The haunting of the Soul’s hill : Uncoupled responses of plant functional traits and soil microbes to serpentine soils lead to Bonsai effect in the Neotropics

Guimaraes, Aretha Franklin and Meirelles, Gabriela Siewerding and Alagao Querido, Luciano Carramaschi and Fernandes, Kaline Miranda and Ribeiro, William and Oliveira, Rafaella Teixeira Maciel and Silva, Elias Roma and Canaan, Monica and Lira, Marines Ferreira Pires and Ostle, Nick and Berg, Eduardo (2025) The haunting of the Soul’s hill : Uncoupled responses of plant functional traits and soil microbes to serpentine soils lead to Bonsai effect in the Neotropics. Tree Physiology. ISSN 0829-318X

Abstract

Purpose We investigated the plant–soil linkages of C. Langsdorffii, a widely distributed species in the Neotropics, and how the serpentine syndrome leads to dwarfism by comparing soil microbes, soil properties and tree functional traits in serpentine and non-serpentine soils. For that we evaluated the presence of heavy metals in the soils and how it affects plant functional traits; differences of C:N ratio between serpentine and non-serpentine sites as well as soil microbiome by using PLFA technique approach to assess microbial functional groups. Methods We explored the relations between soil microbes (by using phospholipid fatty acid, i.e., components of cell membranes in microbes used as an indicator of microbial biomass), soil properties, vegetation attributes, leaf nutrients and leaf functional traits. Results We found correlation between soil gram-positive bacteria and iron in the plant leaves.; the C:N ratios are higher in serpentine sites, but the two areas are similar to the non-serpentine area; there was no difference between the soil microbes in our study areas and finally; there’s a tendency to dwarfism and xeromorphism in the functional traits of C. Langsdorffii in serpentine soils. Conclusions We found that even though we have differences when comparing C. langsdorffii plants in serpentine and non-serpentine sites regarding the functional traits analysed in our study, the only soil microbe that seems to be interacting with the heavy metals is the gram-positive bacteria, possibly due to chelating mechanisms.