TY - JOUR
T1 - Grass bud responses to fire in a semiarid savanna system
AU - Hiers, Quinn A.
AU - Treadwell, Morgan L.
AU - Dickinson, Matthew B.
AU - Kavanagh, Kathleen L.
AU - Lodge, Alexandra G.
AU - Starns, Heath D.
AU - Tolleson, Doug R.
AU - Twidwell, Dirac
AU - Wonkka, Carissa L.
AU - Rogers, William E.
N1 - Funding Information:
We would like to thank Dr. Joe O'Brien for lending us his FLIR camera and Dr. Louise Loudermilk for the python code used to analyze the imagery obtained from the FLIR camera. L. Culpepper, A. Labrecque, H. Hannusch, J. Gaster, C. Ferguson, J. Walker, N. Garza, and R. Moen provided technical assistance. This research was funded by the United States Department of Agriculture Bureau of Land Management Joint Fire Sciences Program Project #17‐1‐04‐7. At the time of experimentation, graduate study was supported by a Teaching Assistantship from Texas A&M University, specifically the Sid Kyle Graduate Fellowship.
Publisher Copyright:
© 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
PY - 2021/6
Y1 - 2021/6
N2 - Increasingly, land managers have attempted to use extreme prescribed fire as a method to address woody plant encroachment in savanna ecosystems. The effect that these fires have on herbaceous vegetation is poorly understood. We experimentally examined immediate (<24 hr) bud response of two dominant graminoids, a C3 caespitose grass, Nassella leucotricha, and a C4 stoloniferous grass, Hilaria belangeri, following fires of varying energy (J/m2) in a semiarid savanna in the Edwards Plateau ecoregion of Texas. Treatments included high- and low-energy fires determined by contrasting fuel loading and a no burn (control) treatment. Belowground axillary buds were counted and their activities classified to determine immediate effects of fire energy on bud activity, dormancy, and mortality. High-energy burns resulted in immediate mortality of N. leucotricha and H. belangeri buds (p <.05). Active buds decreased following high-energy and low-energy burns for both species (p <.05). In contrast, bud activity, dormancy, and mortality remained constant in the control. In the high-energy treatment, 100% (n = 24) of N. leucotricha individuals resprouted while only 25% (n = 24) of H. belangeri individuals resprouted (p <.0001) 3 weeks following treatment application. Bud depths differed between species and may account for this divergence, with average bud depths for N. leucotricha 1.3 cm deeper than H. belangeri (p <.0001). Synthesis and applications: Our results suggest that fire energy directly affects bud activity and mortality through soil heating for these two species. It is imperative to understand how fire energy impacts the bud banks of grasses to better predict grass response to increased use of extreme prescribed fire in land management.
AB - Increasingly, land managers have attempted to use extreme prescribed fire as a method to address woody plant encroachment in savanna ecosystems. The effect that these fires have on herbaceous vegetation is poorly understood. We experimentally examined immediate (<24 hr) bud response of two dominant graminoids, a C3 caespitose grass, Nassella leucotricha, and a C4 stoloniferous grass, Hilaria belangeri, following fires of varying energy (J/m2) in a semiarid savanna in the Edwards Plateau ecoregion of Texas. Treatments included high- and low-energy fires determined by contrasting fuel loading and a no burn (control) treatment. Belowground axillary buds were counted and their activities classified to determine immediate effects of fire energy on bud activity, dormancy, and mortality. High-energy burns resulted in immediate mortality of N. leucotricha and H. belangeri buds (p <.05). Active buds decreased following high-energy and low-energy burns for both species (p <.05). In contrast, bud activity, dormancy, and mortality remained constant in the control. In the high-energy treatment, 100% (n = 24) of N. leucotricha individuals resprouted while only 25% (n = 24) of H. belangeri individuals resprouted (p <.0001) 3 weeks following treatment application. Bud depths differed between species and may account for this divergence, with average bud depths for N. leucotricha 1.3 cm deeper than H. belangeri (p <.0001). Synthesis and applications: Our results suggest that fire energy directly affects bud activity and mortality through soil heating for these two species. It is imperative to understand how fire energy impacts the bud banks of grasses to better predict grass response to increased use of extreme prescribed fire in land management.
KW - bud dormancy
KW - fire management
KW - herbaceous perennial resprouting
KW - plant mortality
KW - vegetative tiller reproduction
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U2 - 10.1002/ece3.7516
DO - 10.1002/ece3.7516
M3 - Article
AN - SCOPUS:85103673532
VL - 11
SP - 6620
EP - 6633
JO - Ecology and Evolution
JF - Ecology and Evolution
SN - 2045-7758
IS - 11
ER -