The landscape is one of the top 10 most important landscapes in the Great Basin ecoregion because of its high biodiversity at the junction of the Great Basin, Mojave Desert, and Colorado Plateau ecoregions. The landscape is also at the western edge of the North American Monsoon that supports vegetation types not usually found in the western Great Basin. While the Pine Valley Mountains are known for a large mule deer populations and extensive browse communities such as Utah serviceberry, Dixie chaparral, different sagebrush systems, and aspen woodlands and forests, recent analyses by The Nature Conservancy (TNC) show that its location near the Virgin River (and Colorado River drainage) and tributaries (e.g., Santa Clara River) provide an important corridor with water resources for animal species dispersing north among the Mojave Desert, the Great Basin, and the Utah High Plateau. The PVRD is a heavily used outdoors recreation area and a hydrologic reservoir to both local economies and water-dependent species. Using TNC's 2012 mapping for Landscape Conservation Forecasting (LCF), the PVRD implemented fuels reduction treatments and experienced many wildfires totaling short of 100,000 acres. The landscape was also designated by the USFS Chief as a Wildfire Crisis Landscape and monitoring funding was allocated to track progress towards achieving goals. The project needs are: 1) economically update with change detection methods the 2012 vegetation map with high resolution satellite imagery and modernized vegetation classification that could be used for LCF modeling and new treatment planning with future funding, 2) analyze the success/failure rates of treatments as vegetation class outcomes since 2012 that will be compared to LCF model assumptions, 3) analyze the vegetation outcomes of non-treatment disturbances and identify need of immediate new treatment areas.

For fiscal years 2026 to 2027, we propose to: 1) Conduct high-resolution change detection remote sensing mapping of ecological systems and their vegetation classes by: a. ordering Spot 6 satellite imagery in early June 2025 (before FY2026 funding year, but required), b. conducting imagery (2012 RapidEye)-to-imagery (Spot 6) comparison using a variety of standard statistical tools to identify changed pixels that will be visited in the field; c. conducting an early July survey to match spectral signatures to vegetation types at detected change locations; and d. completing desktop analysis of vegetation layers. 2) Initial sorting of changed pixel groups by partitioning change among true disturbance change, classification change (scientific renaming of vegetation classification without real change), and both classification and true change. 3) Analysis of true change by: a. partitioning area of change among treatment success (e.g., seeding without cheatgrass), partial success (e.g., seeding with perennial grass and cheatgrass), and failure (e.g., seeding dominated by cheatgrass); b. partitioning the pathways of vegetation class change not caused by treatments (e.g., amount of area not dominated by cheatgrass after wildfires at different elevations); and c. measure change in ecological departure from 2012 to 2025. 4) Write final report.

The PVRD is a USFS Wildfire Crisis Landscape that received federal IRA funding for monitoring. Since 2012, PVRD used existing implementation funding to reduce fuels loads and fire risk mostly working at the wildland-urban interface. There is a requirement to report on the success of those fuels treatments, which this proposal should partly satisfy. However, wildlife habitat improvements that were simulated as part of the 2012 LCF project have not been implemented or delayed as priority was given to hazardous fuels projects because of the Wildfire Crisis Landscape status. PVRD is requesting a new map so the delayed wildlife improvement projects can move forward with current data. Ground-truthed change detection remote sensing is the most cost-effective per unit area form of monitoring and mapping for previously mapped landscapes, especially large ones, because it specifically measures change between at least two dates (monitoring requires at least two dates to measure change). TNC in UT and Nevada have reserved time prior to another WRI proposal (#7363; therefore, no field work overlap) made possible by the southern location. TNC also has an interest in the PVRD mapping as it has proven difficult to find funding to verify model assumptions based on real change data, especially in a landscape of great biodiversity at the edge of the Great Basin ecoregion.

