Keith A. Olsen

Potential effects of forest policies on terrestrial biodiversity in a multi-ownership province.

We used spatial simulation models to evaluate how current and two alternative policies might affect potential biodiversity over 100 years in the Coast Ranges Physiographic Province of Oregon. This 2.3-million-ha province is characterized by a diversity of public and private forest owners, and a wide range of forest policy and management objectives. We evaluated habitat availability for seven focal species representing different life histories. We also examined how policies affected old-growth stand structure, age distributions relative to the historical range of variability, and landscape patterns of forest types. Under the current policy scenario, the area of habitat for old-growth forest structure and associated species increased over time, the habitat for some early-successional associates remained stable, and the area of hardwood vegetation and diverse early-successional stages declined. The province is projected to move toward but not reach the historical range of variation of forest age classes that may have occurred under the wildfire regimes of the pre-Euroamerican settlement period. Ownership explained much of the pattern of biodiversity in the province, and under the current policy scenario, its effect increased over time as the landscape diverged into highly contrasting forest structures and ages. Patch type diversity declined slightly overall but declined strongly within ownerships. Most of the modeled change in biodiversity over time resulted from policies on public forest lands that were intended to increase the area of late-successional forests and species. One of the alternative policies, increased retention of wildlife trees on private lands, reduced the contrast between ownerships and increased habitat availability over time for both early- and late-successional species. Analysis of another alternative, stopping thinning of plantations on federal lands, indicated that current thinning regimes improve habitat for the Olive-sided Flycatcher, but the no-thinning alternative had no effect on the habitat scores for the late-successional species in the 100-year simulation. A comparison of indicators of biological diversity suggests that using focal species and forest structural measures can provide complementary information on biodiversity. The multi-ownership perspective provided a more complete synthesis of province-wide biodiversity patterns than assessments based on single ownerships.

Objective and perceived wildfire risk and its influence on private forest landowners’ fuel reduction activities in Oregon’s (USA) ponderosa pine ecoregion

Policymakers seek ways to encourage fuel reduction among private forest landowners to augment similar efforts on federal and state lands. Motivating landowners to contribute to landscape-level wildfire protection requires an understanding of factors that underlie landowner behaviour regarding wildfire. We developed a conceptual framework describing landowners’ propensity to conduct fuel reduction as a function of objective and subjective factors relating to wildfire risk. We tested our conceptual framework using probit analysis of empirical data from a survey of non-industrial private forest landowners in the ponderosa pine (Pinus ponderosa) region of eastern Oregon (USA). Our empirical results confirm the conceptual framework and suggest that landowners’ perceptions of wildfire risk and propensity to conduct fuel treatments are correlated with hazardous fuel conditions on or near their parcels, whether they have housing or timber assets at risk, and their past experience with wildfire, financial capacity for conducting treatments and membership in forestry and fire protection organisations. Our results suggest that policies that increase awareness of hazardous fuel conditions on their property and potential for losses in residential and timber assets, and that enhance social networks through which awareness and risk perception are formed, could help to encourage fuel reduction among private forest landowners.

Using an agent-based model to examine forest management outcomes in a fire-prone landscape in Oregon, USA

Fire-prone landscapes present many challenges for both managers and policy makers in developing adaptive behaviors and institutions. We used a coupled human and natural systems framework and an agent-based landscape model to examine how alternative management scenarios affect fire and ecosystem services metrics in a fire-prone multiownership landscape in the eastern Cascades of Oregon. Our model incorporated existing models of vegetation succession and fire spread and information from original empirical studies of landowner decision making. Our findings indicate that alternative management strategies can have variable effects on landscape outcomes over 50 years for fire, socioeconomic, and ecosystem services metrics. For example, scenarios with federal restoration treatments had slightly less high-severity fire than a scenario without treatment; exposure of homes in the wildland-urban interface to fire was also slightly less with restoration treatments compared to no management. Treatments appeared to be more effective at reducing high-severity fire in years with more fire than in years with less fire. Under the current management scenario, timber production could be maintained for at least 50 years on federal lands. Under an accelerated restoration scenario, timber production fell because of a shortage of areas meeting current stand structure treatment targets. Trade-offs between restoration outcomes (e.g., open forests with large fire-resistant trees) and habitat for species that require dense older forests were evident. For example, the proportional area of nesting habitat for northern spotted owl (Strix occidentalis) was somewhat less after 50 years under the restoration scenarios than under no management. However, the amount of resilient older forest structure and habitat for white-headed woodpecker (Leuconotopicus albolarvatus) was higher after 50 years under active management. More carbon was stored on this landscape without management than with management, despite the occurrence of high-severity wildfire. Our results and further applications of the model could be used in collaborative settings to facilitate discussion and development of policies and practices for fire-prone landscapes.

