I've never heard of this, but sounds intriguing!
Yes, as zozo mentions, the microorganisms that perform the nitrification live on land as well as in wetlands. They are the same and they function in exactly the same way. There is also a symbiotic relationship between plants and bacteria.
Plants produce Oxygen via photosynthesis in the leaves and they transfer this gas to the roots.
Root cells also need to breathe. The remaining Oxygen sent to the roots which is not consumed then escape out of the roots and out into the substrate.
The area within the vicinity of the roots is called the rhizosphere.
In Aquatic sediments however, there is usually a very poor Oxygen level and this would typically foster the development of anerobic microorganisms.
By sending Oxygen down to the roots the plant oxygenates the rhizosphere and so fosters the development of aerobic microorganisms. Terrestrial plants also transfer CO2 down to the roots.
This community becomes diverse and many of the microorganisms we depend on to detoxify the tank grow in abundance within the rhizosphere.
The roots feed the microorganisms with gasses and carbohydrates and the microorganism return the favor by fixing Nitrogen, Iron and other nutrients which the plant then uptakes.
The closer the soil is to the roots, the higher the Oxygen content tends to be and the richer the population of aerobic and beneficial microorganisms.
So if you pull up any weed, for example , and scrape off the sediment from the roots, you will actually have a rich source of microorganism community with which to seed your substrate and your filter media. These are live and healthy population. The bigger and more robust the weed or grass, the better.
This is a much better source than the flimsy, freeze dried zombie bacteria that vendors pawn off on unsuspecting hobbyists, and it's free.
The same is true of your house plants. Grab some soil from those roots.
People are always fretting over"what kind of substrate do I need?", "How many layers of this product or that product?"
If you stop and think about it, you'll realize that plants grow in every type of sediment. They grow in the concrete of your driveway, or in rocks on a cliff. They grow in dirt. That part is simple, but amazing and complex things happen in the dirt. Plants change the dirt into things that they need and that we need.
A nice little article in plain English:
https://www.pacifichorticulture.org/articles/plants-are-in-control/
Cheers,