When people think of biodiversity, they usually think of the diversity of species, the range of animals and plants inhabiting the world. In agriculture, we usually talk of crop biodiversity, which is slightly different. Farmers deal in domesticated crops, and the raw material for plant evolution is the diversity within any given crop.
There are, for example, more than 200,000 different varieties of wheat, and each of them has a unique set of characteristics. Some varieties have the potential to produce higher yields; others may be resistant to certain pests and diseases or be able to adapt to changes in the climate. This diversity within a species, which at its most basic level is genetic diversity, contains the richness of traits and characteristics that the crop has to offer. It contains the ‘options’ that the crop has for future development.
There is a small number of scientists around the world who specialize in breeding crop varieties, crossing one variety with another to try to combine them in a way that would make the crop good for farmers to grow. This is because the modern varieties of most of our agricultural crops have a limited life-span. After a while they fall prey to pest or diseases, or they don’t do so well in the environment, or a new, higher yielding variety comes along.
Crop yields have increased tremendously in the last few decades and that is largely due to plant breeders using this diversity to create new varieties. And while I believe that the world needs a highly productive agricultural system, it also needs one that is resilient and sustainable. The variety of crops grown in the field has an impact on the long-term future of agriculture, especially if that variety needs a lot of water, pesticides or fertilizer.
But productivity and sustainability are currently under threat, and agriculture is facing probably the greatest challenge of its history, a history that dates back to Neolithic times. Twenty years from now, as our climate changes, it is very likely that we will need new varieties of crops, varieties that we don’t have right now. There is going to have to be a massive effort to locate the genetic diversity in our agricultural crops, the traits for extreme heat resistance or extreme drought tolerance, and to move those into the plant breeding pipeline so that farmers have them when they need them
This, however, is one world problem, perhaps the only one, that we can solve. The enormous amount of diversity that exists in most agricultural crops is like a gigantic toolkit of options for the future development of agriculture. We know how to conserve that diversity and we have the institutions in place to do it. There are now a number of important seed banks throughout the world that preserve samples of hundred of thousands of varieties, and they are backed up by the Svalbard Global Seed Vault in the Arctic.
Technology also plays an important role in the preservation of crop biodiversity. At the Global Crop Diversity Trust we are now using a combination of technologies to create predictive computer models. If we know where a particular variety of crop originally came from we can then predict some of the characteristics of that variety. For example, if the variety comes from an arid area then we could test that for drought tolerance rather than a sample that came from a very wet or tropical country.
Computer modelling also helps us to make climate change and development projections, which can help to pinpoint varieties that are endangered through rising water levels or expanding urban environments. The models would tell us that we have to quickly collect samples from that area.
These are early days for putting ICTs to use for preserving biodiversity, we are only now starting to take advantage of the technology. In the near future, we will be able to use mobile phones and other communication networks to offer crop varieties to farmers in a much more targeted way. We can use the technology to provide information on the best varieties for very specific conditions and locations to give the best yield and protection from pests, diseases and the changing environment. You cannot control everything in the natural environment but such systems could help us deliver information to farmers and give them a better chance for future food security.
I cannot imagine how society is going to adapt to climate change if crops don’t also adapt. I cannot imagine how we are going to save the tropical rainforests if we have an unproductive agricultural system. I cannot imagine how we can deal with water shortages in the future if we don’t have a productive agricultural system since irrigated agriculture already uses 70% of the world’s freshwater supplies.
It is not a solution to every problem, but I think preserving crop diversity can solve and certainly contribute some answers to many issues affecting the planet today. We have the tools and raw materials for an agricultural system that will guarantee future food security, the question is: are we going to be smart enough to conserve it?
Cary Fowler is the executive director of the Global Crop Diversity Trust ( www.croptrust.org )