Spatiotemporal dynamics of simulated wildfire, forest management, and forest succession in central Oregon, USA

We use the simulation model Envision to analyze long-term wildfire dynamics and the effects of different fuel management scenarios in central Oregon, USA. We simulated a 50-year future where fuel management activities were increased by doubling and tripling the current area treated while retaining existing treatment strategies in terms of spatial distribution and treatment type. We modeled forest succession using a state-and-transition approach and simulated wildfires based on the contemporary fire regime of the region. We tested for the presence of temporal trends and overall differences in burned area among four fuel management scenarios. Results showed that when the forest was managed to reduce fuels it burned less: over the course of 50 years there was up to a 40% reduction in area burned. However, simulation outputs did not reveal the expected temporal trend, i.e., area burned did not decrease progressively with time, nor did the absence of management lead to its increase. These results can be explained as the consequence of an existing wildfire deficit and vegetation succession paths that led to closed canopy, and heavy fuels forest types that are unlikely to burn under average fire weather. Fire (and management) remained relatively rare disturbances and, given our assumptions, were unable to alter long-term vegetation patterns and consequently unable to alter long-term wildfire dynamics. Doubling and tripling current management targets were effective in the near term but not sustainable through time because of a scarcity of stands eligible to treat according to the modeled management constraints. These results provide new insights into the long-term dynamics between fuel management programs and wildfire and demonstrate that treatment prioritization strategies have limited effect on fire activity if they are too narrowly focused on particular forest conditions.

A Burning Problem: Social Dynamics of Disaster Risk Reduction through Wildfire Mitigation

Disasters result from hazards affecting vulnerable people. Most disasters research by anthropologists focuses on vulnerability; this article focuses on natural hazards. We use the case of wildfire mitigation on United States Forest Service lands in the northwestern United States to examine social, political, and economic variables at multiple scales that influence fire hazard and risk reduction treatments and their effectiveness. Variables highlighted include policy direction to prioritize wildfire risk reduction in the wildland-urban interface, laws and policies that make treating fuels in some national forest land management allocations challenging, social and political constraints on using prescribed fire, agency budget and target pressures, and integrating fire hazard reduction into forest management projects having multiple objectives. These variables compromise the effectiveness of wildfire mitigation treatments. Understanding the social dynamics of natural hazard mitigation is important because they affect its outcomes, creating differential exposure to natural hazards—one component of social vulnerability. Interdisciplinary research to identify how the social dynamics of natural hazard mitigation influence hazard reduction outcomes can contribute to more informed and effective approaches to disaster risk reduction.

Examining the influence of biophysical conditions on wildland–urban interface homeowners’ wildfire risk mitigation activities in fire-prone landscapes

Expansion of the wildland–urban interface (WUI) and the increasing size and number of wildfires has policy-makers and wildfire managers seeking ways to reduce wildfire risk in communities located near fire-prone forests. It is widely acknowledged that homeowners can reduce their exposure to wildfire risk by using nonflammable building materials and reducing tree density near the home, among other actions. Although these actions can reduce the vulnerability of homes to wildfire, many homeowners do not take them. We examined the influence of risk factors on homeowners’ perceived wildfire risk components using a survey of WUI homeowners in central Oregon (USA) and biophysical data that described wildfire risk as predicted by wildfire simulation models, past wildfire, and vegetation characteristics. Our analysis included homeowners’ perceptions of the likelihood of wildfire and resulting damage, and examined how these factors contribute to homeowners’ likelihood to conduct mitigation actions. We developed an empirical model of homeowners’ risk perceptions and mitigation behavior, which served as input into an agent-based model to examine potential landscape and behavior changes over 50 years. We found homeowners’ wildfire risk perceptions to be positively correlated with hazardous conditions predicted by fuel models and weakly predictive of mitigation behavior. Homeowners’ perceived chance of wildfire was positively correlated with actual probability of wildfire, while their perceived chance of damage to the home was positively correlated with potential wildfire intensity. Wildfire risk perceptions also were found to be correlated with past wildfire experience. Our results suggest that homeowners may be savvy observers of landscape conditions, which act as “feedbacks” that enhance homeowners’ concerns about wildfire hazard and motivate them to take mitigation action. Alternatively, homeowners living in hazardous locations are somehow receiving the message that they need to take protective measures. Mitigation compliance output from the agent-based model suggests that completion of mitigation actions is likely to increase over 50 years under various scenarios.

