by Marie-Blanche Roudaut, WRRC Graduate Outreach Assistant
and Susanna Eden, WRRC
Arizona’s forests need help. The dense, over-stocked forests in Arizona are not natural and create an environment conducive to insect and disease outbreaks, high-intensity wildfires, and unsustainable conditions for forest ecosystems. Years of fire suppression and drought have produced a situation where mega-fires become the norm. Arizona has witnessed an increase in the size, severity, and frequency of wildfires during the past 14 years. The two largest fires in Arizona’s history, the 2002 Rodeo-Chediski Fire and the 2011 Wallow Fire burnt respectively 468,000 and 538,000 acres. The Schultz Fire in 2010, which burned the east side of San Francisco Peak, was not only destructive, but also resulted in devastating post-fire flooding and loss of life.
Arizona’s forests are critical to the state water supply. Most of Arizona’s surface water resources are supplied by high-elevation forested watersheds, which capture rain and snow that feed downstream surface waters. Forest lands provide the majority of the water for the Salt and Verde Rivers, which are vital water supplies for users in the greater Phoenix metropolitan Area.
Fortunately forests are receiving increased attention as understanding grows about threats to water and other resources from past mismanagement. This recent attention is fostering programs that restore forest health to reduce these threats. Many municipalities are investing in forest restoration projects with the goal of returning forests to a more natural state that is more resilient to drought, fire, and insect infestations. The estimated cost of forest treatment and restoration projects aimed at minimizing the harmful effects of wildfires is estimated to cost $500 to $1,000 per acre. This investment could save Arizona hundreds of millions of dollars in wildfire suppression costs and damages.
Arizona Forward, an organization that brings business and civic leaders together over issues of environmental sustainability and economic vitality, published “Threat to Forest Health puts Arizona at Risk” to highlight the urgent need for forest treatment and restoration. The primer was unveiled in early October 2015 to 300 community leaders attending Salt River Project’s two-day “Healthy Forests, Vibrant Economy” forum on how to accelerate forest restoration in Arizona. The document proposes actions that could mitigate the impact of wildfires and threats to water quality.
Healthy forests are characterized by small groves of trees with large spaces between them filled with grass and wildflowers. Ideally, each individual tree has adequate access to water, sunshine, and nutrients. Overgrown forests support far too many trees per acre that compete for water and nutrients. For example, a healthy ponderosa pine forest has about 20-50 trees per acre. In contrast, the unhealthy forests commonly seen in Arizona contain over 1,000 trees per acre, with the ground between them covered with a thick layer of pine needles and very little grass or wildflowers.
A forest with widely spaced trees has a significantly lower risk of catastrophic wildfires and is instead more prone to low-intensity ground fires that rejuvenate soils and control vegetation density. In addition, healthy forests have greater resistance to bark beetle infestations that have devastated large areas of Arizona’s ponderosa pine forests. Healthy forests also support more diverse wildlife and plant species that are vital for the entire forest ecosystem.
When wildfires burn through a dense, unhealthy forest, they burn extremely hot and can be catastrophic in size and intensity. After such catastrophic fires, soils are scorched and are unable to retain or absorb rain, increasing the risk of dangerous flooding. In addition, the amplified runoff washes down burned slopes carrying significant amounts of ash, sediments, and debris into streams, destroying fish habitats and riparian areas. The sediment carried by such flows into reservoirs reduces the reservoir storage capacity and increases the cost for cities to treat the water to potable water standards.
In the Phoenix metropolitan area, increased sediment loading and decreased water quality resulting from intense wildfires in the Salt and Verde River watersheds directly led to an increase in operational costs for city water treatment plants. Proactive forest restoration projects could prevent municipalities from spending millions of dollars for slope stabilization, reservoir dredging, and additional water treatment to mitigate the impacts of wildfires.
The Northern Arizona Forest Fund (NAFF) was created in 2014 to help connect businesses, residents, and other stakeholders in the Phoenix Metropolitan Area with projects that improve forest and watershed health. NAFF provides an opportunity to invest in projects in the Salt and Verde watersheds, and the fund receives significant financial contributions from a variety of investors, including cities, businesses, and civic organizations. For example, the City of Scottsdale is investing $120,000 over three years in the NAFF. Contributions to the NAFF are collected and administered by the National Forest Foundation.
The National Forest Foundation was created by Congress in 1993 to engage the American public in the restoration and public enjoyment of its national forests and grasslands. The official nonprofit partner of the Forest Service, it engages in community-based and national programs to promote the health of national forests. It also administers gifts of funds and land for the benefit of the national forests.
Each year, the National Forest Foundation in collaboration with the U.S. Forest Service identifies priority projects aimed at improving the health and resilience of National Forest lands in the Verde and Salt River watersheds. The NAFF’s six 2015-2016 funded projects were officially announced at the third annual “Healthy Forests, Vibrant Economy” forum in Scottsdale, October 7 and 8, 2015. They include the Stoneman Lake Watershed Health and Habitat Protection Project, located in the ponderosa pine forests along the Mogollon Rim in the Coconino National Forest, near Sedona and the McCracken Woodland Health and Habitat Improvement Project, located within the pinyon-juniper woodlands of the Kaibab National Forest, south of Williams. Other projects deal with degradation of Oak Creek, sedimentation in the Verde River, and riparian protection of Black River. Another erosion control project is located at a popular trail east of Superior. In addition to reducing the risk of catastrophic wildfire, thereby decreasing erosion and sedimentation into streams, rivers, and important reservoirs, these projects will also improve wildlife habitat and enhance recreational opportunities.
The U.S. Forest Service has embarked on a 20-year initiative to restore forests in collaboration with nearly 50 stakeholder groups, including local, county, and state governments, environmental groups, organizations, institutions, and industry representatives. The Four Forest Restoration Initiative (4FRI) is an unprecedented effort to restore the health and ecological function of 2.4 million acres of ponderosa pine forest across the Mogollon Rim within the Kaibab, Coconino, Apache-Sitgreaves and Tonto National Forests. Several types of restoration strategies are used depending on the terrain and the goal of the treatment. Mastication and thinning are both used to eliminate shrubs and small trees, for fire reduction purposes, on slopes no steeper than 40 percent. The shrubs and small trees are shredded into chips to be left on site or removed as fuelwood. Mastication and thinning are sometimes followed by prescribed surface fires. These low- to moderate-intensity fires are used to reduce high fuel loads, thin overcrowded forests, release nitrogen and other nutrients into the soil, and encourage germination of various plant species. It is a particularly useful tool in rugged terrain with steep slopes.
A key component of 4FRI is the involvement of local private industry in conducting the restorative treatments that are paid for by the sale of the timber products. The Forest Service contracts out the work through stewardship contracts, which allow private industry to use the timber and biomass resulting from restorative treatments for products such as lumber, wood pellets, and biomass power. With this system, the restorative treatments not only pay for themselves, but also strengthen local economies by re-establishing a strong forest product industry.