Soil microbes love invasive plants
He, Y., Li, J., Siemann, E., Li, B., Xu, Y. and Wang, Y., 2025. Plant Invasion Increases Soil Microbial Biomass Carbon: Meta‐Analysis and Empirical Tests. Global Change Biology, 31(3), p.e70109. https://doi.org/10.1111/gcb.70109
Written by Bethany Bradley, edited by Fitz Dettmer
Summary
Thakur et al. (2025) — our previous research summary — showed through a meta-analysis that the presence of invasive plants correlates with increased soil organic carbon, suggesting that our invasive plant friends are actually contributing a small bit to mitigating climate change (hey, we’ll take what we can get!). However, there are multiple components that make up soil organic carbon. He et al. (2025) “dig a little deeper” to understand how soil organic carbon is changing with plant invasions. They analyzed 61 papers, mainly from China, and show that invasive plants are related to a significant increase in microbial biomass carbon and a significant decrease in particulate organic carbon. Increasing microbial biomass carbon tends to be associated with greater breakdown of soil organic matter and can increase soil fertility. Decreasing particulate organic carbon tends to be associated with lower water storage capacity and soil stability. While it is unclear from this paper whether one of these components is ‘winning’, when coupled with Thakur et al. (2025) these two papers suggest that invasive plants are related to increased microbial biomass carbon, which in turn increases soil organic carbon storage.
Take Home Points
Invasive plants tend to increase microbial biomass, which also increases carbon stored in the soil as microbial biomass (aka microbial biomass carbon).
Invasive plants tend to decrease particulate organic carbon, which also decreases carbon stored in the soil as organic matter.
On the whole, it is unclear from this paper whether increases in microbial biomass carbon are offset by decreases in particulate organic carbon.
Management Implications
Increasing microbial biomass tends to lead to faster decomposition and higher soil fertility. This suggests that invasive plants can increase soil resources - potentially leading to a feedback loop that facilitates further plant invasions because invasive plants tend to have competitive traits that require high resource availability.
Losses of particulate organic carbon associated with invasive plants could offset some gains from microbial biomass, but the meta-analysis paper by Thakur et al. (2025) suggests that overall invasive plants increase soil organic carbon.
Related Papers
Fei et al. 2019, Quirion et al. 2021, Thakur et al. 2025
Keywords
Impact studies, invasive plants, meta-analysis, soil organic carbon, microbial biomass carbon