The number of people out there today seriously worried about the health of all the plants and seeds on which modern agriculture depends must be very limited, and the number of people actively campaigning to protect them vanishingly few. ... Of the Earth's 250,000 plant species, only 200 are cultivated for food on any serious scale.
Even more extraordinary, the vast majority of the world's food comes from just 20 crops, in just eight plant families. Most of these monocultures are dangerously vulnerable to diseases (both old and new), pest infestations, and a rapidly changing climate.Yet the "genetic pool" on which plant breeders might need to draw to build resistance and adaptability is being constantly eroded as older, non-commercial varieties disappear. ...
[S]eed banks can only do so much in this massive salvage operation. The seeds they store need to regularly germinated, otherwise they too die. The best way of maintaining an active and vibrant seed bank is to ensure that farmers (and gardeners) are planting out those 'land races' and rare varieties of plants which are now so endangered.
More often than not, that sets small-scale, subsistence farmers (on whom this kind of "active conservation" depends) in conflict with the juggernaut of industrialised, intensive agriculture."