Drought and Heat Tolerance of Quercus austrina Small

Anna Sisson, Esteban Galeano, Joshua J. Granger, and Ashley Schulz

Published May 2025 in International Oaks No. 36: 69–78

Abstract

Quercus austrina is a threatened species found in the Southeastern US Coastal Plain. Listed as Vulnerable (VU) by IUCN, it is one of 29 oak species of conservation concern identified in a recent conservation gap analysis. Impacts of climate change are reported to be the key threats to Q. austrina. As there are no other studies, to date, on the impacts of climate change-induced stressors on Q. austrina, this study aimed to assess the effects of drought and heat on the growth and vigor of Q. austrina. Acorns were collected from a parent tree near West Point, Mississippi, then grown into 84 seedlings randomly placed into three blocks, each with 28 plants and four treatments (control, drought, heat, drought + heat). The growth and color of the seedlings were assessed at six time-points during summer 2024. Results demonstrated that the seedlings were significantly shorter under drought treatments and were more chlorotic under heat treatments. Though the stressors negatively impacted the seedlings, the results demonstrate adaptations that oaks have to tolerate stress. Research on the stress tolerance of vulnerable oak species offers crucial insights for enhancing forest management and conservation strategies in the face of climate change.

Keywords

Quercus, Latin American oaks, neotropical botany, taxonomy, nomenclature, etymology

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