Wildfire Effects and Interactions with Treatments
Managed Fire
Fire is a key process that plays a central role in structuring and regulating the function of forest ecosystems. Historical interruption of natural fire regimes and continued fire suppression in dry forests of the western US resulted in substantial changes in forest structure, composition, and function. These changes are associated with decreases in ecological resilience and reduction of ecosystem services. Ecological restoration and fuels reduction programs target these conditions and attempt to assist in the recovery of ecosystem function in fire-excluded forests. Recent federal policies mandate accelerated ecological restoration on national forests and other public lands that show degraded conditions due to fire regime disruption.
Prescriptions for ecological restoration of ponderosa pine (Pinus ponderosa) forests of the Southwest aim to approximate pre-fire-exclusion conditions by reducing tree densities and hazardous fuels and reintroducing fire to the landscape. It is widely understood that treatments including mechanized tree thinning and application of prescribed fire can help reverse these patterns and assist in restoration of more resilient forest conditions. However, these treatments can be expensive and are not appropriate for all lands (e.g., wilderness). Increasingly, land managers are using natural fire ignitions to achieve restoration and hazardous fuels reduction objectives, and to complement mechanical thinning on some sites. Small patches (e.g., < 60 acres) of high-severity fire (i.e., where most trees are killed) can contribute to landscape-scale heterogeneity and emulate historical patterns in some forests. Fires that leave standing dead trees, dead and down logs, and patches of early successional plants may provide important habitat for a range of wildlife species. However, wildfires may also have unintended effects such as killing large, old trees and creating conditions suitable for establishment of invasive plants. Although, management of naturally ignited wildfires to benefit forest ecosystems is becoming a more common approach, few studies have examined these fires to compare outcomes with specific restoration objectives, or in terms of natural ranges of variation.
Treatment Effectiveness
Although fire is a critical ecosystem process in dry forests around the world, decades of fire exclusion and related ecological changes have led to volatile fuels conditions and susceptibility of many forests to catastrophic crown fire. This is particularly true for southwestern ponderosa pine and dry mixed conifer forests.
Ecological restoration treatments that include thinning small, young trees that have established during decades-long fire free periods, and use of controlled burning of slash and forest floor fuels, are intended to help these forests recover and return to more natural ecological trajectories. It is assumed that a restored forest ecosystem will be resilient to natural disturbances and their agents such as fire, drought, insects and diseases.
Post-fire Regeneration and Recovery
As large, severe fires are becoming more common on western landscapes, it is important to better understand long-term dynamics and patterns of forest structure and tree regeneration. More work will be needed to test strategies for conservation and restoration of ponderosa pine forests after severe fire and as climate continues to change.
Recent Publications
Huffman, D.W., J.E. Crouse, A.J. Sanchez Meador, J.D. Springer, M.T. Stoddard. 2018. Restoration benefits of re-entry with resource objective wildfire on a ponderosa pine landscape in northern Arizona, USA.Forest Ecology and Management, 408:16-24.
Roccaforte, J.P., A.J. Sánchez Meador, A.E.M. Waltz, M.L. Gaylord, M.T. Stoddard, D.W. Huffman. 2018. Delayed tree mortality, bark beetle activity, and regeneration dynamics five years following the Wallow Fire, Arizona, USA: Assessing trajectories towards resiliency. Forest Ecology and Management, 428:20-26.
Springer, J.D., D.W. Huffman, M.T. Stoddard, A.J. Sánchez Meador, A.E.M. Waltz. 2018. Plant community dynamics following hazardous fuels treatment and mega-wildfire in a warm-dry mixed-conifer forest of the USA. Forest Ecology and Management, 429:278-286.
Huffman, D.W., A. Sanchez Meador, M.T. Stoddard, J.E. Crouse, J.P. Roccaforte. 2017. Efficacy of resource objective wildfires for restoration of ponderosa pine (Pinus ponderosa) forests in northern Arizona. Forest Ecology and Management, 389:395-403.
Owens, S.M., C.H. Sieg, A.J. Sánchez Meador, P.Z. Fulé, J.M. Iniguez, L.S. Baggett, P.J. Fornwalt, M.A. Battaglia. 2017. Spatial patterns of ponderosa pine regeneration in high-severity burn patches. Forest Ecology and Management, 405:134-149.
Ouzts, J., T. Kolb, D.W. Huffman, A.J. Sánchez Meador. 2015. Post-fire ponderosa pine regeneration with and without planting in Arizona and New Mexico. Forest Ecology and Management, 354:281-290.
Waltz, A.E.M., M.T. Stoddard, E.L. Kalies, J.D. Springer, D.W. Huffman, A.J. Sánchez Meador. 2014. Effectiveness of fuel reduction treatments: Assessing metrics of forest resiliency and wildfire severity after the Wallow Fire, AZ. Forest Ecology and Management, 334:43-52.
Strom, B.A., and P.Z. Fulé. 2007. Pre-wildfire fuel treatments affect long-term ponderosa pine forest dynamics. International Journal of Wildland Fire, 16:128-138.
Greater Flagstaff Area Fire History Map
This map compiles the greater Flagstaff area fire history from 1880 to present. It delineates wildfires more than 100 acres through time to provide a visual story of area fires through the decades.
- A “layer” icon in the upper right-hand corner of the map allows you to toggle through the fire layers by decade.
- Use Ctrl + scroll to zoom in on the map.