Productivity and diversity of morel mushrooms in healthy, burned, and insect-damaged forests of northeastern Oregon

Large commercial crops of morels are harvested annually from montane coniferous forests of the northwestern United States. Although some morels fruit annually in nondisturbed forests, others fruit copiously in areas experiencing fire, insect infestations, tree mortality, and soil disturbance. Many forest managers currently use thinning and prescribed fire to re-create forest conditions that existed before the advent of wide-scale fire suppression, thus opportunities exist to promote morel crops while achieving fire control and timber production goals. However, our limited understanding of morel productivity, diversity, and ecology hinders such synergistic management. We used morphological, genetic, and ecological data to identify and characterize five putative species found at our study sites. Three of these putative species fruited only on burned soils the first spring season following a wildfire. The other two putative species fruited in nonburned forests, in islands of nonburned soils in burned forests, or the second year following fire on burned soils. Unbiased landscape-level estimates of genus-level morel productivity (not partitioned by putative species) ranged from 80 to 4350 morels per hectare and from 0.550 to 9.080 kg per ha. Productivity followed the general trend of wildfire-burned forests>insect-damaged forests>healthy forests. We discuss the implications of our results for forest management.