Seeds are tricky things. On one hand, we have the whole Omnivore’s Dilemma argument, that industrialized and genetically engineered food is probably bad. And on the other, we have strains of vegetables that can grow four times as much produce on the same plot of land as their heirloom counterparts–a successful, man-dictated genetics that we’ve actually been fueling for millennia. After all, we wouldn’t have the heirloom seeds of today if our grandfather’s grandfather’s grandfather hadn’t saved the seeds from the sweetest watermelons or the most drought-resistant cantaloupes.

I don’t know that any of us can honestly assess the repercussions of our actions, but I do know one thing: This National Geographic infographic by John Tomanio is staggering. Using the metaphor of a tree, it charts the loss of U.S. seed variety from 1903 to 1983. And what you see is that we’ve lost about 93% of our unique seed strands behind some of the most popular produce. (Clever details: Where the root system should be strong, Tomanio has rendered a tree that looks like it could tip right out of the ground.)

In 1903, we had almost 500 varieties of lettuce. By 1983, we had just 36. Radishes, peas, and beets have fared no better. In fact, the most steadfast of the crops has been the tomato, which, probably due to the popularity of strange and tasty heirloom varieties, only lost about 80% of its seed diversity. It’s a shame to lose so many intricacies of nature’s tastiest gifts. But more worryingly, monocultures strip the land of nutrients: Where you once had self-sustaining harvest cycles, you get farm land denuded of nutrients that then needs copious chemical fertilizers to grow more food. And the crops themselves become vulnerable to plant diseases.

Still, a lot has changed in the public consciousness since 1983. Farmers markets aren’t just for hippies anymore–they’re lifestyle statements for everyone from young foodies to soccer moms. And as long as this trend stays alive, so too will many of the heirloom seed strands we have remaining.

[Image: NixPhotography/Shutterstock]