Diverse landscapes yield diverse outcomes: Variation in response to land management interventions

Authors: Harrison, Georgia; Bestelmeyer, Brandon; Burkett, Laura; James, Darren; McCord, Sarah

Submitted to: Ecological Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2025
Publication Date: 8/15/2025
Citation: Harrison, G.R., Bestelmeyer, B.T., Burkett, L.M., James, D.K., McCord, S.E. 2025. Diverse landscapes yield diverse outcomes: Variation in response to land management interventions. Ecological Society of America Abstracts. Abstract.

Interpretive Summary:

Technical Abstract: Assessing the effectiveness of restoration treatments in rangelands is challenging due to the broad spatial extent of treatments, temporal variability, remoteness of sites, and heterogeneity in environmental settings. Moreover, restoration techniques vary in success, and treatment effects are often short-lived. Satellite-derived vegetation cover data can complement field monitoring by providing continuous, spatially explicit information to help practitioners better understand treatment responses across landscapes. We used remotely-sensed vegetation cover data to evaluate vegetation change following 279 herbicide treatments in southern New Mexico aimed at reducing shrub cover and increasing perennial grass. Of these, 248 treatments used Tebuthiuron to target creosotebush (Larrea tridentata), and 30 used various combinations of clopyralid, triclopyr, or aminopyralid to target honey mesquite (Prosopis glandulosa). Treatment sizes ranged from 13.5 to 11,448 hectares. Each treated area was paired with nearby, untreated reference areas matched using soil and topographic characteristics. We extracted plant functional group cover from the Rangeland Analysis Platform and applied a Bayesian structural time series model to estimate treatment effects as the difference between observed and predicted cover trajectories over time. To assess treatment outcomes and longevity, we used linear mixed effects models stratified by target shrub species. We considered treatment characteristics (target species, herbicide, application rate), environmental factors (e.g., precipitation in the application year and subsequent years, elevation), pre-treatment vegetation conditions, and ecological site groupings. Results suggest that Tebuthiuron treatments targeting creosotebush were most effective in reducing shrub cover and increasing perennial herbaceous cover within Hill ecological sites. Shrub response varied with elevation, and treatment effects diminished over time as shrubs recovered. Treatments targeting honey mesquite were most effective in fine-textured lowland ecological site groups, also showing initial gains in perennial herbaceous cover that declined post-treatment. This study highlights both the potential and limitations of using remotely-sensed vegetation maps and causal inference approaches to evaluate restoration treatments. Ultimately, our results demonstrate how these tools can be used to understand patterns of restoration effectiveness and to inform future treatment planning at landscape scales.