HUMANS are dependent on a handful of plant species. A lot could be gained by diversifying our agriculture and our eating habits, Cristián Samper believes.
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The director of the Smithsonian Institution's National Museum of Natural History observes that there are about 400,000 recorded plant species, of which 30,000 have been used by humans but only a few dozen have been domesticated.
Lifting the diversity of domesticated species "is a good insurance policy in terms of our future needs and responses to climate change", said Dr Samper, in Australia for the Biodiversity and World Food Security conference in Canberra.
However, he acknowledges that lifting food diversity is not something that is going to happen overnight.
Researchers are continually pushing back the earliest dates for the domestication of our current food crops. It now appears that maize was domesticated more than 8000 years ago, and in more than one site.
To compound the challenge, the plant gene banks set up in the 20th Century are under assault from economic cutbacks, after decades of relative food abundance have moved the spotlight from agriculture's central importance to human affairs.
This is occurring as it becomes apparent that agriculture, rather than being separate from "the environment", is now a significant environment in its own right.
"The figure we came up with in the Millennium Ecosystem Assessment was about 25 per cent of the terrestrial ecosystems have been transformed into predominently agricultural systems," Dr Samper said.
"But we've also learned that depending on how you produce the food, it can be more or less friendly to biological diversity."
Agricultural production systems need to be assessed on much more than just crops and crop yields.
"We've focused on providing services like food, but we do it at the expense of elements like water regulation and nutrient cycling, or even cultural values that may be important locally.
"We also need to look beyond just food security to other aspects of human wellbeing, such as health and social relations. We need to shift the paradigm and look at this in a much more holistic way."
How agriculture uses and affects biodiversity should be a primary consideration, in Dr Samper's view.
"We still need areas that we set aside for natural ecosystems, but we also have to understand how different kinds of production systems house biodiversity, and look at them as part of the solution going forward.
"Biodiversity scientists and agricultural scientists have tended to approach their interests in very different ways. I think there's a lot we can learn from each other.
"We're looking at how basic biodiversity science can inform us not only about crops and relatives, but entire ecosystems. Like the services provided by parasitic wasps or fungal endophytes - many of these are going to be important to the food production systems of the future."
Inevitably, any consideration of agriculture's impact on the environment circles back to economics.
Agricultural subsidies in North America and Europe have had a huge impact on land use patterns, "not always for the better", Dr Samper said.
"One of the recommendations in the Millennium Report was that we really need to move toward dismantling some of those agricultural policies."