This project will update at high resolution ecological systems and vegetation class map layers and measure ecological departure that will inform efficacy of recent treatments and allow USFS and state land managers to plan for effective wildlife management and riparian management. Two important game species will benefit: primarily mule deer and, to limited extent, elk. The Pine Valley Mule Deer Herd Unit #30 is well studied by UDWR where the population was 13,500 individuals in 2014 with the stated 2015-2020 management objective of 16,000 individuals. Unit #30 is larger than the PVRD but most mule deer are found in the Pine Valley Mountains. Uncharacteristically large wildfires since 2010 caused burns in areas dominated by non-native annual species and conifer encroachment in shrublands and aspen-conifer were reported to degrade habitat. The elk population in the Pine Valley Elk Herd Unit #30 is currently estimated between 50-75 animals and stable, with a state objective of 50 individuals. While the Utah State Wildlife Action Plan (2015-2025) is not as specific as single species management plans shown below, it did identify in Key Habitats sections for aspen-conifer and various shrublands (sagebrush and mountain browse) the need to improve habitat by reducing conifer dominance and encroachment and recruited younger vegetation classes using various restoration tools and in partnership with federal agencies and private landowners. Utah Mule Deer Statewide Management Plan: A. Watershed Restoration Initiative a. Continue to support and provide leadership for the Utah Watershed Restoration Initiative, which emphasizes improving sagebrush-steppe, aspen, and riparian habitats throughout Utah. b. Work with land management agencies, conservation organizations, private landowners, and local leaders through the regional Watershed Restoration Initiative working groups to identify and prioritize mule deer habitats that need enhancement or restoration. Emphasis should be placed on crucial habitats including sagebrush winter ranges and aspen summer ranges. d. Initiate broad scale vegetative treatment projects to improve mule deer habitat with emphasis on drought or fire damaged sagebrush winter ranges, ranges that have been taken over by invasive annual grass species, and ranges being diminished by encroachment of conifers into sagebrush or aspen habitats, ensuring that seed mixes contain sufficient forbs and browse species. e. Encourage land managers to manage portions of pinyon-juniper woodlands and aspen-conifer forests in early successional stages using various methods including timber harvest and managed fire. Utah Statewide Elk Management Plan B. Habitat Management Goal: Conserve and improve elk habitat throughout the state. Habitat Objective 1: Maintain sufficient habitat to support elk herds at population objectives and reduce competition for forage between elk and livestock. Strategies: C. Habitat Improvement a. Utilize Habitat Council, Utah Watershed Restoration Initiative, Wildlife Conservation Permit funds, and other funding mechanisms to restore or improve crucial elk habitats. b. Increase forage production by annually treating a minimum of 40,000 acres of elk habitat. c. Coordinate with land management agencies, conservation organizations, private landowners, and local leaders through the regional Watershed Restoration Initiative working groups to identify and prioritize elk habitats that need enhancement or restoration. i. Identify habitat projects on summer ranges (aspen communities) to improve calving habitat and summer forage. ii. Encourage land managers to manage portions of forests in early succession stages using controlled burning, logging or other methods. Controlled burning in areas with invasive weed and/or safety concerns should be supported only when adequate planning and mitigation measures have been identified. iii. Promote Fire Use (let-burn) policies in appropriate areas that will benefit elk, and conduct reseeding efforts post wildlife.

PVRD staff stated that various shrublands (sagebrush and, especially, mountain browse), aspen-mixed conifer, aspen-subalpine conifer, contain extensive woody (heavy fuels) fuel loadings typical of historically fire-excluded landscapes. Fuels loadings in lower and middle elevations are not in compliance with the natural range of variation as closed-canopy vegetation classes dominate many areas. Staff are also concerned by the extent of burned shrublands dominated by non-native annual species and the high fire risk that non-native annual species presence in understories pose to unburned shrublands and true subxeric woodlands such as pinyon-juniper and curl-leaf mountain mahogany. Finally, increased fire risk from lower elevation ignitions causing uncharacteristic large high-severity fires to montane forests such as ponderosa pine with fuel ladders and to waterways, because of sedimentation, also worry PVRD staff.

The Pine Valley Mountains is in the watershed of the Santa Clara River, a tributary to the Virgin River. Different creeks on the east side flowing underneath I-15 eventually reach the Virgin River, and western subbasins of the PVRD likely contribute surface and groundwater flows to Beaver Dam Wash. The Santa Clara River and Virgin River support sensitive and federally-listed fish species. The cities and towns of St. George, Enterprise, New Harmony, and the Shivwits Reservation obtain all or important volumes of surface and groundwater water from the Pine Valley Mountains. The main threat to water quality is likely sedimentation and powerful debris flows in burns after high severity fires followed by at least 25-year precipitation events. The fate of water quantity is less clear after high severity wildfire and tree removal at lower and middle elevations because soils and vegetation are water limited; therefore, change in canopy structure would only cause a shift in species dominance and uptake of soil moisture without release of surplus water. At subalpine elevations, however, water quantity might be changed through carefully placed tree thinning actions in forested close canopy systems.

