The Yakama Reservation in southcentral Washington State is a magnificent cultural resource for the 9,800 enrolled members of the Yakama Nation. Abundant natural resources provide practical opportunities for sustainable management of fish, food and medicinal plants, forests, range, water, and wildlife.

The 1.4-million-acre Yakama Reservation includes agricultural and rangelands in the east, and 650,000 acres of forest and woodland mostly in the west (Figure 1). There is a pronounced precipitation gradient across the Reservation, which greatly affects the distribution and growth of vegetation. Annual precipitation ranges from seven inches along the Yakima River (eastern boundary) to 100 inches along the Cascade Crest (western boundary).

The Yakama Forest is a place for spiritual renewal, hunting, fishing, and a traditional source of edible and medicinal plants. In addition, timber harvesting is an important source of revenue for the Yakama Nation, and employment for tribal members.

Unfortunately, the health of the Yakama Forest has declined over the last century—mainly as a result of livestock grazing, fire exclusion, and selective timber harvesting. Livestock grazing decreased the amount of fine fuels, which prevented surface fires from burning across the landscape, as they did historically. Suppression of natural fires also prevented fires from performing important ecosystem functions such as recycling nutrients, regulating species composition, and adjusting forest stand densities. Shade-tolerant grand firs and Douglas-firs regenerated in place of the large ponderosa pines that were removed in selective timber harvesting. Recent pest epidemics are symptoms of a major problem, that is, a forest that has gradually changed in species composition and density.

Four timber types make up most of the forest area: ponderosa pine (PP) 26%; pine-fir (PF) 23%; mixed conifer (MC) 32%; and true fir-mountain hemlock (FM) 15%. Lodgepole pine and other minor timber types occur on the remainder of the area. In general, these four forest types, PP, PF, MC, and FM, represent a gradient from open-canopy, low-density PP stands to closed-canopy, high-density MC and FM stands; PF stands are intermediate in density.

Timber inventories from 1934 and 1996 and timber type maps from 1934 and 1997 provide references for how the forest has changed in recent times. The 1934 forest inventory showed a standing merchantable volume of four billion board feet (BF). Sixty-two years later, stand densities increased and the standing volume increased to 11 billion BF, while in the same time period six billion BF was harvested from the Reservation.

A comparison of the timber type acres shows ponderosa pine stands decreased from 58% of the area in 1934 to 26% in 1997 (Figure 2). As Douglasfirs became established beneath ponderosa pines, many of the pine stands converted to pine-fir while, at the same time, some of the pine-fir stands converted to mixed conifer stands.

Mixed conifer forest types increased from 8% of the area in 1934 to 32% in 1997. The 1934 mapping also showed large areas that burned in the early 1900s, for example, the 1911 Clearwater Burn. Many of these areas have regenerated and are now classified as true firmountain hemlock timber types.

As a result of the change in tree species composition and increased stand densities, competition increased in many areas and tree vigor decreased. Forested landscapes gradually became more susceptible to outbreaks of defoliators, such as the western spruce budworm and the Douglas-fir tussock moth. Landscapes are also now susceptible to attack by bark beetles, such as the Douglas-fir beetle and the mountain pine beetle. In addition, as a result of hazardous fuels buildup, extensive areas are at risk of being burned by unnatural, high-intensity fires.

A Forest Management Plan (FMP) for 2005 to 2014 was developed to guide the restoration of forest health and achieve the Yakama Nation’s goals and objectives of sustainable forest management on the Yakama Reservation. The FMP describes the new management strategies to deal with the changes in forest conditions that have occurred over the last century.
   
The FMP is the result of the contributions of many Yakama Nation and Bureau of Indian Affairs programs including Archaeology and Cultural Resources, Environmental Quality, Fisheries, Forestry, Range, Roads, Soil, Vegetation, Water Code, Water Resources, and Wildlife.

A number of issues, concerns, and opportunities were identified during the development of the FMP. The main topics included big-game habitat, forest health, old growth, revenue and employment, threatened and endangered species, and water quality.

The FMP uses an ecosystem management approach, which considers the sustainability of all resources. Emphasis is on achieving management objectives at the scale of sub-basins. Silvicultural prescriptions are based on forest habitat types, which are used to classify land according to potential vegetation and productive capability. A guiding principle for the silvicultural prescriptions is to manage for appropriate tree species and stand densities with regard to the carrying capacity of the land. Prescriptions are modified in areas of special concern, such as riparian areas, canyons, and areas that provide winter wildlife habitat.

Forest restoration implies that a forest will be returned to a prior condition. Nineteenth-century forest conditions on the Yakama Reservation appeared to be more sustainable than  present conditions. For example, open pine stands were maintained in a healthy condition by frequent, low-intensity fires (Figure 3,, page 40). The forestry program is using historic species composition and stand densities as references for restoration of forest health.

Forest health describes the ability of a forest ecosystem to remain productive and withstand disturbances over time. It is usually easy to recognize the differences between a healthy forest and an unhealthy forest. A healthy forest maintains a diversity of plants and animals, aesthetic appeal, and resource sustainability (that is, a dependable source of roots, berries, clean water, fish, vigorous trees, forage for animals, and clean air). In addition, a healthy forest is resilient to periodic disturbances such as drought, insects, diseases, fires, climatic change, and management practices.

