Post-fire morel (Morchella) mushroom abundance, spatial structure, and harvest sustainability

This study is one of only four that provide unbiased estimates of post-fire morel abundance. Our morel abundance estimates are generally consistent with prior work in high-latitude North American conifer forests. The strong spatial autocorrelation of morel-occupied microsites at scales <7 m indicates that key factors controlling post-fire morel productivity are heterogeneous at small spatial scales. We propose a simple conceptual model to explain this spatial structure that includes spatial variability of pre-fire Morchella colonies; pre-fire vegetation community and fuelbed; fire behavior, intensity, and effects; and soil moisture and temperature. Relatively liberal harvest limits for recreational and subsistence harvesters appear appropriate and sustainable, at least for coniferous forests in the first year following fire. However, intensive commercial harvest, in jurisdictions where it is allowed, may warrant monitoring to assess potential impacts to long-term morel productivity, conflict with recreational harvesters, and non-target effects.