2.2 Sampling of vegetation data
First, 12 plots (50 x 20 m) were delimited for sampling the adult tree stratum, totaling a sampling area of 1.2 ha. The adult stratum represented the vegetation cover of our study and was composed of 2,519 individuals. A total of 1,053 individuals were sampled in Area I, distributed in 24 species and ten families, while Area II presented 1,466 individuals distributed in 36 species and 16 families.
Each plot was subdivided into 10 subplots (10 x 10 m), with four subplots being randomly chosen for sampling the regenerative stratum. The height and diameter of all individuals were measured. The species of all individuals were identified in the field. The main descriptive characteristics (height, diameter, habit, floral attributes) for unidentified individuals were recorded, and samples were collected for later taxonomic determination in the laboratoryusing specialized bibliography and consulting digitalized and herbal databases, and classified according to the Angiosperm Phylogeny Group IV (APG IV, 2016). All living individuals with height ≥1 m and diameter at ground level (DGL) ≥3 cm were identified as adult individuals (Rodal et al., 2013). Living specimens with a height <1 m and a DGL between 0.5 and 2.9 were identified as seedlings (Farias et al., 2016).
Hill numbers of order 0, 1, and 2 were used to quantify diversity (Jost, 2006). The diversity of order 0 (D0) refers to species richness, which is not sensitive to abundance; the diversity of order 1 (D1) considers the abundance of each species and its weight in the community is given accordingly. Thus, it is interpreted as the number of common species in the community; diversity of order 2 (D2) is also sensitive to abundance and favors the highest number of species, being interpreted as the number of dominant species in the community (Jost, 2006). Since the focus of our work is the data from the regenerating stratum, we will use RegD0, RegD1, and RegD2 to refer to the diversity data of orders 0, 1, and 2, respectively, of that stratum. The calculations were performed through the website https://chao.shinyapps.io/iNEXTOnline/. TheiNext is a species diversity interpolation and extrapolation software program.