Methodology
Introduction
Ecological disturbances, such as invasive species and altered fire regimes, profoundly impact carbon storage and stability in ecosystems. These disturbances are particularly significant in dryland soils, which serve as substantial carbon reservoirs but are increasingly vulnerable to species invasions and the exotic-grass-fire cycle, as seen in the sagebrush steppe of North America.
The latest science indicates that the conversion of perennial pastures to invasive annual grasses, currently impacting approximately 1 million acres annually, results in soil carbon losses of 42–49%, with the deepest and most persistent storage horizons being the hardest hit. This equates to annual carbon losses of 1 to 3.5 tCO₂e per acre. While these disturbances reduce soil carbon to a "floor"—a resilient baseline beyond which further losses are unlikely—this highlights a critical opportunity: through restoration, perennial grasses can stabilize and rebuild soil carbon stocks, enhancing long-term ecosystem resilience and contributing to carbon sequestration.
Today, over 100 million acres of U.S. pasture and rangelands are affected by invasive annual grasses, with an additional 75 million acres projected to be impacted within the next decade. Conversion from perennial to invasive annual species contributes to a vicious invasive-fire cycle. These invasive species burn more frequently and at higher intensities than native perennials, perpetuating the degradation of soil carbon and ecological stability.
However, targeted interventions that both protect existing ecosystems and enable restoration of degraded areas offer a promising pathway to reverse these trends. In treated pastures where the spread of invasive species is controlled, and native perennial species are re-established, further soil degradation can be prevented and reversed as deeper root systems, increased biomass, and improved soil coverage work to progressively rebuild soil organic carbon (SOC). This process creates a distinctive carbon asset characterized by:
Avoided Emissions: Preventing the conversion of native perennial grasslands into exotic annual species.
Carbon Removal: Restoring native perennials to sequester atmospheric carbon in degraded rangelands.
This methodology integrates cutting-edge science and ecological principles to quantify and capitalize the carbon benefits of rangeland restoration, ensuring measurable contributions to the global carbon cycle while improving ecosystem resilience.
Climate Impact
Research findings highlight the profound impact of exotic annual grass (EAG) invasions and wildfires on carbon storage within the sagebrush steppe ecosystems of North America, a vital dryland carbon reservoir. Key findings include:
Soil Carbon Depletion: EAG invasions and wildfires lead to a loss of 42–49% of soil carbon, particularly from deep soil horizons, which store 66% of the region's carbon.
Total Carbon Loss: Degraded areas release approximately 18.5 million metric tons of carbon per year. This represents about 1% of the total carbon stored in Western U.S. cold desert soils, or the rough equivalent to 16 million gas-powered passenger vehicles.
Aboveground Biomass Reduction: Areas affected by wildfires lose 93% of aboveground biomass, while invaded areas lose 55% compared to intact ecosystems.
Ecosystem Shift: Invasion accelerates the replacement of deep-rooted native perennials with shallow-rooted annual grasses, creating a "grass-fire cycle" that perpetuates frequent, intense wildfires and further carbon loss.
Global Relevance: Similar exotic grass-fire cycles impact ecosystems worldwide, including Central and South America, Hawaii, and Australia, with unknown consequences for global carbon stocks.
Conservative estimates suggest carbon losses could reach 75 million metric tons of CO2e by 2030 - just over 1% of total annual U.S. GHG emissions. Remarkably, these emissions stem primarily from just 1-2 species of invasive plants, underscoring the critical importance of addressing this issue in national climate strategies.
These estimates only reflects the lower bounds of avoidable emissions and do not account for the potential carbon removals from restoring the 100 million acres already affected. When combining both avoidance and restoration efforts, the total carbon impact could exceed 100 million metric tons of CO2e annually, making this strategy essential for long-term climate mitigation.
This analysis emphasizes the urgent need for restoration and proactive management of native perennial shrublands. Stabilizing soil carbon stocks and reversing the shift of these ecosystems from carbon sinks to carbon sources are essential steps to mitigating global greenhouse gas emissions and ensuring ecosystem resilience.