Evaluating carbon storage, timber harvest, and habitat possibilities for a Western Cascades (USA) forest landscape

Forest policymakers and managers have long sought ways to evaluate the capability of forest landscapes to jointly produce timber, habitat, and other ecosystem services in response to forest management. Currently, carbon is of particular interest as policies for increasing carbon storage on federal lands are being proposed. However, a challenge in joint production analysis of forest management is adequately representing ecological conditions and processes that influence joint production relationships. We used simulation models of vegetation structure, forest sector carbon, and potential wildlife habitat to characterize landscape-level joint production possibilities for carbon storage, timber harvest, and habitat for seven wildlife species across a range of forest management regimes. We sought to (1) characterize the general relationships of production possibilities for combinations of carbon storage, timber, and habitat, and (2) identify management variables that most influence joint production relationships. Our 160 000-ha study landscape featured environmental conditions typical of forests in the Western Cascade Mountains of Oregon (USA). Our results indicate that managing forests for carbon storage involves trade-offs among timber harvest and habitat for focal wildlife species, depending on the disturbance interval and utilization intensity followed. Joint production possibilities for wildlife species varied in shape, ranging from competitive to complementary to compound, reflecting niche breadth and habitat component needs of species examined. Managing Pacific Northwest forests to store forest sector carbon can be roughly complementary with habitat for Northern Spotted Owl, Olive-sided Flycatcher, and red tree vole. However, managing forests to increase carbon storage potentially can be competitive with timber production and habitat for Pacific marten, Pileated Woodpecker, and Western Bluebird, depending on the disturbance interval and harvest intensity chosen. Our analysis suggests that joint production possibilities under forest management regimes currently typical on industrial forest lands (e.g., 40- to 80-yr rotations with some tree retention for wildlife) represent but a small fraction of joint production outcomes possible in the region. Although the theoretical boundaries of the production possibilities sets we developed are probably unachievable in the current management environment, they arguably define the long-term potential of managing forests to produce multiple ecosystem services within and across multiple forest ownerships.

Sustaining Biodiversity in the Oregon Coast Range: Potential effects of Forest Policies in a Multi-ownership Province

To understand the potential effects of forest policies on sustaining biological diversity at broad scales, we used spatial simulation models to evaluate current and potential future habitat availability over 100 yr for three focal species: Pacific Fisher (Martes pennanti), Pileated Woodpecker (Dryocopus pileatus), and Warbling Vireo (Vireo gilvus). The habitats of these species represent a broad range of spatial scales and forest types. Area of habitat for fishers and Pileated Woodpeckers is predicted to increase over time under current forest land management policies. Habitat for Warbling Vireos is predicted to decline. These patterns are consistent with past analyses that predicted declines in diverse early successional forests and hardwood forests and increases in late-successional forests under current and two alternative policies. Land ownership influenced the spatial arrangement of habitat for all three focal species. Public lands subsidized habitat for wide-ranging species on adjacent private lands. A land use policy that required greater green tree retention on private lands seemed to result in modest increases in habitat quality over 100 yr for Pileated Woodpeckers. Thinning of plantations on federal lands had little effect on these focal species. Policy analyses such as these highlight incongruities between historic habitat patterns and contemporary spatial and temporal scales of habitat in managed landscapes. This information can be used to assess risks and inform the policy debates surrounding biodiversity conservation.