Background: Evaluating fuel treatment effectiveness is challenging when managing a landscape for diverse ecological, social, and economic values. We used a Participatory Geographic Information System (PGIS) to understand Confederated Colville Tribal (CCT) member views regarding the location and effectiveness of fuel treatments within their ancestral territory within the Colville National Forest (CNF) boundary. The 2015 North Star Fire burned 88 221 ha (218 000 acres) of the CCT ancestral territory.

Results: We sampled thirty plot pairs that were treated or untreated prior to being burned by the North Star Fire and again one growing season post fire. Species diversity was significantly increased by wildfire in both treated and untreated plots. Species richness was significantly increased in the plots that were treated, and there was no significant change in species richness from wildfire within the untreated plots. The percent canopy cover of two of the six culturally important plants (Fragaria spp. L. and Arnica cordifolia Hook.) significantly increased one growing season post wildfire within treated plots and one (Arctostaphylos uva-ursi [L.] Spreng.) significantly decreased in the treated plots post wildfire. These post-fire monitoring results were consistent with CCT member management recommendations and desired outcomes of understory thinning, prescribed fire, and natural ignition found using PGIS.

Conclusions: Together, the results suggest that prior thinning and prescribed burning can foster vegetation response to subsequent wildfires, including culturally important plants. Further, integrating Traditional Knowledge (TK) into fuels treatments can improve ongoing adaptive management of national forests that include tribal ancestral lands.