Predicting edible mushroom productivity using forest carbon allocation modeling and immunoassays of ectomycorrhizae

Our Central Hypothesis:

Average (5-10 years) site productivity of selected edible EM mushroom species can be predicted by:

  1. The amount of net primary productivity (NPP) allocated below-ground by EM trees in a stand.
  2. The occupancy of that stand by the fungus of interest.

Definitions and Acronyms


Mycorrhizal fungi

Fungi that form nutrient exchange structures called mycorrhizae (literally "fungus-roots") with healthy plant rootlets. The relationship is symbiotic in the sense that it is mutually beneficial, although to varying degrees. The fungus extends hyphae (one-cell wide fungal "threads") away from the mycorrhizae to form a fine network of absorption and then translocates absorbed mineral nutrients and water to the plant. As such, the fungus acts as a fine root system for the plant. The plant in return provides the mycorrhizal fungus with carbohydrates it has produced through photosynthesis. (See Trappe 1996 for a more precise definition).

Ectomycorrhizal (EM) fungi

A subset of mycorrhizal fungi that form a characteristic fungal mantle or sheath on the small root tips of certain trees (predominantly tree species in the Pinaceae and Fagaceae). Many prized forest mushrooms such as chanterelles, matsutake, boletes, truffles, and others are ectomycorrhizal species and therefore derive their carbohydrate nutrition from the host trees through this symbiotic relationship. Sample photographs of EM fungi.

Gross Primary Productivity (GPP)

Total quantity of carbon fixed through photosynthesis in the form of carbohydrates or other metabolic compounds.

Net Primary Productivity (NPP)

Net quantity of carbon available to the tree or its mycorrhizal fungus partners for growth or other functions after subtracting the amount used for tree respiration (maintenance metabolism). Net primary productivity is a relatively constant 47%, of gross primary productivity across a wide range of forest types and conditions.

Belowground Allocation

The proportion or amount of net primary productivity that the tree allocates for large structural roots, fine feeder roots, and mycorrhizal symbionts.

Fruiting Potential

The maximum productivity that is possible on a given site in a given year if weather is favorable for mushroom development during the fruiting season.

Average Site Productivity

The average mushroom productivity of a site over 4-10 years, measured in kg/ha/yr or equivalent units. This variable provides a mean of expressed fruiting potential by averaging across multiple years of annual variation in weather patterns during the fruiting seasons. Conversely, 4-10 years is a sufficiently short interval that natural changes in stand conditions should not unduly interfere with deriving correlations for our model.

Site Occupancy

The percentage of potential habitat that is occupied by the edible EM fungal species of interest relative to competing EM fungi as measured by the percentage of EM root tips colonized by the species of interest or by the spatial extent of its mycelium.


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