A few folk enjoyed a couple of enjoyable hours on the Coquet recently, being educated by the Rivers Trust.
We learned about the Alder trees, how they love to have their feet in the water, and about their symbiotic relationship with a certain bacterium: Frankia alni. See the red nodules in the photo:
Symbiosis works on many different scales. For example there is a relationship between alder and a bacterium called Frankia alni. In this case, Frankia lives inside nodules on alder roots. The bacteria absorb nitrogen from the atmosphere and fix it in the soil. This benefits the alder, which via photosynthesis provides the bacteria with sugars. The soil becomes enriched as a result of this process. In fact people have used alder in various parts of the world, to restore depleted soils." Symbiosis in nature | Trees for Life
There are to be more walks in the future, I will be attending for sure!