Discovering the role of micro-organisms on ‘plant-soil feedback approach to assist the restoration of forest areas in the Atlantic Forest

Abstract

The Atlantic Forest is one of the richest tropical forests in diversity of animal and plant species and is considered one of the most important biodiversity hotspots in the world. Despite this, this biome is the second most threatened on the planet, and the most devastated of Brazil, therefore, its conservation and restoration is a priority issue. Several aspects must be considered in order to a successful restoration, one of which is to know the below-ground biodiversity, which in turn reflects the plant diversity above-ground, and this plant-soil interactions can be studied through the so-called Plant-Soil Feedbacks (PSFs). PSFs are based on the idea that a plant species, with its associated microbiota, modifies the soil property(s) in such a way that this modification affects its own performance and/or other plants in a positive or negative way. Therefore, the aim of this study is to identify the differences between the soil microbiomes of native forest, restored forests and under agricultural use (biological soil legacy) in Atlantic Forest regions in the São Paulo State, and to evaluate plant-soil feedback in these different landscape following an ecological view of plant and microbial communities. In order to reach this objective, initially (study I) we will characterize the soil microbiome through molecular biology techniques, such as sequencing of the 16S rRNA gene of Bacteria and Archaea and quantitative PCR, as well to integrate physical and chemical data of the different soils. Other tasks in study I will be the collection of soil (in dry and rainy season) and the phytosociological survey of the areas to be used later in study II. In study II, the collected soil will be used to install two-stage PSFs (conditioning and feedbacks) using the three most frequent plant species identified in the phytosociological survey, and at the end of these, calculate the strength and direction (positive and negative) of the feedbacks. At the end of experiment phase II, the most representative samples of each landscape will be selected based on sequencing of the 16S rRNA gene amplicons, and then sent for metagenomic and bioinformatic analysis. The results of these two studies will allow (a) to show which sites have a community where soil ecology is more similar to that of a native forest; (b) including metadata by metagenomics will allow to identify which are the key-microorganisms in plant-soil interaction correlating them to the genes involved in biogeochemical cycles, thus consolidating the functional role of microbial communities in these different landscapes and finally (c) will generate information that can improve/accelerate the recovery of deforested areas in the Atlantic Forest. (AU)