Pritzlaff Ranch

This virtual tour of forest restoration completed at the Pritzlaff Ranch in northern New Mexico is intended to create a visual example of desired conditions in forest restoration.

What should a forest look like after a restoration project? In an age of increasing threats to the health and productivity of ecosystems, restoration and maintenance of ecosystem function and resilience should be an integral part of forest management plans. Desired conditions include attributes and characteristics that comprise structure, function, and composition of resilient systems while providing services that benefit both people and nature. One common result of restoration protocols, especially in southwestern ponderosa pine, is a residual stand with grouped trees and much more grass on the forest floor.

This Story Map highlights three different examples of the role restoration plays in achieving desired conditions, each developed with different emphases: remnant-based structural restoration, northern goshawk habitat, and genetics. Original Story Map imagery was collected April 2021.

This Story Map was updated to include June 22 imagery of the three stands after the Calf Canyon/Hermit's Peak Fire. The CCHP was the largest and most destructive wildfire in recorded history in New Mexico. The fire was formed from the merging of two individual wildfires—the Hermits Peak Fire and the Calf Canyon Fire—which started on April 6 and April 19 respectively, and burned into each other during extreme fire weather conditions on April 22, 2022. Afterwards, the two fires were referred to and managed as a single incident, or fire complex. The Calf Canyon/Hermits Peak Fire burned 341,471 acres, first igniting on April 6, growing until June 24, and not being declared 100% contained until August 21st.  ^[1]   The fire destroyed at least 903 structures and damaged 85 more, including hundreds of homes, and threatened more than 12,000 other structures in many communities in the region.

Forest Restoration prescriptions generally have these common goals:

• Reduce the severity of forest fire
• Increase the resilience to climate variability, insects, and disease
• Restore hydrologic function of the area
• Improve plant and animal habitat and biodiversity

Forest Restoration works in part with the larger goal of Ecological Restoration. Ecosystem restoration approaches not only reduces severe fire threats, but also works to improve forest health and resource use opportunities for present and future generations.

Thinning forest stands help to improve forest function and reduce the threat of catastrophic wildfire. There are different ways to thin forest stands according to different restoration prescriptions. At the Pritzlaff Ranch three different restoration prescriptions are highlighted.

Between 2008-2009, The New Mexico Forest and Watershed Restoration Institute marked and helped coordinate the thinning of 11 acres according to three different restoration guidelines. These 11 acres were almost pure ponderosa pine, with some Gambel oak and an occasional Douglas-fir. On these sites a prescribed burn took place in November of 2010.

Before European settlement, western forests had a more frequent fire history. Over time these frequent-fire forests became adapted to low intensity surface fire as a regulatory mechanism. Under natural conditions, frequent fires kept tree populations in check, prevented fuel accumulation, and improved understory productivity. Ponderosa pine stands were characterized by groups of trees growing in a matrix of grass.

Current conditions of increasingly dense and homogenous forest stands are a result of several factors. These factors include but are not limited to: fire exclusion, overgrazing of fine surface fuels, over-cutting of old growth trees, and failure to control density and composition of young trees.

Looking back at the historical record to determine forest reference conditions, using tree ring and fire history analysis, is a starting point for forest restoration. Keeping in mind reference conditions vary with soil type, elevation ranges and climatic regimes, there are general patterns that occur. A remnant-based restoration protocol takes these local conditions into account, while reestablishing pre-settlement groups and openings (Waltz et al, 2019, ERI Working Paper No. 41).

