Using native soil to cultivate seedlings of the threatened Melanoxylon brauna Schott (Fabaceae): A path for ex-situ conservation

Abstract

Melanoxylon brauna is a species vulnerable to extinction, mainly due to intense wood exploitation. However, there is not enough information about seedling growth of this tree, which hinders the seedlings production. Thus, our purpose was to analyze the growth of M. brauna seedlings in different substrates: (1) native soil, (2) commercial substrate (sand, soil, and organic compost), and (3) commercial fertilized substrate (sand, soil, organic compost, phosphate fertilizer, and osmocote). We also evaluated the seedlings growth in sterilized (by autoclaving) and non-sterilized native soil. At the end of the experiments, the growth parameters and photosynthetic pigment content of the seedlings were measured. The native soil provided seedlings with the highest growth and accumulation of biomass. According to our findings, seedlings grown in sterilized native soil showed a decrease in shoot length and biomass compared to the ones grown in non-sterile soil. This suggests that the chemical and biological properties of the non-sterile native soil are conducive to seedling growth. Therefore, using of native soil can be a viable alternative for producing difficult-to-cultivate seedlings for ex-situ conservation and reintroduction projects of the threatened species into the wild, emphasizing the importance of plant-soil relationships understanding for seedling production and tropical forest restoration.