Allometric Relationships to Calculate Aboveground Biomass for Eight Rangeland Shrubs Using the SageSTEP Network

Accurately estimating shrub biomass in sagebrush-dominated ecosystems is essential for understanding fire behavior, fire effects, and other ecological processes. Traditional destructive sampling methods, while highly accurate, are time-consuming and labor-intensive. Allometric equations employ a double sampling technique, which correlates destructively sampled biomass measurements with field-measured height and canopy size. However, allometric equations are limited by the species and location they represent. To create new allometric equations that encompass 8 shrubland species and span a range of site conditions, we sampled 631 shrubs of eight species at 13 sites in the Great Basin within the Sagebrush Steppe Treatment Evaluation Project (SageSTEP) monitoring network. This effort generated both generalized species-specific and site-specific biomass equations through linear regression models. This dual modeling approach offers users the flexibility to apply general species relationships or tailor biomass estimation based on geographical location or species distribution. Additionally, our research provides biomass estimates within fuel size classes, enhancing the utility of these equations for future research and management applications in the Great Basin. Our equations are shared as R code and an spreadsheet, allowing users to implement these equations. By advancing the availability and precision of allometric equations for upland shrub species, our study contributes valuable tools for understanding shrub biomass dynamics in sagebrush shrubland ecosystems.