High-intensity fire experiments to manage shrub encroachment: Lessons learned in South Africa and the United States

Authors: SCHOLTZ, RHEINHARDT - University Of Nebraska; DONOVAN, VICTORIA - University Of Nebraska; STRYDOM, TERCIA - South African National Parks; Wonkka, Carissa; KREUTER, URS - Texas A&M University; ROGERS, WILLIAM - Texas A&M University; TAYLOR, CHARLES - Texas A&M University; SMIT, IZAK - South African National Parks; GOVENDER, NAVASHNI - South African National Parks; TROLLOPE, WINSTON - Nelson Mandela University; FOGARTY, DILLON - University Of Nebraska; TWIDWELL, DIRAC - University Of Nebraska

Submitted to: African Journal of Range and Forest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2021
Publication Date: 2/15/2022
Citation: Scholtz, R., Donovan, V.M., Strydom, T., Wonkka, C.L., Kreuter, U.P., Rogers, W.E., Taylor, C.A., Smit, I.P., Govender, N., Trollope, W.S., Fogarty, D.T., Twidwell, D. 2022. High-intensity fire experiments to manage shrub encroachment: Lessons learned in South Africa and the United States. African Journal of Range and Forest Science. 39(1):148-159. https://doi.org/10.2989/10220119.2021.2008004.
DOI: https://doi.org/10.2989/10220119.2021.2008004

Interpretive Summary: Humans have changed the timing, frequency, extent, and intensity of fire in modern times; yet few studies have fully explored the implications of these changes for grasslands and savannas. Decades of fire research in South Africa inspired a unique convergence of high-intensity fire experiments across continents. In the Great Plains of North America, the Extreme Fire Trials were designed to remove traditional research constraints that minimized variability in fire intensity and explore woody plant death across a broader suite of experimental conditions. At the same time, studies at Kruger National Park, South Africa, similarly investigated high-intensity fires to examine previously unstudied relationships between high-intensity fires and woody plant densities. While these scientific pursuits have contributed to advancements in our understanding of fire-vegetation dynamics, they also underpin how changes in human actions and decision-making have changed grasslands and savannas. In this paper, we synthesize these high-intensity fire experiments, their importance for managing grassland and savanna ecosystems, and the lessons learned and challenges ahead to maintaining variation in fire regimes during the modern era of human-driven global change.

Technical Abstract: Human alteration of fire regimes is a hallmark signature of the Anthropocene; yet few studies have fully explored the implications of altering fire regimes in grasslands and savannas. Decades of fire research in South Africa inspired a unique convergence of high-intensity fire experiments across continents. In the Great Plains of North America, the Extreme Fire Trials were designed to remove traditional investigator constraints that minimized variability in fire intensity and explore woody mortality thresholds across a broader suite of experimental conditions. At the same time, studies at Kruger National Park, South Africa, similarly investigated high-intensity fires to examine previously unstudied relationships between high intensity fires and woody encroachment. While these scientific pursuits have contributed to major theoretical advancements in our understanding of fire-vegetation dynamics, they also underpin how changes in human actions and decision-making have altered grasslands and savannas. In this paper, we synthesize these high-intensity fire experiments, the empirical evidence emerging from them and their importance for managing grassland and savanna ecosystems, and the lessons learned and challenges ahead to maintaining critical ranges of variation in fire regimes during the Anthropocene.