ECOTOXICOLOGICAL EVALUATION OF Lippia alba Mill PLANT RESIDUES ON TERRESTRIAL ECOSYSTEM REPRESENTATIVES

Lippia alba is a medicinal plant commonly used in Cuba and the Caribbean for thedevelopment of herbal formulations against skin inflammatory illnesses thus generating residual biomass whose environmental impact remains unassessed. This study aimed to evaluate the ecotoxicological effects of L. alba residues and their aqueous extract fractions on key terrestrial ecosystem organisms. Soil microbial community activity was analyzed through CO2 emissions and ammonium (NH4+) quantification, as well as degradation and toxicity tests on earthworms (Eisenia andrei). Phytotoxicity was assessed using Phaseolus vulgaris seeds to determine germination rates and radicle length. Results showed that CO2 emissions increased in the groups treated with L. alba residues, suggesting enhanced microbial respiration, whereas NH4+ levels remained unchanged across all treatments. Seed germination rates remained above 75% at all tested extract concentrations except at 75%. Radicle length, however, was significantly reduced at higher concentrations (75% and 100%). No toxic effects were observed in E. andrei (earthworms). These findings indicate that L. alba residues are not toxic to soil macro- or microfauna and may contribute to soil organic enrichment, although higher concentrations of aqueous extracts exhibit moderate phytotoxic effects. The study supports the potential incorporation of L. alba waste into sustainable soil management strategies, such as composting and vermicomposting.