Watch a video slideshow of a visit to Rosario's home.
The coffee-colored waters at the mouth of the Amazon River rise and fall with the tide, dictating what farmers can grow along the banks of its many tributaries.
Yet on a small river homestead — where crops are under water twice a day — an intrepid farmer is pushing the limits of agriculture with no more than a machete and a forest full of mulch.
Rosario Costa Cabral, an extremely petite woman with short graying hair and prominent cheekbones, has made the forest her domain.
Costa Cabral grows crops no one's tried to grow in her neck of the woods before, upland species that, in theory, shouldn't tolerate the twice-a-day flooding from the river.
Along with her mother, brothers, stepsons and uncles, Costa Cabral started farming her patch of jungle in 1991. Within three years a forest once undermined by logging was feeding a family, generating income and earning Costa Cabral quite a name.
Her first success was with cassava, its starchy roots the staff of life in the tropical world.
She started with hand-picked seeds that she'd brought with her from her last home, also in the Amazon. Then she planted in November, when the tides were at their lowest and her seedlings could get a head start.
Finally, Costa Cabral watched the floodwaters, where they went, how deeply they pooled. Through trial and error she learned that cassavas could take up to two feet of quick, tidal flooding. Now lemon trees and chili peppers are among the other crops growing along with the cassavas.
Miguel Pinedo-Vasquez, a family friend and an ecologist from Columbia University, has spent a decade observing farmers like Costa Cabral. He says she's one of the best, a master of adaptation in a landscape of constant change.
Pinedo-Vasquez says that the knowledge gathered by Costa Cabral is as valuable as that produced by academics, institutions and politicians and can point the way to strategies for dealing with climate change.