Diversity and Food Security

In a world where inventing the new is seen as the default solution to problems, consider the research by Dr Nigel Maxted, Senior Lecturer in Genetic Conservation at the University of Birmingham. Maxted along with collaborators such as Kew Gardens, Global Crop Diversity Trust, and the 
International Center for Tropical Agriculture (CIAT) are attempting to identify which wild plant species will be most benefical for future food security. In our understandable haste to develop the new, this research is about identifying what functions well in ‘the old’. It’s about conservation and the immense practical benefits of diversity for providing food in a world facing the unknowns of climate change and population expected to reach 9.6 billion by 2050.  

Dr Maxted is exploring wild species closely related to crops – crop wild relatives (CWR) – because suitable traits from these species can be transferred to crops, and he is also studying traditional varieties of crops. It’s sometimes believed that in a highly developed agriculture sector such as the UK, all farming might be based around high-yielding modern crop varieties. ‘Actually, it’s not,’ explains Dr Maxted, ‘we still need wheat for things like thatching, thatching-wheat is completely different to the high-yielding bread-making wheat and the same is true with many vegetables. In certain areas people have associations with local old varieties, so a lot of work has been trying to conserve both of these groups of plants. Dr Maxted is leading research in creating a worldwide database for CWRs. Yet the crop wild relatives are also under threat from creeping urbanisation, deforestation or unhelpful farming methods.

Resilience

‘We shouldn’t think we already have enough genetic diversity’, as Dr Maxted explains. When a very diverse wild variety is domesticated, it reduces the percentage of genetic diversity. To keep ahead of the impact of climate change we will need to seek out varieties and wild species to increase the characteristics that make crops resilient.  

Crop wild relatives and local varieties need to be mapped and listed before they can be put in a seed gene bank and the expertise at the University of Birmingham is widely valued. ‘At the national level I have one British student who is preparing a crop wild relative inventory and conservation strategy for Norway and this is funded by the Norwegian government,’ says Maxted. This student is going from island to island plotting the distributions of crop wild relatives, she is ‘helping to draw up where they might insert new protected areas or upgrade existing protected areas to get conservation for these wild species.’

For gathering information on local varieties of crops, it is a race against time. Dr Maxted did a study in 2003 with some funding from the UK’s Department for Environment, Food and Rural Affairs. We showed that the average age of the ‘landrace maintainer’  – these traditional varieties are called landraces – in the UK was 65. That was eleven years ago, now this person is 76, so we really need to be urgent, in another ten years they will be lost altogether.’

Diversity isn’t a worthy, noble ideal – it’s a practical, necessary instrument of farming, a shield against the unknown. Dr Maxted points out that in sub-Saharan Africa where farmers have subsistence farming, farmers grow multiple varieties, ‘so if they have a dry season then all their dry material will die out but the rest will be ok, and similarly for a wet season. They may get a lower yield but they do get a consistent yield.’ It is difficult to predict exactly what impact climate change may bring to the ecology of crops, plants and insect life, but relying on a small number of species, no matter how effective they appear in the current climate, is a gamble. Dr. Maxted asks the question, ‘If you look at the number of wheat varieties in Europe which are cultivated and it is a handful, then what happens if something goes wrong?’