Camas flowers in the Willamette Valley in Oregon. Credit: Jon Boeckenstedt, Oregon State University.
Researchers at Oregon State University have discovered that Indigenous groups in the Pacific Northwest were selectively harvesting edible camas bulbs at their optimal growth stages as far back as 3,500 years ago. These findings, published in The Holocene, provide valuable insights into Traditional Ecological Knowledge and practices by demonstrating how these groups have been managing and nurturing natural resources for thousands of years.
The Ecological and Cultural Significance of Camas
Camas, a striking blue flower that grows throughout the Pacific Northwest, serves as an ecological and cultural keystone, supporting many different organisms playing a significant role in numerous cultural traditions.
Molly Carney, the lead author of the study and an assistant professor of anthropology at Oregon State University, highlights its significance: “If you think about salmon as being a charismatic species that people are very familiar with, camas is kind of the plant equivalent,” she explained. “It is one of those species that really holds up greater ecosystems, a fundamental species which everything is related to.”
Camas flowers. Credit: Oregon State University
Camas in Indigenous Culture and Diet
Camas is referred to in Indigenous calendars across the region, with the plant’s growth stages used to mark seasonal transitions. It is often included in traditional First Food ceremonies, in which tribal communities mark the coming of spring with the first salmon run or the first edible roots after a long winter, Carney said. Notably, Lewis and Clark also recorded consuming camas provided by Nez Perce tribal members in their diaries.
Carney explains that camas bulbs require two to three days of baking to become edible and that, once softened, they have a taste similar to sweet potatoes. Historically, this baking occurred in underground ovens lined with heated rocks. During Carney’s research, she examined an archaeological record that included the remnants of one of these large pit ovens. The researchers discovered that after cooking, Indigenous peoples employed various methods to process and store camas, allowing them to be preserved for extended periods.
Camas flowers. Credit: Oregon State University
Archaeological Insights into Camas Harvesting
The researchers analyzed camas bulbs from the Willamette Valley dating back 8,000 years. By counting the interior leaf scales, similar to reading tree rings, researchers can estimate the age of camas bulbs, which typically reach a harvestable size in three to five years depending on the soil conditions.
Camas baking ovens from 4,400 years ago have been recorded at a Long Tom River archaeological site near Veneta, Oregon, but for several thousand years, the bulbs appeared to have been harvested somewhat indiscriminately. Carney found that around 3,500 years ago, the bulbs started being harvested more selectively at the point when the plants were four or five years old and had reached sexual maturity.
Camas flowers. Credit: Oregon State University
Environmental Management Through Controlled Burns
This timing in the Late Holocene period lines up with broader climatic shifts in the region, the researchers noted, coming around the same time as low-magnitude fires became more commonplace in the landscape. Carney also studied lake-core evidence from the floor of Beaver Lake, collected by Central Washington University researcher Megan Walsh, that gives credence to the theory that controlled burns were used intentionally to create optimal conditions for camas and other plants starting 3,000 to 4,000 years ago.
Sustainable Practices and Cultural Stewardship
Based on her research, Carney says it’s clear that Native communities at the time were not selectively harvesting for the biggest possible bulbs, but rather stewarding camas to be sustainable over time.
“They were trying to maintain the age structure of these camas populations within a pretty narrow window,” she said. “When I had the opportunity to harvest alongside tribal communities, as they harvest, they replant the smaller bulbs as they go. They’re really sowing for future harvest, and that’s what I think was happening here.”
The shift from haphazard harvesting to selective stewardship among tribal communities appears to have occurred at approximately the same time throughout the Pacific Northwest, Carney said. For the practice to be successful, it would have required community-wide agreement and cooperation to leave immature camas bulbs in the ground until the optimal harvest point, as well as to conduct the type of cultural burning necessary to maintain healthy growing spaces, the researchers note.
“We have these records showing that people were taking active roles in creating landscapes that fit their needs, and that they’ve been doing so for 3,500 years at least, based on these two proxies of camas and fire,” Carney said. “That provides a powerful claim for restoring these practices.”
Reference: “Scales of plant stewardship in the precontact Pacific Northwest, USA” by Molly Carney and Thomas Connolly, 5 May 2024, The Holocene.
DOI: 10.1177/09596836241247307
Co-author on the study was Thomas Connolly from the Museum of Natural and Cultural History at the University of Oregon. The project was approved by the Confederated Tribes of Grand Ronde Historic Preservation Office.