It seems the deeper we look, the more and deeper inter-relationships we find in nature. It never ends.
During my two weeks camped in Tuolumne Meadows this summer, I took a ranger-led walk from the head of Tenaya Lake to Olmsted Point. On the way, we saw a variety of mushrooms and other fungi living in a harmonious, symbiotic relationship with the trees. Tiny fibers wrap around the roots of the trees, where they provide minerals from the soil to the trees while gaining sugars for their own growth. Other types of fungus help to break down dead plant material in the soil in a constant cycle.
This website has more information on the mutual relationships between one kind of fungi and forest trees, using clear text and pictures: http://www.waldwissen.net/wald/baeume_waldpflanzen/oekologie/wsl_mykorrhiza_lebensgemeinschaft/index_EN
This one describes the wide variety of forest fungi and the many roles they play: http://www.gbbr.ca/download/Kids%20in%20the%20Biosphere/Fungi%20in%20the%20Forest%201.pdf
With the trunks and branches of the forest in front of us and rising far above our heads, the continuous activity of the fungi below us isn’t obvious. However, the fungi and the forest function as one. In the larger picture, the forest helps to capture carbon dioxide from the air and to give us oxygen to breath–part of the grand symphony of life and the universe of which each of us is part also. What a gift to belong to all this!