Signatures and legacies of Indigenous soil stewardship in Laxyuubm Ts’msyen: Nutrient-rich dark earths in Northwestern Canada

Across diverse global contexts, Indigenous stewardship practices have transformed forested landscapes into dynamic and productive foodsheds, demonstrating that sustainable forest management is not a modern invention. This research investigates soil development in Gitselasu (Ts’msyen) forest gardens in northwestern British Columbia (BC, Canada), where ancestral interventions have structured diverse forest garden systems that persist today. Through comparative analysis of forest garden soils, ambient conifer forest soils, and evaluating Ts’msyen ethnopedological indices, we assess people’s longstanding influence on soil formation and properties. Findings reveal that forest garden soils contain substantially higher levels of organic matter and nitrogen, with a substantially higher cation-exchange capacity and elevated pH. Additionally, we observed increased phosphorus and calcium bioavailability. These results reflect stewardship legacies akin to dark earth (terra preta) development in other global contexts, further highlighting how Indigenous soil knowledge, practices, and governance structures provide insights that fundamentally differ from conventional western agricultural approaches.