Traços funcionais de Elionurus muticus (Spreng.) Kuntze e inflamabilidade

Abstract

Fire plays a key role in shaping the dynamics of vegetation in terrestrial ecosystems, influencing plant species composition through selective pressure based on their sensitivity to fire. In the Pantanal, extreme droughts have increased the risk of wildfires, impacting native vegetation and biodiversity. Elionurus muticus, a native grass, is highly flammable due to its chemical composition, including essential oils and phenolic compounds. This study investigates the functional traits of E. muticus leaves, focusing on their anatomy and histochemistry, to understand the relationship between tissue distribution, chemical substances, and fire susceptibility. Samples were collected from burned areas in the Pantanal and processed for anatomical analysis and histochemical testing. The results revealed that E. muticus leaves exhibit an amphistomatic and uniseriate epidermis with tector trichomes on the upper surface. The Kranz venation pattern, characteristic of C4 plants, was identified, with vascular bundles showing lignified sheaths. Histochemical tests revealed the presence of lipids throughout the mesophyll, as well as cells rich in lipids and phenolics compounds near the vascular bundles, particularly in medium and small-caliber bundles. These substances, known for their role in combustion, increase the plant’s susceptibility to fire. The results highlight the relationship between anatomical traits and chemical composition that contribute to the high flammability of E. muticus, providing valuable information for fire management and conservation in the Pantanal ecosystem.