Comparação florístico-estrutural dos estratos adultos e regenerantes em área minerada de campo rupestre, Diamantina, MG

Abstract

The objective of this work was to compare the phytosociological structure and to verify the similarity of the adult and regenerating stratum in an old mining site. For the arboreal vegetation sampling, 50 plots of 10 x 10 m were placed in a transect of 50 x 100 m, where all of the living individuals with 0.3 m diameter from the soil ≥ 3 cm (DAS30 ≥ 3 cm) were sampled. The natural regeneration was sampled in sub plots of 2 x 2 m and 5 x 5 m for plants with 0.1 m ≤ height < 0.5 m and 0.5 < height < 1.5 m, respectively. The sub portions were located in the superior right corner of the 50 permanent 10 x 10 m plots where individuals with DAS30 ≤ 3 cm and height superior to 10 cm were sampled. 1262 individuals were sampled for the adult and regenerating communities, spread in 21 families and 45 species. The index of Shannon Weaver (H’), for the adult and regenerating stratums was: 2.18 nats.ind-¹ and 2.73 nats.ind-¹, respectively. The species with the larger natural regeneration index were Lavoisiera montana (14.28%); Lavoisiera pectinata (14.26%); Microlicia isophylla (14.13%); Baccharis elliptica (10.71%); Baccharis sp 1 (7.15%) and Cambessedia menbranaceae (3.63%). The species that presented the largest values of importance in the adult stratum were Lavoisiera montana (28.59%); Eremanthus erythropappus (29.98%); Microlicia isophylla (5.87%); Pseudobrickellia sp (5.26%); Baccharis elliptica (5.18%) and Palicourea rigida (4.31%). The Jaccard index of similarity between the regenerating and the adult stratums was 69.56%. This study identified the main floristic and structural differences of the studied stratums, contributing to the knowledge of the main species that colonize this environment.