Spatial genetic structure, population dynamics, and spatial patterns in the distribution of <i>Ocotea catharinensis</i> from southern Brazil: implications for conservation

Abstract

In this study, we employ an integrated demographic–genetic approach with the aim of informing efforts to conserve Ocotea catharinensis Mez., an endangered tree species from the Brazilian Atlantic Rainforest. After establishing two permanent plots (15 and 15.5 ha) within protected areas in Santa Catarina state, Brazil, we evaluated demographic aspects (density, recruitment, mortality, and growth), spatial pattern, genetic diversity, and spatial genetic structure (SGS) in three categories (seedlings, juveniles, and reproductive individuals) over 2 years. Studied populations presented low recruitment of individuals and low rates of increment in diameter and height. Aggregation was the main spatial pattern observed for both populations. High levels of genetic diversity were estimated for both populations, as well as high levels of fixation index, signaling the risk of losing genetic diversity over generations. Significant SGS was found for both populations, reflecting nonrandom distribution of the genotypes. Demographic and genetic surveys also allowed the estimation of minimum viable areas for genetic conservation (&gt;170 ha), deme sizes (around 10 ha), and distances for seed collection (at least 60 m). Effective population size is restricted in studied populations, locally threatening the species perpetuation over generations. Further research can clarify how this condition will change in subsequent years.