Not applicable as no proposed physical action will be used anywhere in the AOI.

The Nature Conservancy proposes: 1. April to May 2025 (prior to award but essential step): TNC staff works with forest botanist and wildlife biologist to revise outdated 2012 vegetation description. 2. April-May 2025 (prior to award but essential step): Remote sensing contractor orders Spot 6 satellite imagery from Airbus Defence and Space for capture during the last week of May to early June depending on snow cover. 3. June 2025 (prior to award but essential step): Remote sensing contractor performs image-to-image statistical comparison analyses. Image-to-image analysis algorithms include image subtraction, vegetation index comparison, and principal components analysis. Allowed cutoff variance for change detection will vary among techniques due, in part, to annual precipitation differences. While variance cutoffs will be used, tools will not be allowed to be fully automated to detect differences and the final step of analysis will be manually examined. 4. July 2025: Remote sensing contractor and TNC staff conduct field survey for at least 10 days where all passable roads will be driven, some trails will be hiked, and 2.5 days (7 hours per day, including taxiing) of helicopter will be used for remote and rugged areas. At each selected spectral signature, the ecological system and vegetation class and local biophysical observations will be noted (as per the revised vegetation description), the most likely cause of change noted, and at least one ground and landscape photographs will be taken before moving on to the next site. 5. August 2025 to September 2026: Remote sensing contractor conducts desktop change detection remote sensing analysis with the 2012 and 2025 satellite imageries supplemented with observations. Delivery of ecological system by vegetation class raster map (tiff format to TNC) in September 2026. 6. September 2025 to October 2026: Remote sensing contractor creates a table and rasters of area change partitioned among real change due to disturbances, classification change due only to renaming an ecological system and, occasionally, vegetation class, and classification and real change (disturbance caused a class change but the system or class were also renamed). 7. October 2026 to December 2026: TNC staff estimate (i) the success/failure rates of management actions by measuring the proportions of treatment area that was intended (success), partially intended with undesirable components, and not intended and not desirable over 13 years; (ii) the change in ecological departure per system from 2012 to 2025; and (iii) the proportions of change among vegetation classes from the original vegetation class due to recognizable disturbances (e.g., fire, drought/insect mortality, flooding, and so on). 8. June 2026 -January 2026: Write and submit final report and deliver geodata to WRI and USFS PVRD.

While remote sensing field work will occur once to match spectral signatures to vegetation in the field, no true (repeated) field monitoring (e.g., of wildlife or vegetation) will be conducted during the project. Project progress will be measured by 1) the completion of field work, 2) delivery of the raster-based vegetation maps (ecological system and vegetation class), and 3) delivery of final report and geodata containing the analysis of measures of success for treatments and ecological departure, and of rates of natural disturbances.

The partner organization is the Pine Valley Ranger District of the Dixie National Forest. TNC staff Elaine York (Utah) and Louis Provencher (Nevada) have been in discussion with PVRD staff Rhett Boswell (wildlife biologist) and different District Rangers (more recently, Joe Rechsteiner) for three years about funding change detection and even Landscape Conservation Forecasting modeling and metric estimation. Rechsteiner, Boswell, York, and Provencher recently discussed the details of a proposal focused on monitoring through change detection remote sensing on November 20 and December 11, 2024.

No management will occur during the project as the result of modeling (but existing proposed actions will continue) because the entire LCF process is to inform new management decisions by federal and state agencies and landowners, and help the federal regulatory process (NEPA) in future years. However, USFS managers will be able to use update map layers after delivery of the updated vegetation layers in December 2026.

This two-year project should inform future natural resource management by determining past treatment effectiveness per ecological system and treatments to either promote or minimize in the future. Also, the new vegetation map will allow USFS to improve mule deer habitat, which will also benefit elk, and seek funding to complete the modeling and metric calculation for a revised Landscape Conservation Forecasting project without incurring the sizable cost of remote sensing. Treatments that could be implemented based on 2012 simulations and a new map would attempt to 1) reduce conifer dominance in aspen-conifer and shrublands, 2) recruit younger or more palatable forage for herbivores, 3) reduce the risk of extensive high severity fires, and 3) reduce the area of closed-canopy conifer classes in naturally open-canopy conifer forests.