A Systematic Review of Terrestrial Plant Invasion Mechanisms Mediated by Microbes and Restoration Implications

K Dawkins,J Mendonca,N Esiobu,O Sutherland

doi:10.4236/ajps.2022.132013

Abstract

Terrestrial invasive plant species continue to wreak havoc on a global economic and ecological scale. With the advent of climate change and pending future catastrophes, the spread of resilient invasive plants will only increase exponentially. Here, the search continues for a better understanding of the below-ground microbially driven mechanisms involved in plant invasion where other above-ground mechanisms have been exhausted. Microbes govern the world around us and interact with every living and non-living facet of the world. To reinforce the important underpinnings of the role of microorganisms in plant invasion, a systematic review of recently published articles was undertaken. Using the ScienceDirect database, five (5) search queries were used to generate 1221 research articles. After a two-step reduction was made based on relevance of the articles, a final total of 59 articles were retrieved. An additional 18 relevant articles were also assessed through the PubMed database for analysis to account for other invasive plants. Thirty-seven (37) invasive species were investigated where soil physiochemical and microbial community structure changes were most prevalent (32% & 39% respectively) while enhanced mutualism, allelopathy and pathogen accumulation were reported less (16%, 10% & 3% respectively). In all invasive species assessed, the impact on plant invasion and inability of the native plants to compete was due to specific microbial associations of the invasive plant or disruption of the soil microbial community. This microbial community shift coincided with changes in physiochemical properties of the soil and the subsequent negative soil feedback for native plants. There is still an expanding potential for the use of biocontrol agents to aid restoration once the underpinnings of biotic resistance and enemy release are understood in a microbial and physiochemical context. The active and functional microbial community structure of the invasive plant rhizosphere and adjacent soil in its native and non-native region can offer a better inference of how they can be controlled using novel-below ground biocontrol methods.

Highlights

The number of invasive plant species across the globe is astronomical
A total of 37 terrestial invasive plants were used in this review and includes some of the most invasive plant species across the globe, including Alliaria petiolata, Chromolaena odorata, Solidago canadensis (Canada goldenrod), Ageratina adenophora (Crofton weed), Berberis thunbergii (Japanese barberry) and Schinus terebinthifolius (Brazilian pepper tree)
Competition was not added as a possible mechanism as it is certain that all invasive plant species through these different mechanisms improve their competitive advantage against native plant species through a positive soil feedback effect

Summary

Introduction

The number of invasive plant species across the globe is astronomical. North America and Oceania have the highest prevalence of terrestrial invasive plant species (341) (Figure 1) with 1662 total invasive plants spread out across the major continents [1]. Many microorganisms in soil such as AMF/EMF, saprophytic and pathogenic fungi, N-cycling bacteria, sulfate reducers [14] [15] [16] [17] and others with yet to be discerned mechanisms influence the soil nutrient, physiochemical and biogeochemical profile. If these changes are of benefit to the plant, a positive-soil feedback effect will result, enabling the proliferation of that plant or in the opposite scenario, development of a more negative-soil feedback reducing plant success. The microbial component of native and non-native soils plays an important role in plant success and inevitably plant invasion [11] [18]

Methods

Results

Conclusion