General Principles for developing Remnant-Based Prescriptions:

• Retain all old, yellow ponderosa pine, regardless of size, form, or damage

• Locate remnant evidence of pre-settlement trees, including stump holes, stumps, and snags  

•  Retain better post-settlement trees closest to the remnants, at ratios of 1.5 larger diameter trees per remnant, up to 3 small-diameter trees per remnant

• Stay within an envelope of sustainability

• Thin and remove excess trees

• Burn at more natural intervals to hold tree densities and fuel loads in check

Frequent-fire forests had an uneven-aged structure consisting of different aged tree groups and scattered individual trees in an open grass-forb-shrub landscape. This spatial and temporal pattern provided and sustained plant and animal habitat and biodiversity. The remnant-based protocol is founded on the idea that since the pre-settlement system functioned as it had evolved to function, and that pre-settlement trees were established during that time, a good way to reestablish a properly functioning system is to establish groups and leave open areas as they were at settlement.

Key compositional and structural elements of our restoration framework are: (1) species composition (tree and understory vegetation); (2) groups of trees; (3) scattered individual trees; (4) open grass-forb-shrub interspaces between tree groups and individual trees; (5) snags, logs, and woody debris; and (6) variation in arrangements of these elements in space and time.

This framework is informed by

• Remnant evidence (conditions of ecosystems before significant industrial human disturbance),

• Natural ranges of variability

• Observed changes in disturbance regimes, and

• Lessons learned during applications in frequent-fire forests in the Southwest.

The type, frequency, and severity of disturbances (e.g., fires, insects, and diseases) played an important role in shaping the historical composition, structure, and function of frequent-fire forests. Therefore, where forest composition and its structure allow, the framework recommends that fire, the primary historical disturbance agent in these forests, play a prominent role in their restoration. 

Walk through this Remnant-based Patch by clicking on the image below. Click on the arrows to advance through the image. This 360 image was collected in May 2021. If you would like to view this tour in a separate window  click here.  

The center treatment area was thinned according to Northern Goshawk guidelines in order to improve the habitat of 14 species that the goshawk preys upon. The 14 prey species include forest birds and small mammals in which the thinning guidelines make considerations for by leaving a combination of open and closed tree spacing.

The northern goshawk (Accipiter gentilis atricapillus) is the largest North American member of the genus Accipiter, which includes both the sharp-shinned hawk (A. striatus) and the Cooper's hawk (A. cooperii).

The principal forest types occupied by the goshawk in the Southwest are ponderosa pine, mixed-species, and spruce-fir. Populations and reproduction of the goshawk are declining in these forests and elsewhere in the western United States. Because of the concerns over the effects of timber harvesting, the goshawk was listed as a "sensitive species" by the Southwestern Region of the Forest Service in 1982.

Nest areas are a key component of goshawk home ranges. Goshawks nest in older-aged stands that have a high density of large trees, high tree canopy cover, and high basal areas. Nest areas are usually on cool, shady slopes or canyon sides, and near streams. (GTR RM-217)

About the time this patch was thinned, the Goshawk guidelines were transitioning into a more general set of guidelines, Desired Conditions (RMRS GTR-310), that carried forward the same focus on tight groups and extensive openings. An early version of Desired Conditions thinning protocols were applied to this stand, although it always has been called the Goshawk patch.  

General Principles for developing Desired Conditions-Based Ponderosa Pine Prescriptions: 

1)      Groups vary in area between 0.1 and 0.75 acres.

2)      Openings between groups ideally are the same distance as the diameter of the group, but this can vary depending on pre-treatment stand conditions. 

3)      The largest trees and the smallest trees in the stand should be retained. 

4) Within a group, the trees ideally will be about the same diameter and height, to avoid the presence of ladder fuels that can carry fire into mature canopies. 

5) About 10% of the groups will have the trees removed during the initial thinning so that natural regeneration will occur, forming new groups. 

6) Snags and large downed logs are retained.

Walk through the Northern Goshawk patch stand by clicking on the image below. Click on the arrows to advance through the image. This 360 image was collected in May 2021. If you would like to view this tour in a separate window  click here.  

The easternmost treatment site was thinned according to genetic characteristics, using a “Lean Wolf 2 Low Doc” guideline. Trees were removed if they met the following criteria: 1) Leaner, 2) Undesirable branch structure (a wolf tree) 3) Two (2) or split topped 4) Sickly or low vigor5) Diseased or unhealthy 6) Overtopped or suppressed, 6) Crooked or sweep.