Biochemical Management Mechanism
Indaziflam, the active ingredient in Rejuvra®, is a pre-emergent herbicide that targets the seed bank of invasive annual grasses. It works by inhibiting the growth of new weeds before they can establish, providing long-term control. Indaziflam’s unique formulation prevents weed seeds from germinating without affecting established perennial plants, making it particularly effective for rangeland restoration. It is also known for its stability, as it is not easily degraded by sunlight and does not volatilize, allowing it to remain active in the soil for extended periods. This makes it a valuable tool for controlling invasive species in both public and private lands.
Rejuvra® is approved for use in a wide range of environments, including rangelands, Conservation Reserve Program (CRP) lands, natural areas, parks, wildlife management areas, recreational spaces, fire rehabilitation zones, prairies, and firebreaks. It is also safe for areas that are grazed or cut for hay. Registered with the EPA, Rejuvra® is approved for use on both public (BLM) and private lands across 14 states, including Washington, Oregon, California, Nevada, Idaho, Montana, Wyoming, Utah, Colorado, New Mexico, Kansas, Nebraska, and the Dakotas.
Indaziflam's long-term, stable control of invasive grasses while preserving native perennials makes Rejuvra® an ideal choice for large-scale rangeland protection and restoration efforts. In alignment with the R3 mission, key advantages include:
Wide approval for diverse environments: Rejuvra® is approved for use across various landscapes, including public and private lands.
Proven success in restoring rangeland health: It has demonstrated effectiveness in promoting rangeland recovery.
Sustained control of invasive annuals: One application provides long-lasting results, reducing the need for frequent and costly retreatments.
Supports recovery of desirable perennials: Native plants can regain dominance, enhancing rangeland ecosystems.
Enables productive grazing: Grazing can continue with minimal disruption, benefiting ranchers economically.
Co-Benefits
Cheatgrass landscapes burn 4x more frequently than in native vegetation types - Jolie Pollet, Division Chief of Fire Planning & Fuels Management BLM
In the context of climate mitigation market mechanisms, co-benefits refer to the additional positive outcomes that occur alongside the primary goal of reducing or avoiding GHG emissions. While the main focus is often on carbon reduction, co-benefits can enhance the overall value of a project or action.
Rejuvra® delivers a range of co-benefits that extend beyond carbon mitigation, making it a powerful tool for climate action and rangeland restoration. These co-benefits include:
Wildfire Mitigation: By reducing fine fuel loads and increasing perennial plant cover, Rejuvra® lowers the intensity and spread of wildfires. Even one prevented fire can significantly protect community resources and enhance long-term ecosystem resilience.
Water Retention: Enhanced soil health conditions improve water holding and filtration capacity, which is critical in arid regions with low precipitation, contributing to more sustainable land management.
Watershed Quality Impact: Deeper roots and better ground cover reduce soil erosion, while mitigating fire impacts provides substantial, though often unmeasured, benefits to watershed health and water quality.
Enhanced Biodiversity: Rejuvra® encourages a greater variety of plant and animal species richness, which protects and restores native wildlife habitats.
Desirable Forage Increases: Measured increases of forage availability by 2-10 times in previously affected areas, improving the productivity of grazing lands and directly benefiting ranchers' livelihoods.
Improved Livestock Health: A diverse range of forage species leads to better body condition scores (BCS) for livestock, resulting in healthier, more productive and profitable animals.
These co-benefits not only enhance rangeland restoration but also offer tangible economic, environmental, and social returns, aligning with the R3 initiative's mission. Alongside carbon as a financing mechanism, R3 will explore alternative pathways related to these co-benefits, with the specific focus on:
Increased Forage: Financed through agricultural lenders to boost productivity and profitability for ranchers.
Wildfire Mitigation and Watershed Protection: Supported by municipal green bonds to reduce fire risks and enhance water quality.
The primary limitation to these pathways (and carbon financing) is the current lack of sufficient science to underwrite outcomes with statistical confidence. Each financing strategy will require a scale-up period alongside continued research and transparent risk mitigation to ensure credibility in the environmental marketplace.
