Post-fire resprouting and growth dynamics in a Burseraceae tree from the Brazilian Cerrado

In the Brazilian Cerrado, fire is a determining factor of vegetation structure, and regrowth is a strategy that ensures plant survival. In this phytogeographic domain, different plant species use different strategies for survival and growth recovery after injuries caused by fire. Protium heptaphyllum (Aubl.) Marchand is a tree species belonging to the Burseraceae family that is common in the Cerrado. This study aimed to identify the morphological responses and strategies involved in the survival of P. heptaphyllum after fire exposure. Individuals ∼9 months old were subjected to a controlled fire experiment and subsequently monitored in a greenhouse for 6 months. Quantitative morphological analyses were performed monthly. Samples collected from the root crowns of control plants and plants subjected to fire were processed for anatomical studies to verify the presence of buds. All individuals subjected to fire exhibited regrowth, mainly in the basal portion of the stem and underground regions. These plants also exhibited a higher growth rate than plants in the control group, suggesting a possible re-establishment strategy in the environment. In contrast, the length of the underground organs and fresh and dry biomasses were greater in the control individuals. Buds were observed in the root crowns of plants subjected to fire and in control individuals. Organs originating from the buds of individuals exposed to fire showed an abundance of trichomes. Our results contribute to the understanding of the responses of native plants to fire, an important modulator of the relationship between plants and the Cerrado. In addition, our data support the establishment of techniques for recovering areas degraded by fire, which is extremely important in current scenarios of increases in the number and intensity of fires in areas with natural vegetation.