Glossary

Mycelium (my-SEE-lee-um) is the thread-like root network of a fungus — a web of microscopic filaments, called hyphae, that spreads through soil and organic matter to absorb water and nutrients.

In the Santa Cruz Mountains, mycelium is most consequential when it functions as the underground partner in a mycorrhizal relationship with native plants. Mycorrhizal fungi attach to the roots of host plants and extend their mycelium far beyond what the plant’s own roots can reach — pulling water, phosphorus, and other nutrients from the surrounding soil and delivering them back to the host in exchange for sugars the plant produces through photosynthesis. This exchange is not incidental: for many native plants in the SLV, including California Huckleberry (Vaccinium ovatum), the relationship is essential to survival in the acidic, organic-rich forest soils they depend on.

The mycelium supporting these relationships is concentrated in the upper soil layer and duff. Digging, compaction, and the removal of leaf litter can sever the network and break the exchange, which is why soil disturbance around established native plants is avoided even when the plants appear healthy aboveground.

« Back to Glossary Index