I recently found out that alder trees have root nodules which contain nitrogen-fixing bacteria and that alders are primary colonizers in primary succession. That leads me to this question: since there are really no fungi in the soil and since the alder is a colonizing species, where does the fungi come from? Or is my assumption that there are no fungi in the soil incorrect?
Any soil microbiology textbook will tell you that there are a great number of fungi in most soils. I believe there are 12 or 13 species of non-legumes capable of fixing atmospheric nitrogen. Podocarpus is one of them. Look at the roots of podocarpus and you will see nodules all along the roots.