Meta-analysis of the impact of plant invasions on soil microbial communities

Nardi Torres,Laurie Fajardo,Ramiro O Bustamante,Ileana Herrera

doi:10.1186/s12862-021-01899-2

Abstract

BackgroundOne of the ecological impacts of exotic plant invasions may be alteration of the soil microbial community, which may cause changes to the diversity, richness and function of these communities. In order to explore to what extent invasive plants affect the soil microbial community, we performed a meta-analysis based on 46 scientific articles to document the effect of invasive plants on species richness and diversity of bacteria and fungi. We conducted our study across a range of invaded ecosystems including native communities, and evaluated biomass, richness and diversity. We use a random effects model to determine the increase or decrease in the values of the response variables in the presence of invasive plants.ResultsThe results indicated that the response variable that changed with the invasion of plants was the diversity of bacteria. Bacterial diversity in the soil increases with the presence of invasive plants, specifically herbaceous plants producing allelopathic substances growing in forest ecosystems of temperate zones.ConclusionsWe provide evidence that invasive plants affect the soil biota differentially; however, it is important to consider more variables such as the N and C cycles, since these processes are mediated by soil biota and litter, and chemical compounds released by plants influence them. Changes in bacterial diversity have consequences for the nutrient cycle, enzymatic activity, mineralization rates and soil carbon and nitrogen content.

Highlights

One of the ecological impacts of exotic plant invasions may be alteration of the soil microbial community, which may cause changes to the diversity, richness and function of these communities
Case description We found 211 cases published in 46 scientific papers that evaluated the impact of 50 species of invasive plants on the soil microbial community (SMC) (Additional file 1)
We found that studies of the impact of invasive plants on soil microorganisms have concentrated on six species (Alliaria petiolata, Berberis thunbergii, Ageratina adenophora, Impatiens glandulifera, Bromus tectorum, Jatropha curcas), these being 35% of cases (76 studies)

Summary

Introduction

One of the ecological impacts of exotic plant invasions may be alteration of the soil microbial community, which may cause changes to the diversity, richness and function of these communities. One well-known mechanism to explain how exotic plants can affect soil microbiota is through allelochemicals (“the novel weapon hypothesis”) These plants exude chemical substances which besides reducing survival and regeneration of native plants [18, 47], can significantly change the SMC in the rhizosphere [43, 49], affecting decomposition processes [3], metabolizing labile and recalcitrant substrates [9] such as nitrogen mineralization and nitrification [10], and modifying soil enzyme activities [22], as well as changes in the SMC as a result of other ecosystem impacts [11].

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Discussion

Conclusion