Underground Web Gives Hope for Healing Broken Ecosystems

New research published in the American Journal of Botany by Johannes Le Roux and colleagues suggests manipulating soil microbes could help restore plant ecosystems damaged by invasive species. The scientists from Macquarie University in Australia focused on reestablishing beneficial relationships between native plants and helpful soil fungi and bacteria.

The study examined Australian shrublands invaded by African olive trees (Olea europaea subsp. cuspidata). These disrupt partnerships between native Acacia implexa trees and underground rhizobia bacteria. Acacia implexa gets nutrients from rhizobia housed in root nodules while providing the bacteria with sugars.

But in soils damaged by invasive olives, populations of these useful rhizobia plunged. Acacia seedlings in those soils formed fewer nutrient-providing nodules than the seedlings grown in healthy soils. Reintroducing the right rhizobia strains originally present could restart successful teamwork between the trees and bacteria.

The paper states that analysing interaction networks between species can pinpoint the most valuable microbes to replenish. Generalist bacteria and fungi that partner with many native plants may be especially useful. They can give restored ecosystems a jumpstart in recovering diverse, functional plant communities.

However, the paper cautions there is much still to learn about managing plant-associated microbial networks. Understanding the assembly processes of plant microbiomes will be critical moving forward.

The research highlights soil microbe reintroduction as a promising way to reboot complex plant-environment interactions. With careful selection, adding vital missing links in the underground web of life could get damaged habitats back on track to full health.

By illuminating how ecosystems can be rewired, the study suggests degraded habitats have hope of flourishing once again.

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Le Roux, J.J., Leishman, M.R., Geraghty, D.M. and Manea, A. (2023) “Rewiring critical plant–soil microbial interactions to assist ecological restoration,” American Journal of Botany. Available at: https://doi.org/10.1002/ajb2.16228.