The impact of root systems and their exudates in different tree species on soil properties and microorganisms in a temperate forest ecosystem

Abstract

Background The species composition of tree stands plays an important role in shaping the properties of forest soils. The aim of our research was to determine the influence on soil properties of the root systems of six species of trees which form forest stands in the temperate climatic zone. The research covered areas including six tree species – Scots pine (Pinus sylvestris L.), European larch (Larix deciduas Mill.), English oak (Quercus robur L.), English ash (Fraxinus excelsior L.), European beech (Fagus sylvatica L.) and European hornbeam (Carpinus betulus L.). In our study, we determined the characteristics of the roots and the amount of carbon excreted alongside their exudates. Enzymatic activity, and the composition and diversity of the fungi and bacteria, were also determined in addition to the basic physicochemical properties of the soil samples. Results A strong relationship between the root characteristics and soil properties, including the pH, basic cation content and phosphorus content, was confirmed. In addition, the enzymatic activity of phosphatase, β-glucosidase, N-acetyl-β-D-glucosaminidase and β-D-cellobiosidase were positively correlated with the root characteristics. The study on soil bacteria across different tree species revealed Proteobacteria and Actinobacteriota to be the most abundant phylum. Fungal analysis showed Basidiomycota and Ascomycota as the dominant phyla. Ascomycota dominated in hornbeam and oak soils. Mortierellomycota was remarkably more present in pine soil. Conclusions This analysis of root systems and soil properties confirmed the distinctness of ash stands, which were also more abundant in various microorganisms. It was also found that soils affected by different tree species were characterised by varied fungal and bacterial composition. The ash had particularly beneficial impact on soil microbiota.

Metabolic niches in the rhizosphere microbiome: dependence on soil horizons, root traits and climate variables in forest ecosystems

“…Recent research has increasingly highlighted the crucial role that root exudates play in the interactions between forest trees and microbes in the rhizosphere (Sasse et al, 2018;Pascale et al, 2020;Williams and de Vries, 2020;Oppenheimer-Shaanan et al, 2022;Jing et al, 2023;Staszel-Szlachta et al, 2024). In this context, it is well understood that plants supply photosynthetic carbon to rhizospheric microbes and release various key molecules (Figure 2) into the soil, thereby fostering a bidirectional relationship.…”

Root Respiration–Trait Relationships Are Influenced by Leaf Habit in Tropical Plants

“…In subtropical regions, the RNC and root respiration increase with rising soil temperatures [49,50]. Despite the fact that our experiment was conducted in a botanical garden where climatic and topographical conditions were uniform, the different quantity and quality of litters provided by individual plant species' input to soil result in divergent physicochemical properties [51,52]. Therefore, plant root traits must diversify and form various combinations to effectively acquire resources from complex soil environments.…”