I was unfamiliar with how mycorrhizal networks connect the roots of trees, facilitating the sharing of resources. Dr. Suzanne Simard writes:

Graduate student Kevin Beiler has uncovered the extent and architecture of this network through the use of new molecular tools that can distinguish the DNA of one fungal individual from another, or of one tree’s roots from another. He has found that all trees in dry interior Douglas-fir (Pseudotsuga menziesii var. glauca) forests are interconnected, with the largest, oldest trees serving as hubs, much like the hub of a spoked wheel, where younger trees establish within the mycorrhizal network of the old trees. Through careful experimentation, recent graduate Francois Teste determined that survival of these establishing trees was greatly enhanced when they were linked into the network of the old trees.Through the use of stable isotope tracers, he and Amanda Schoonmaker, a recent undergraduate student in Forestry, found that increased survival was associated with belowground transfer of carbon, nitrogen and water from the old trees. This research provides strong evidence that maintaining forest resilience is dependent on conserving mycorrhizal links, and that removal of hub trees could unravel the network and compromise regenerative capacity of the forests.

Love this representation by Beiler of one of these networks:

Serendipity alert: I just finished reading John Vaillant’s The Golden Spruce, a remarkable story combining bizarre psychology, ecology and history. Dr. Simard figures in the book briefly (as she worked with Grant Hadwin when she was a student). There is a propagated genetic copy of the destroyed spruce at UBC’s Botanical Garden. Daniel Mosquin has a photo and write-up on the wonderful blog that he has maintained for the Botanical Garden for years now.