Quantification of Climate Mitigation Benefits
As R3 develops its framework, the United States Geological Survey (USGS) has published a comprehensive study quantifying the carbon impact of invasive annual grasses on Western rangelands. This landmark research focuses on soil carbon stocks to depths of 100 cm across key inter-mountain ecoregions within the sagebrush steppe, including the Northern Great Basin, Snake River Plain, and Idaho Batholith. The study underscores the profound effects of invasive annual grasses and altered fire regimes on carbon storage, revealing a 42–49% depletion in soil carbon stocks, with the greatest losses observed in deeper soil horizons. Annually, approximately 20 million metric tons (Tg) of carbon are released across the ~400,000 hectares of sagebrush steppe degraded by wildfire and invasion—a significant fraction of the region's soil carbon pool.
The research also introduces the concept of a "soil-carbon floor," where remaining carbon reaches a resistant baseline below which further losses are unlikely. While these findings highlight the magnitude of degradation, they also signal potential for stabilization and recovery through targeted restoration efforts. The USGS study provides foundational data for developing a regional carbon model, offering critical insights into the dynamics of soil carbon loss and restoration across Western rangelands.
Building on these findings, R3’s methodology leverages two key quantification approaches: one for carbon avoidance and another for carbon sequestration. These dual objectives require clear delineation of boundaries between avoided emissions and restored carbon stocks. Tools like Envu’s RangeView™ facilitate this by using satellite imagery to establish the baseline extent of invasive annuals and prioritize interventions.
With the comprehensive data and tools provided by the RangeView™ platform, R3 can effectively map, monitor, and manage invasive species, ensuring targeted interventions in rangelands. This detailed tracking enables R3 not only to restore ecosystems but also sets the stage for quantify the broader environmental benefits as follows:
Use RangeView™ to estimate the total area invaded as a percentage of the project area.
Extrapolate the future impact zone over five years, assuming a 15% annual cheatgrass invasion rate (the accepted scientific rate of cheatgrass encroachment).
Claim carbon avoidance on the projected invasion zones by either:
Measuring, modeling, and remeasuring, or
Measuring and modeling only.
Claim carbon removals on existing invasion zones where Rejuvra® was applied by:
Measuring, modeling, and remeasuring.
This structured approach, driven by high-accuracy data and ongoing monitoring, allows for precise quantification of both carbon avoidance and sequestration, providing valuable insights into the climate mitigation benefits of rangeland restoration efforts.
Below is an example of a pasture that is 50% invaded at pre-treatment and the projected climate benefit results:
These results visually illustrate the projected mitigation of cheatgrass invasion over a five-year period, aligning with the example scenario shared earlier. As seen in the Low, Medium, and High Avoidance Scenarios, the combination of carbon sequestration and avoidance directly correlates to the scale of cheatgrass control and restoration efforts. Conservatively assuming ~ 0.5 tCO2e/ac in avoided emission per year (note, studies suggest a range closer to 1-3.5 tCO2e/ac per year) over five years, cumulative carbon avoidance reaches just under 1 tCO2e in the Low Scenario, over 1.5 tCO2e in the Medium Scenario, and exceeds 3 tCO2e in the High Scenario. This demonstrates how effective cheatgrass management can significantly reduce emissions while restoring rangeland health, with avoidance consistently playing a key role in the total climate mitigation impact.
Monitoring, Reporting & Verification
The RangeView™ platform is designed for Monitoring, Measurement, Reporting, and Verification (MMRV) of infested areas and for ensuring the ongoing protection of project sites. It utilizes satellite reflectance data, which measures sunlight reflected from the Earth’s surface, corrected for atmospheric effects. This data helps analyze land cover and assess vegetation health. The platform also incorporates high-resolution daily imagery to enhance monitoring precision.
Additional data sources include the Soil Survey Geographic Database (SSURGO), providing detailed soil properties and productivity information, and meteorological data to understand climate conditions and predict weather patterns. Ground-level data, collected since 2019 by Envu and Satelytics, includes verified geospatial and reflectance data through sub-meter GPS units and backpack spectrometers. This comprehensive dataset underpins cheatgrass infestation mapping across the western U.S.
To further support cheatgrass predictions, the model trained on approximately 250,000 observations of native and exotic grasses achieves an accuracy rate of 94%. Ongoing ground verification ensures the model's continued accuracy and helps verify interventions.
The current process for treating pastures involves identifying at-risk areas, mapping them through the RangeView™ platform, and sharing these target zones with aerial applicators for precise herbicide application.
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