Effects of prescribed fire on spatial patterns of plant functional traits and spectral diversity using hyperspectral imagery from savannah landscapes on the Edwards Plateau of Texas, USA

Authors: JAIME, XAVIER - Texas A&M University; Angerer, Jay; Yang, Chenghai; TOLLESON, DOUG - Texas A&M Agrilife; FUHLENDORF, SAMUEL - Oklahoma State University; WU, X. BEN - Texas A&M University

Submitted to: Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2025
Publication Date: 11/28/2025
Citation: Jaime, X.A., Angerer, J.P., Yang, C., Tolleson, D.R., Fuhlendorf, S.D., Wu, X. 2025. Effects of prescribed fire on spatial patterns of plant functional traits and spectral diversity using hyperspectral imagery from savannah landscapes on the Edwards Plateau of Texas, USA. Remote Sensing. 17(23). Article 3873. https://doi.org/10.3390/rs17233873.
DOI: https://doi.org/10.3390/rs17233873

Interpretive Summary: In the Great Plains, fire and grazing can enhance ecosystem function by increasing plant species. Research assessing the effects of fire and grazing on rangeland plants has been conducted using traditional field methods; however, a research gap exists regarding the application of spectral data from remote sensing imagery as a proxy for these assessments on rangelands. Hyperspectral remote sensing offers a promising, high-resolution methodology for evaluating these dynamics, potentially improving assessments of post-fire recovery and vegetation function, especially in large or remote areas where traditional field campaigns are complex. This study utilized airborne hyperspectral and multispectral imagery to investigate the impact of fire on plant functional traits, spectral diversity, and their spatial patterns within a savanna landscape. Results indicated that fire reduced spectral evenness (meaning spectral signals became less uniformly distributed) and increased ß-diversity (indicating more variation in spectral signals between different locations). However, weather had an even stronger influence on these post-fire spectral patterns. Additionally, spectral proxies for plant biophysical and biochemical traits varied across different soil types, with high variability in some cases and less in others. Spectral indices varied similarly across the landscape in both pre- and post-fire assessments. These findings demonstrate that fire effects on spectral diversity are context-dependent and shaped by environmental factors. These results suggest that hyperspectral imaging is effective at capturing these complex dynamics, supporting its use in monitoring vegetation responses after fire.

Technical Abstract: Vegetation heterogeneity supports biodiversity, while homogeneity limits it. In the Great Plains, fire and herbivory enhance ecosystem function by increasing spatial heterogeneity. However, quantifying their effects on plant functional traits and spectral diversity remains challenging due to landscape complexity and scaling limitations. Hyperspectral remote sensing offers a high-resolution approach to assessing these dynamics, improving evaluations of post-fire recovery and vegetation function. This study examines the impact of fire on plant functional traits and spectral diversity within a savanna landscape in the Edwards Plateau, Texas, using airborne hyperspectral and multispectral imagery. Specifically, it aims to (1) quantify spatial patterns of plant functional traits and spectral diversity, (2) assess fire effects on these patterns, and (3) evaluate how soil type, vegetation structure, and burn patterns mediate fire responses. High-resolution airborne images from 2018 (pre-fire) and 2020 (post-fire) were analyzed to classify burned and unburned areas, calculate patch-based metrics, and derive spectral indices representing plant functional traits and spectral evenness. Results indicate that fire reduced spectral evenness and increased ß-diversity, but weather exerted an even stronger influence on post-fire spectral patterns. The post-fire spectral evenness index exhibited negative spatial autocorrelation, suggesting increased spectral dissimilarity among nearby areas. Changes in biophysical and biochemical traits varied across soil types, with spectral heterogeneity increasing in some cases and decreasing in others. Strong spatial cross-correlations were observed between pre- and post-fire spectral indices. These findings demonstrate that fire effects on spectral diversity are context-dependent and shaped by environmental factors. Hyperspectral imaging effectively captured these dynamics, supporting its role in monitoring post-fire vegetation responses. In addition to the use of hyperspectral imaging, fire management strategies should consider broader ecological drivers, including soil and climate interactions, to improve assessments of ecosystem resilience and recovery.