Influência do Fogo e da Inundação Sobre a Invasão de Leucaena leucocephala (Lam.) de Wit. e o seu Impacto Sobre a Flora Nativa

Abstract

This study aimed to evaluate the post-fire regeneration and the influence of flooding on Leucaena leucocephala (Lam.) de Wit (Fabaceae), and co-occurring species in the9 Pantanal region of Brazil. We identified the frequency of fires and proximity of the invasion through satellite images and interviews. We established 10 plots and 20 subplots per treatment (3 levels of topography and 3 of fire frequency) and measured the circumference of adult trees and counted regenerating Leucaena and native species. We applied linear Generalized Mixed Model and rarefaction and extrapolation curves for data analysis. Results showed a higher number of L. leucocephala individuals in the high topography and a significant positive relationship between fire frequency and recruitment of Leucaena. The topography influenced the colonization of invasive species, resulting in a lower richness of the native species, particularly in non-floodable areas. GLMM revealed that the model explaining the distribution of regenerant data included topography and fire frequency acting on Leucaena recruitment. Hence, using fire as a means of managing L. leucocephala invasions is not recommended, and alternative methods should be sought.