My mom is an ethnobotanist and getting people to understand this is literally her life’s work. A lot of native tribes just had a whole different way of looking at agriculture. Instead of planting orchards in tidy rows near their villages, they went to where the trees were already growing and tended them there. They would girdle trees by stripping the bark in order to stop the spread of disease or thin out badly placed saplings. And they would encourage the companion plants they wanted and weed out the ones they didn’t, so that in the end the whole forest would be productive while remaining an ecosystem and not a monoculture. It is still agriculture, but it is a form of agriculture that is so much gentler on the landscape that, as OP says, the European settlers could not recognize what they were seeing. To them the natives must have seemed to magically live in abundance while they starved.
They did do controlled burns, but so-called slash and burn agriculture was never a primary farming strategy in North America. They were just way more subtle than that. They also made the amazing Mississippian mound structures so it’s not like they couldn’t do dramatic reshapings of the landscape when they wanted: but they changed their minds about that, walking away from Cahokia and the dense, farming-supported urban structure they had build there in the 13th century, well before any European contact.
My mom says it wasn’t a collapse, it wasn’t a war, it wasn’t a natural disaster; the farmers in Cahokia just voted with their feet. They just gradually left, dispersing in different directions but generally not very far, and it was probably because they’d gotten tired of men’s bullshit.
See, agriculture was a female domain in pretty much all the native American cultures. The specifics differed by tribe, but often they had gender-specific age-grade societies: for example, the Hidatsa Goose Society was composed of married women of childbearing age. Not only did they physically plant the fields, they also had responsibility for conducting the social and ritual events around ensuring the harvest. This included things like digging the storage pits, and organizing feasts in order to bring the whole community together to plant plots for families who were suffering illness or disability, and could not do it themselves.
So, as Cahokia urbanized (at its “height” it was a population center of between 10,200 and 15,300 people), it is very likely that the traditional, informal systems of land use-right allocations–again, always the women’s domain–became stressed by top down political pressures from the rulers (who were men). And as my mom puts it in her book Feeding Cahokia: “If rights to land ever became highly restricted as a result of a top-down, centralized process of allocation, the likelihood of poorly informed and unfair decision making is extremely high.”
So basically, the farmers took their families and they moved away. Not all at once, no mass exodus, just…gradually, they decided that they’d tried doing things the urban way, and they didn’t like it. They went back to living in smaller villages sustained, not by intensive farming, but by more garden-style plots and the traditional, sophisticated management of “wild” lands that they had never stopped practicing.
It takes a shift in thinking to recognize that was a deliberate choice on their part. Not a failure: Cahokia never collapsed, not dramatically–it just gradually wound down. They were perfectly capable of feeding themselves and they did for well more than a century. They went back to the old way because they liked it better.
And again, different tribes had different specific ways of doing it, but farming was always the women’s domain–and there are also important spiritual figures who occur under different names in different tribes. One of these is Grandmother/Old Woman Who Never Dies: giver of all plant food, protector of children, bringer of summer, and rejuvenator of living and dying things. I’m just gonna end by dropping this passage from my mom’s book because it’s amazing:
“I think it likely that the female flint-clay statues from BBB Motor and Sponemann represent an Earth Mother personage in a manifestation known to all early Cahokians, and that their Woodland ancestors had sought her powers and favors for centuries preceding the Mississippian period, just as Siouan speakers continued to protect her sacred bundles and conduct rituals focused around them long after Cahokia was abandoned. She never died. Several years ago, I accompanied a traditional Hidatsa farmer named Amy Mossett from New Town, North Dakota, to the Cahokia Mounds Interpretive Center [in Illinois]. When we came to the display case containing a cast reproduction of the Birger figurine, Mossett froze, took a step backward, put her hand on her chest, and said, ‘That’s Grandmother. And the snake is her husband.’“