Trees with visible nests were left no matter the condition of the tree. Spacing, clumping, and openings of the trees were not considered. Small-diameter trees were removed more strictly than bigger ones.

Walk through the Genetics Patch forest stand by clicking on the image below. Click on the arrows to advance through the image. This 360 image was collected in May 2021. If you would like to view this tour in a separate window  click here.  

The Hermit's Peak/Calf Canyon Fire began as a  prescribed fire  in the Pecos Wilderness area of the Santa Fe National Forest on April 6, 2022. On April 19, another wildfire began in Calf Canyon when a US Forest Service  pile burn holdover  from the previous winter reemerged. The two fires merged a few days later and by the end of the month almost 150,000 acres of forest had burned.

The Hermit's Peak/Calf Canyon fire went through the Pritzlaff Ranch area between April 23 and 24, a little over two weeks after the fire started. The satellite images below were collected in June 2021 and June 2022. Use the swiper to see how much forest was lost during the Hermit's Peak/Calf Canyon fire. The images are not true color, but green still represents healthy vegetation and brownish red shows burned or damaged vegetation (the white objects in these images are clouds, not smoke).

Below is a map showing the soil burn severity in the area of Pritzlaff Ranch. Soil burn severity focuses on the impacts a fire had on the soil rather than vegetation. Fire can affect the biological and physical conditions of soil, turning healthy soil into ashy, loose grains that cannot support vegetation regrowth and can no longer retain water. Soil that cannot absorb and retain water means there will be a greater chance of flooding after rainstorms. Soil burned in the Hermit’s Peak/Calf Canyon fire contributed to devastating floods that impacted local residents as well as the entire city of Las Vegas, New Mexico.

Proper forest management and forest restoration are effective ways to reduce the severity of forest fire which can directly impact soil burn severity.

For more information about the Calf Canyon/Hermit's Peak Fire, visit our  Story Map .

Stand characteristics before and after thinning prescriptions provide insight on how much the stands have changed with time and assess whether desired conditions have been achieved. The measurements below were acquired using common stand exam monitoring techniques.

The Pritzlaff Ranch restoration treatments highlight the capacity for restoration efforts to reflect unique management goals and desired forest conditions that can help to improve forest function and reduce the threat of catastrophic fire. In partnership with post treatment monitoring, forest restoration can contribute to an adaptive ecosystem management framework in which the resilience of both ecosystems and communities are strengthened.

Follow  NMFWRI’s  series of StoryMaps that highlight further forest restoration efforts across New Mexico. 

These websites provide more information about Forest Restoration:

References:

Reynolds, Richard T.; Graham, Russell T.; Reiser, M. Hildegard. 1992. Management recommendations for the northern goshawk in the southwestern United States. Gen. Tech. Rep. RM-GTR-217. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 90 p. https://www.fs.fed.us/rm/pubs_rm/rm_gtr217.pdf

Reynolds, Richard T.; Sanchez Meador, Andrew J.; Youtz, James A.; Nicolet, Tessa; Matonis, Megan S.; Jackson, Patrick L.; DeLorenzo, Donald G.; Graves, Andrew D. 2013. Restoring composition and structure in Southwestern frequent-fire forests: A science-based framework for improving ecosystem resiliency. Gen. Tech. Rep. RMRS-GTR-310. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 76 p.  https://doi.org/10.2737/RMRS-GTR-310 .

VanderSchaaf, C. L. (2013). Reineke’s stand density index: a quantitative and non-unitless measure of stand density. Proceedings of the 15th Biennial Southern Silvicultural Research Conference. Gen. Tech. P. 577–579.   https://www.srs.fs.usda.gov/pubs/gtr/gtr_srs175/gtr_srs175_577.pdf