Fuels Treatment Cost Analysis at Bandelier National Monument

Introduction

Fuels Treatment Unit UF-9, located in upper Cañon de los Frijoles, is an area of great concern to the fire staff at Bandelier National Monument. This portion of the park has experienced an increase in fuel buildup, making it susceptible to stand-replacement fires. It also encompasses the beginning of the Frijoles watershed, which flows into the canyon and extends along the northern region of Bandelier National Monument for approximately 13 miles before draining into the Rio Grande.

Given the right environmental conditions, an unwanted fire could occur — one that could threaten life and property, including Los Alamos National Laboratory, the cities of Los Alamos and White Rock, the adjacent Santa Fe National Forest, and the Valles Caldera National Preserve. Major flooding and soil erosion could occur in the watershed, causing significant damage to Bandelier National Monument headquarters, cultural and historic sites, and riparian areas located in the lower elevations of the canyon.

The last major fire to burn through upper Cañon de los Frijoles occurred in 1893. This date was obtained from fire scar sampling conducted in 1987 by Craig D. Allen, with the assistance of Ms. Lee Sullivan, in the riparian mixed conifer forests of upper Cañon de los Frijoles. The results found that there were widespread surface fires with a mean interval of occurrence every 11 years, and that fire typically spread down into the canyon bottoms from adjacent mesa tops.

Historically, human interactions with natural processes have been occurring in Bandelier since the development of sedentary agricultural lifeways, with communities of permanent dwellings beginning around 1100 AD. Populations gradually increased, leading to large pueblo settlements of up to 1,000 or more rooms. Bandelier contains an estimated 3,000 to 4,000 archaeological sites.

The first Spanish settlement occurred in 1598 at the base of the Jemez Mountains, bringing domestic livestock. The Anglo population steadily increased following the opening of the Santa Fe Trail in 1821. By the 1880s, large numbers of sheep and cattle were being grazed in the area, which diminished the herbaceous ground cover across the Cañon de los Frijoles watershed, altering the pattern of vegetation succession and reducing the spread of surface fires.

Background and Fire Regime

Adolph Bandelier conducted some of the first archaeological work in this area in the late 1800s. Bandelier National Monument was established in 1916 to protect the ruins that Bandelier made famous through his research. The U.S. Forest Service operated the Monument until it was transferred to National Park Service control in 1932. Monument boundaries were enlarged in 1956, 1963, and 1977 to encompass the entire Cañon de los Frijoles watershed.

On neighboring lands at Los Alamos, nuclear weapons and other defense and energy-related projects were developed beginning in 1943, when Los Alamos was created to build the first atomic bomb. Los Alamos National Laboratory and the town of Los Alamos are built on mesa tops separated by deep canyons containing much of the same fuel and vegetation as Cañon de los Frijoles, presenting many of the same fire control challenges.

In May and June of 2000, the Cerro Grande Fire originated adjacent to the northern portion of Treatment Unit UF-9. This fire was ignited by National Park Service personnel as a prescribed burn to reduce fuel loads. The origin area contained the same type of fuels as Treatment Unit UF-9. Sporadic wind changes caused spotting over the fire line, resulting in a slop-over, and the prescribed burn was declared a wildfire. Although the fire was initially contained, winds increased significantly, producing major fire activity. The fire spread to Los Alamos National Laboratory and the towns of Los Alamos and White Rock, burning more than one-fourth of Laboratory lands; numerous small structures, including historic structures; vehicles; utilities; and environmental monitoring stations. The fire destroyed a total of 235 residences as well as an assortment of other structures, and burned approximately 42,878 acres encompassing Santa Fe National Forest, Department of Energy lands, Santa Clara Pueblo, Los Alamos City/County, Bandelier National Monument, Valles Caldera National Preserve, and San Ildefonso Pueblo.

During a fire management program review in February 2003, questions arose concerning crown fire risk in Cañon de los Frijoles. Recommendations from this review encouraged Bandelier to continue investigating ways to address recurring fuel buildup, to model fuels in the area, and to evaluate possible treatments. Additional recommendations included informing Bandelier staff and increasing awareness among cooperators, including Santa Fe National Forest, Valles Caldera National Preserve, Los Alamos National Laboratory, the Los Alamos Fire Department, and local volunteer fire departments. This type of unwanted fire produces high-severity burns, leading to cultural and natural resource damage as well as threats to life and property.

The fire regime on Unit UF-9 should be Group I — a low-severity fire occurring on a 0-to-35-year return interval in ponderosa pine, other long-needle pine species, and dry-site Douglas fir. Under Condition Class 1, fire regimes are within their historical range, vegetation composition and structure are intact, and the risk of losing key ecosystem components from fire is relatively low. Currently, Unit UF-9 is in Condition Class 3, where fire regimes have been significantly altered from their historical return interval. Vegetation condition, structure, and diversity have been substantially changed. Because fire regimes have been extensively altered, the risk of losing key ecosystem components from fire is high. Restoring the historical fire regime may require multiple restoration treatments before prescribed fire can be used to manage fuels or obtain desired ecological benefits.

