We know the soil microbiome is a complex community, and species may react differently to various treatments. For instance, under tillage, fungi mycelium can be compromised with a reduction of activity, and it takes time for them to re-establish. Some studies have shown that tillage is far worse than herbicides as it breaks down soil structure. Whereas some herbicides cause an uptick in some microbes as they feed on them (Harris, et al. 1994). Glyphosate, for one, has been shown to have no effect at label rates in a meta study (Nguyen et al. 2016).
Every spring, the first signs of life in my mulch (and everywhere else in my garden and neighborhood) are these ubiquitous weeds. You probably have them too. They invade lawns, landscapes, parkways, parking lots, drainage ditches, and all nooks and crannies when the weather is cool and damp. I