poor natural vegetation rather than chase the false dogma of “more biodiversity is (always) better”.

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