An unhealthy forest is characterized by high levels of insects and diseases. Pest epidemics reduce productivity, increase tree mortality, and present great challenges to forest planners, silviculturists, and Tribal Council members. Maintaining forest health is critical for sustaining natural resources.

Sustainable forest management links environmental protection, economic prosperity, and social well-being in the forest management planning and decision-making process. The Yakama’s goal for sustainable forest management is to meet the Yakama Nation’s present needs and values without compromising the management options of future generations.

In the pursuit of sustainability, you have to answer the basic questions, “What resources do you want to sustain? Where do you want to sustain them? and How?” The primary goal of the FMP is to maintain the Yakama Forest in a healthy condition in order to sustain multiple resources, including cultural resources, such as camas and huckleberries, forests and woodlands, water quality, fish, and wildlife.

The ability to attain forest management goals was hindered by a western spruce budworm epidemic that lasted two decades. The western spruce budworm is a native insect that prefers to eat grand fir and Douglas-fir foliage. Budworm populations began to increase in the southwest portion of the Reservation in 1985 with a corresponding increase in defoliation of Douglas-firs and grand firs. Many stands of Douglasfir were defoliated for several consecutive years, and subsequently attacked by Douglas-fir beetles, which resulted in high amounts of mortality. The large numbers of dead trees has greatly increased the fire hazard. The risk of fire is greatest during late summer when fuels are dry and lightning storms move across the area. Now there is a greater likelihood of high-intensity, stand replacement fires occurring where there used to be low-intensity, surface fires.

The number of acres affected by budworm increased steadily from 1985 to 1989. In 1990, 70,000 acres were treated with a biological control agent, Bacillus thuringiensis (Bt), which greatly reduced the budworm population. The stand conditions, however, remained favorable for the budworm and the population resurged in 1992 and continued to rise thereafter.

In 1998 a two-fold strategy was developed to deal with the budworm epidemic. The short-term strategy minimized economic losses by recovering the value of dead and dying trees and reduced hazardous fuel loads. The longterm strategy is to promote the development of a forest that will be more resilient to natural and human-caused disturbances. Silvicultural treatments are being used to change the conditions that are favorable for the spruce bud-worm. In general, ponderosa pine and western larch are favored over Douglas fir and grand fir, and stand densities are being reduced. Timber sales were prioritized to treat areas that were most severely affected by the budworm. Between 1999 and 2003, silvicultural treatments were implemented on approximately 20,000 acres of budworm habitat per year. Also, in an effort to slow tree mortality, 97,000 acres were treated with Bt between 1999 and 2001. The epidemic peaked in 2000 when the budworm defoliated trees on 206,000 acres (Figure 4). Defoliation then decreased dramatically, primarily as a result of the silvicultural treatments. In 2002, 1,207 acres were defoliated.

Timber harvesting on the Yakama Reservation began in 1944, when the Dry Creek Timber Sale was initiated because of a western pine beetle epidemic. Approximately nine million BF of ponderosa pine was salvaged over  a three-year period. The annual timber harvest level peaked at 226 million BF in 1999 in response to the western spruce budworm epidemic and then decreased in the following years.

In 2004, 150 million BF were harvested. The projected annual timber harvest for the next ten years will start out at 158 million BF and then gradually drop down to 143 million BF by 2014 (Figure 5). The Allowable Annual Cut (AAC) during the last ten-year planning period was 143 million BF.Harvest levels remained below the AAC  for the first half of the planning period. Harvesting was accelerated in the second half of the planning period to aggressively deal with the western spruce budworm epidemic.

The amount of pine harvested, as a percent of total volume harvested, decreased in recent years while the amount of Douglas-fir and grand fir harvest increased. This reflects the increased number of trees and growth of Douglas-fir and grand fir, as well as the deliberate removal of these species because they are the budworm’s preferred food. The volume and species mix of future timber harvests is anticipated to change as a result of the increased planting of pine and larch, and as the emphasis of forest management shifts to establishing and maintaining uneven-aged stands of ponderosa pine.

Following commercial harvesting, precommercial thinning is done to regulate stand density and tree species  composition. The Forest Development Program thins 5,000 acres per year, which provides jobs for tribal members. In some areas there is adequate natural regeneration of the desired species; however, if there is not a reliable seed source then the areas will be planted with ponderosa pine and larch. Forest Development plants 2,000 acres per year, which provides additional jobs for tribal members. The Fuels Management Program conducts controlled burns on 1,700 acres per year. Prescribed fire is beneficial by recycling nutrients, regulating plant species composition, and adjusting stand density.

The pathway to sustainable forestry requires proactive management. Forest health can be restored and maintained by promoting the development of more open forest stands composed of ponderosa pine and western larch on much of the forest.

Achieving the management goals of the FMP will ensure that the forest resource will be maintained as a source of spiritual renewal, food and medicinal plants, revenue for the Yakama Nation, and employment for tribal members.