Skip to content

Do spatial simulations change reference conditions?

Published Article

Nevada, United States

Publication date: April 20, 2026

File format: URL

View resource

This study evaluates differences in reference vegetation conditions generated by spatial and non-spatial state-and-transition simulation models across ecological systems in eastern Nevada. Results show that spatial simulations produce shorter fire return intervals and different vegetation class proportions, especially in small systems and those with long fire return intervals, with important implications for vegetation treatment and management decisions.

Subject Tags

  • Land management
  • Fire management
  • Ecosystem management

Abstract

The reference condition is the expected proportions of reference vegetation classes per ecological system (hereafter, system) within an area and has been measured with non-spatial state-and-transition simulation models (STSM). We aimed to Demonstrate that reference conditions varied between non-spatial and spatial STSMs from an eastern Nevada USA landscape. The same STSM database was used to simulate the non-spatial and spatial reference conditions, except additional input were added for spatial simulations. The reference condition was obtained from averaged vegetation class proportions of replicated simulations. Mean fire return intervals (MFRI) were always shorter in spatial than non-spatial simulations. The dissimilarity between the spatial and non-spatial reference conditions was generally higher for smaller systems and those with long MFRIs (≥ 100 years). Non-spatial and spatial reference conditions were comparable for large systems with 50-100-year MFRI. The proportions of older vegetation classes for spatial systems were smaller for large systems with long MFRIs compared to non-spatial results, but those proportions were larger for smaller systems with shorter MFRIs likely because fires can spatially exit small narrow systems. National and local assessments that use departure from non-spatial reference conditions to determine vegetation treatments should recognize that spatial simulations can lead to revisions of treatments decisions.

Citation

Provencher, L., Byer, S., Badik, K., Horner, M., Hamilton, B., Mchugh, D., ... & Saito, L. (2026). Do Spatial Simulations Change Reference Conditions?. International Journal of Wildland Fire, WF25169.

TNC Authors

TNC Authors