Bandelier National Monument fire staff is uncertain as to which fuel treatment alternative to implement that provides the highest Net Present Value while protecting life, property, and park resources from the effects of unwanted fire in Unit UF-9.

According to Bandelier National Monument's 1997 Fire Management Plan, the fire staff's goal is to preserve, protect, and manage the park's cultural and natural resources within naturally functioning ecosystems, consistent with cultural resource preservation, in order to protect life, property, and park resources from the effects of unwanted fire.

The following alternatives are evaluated:

A. No Action — the baseline against which all other alternatives are measured.
B. Thinning, hand piling, and burning of downed woody material.
C. Two entries of prescribed under burning.
D. Thinning, followed by two entries of prescribed under burning.

Problem, Goal, and Objectives

Alternatives are evaluated based on whether the treatments result in flame lengths of less than 3 feet and produce a surface fire rather than a crown fire under 90th percentile weather conditions. They are also evaluated on which alternative produces the highest Net Present Value (NPV) over a 20-year time period.

Vegetation data for Fuels Treatment Unit UF-9 was collected by the Bandelier fire effects module using random plot sampling with tree stand input. This data was analyzed to determine tons per acre of surface fuels and trees per acre in Unit UF-9, then evaluated against existing fire and resource management fuel loading and tree density goals. Fire Family Plus was used to analyze historical weather data from the Jemez and Tower fire weather stations, providing 90th percentile weather conditions. Fuels Management Analyst Plus® was used to predict fire behavior under existing fuel load conditions and post-treatment conditions, at both 90th percentile and prescribed fire weather. Fuels Management Analyst® was also used to predict tree mortality. Cost data for full suppression, prescribed fire, and thinning were collected, and Net Present Value was calculated using suppression costs as revenue (representing a fire that did not occur because treatments were applied), minus the costs of the treatments over a 20-year period.

1. Slope variability is substantial in Unit UF-9; a 50 percent slope is used in calculations to represent the average of the more extreme slopes and the flatter terrain.

Methodology and Assumptions

2. Wind speed values are represented on a landscape scale. The wind speed used represents the southwestern slope of the Jemez Mountain Range.

3. Fuel Model 10 represents surface fuel loading with an overabundance of fuels greater than 3 inches in diameter. Fuel Model 8 represents surface fuel loading with fuels greater than 3 inches in diameter reduced by 40 to 80 percent.

4. Prescribed weather conditions used are those necessary to achieve the desired objectives.

5. Trees under 6 inches DBH are in a mixed conifer forest type with Douglas fir as the most abundant species at 70%. Other species included are Quaking Aspen at 18% and White Fir at 12%.

Vegetation Analysis

6. Trees over 6 inches DBH are Douglas fir.

7. Quaking Aspen is not reduced in thinning calculations, as Bandelier National Monument is not targeting this species for reduction.

To avoid bias, random selection was employed for fire effects monitoring plot locations. Data for the plots was gathered by the Bandelier fire effects crew using Brown's methods to inventory downed woody material (Brown 1974). Data is recorded on form FMH-19 (Fire Monitoring Handbook), forest plot fuels inventory data sheet. Inventory data is then entered into DDWoodyPC®, which calculates tons per acre of each fuel element. Surface fuel loading calculations from DDWoodyPC® are then transferred into CrownMass® to calculate fire behavior. Twelve plot locations in UF-9 were read in 2003, resulting in a total fuel load of 49.9 tons per acre.

Tree data is collected at the same plots. Trees under 6 inches diameter breast height (DBH) are measured and their height recorded, as these are considered ladder fuels. Other trees measured include those 6.1 to 19.9 inches DBH, 20 to 50 inches DBH, and dead over-story trees (all dead trees greater than 6 inches DBH). All species are included and labeled according to the area in which they are found. Trees per acre in the area total 690. Tree data is input into CrownMass® to calculate crown fuels characterization, fire behavior, and tree mortality.

The total surface fuel loading in Unit UF-9 is 49.9 tons per acre. The Fire and Resource Management Fuel Loading Objective is to reduce the total fuel load by 40 to 80%, resulting in 10 to 30 tons per acre.

The total 0–6 inch DBH tree density is 445 trees per acre. The Fire and Resource Management Objective is to reduce trees under 6 inches DBH by 30 to 90%. Trees 6.1 to 19.9 inches DBH would be reduced by 20 to 60%. Trees 20 inches DBH and greater are to be maintained at a minimum of 13 trees per acre, and the dead over-story is maintained at 1 to 2 trees per acre.