Morels appear in patches after wildfires

Figure 1. Location of sampling plots in Yosemite National Park

Figure 1. Location of sampling plots in Yosemite National Park.

As a Michigander, spring morel (Morchella) forages are a highly anticipated time of the year for this tasty fungus. Anecdotally, many foragers will consistently find this mushroom in great abundance one year after a wildfire. To document whether this common knowledge is correct, scientists documented the abundance and spatial variance of morels across a research site in the Sierra Nevada, one-year post burn. The study site was in Yosemite National Park during 2014, surveying 1,119-3.14 m2 plots over 2,240 m of transects (Figure 1). The researchers found morel fruiting bodies in 17.8% of plots. When estimated, this indicates an average of 1693 morels per ha. When spatially analyzed up to 9 m, an autocorrelation was discovered up to 7 m, but was strongest below 3 m, indicating a patchiness in Yosemite National Park. Therefore, it was recommended to foragers to search up to 7 m near a discovered morel.

However, the question remained as to the causation for patchiness in morel mushrooms after a fire. The authors created a conceptual model based up the following hypotheses to address this question: 1) Pre-fire morel mycelial colonies are distributed in small spatial scales, 2) The pre-fire vegetation is also spatially heterogeneous at small scales, 3) The fire may vary in intensity and behavior, creating diverse post-fire biogeochemistry, 4) Post-fire environmental conditions may vary and alter fruiting season production, and 5) All aforementioned conditions need to align to create a productive morel patch.

A final conclusion from this study addresses the concerns from over harvesting if governmental regulation on collections were lifted. Authors state at least 4 L per person per day of morels could be harvested the first year post-fire and not harm the future production. This would be an increase from the current 1 pint per person per day.

University of Washington. (2016, October 11). Morel mushrooms pop up, cluster together after wildfires. ScienceDaily. Retrieved November 9, 2016 from www.sciencedaily.com/releases/2016/10/161011130005.htm

Larson AJ, Cansler CA, Cowder SG, Hiebert S, Furniss TJ, Swanson ME, Lutz JA (2016) Post-fire morel (Morchella) mushrooms abundance, spatial structure, and harvest sustainability. Forest Ecology and Management. 377:16-25. 

11.09.16

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