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SignificanceWe provide the first assessment of aboveground live tree biomass in a mixed conifer forest over the late Holocene. The biomass record, coupled with local Native oral history and fire scar records, shows that Native burning practices, along with a natural lightning-based fire regime, promoted long-term stability of the forest structure and composition for at least 1 millennium in a California forest. This record demonstrates that climate alone cannot account for observed forest conditions. Instead, forests were also shaped by a regime of frequent fire, including intentional ignitions by Native people. This work suggests a large-scale intervention could be required to achieve the historical conditions that supported forest resiliency and reflected Indigenous influence.

We review science-based adaptation strategies for western North American (wNA) forests that include restoring active fire regimes and fostering resilient structure and composition of forested landscapes. As part of the review, we address common questions associated with climate adaptation and realignment treatments that run counter to a broad consensus in the literature. These include the following: (1) Are the effects of fire exclusion overstated? If so, are treatments unwarranted and even counterproductive? (2) Is forest thinning alone sufficient to mitigate wildfire hazard? (3) Can forest thinning and prescribed burning solve the problem? (4) Should active forest management, including forest thinning, be concentrated in the wildland urban interface (WUI)? (5) Can wildfires on their own do the work of fuel treatments? (6) Is the primary objective of fuel reduction treatments to assist in future firefighting response and containment? (7) Do fuel treatments work under extreme fire weather? (8) Is the scale of the problem too great? Can we ever catch up? (9) Will planting more trees mitigate climate change in wNA forests? And (10) is post-fire management needed or even ecologically justified? Based on our review of the scientific evidence, a range of proactive management actions are justified and necessary to keep pace with changing climatic and wildfire regimes and declining forest heterogeneity after severe wildfires. Science-based adaptation options include the use of managed wildfire, prescribed burning, and coupled mechanical thinning and prescribed burning as is consistent with land management allocations and forest conditions. Although some current models of fire management in wNA are averse to short-term risks and uncertainties, the long-term environmental, social, and cultural consequences of wildfire management primarily grounded in fire suppression are well documented, highlighting an urgency to invest in intentional forest management and restoration of active fire regimes.

Walnut Creek: Left Coast Press, 2010, 220 pages, 152 gures/photographs $30.00 (paperback)

Understanding how plant populations respond to multiple drivers is increasingly critical for biodiversity conservation under global change. Indigenous knowledge can provide guidance for sustainable management, but the outcome of its application in novel ecosystems is rarely known. Simulating the re‐introduction of Indigenous stewardship in contemporary contexts with population models allows for the comparison of different management scenarios and the elucidation of the mechanisms driving population outcomes.Beargrass Xerophyllum tenax is an ecologically and culturally important understorey plant managed through fire and leaf harvest by Native Americans. We collected demographic and abiotic data on beargrass over 3 years across fire severities in nine populations and conducted an experiment to simulate Native American leaf gathering. These data were used to build integral projections models (IPMs) with soil moisture and light availability as covariates. With these IPMs, we simulated stochastic population growth rates across future fire and leaf harvest scenarios. We then decomposed our simulation results using stochastic life table response experiments (SLTREs).The 'no fire' and 'business as usual' (180‐year fire return interval, 58% probability of high‐severity fire) scenarios resulted in lower population growth rates than 'Indigenous fire stewardship' (10‐year fire return interval, 10% chance of high‐severity fire). SLTREs revealed that Indigenous stewardship led to higher beargrass population growth rates due to greater fire frequency, higher adult survival and increased vegetative reproduction. Fire also interacted with harvest in the simulations; leaf harvest increased population growth rate only in combination with Indigenous fire stewardship.Synthesis. Stochastic and retrospective population dynamics tools combined with an understanding of Indigenous management practices allow for the comparison of future socio‐ecological scenarios as well as mechanistic understanding of differences between scenarios. Simulated Indigenous stewardship supported the long‐term persistence of X. tenax populations while business as usual and no fire did not. The benefits of Indigenous stewardship to population dynamics, and the complexity of interactive effects of multiple drivers, provide further impetus for collaboration across Indigenous and western knowledge systems. Xerophyllum tenax is presented as a model system to explore the influence of Indigenous stewardship, or its absence, on population dynamics. [ABSTRACT FROM AUTHOR]

