The growth rate of trees varies: some trees grow slower and others faster by nature. The amount of nutrients and water a tree receives depends on its root system and the symbiotic mycorrhizal fungi growing in the root system. Earlier studies have determined that fast-growing spruce clones have more diverse selection of symbiotic fungi in their root systems. One cannot determine based on this result whether the diversity is the underlying reason for the fast growth rate or its consequence, however.
* This article was originally published here
