O efeito do fogo na fenologia de Chamaecrista neesiana (Fabaceae) e nas suas interações com as aranhas.

Abstract

The Cerrado is a diverse tropical savanna, made up of different plant formations, such as savannas, forests, fields and humid areas. Fires are a striking feature of this ecosystem, which can occur naturally or through human action, and exert a great influence on the structure and dynamics of the biome. Although the Cerrado is resilient to this type of disturbance, fires can reduce diversity and affect the phenology of plant organisms. Furthermore, they can interfere with complex interactions between animals and plants, such as some species of spiders that interact with plants that have glandular trichomes. The study investigated the effect of fire on the phenology of the plant Chamaecrista neesiana (Fabaceae) and the production of glandular trichomes, in addition to the influence of spiders on the abundance of herbivores in pre- and post-fire environments. The study was carried out in the Private Reserve of the Clube Caça e Pesca Itororó de Uberlândia (CCPIU), Minas Gerais, after a fire of anthropogenic origin. Post-fire collection was conducted from November 2022 to October 2023. Pre-fire data was compared with previous studies in the collection area carried out from July 2012 to November 2013. This way we evaluated the impact of fire on plant phenology, in the density of glandular trichomes and abundance of arthropods in plants with and without spiders. It was observed that the reproductive phenology of C. neesiana was anticipated compared to the pre-fire period, and that the fire reduced the density of glandular trichomes on the plants compared to the pre-fire period. Furthermore, our results demonstrate that spiders continue to act as controlling agents for the abundance of herbivores even after the fire. This study suggests that fire plays an important role in ecological interactions in the Cerrado, and can negatively affect plants, spiders and herbivores in their interactions.