The concept of forest landscape restoration (FLR) is being widely adopted around the globe by governmental, non‐governmental agencies, and the private sector, all of whom see FLR as an approach that contributes to multiple global sustainability goals. Originally, FLR was designed with a clearly integrative dimension across sectors, stakeholders, space and time, and in particular across the natural and social sciences. Yet, in practice, this integration remains a challenge in many FLR efforts. Reflecting this lack of integration are the continued narrow sectoral and disciplinary approaches taken by forest restoration projects, often leading to marginalisation of the most vulnerable populations, including through land dispossessions. This article aims to assess what lessons can be learned from other associated fields of practice for FLR implementation. To do this, 35 scientists came together to review the key literature on these concepts to suggest relevant lessons and guidance for FLR. We explored the following large‐scale land use frameworks or approaches: land sparing/land sharing, the landscape approach, agroecology, and socio‐ecological systems. Also, to explore enabling conditions to promote integrated decision making, we reviewed the literature on understanding stakeholders and their motivations, tenure and property rights, polycentric governance, and integration of traditional and Western knowledge. We propose lessons and guidance for practitioners and policymakers on ways to improve integration in FLR planning and implementation. Our findings highlight the need for a change in decision‐making processes for FLR, better understanding of stakeholder motivations and objectives for FLR, and balancing planning with flexibility to enhance social–ecological resilience. [ABSTRACT FROM AUTHOR]

A long history of tribal disenfranchisement through government policies has contributed to a lack of trust and participation by tribal communities in nontribal organizations and initiatives. This article will discuss the process through which new partnerships were forged using a community-based participatory research (CBPR) approach among university researchers, local nontribal organizations, and three Tribes in the Klamath River Basin of southern Oregon and northern California through a five-year federal food security grant. The partnership’s shared goal was to enhance tribal health and food security and food sovereignty in the Klamath River Basin by building a healthy, sustainable, and culturally relevant food system. We describe the context that gave rise to this collaborative partnership; share reflections on how project goals, objectives, and activities were co-created, adapted, and implemented; and highlight specific examples of research, education, and extension activities, informed by CBPR, that support the tribal goals of strengthening Indigenous food sovereignty. We also share lessons learned from navigating unforeseen challenges in ways that we hope can provide insight for scholars, cooperative extension advisors, nonprofit organizations, and government agencies seeking to build effective partnerships with tribes working toward food system change in Native American communities. [ABSTRACT FROM AUTHOR]

Forest densification, wildfires, and disease can reduce the growth and survival of hardwood trees that are important for biological and cultural diversity within the Pacific Northwest of USA. Large, full-crowned hardwoods that produce fruit and that form large cavities used by wildlife were sustained by frequent, low-severity fires prior to Euro-American colonization. Shifts in fire regimes and other threats could be causing declines in, large hardwood trees. To better understand whether and where such declines might be occurring, we evaluated recent trends in Forest Inventory and Analysis (FIA) data from 1991–2016 in California and southern Oregon. We included plots that lay within areas of frequent fire regimes during pre-colonial times and potential forest habitats for fisher, a rare mammal that depends on large live hardwoods. We analyzed changes in basal area for eight hardwood species, both overall and within size classes, over three time periods within ecoregions, and in public and private land ownerships. We found the basal area to generally be stable or increasing for these species. However, data for California black oak suggested a slight decline in basal area overall, and among both very large trees and understory trees; that decline was associated with fire mortality on national forest lands. In addition, mature trees with full crowns appeared to sharply decline across all species. Many trends were not statistically significant due to high variation, especially since more precise data from remeasured trees were only available for the two most recent time periods. Continued analysis of these indicators using remeasured trees will help to evaluate whether conservation efforts are sustaining large, full-crowned trees and their associated benefits. [ABSTRACT FROM AUTHOR]