Tallgrass prairie responses to weather variability and management: Analyses of vegetation dynamics and water use

Authors: Wagle, Pradeep; TANKA, KANDEL - Natural Resources Conservation Service (NRCS, USDA); Northup, Brian; XIANGMING, XIAO - University Of Oklahoma; Moffet, Corey; Teet, Stephen; Hunt, Sherry; Gunter, Stacey

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/6/2025
Publication Date: 9/17/2025
Citation: Wagle, P., Tanka, K., Northup, B.K., Xiangming, X., Moffet, C., Teet, S.B., Hunt, S., Gunter, S.A. 2025. Tallgrass prairie responses to weather variability and management: Analyses of vegetation dynamics and water use. Rangeland Ecology and Management. 103:171-183. https://doi.org/10.1016/j.rama.2025.08.003.
DOI: https://doi.org/10.1016/j.rama.2025.08.003

Interpretive Summary: Tallgrass prairies are vital to the Great Plains of the United States, providing essential habitat and supporting livestock grazing. However, these grasslands face growing challenges from unpredictable weather, including droughts and heat waves, as well as various management practices like controlled burning, hay cutting, and grazing patterns. This study investigated these impacts at five co-located native tallgrass prairie pastures managed with different combinations of burning, haying, and grazing in central Oklahoma. The major objectives were to 1) quantify the variations in eddy covariance (micrometeorological technique) measured evapotranspiration (ET) at different temporal scales across pastures, and 2) combine remotely sensed enhanced vegetation index (EVI – greenness index) with ET and meteorological data to assess their potential for monitoring and examining ecosystem responses to variable weather and management. Results showed that interannual variations in the amounts and distributions of precipitation influenced vegetation dynamics, forage production, and ET. Temperature also played a significant role, especially affecting plant growth early and late in the growing season. Water use varied considerably across the different pastures depending on the management style. The study found a strong correlation between satellite measurements of vegetation greenness and ground measurements of water use. This study provides valuable insights into the water use of differently managed native tallgrass prairies and illustrates that satellite remote sensing offers a practical way to monitor the health and water use of these important grasslands.

Technical Abstract: The tallgrass prairie of the Great Plains is a vital ecological and economic grassland in the United States. Prairies face significant challenges from weather variability (such as changing precipitation patterns, increased droughts, and heat waves) and management-related disturbances (such as prescribed burns, hay production, and grazing). This study examines the responses of tallgrass prairie to weather variability and management practices using data from the long-term, multi-factor “integrated Grassland-Livestock and Burning Experiment (iGLOBE)” in central Oklahoma. The experiment includes a cluster of eddy covariance (EC) systems across five native tallgrass prairies managed with different grazing, hay production, and burning regimes. The major objectives were to 1) quantify the variations in EC-measured evapotranspiration (ET) at different temporal scales across differently managed prairies under varying environmental conditions, and 2) combine remotely sensed vegetation indices with ET and meteorological data to assess their potential for monitoring and examining ecosystem responses to variable weather and management. Interannual variations in the amounts and distributions of precipitation during the study period (2019-2024) influenced vegetation dynamics, forage production, and ET. Temperature variability also played a crucial role in modifying the impact of precipitation, particularly during the early and late growing seasons. The observed ranges of maximum daily, growing season (April-October), and annual ET were 4.9-8.64 mm d-1, 468-716 mm, and 546-861 mm, respectively, across pastures. Annual ET:precipitation ratios ranged from 0.67 in wet years to 1.15 in dry years. This study provides a ground-truth ET dataset across different weather and management scenarios, enabling validation of ET estimates from models and satellite-derived products for tallgrass prairies, including in areas without direct ET measurements. The strong agreement (R2 = 0.70) between satellite-derived enhanced vegetation index (EVI) and EC-measured ET demonstrated the potential for their integration in research aimed at quantifying the effects of weather and management on pastures.