ABSTRACTS OF THE 87th MEETING OF THE MSA “DIVERSITY IN ALL DIMENSIONS” August 10-14, 2019, Minneapolis, MN MON 1 A tropical mycological journey Sharon A. Cantrell Department of Biology, Universidad Ana G. Méndez, Gurabo, Puerto Rico Abstract Since starting my M.S. degree in 1989 at the University of Puerto Rico-Mayagüez, I have been involved in studying tropical fungi, and this has been a wonderful journey from the beginning. Throughout my career, I have been blessed, and I have met multiple mycologists that have impacted my life. My studies in tropical fungi have included a diversity of ecosystems from extreme to the wettest tropical forests in the Caribbean. My contributions not only include describing new species but also their ecosystem function and particularly how fungi can be affected by natural disturbances and climate change. Diversity is the theme of this year’s meeting, and I feel blessed to have served as MSA President from 2018-2019, especially being the first Latin- American to serve as President. This was a dream I had a long time ago, and throughout my life everything that I have planned has become a reality, so to all the young mycologists, never be afraid of setting the highest goals in your life because dreams come true. Life is a journey and we have to make the best of it. MON 2 Prescribed fire intervals impact soil fungal community trajectories in Florida Longleaf Pine ecosystems Sam Fox1, Melanie K. Taylor2, Mac Callaham Jr.2, Ari Jumpponen1 1Kansas State University, Manhattan, USA. 2USDA Forest Service, Center for Forest Disturbance Science, Southern Research Station, Athens, USA Abstract Prescribed fires are a management practice designed to mimic naturally occurring fire regimes and reduce fuel loads. However, it remains unclear how the soil-inhabiting fungal communities respond to frequent prescribed fires. To record fungal community responses, we utilized a 60-year fire experiment in the longleaf pine dominated Olustee Experimental Forest located in the Osceola National Forest in Northeastern Florida. The experiment includes replicated (6 replicates) stand-level fire treatments applied at 1-, 2-, and 4-year intervals in addition to unburned stands during the experiment. We sampled the A, E, and B soil horizons from all stands a week before and one month after prescribed burning stands assigned to the 1-, 2-, and 4-year burn cycles. The extracted genomic DNA was amplified with fungus specific primers (fITS7; ITS4). Congruent with other experiments, our data suggest that prescribed burn intervals maintained on decadal scales result in distinct fungal communities and that the top most soil horizons are most strongly impacted. Our work contributes to building foundational knowledge on how soil fungal communities are impacted by fires, whose intervals vary. Our data aids in choosing strategies for optimal management to maintain fungal biodiversity in soils. MON 3 Wildfire impacts on below-ground communities depend on soil horizon, site location, and burn severity: toward a framework of ecosystem recovery Shawn Brown1, Allison Veach2, Jonathan Horton3, Ari Jumpponen4, Richard Baird5 1University of Memphis, Memphis, TN, USA. 2Oak Ridge National Lab, Oak Ridge, TN, USA. 3University of North Carolina-Asheville, Asheville, NC, USA. 4Kansas State University, Manhattan, KS, USA. 5Mississippi State University, Starkville, MS, USA Abstract Decades of fire suppression coupled with climatic changes have increased the frequency and severity of wildfires. The Southern Appalachia region of the United States is particularly susceptible to increased fire severity and occurrence. These fires can reorganize local biodiversity and elicit short- and long-term shifts in microbial communities, which can lead to fire adapted communities that follow novel community trajectories and facilitate ecosystem recovery in different ways. Following the record- breaking 2016 fire season in Southern Appalachia, we examined wildfire impacts on below-ground communities within two substrates (duff and soil) at two adjacent locations with similar plant communities (Great Smoky Mountains National Park – Chimney Top 2 Fire and Nantahala National Forest– Cliffside Lake Fire) from eight replicate plots representing a range of fire severities (Unburned, Low Severity, Moderate Severity, Severe). Soil-inhabiting communities differed across the fire severities. Further, fire impacts on communities and functional guilds were location- and substrate-specific: Nantahala National Forest sites were relatively more fire-sensitive than Great Smoky Mountains National Park sites and soil more fire-sensitive than duff. Ectomycorrhizal abundance did not change in duff with fire but decreased in soil with burn severity whereas putative plant pathogens increased with burn severity but did not change in soil. Despite distinct communities across fire severities, traditional fire- responsive (phoenicoid) fungi remained absent although several fire-responsive OTUs could be identified thus highlighting our poor understanding of fire responsive fungi. Taken together, our results suggest context-dependency in fungal responses to fire that must be accounted for to generate ecosystem-wide recovery predictions. MON 4 Mycorrhiza of Pine Seedlings (Pinus pungens) germinating after the Chimneys 2 fire in the Great Smoky Mountains National Park Karen Hughes1, Alexis Case1, P. Brandon Matheny1, Ronald H. Petersen1, Andrew N. Miller2, Teresa Iturriaga3 1University of Tennessee, Knoxville, USA. 2University of Illinois, Urbana-Champaign, USA. 3Cornell University, Ithaca, USA Abstract A wildfire in the Great Smoky Mountains National Park (November 2016) burned three ridgetop populations of the Appalachian endemic Table Mountain Pine (Pinus pungens). Pinus pungens is serotinous and by June, 2017, small pine seedlings were sprouting in these severe burn areas. Throughout 2017 and 2018, mycorrhiza on the roots of these seedlings were examined for ectomycorrhizae and, where feasible, their nrITS sequences were obtained. We show that even tiny pine seedlings formed mycorrhizae prolifically. Mycorrhizae on pine roots differed between the three high severity burn sites and changed over time. Some mycorrhizae apparently acted to bind soil, forming a sticky outer coating that was complexed with small soil particles. Predominant mycorrhizae on pine seedlings were in the Pezizaceae (including Sphaerosporella), and the basidiomycetes Laccaria trichodermophora and Thelephora spp. Mycorrhizae shared across the three severe burn areas included Hydnotra, Rhizopogon and Tuber, all sequestrate fungi which may have survived the fire. MON 5 Ectomycorrhizal dynamics of whitebark pine seedlings in wildfire-impacted soil: and implications for restoration Cathy Cripps, Martha Jenkins Montana State University, Bozeman, USA Abstract White bark pine (Pinus albicaulis) is an iconic, five-needle, high-elevation pine whose existence is threatened by an exotic rust, mountain pine beetles, fire suppression, and climate change. Its distribution is limited to western North America and populations have declined 90% in recent decades. The pine is shade intolerant and depends on wildfire to reset the successional clock. Regeneration occurs mainly through germination of un- retrieved seeds planted by nutcrackers on burns after wildfire. However, regeneration does not always follow wildfires or prescribed burning, and thousands of nursery seedling are being planted across the landscape to compensate losses. We examined how the ectomycorrhizal fungi (EMF) in whitebark pine forests are impacted by fire through a series of field and greenhouse studies. Field studies in Montana and Alberta found that 1) species richness of EMF was low 2) intense fire in compromised beetle- killed stands could wipe out all EMF 3) intense fire in a healthy mature forests reduced EMF species richness 40-50%, shifted EMF communities, and reduced suilloids (Suillus, Rhizopogon) on seedling roots five years postfire 4) EMF can survive light prescribed burns. In greenhouse and in vitro studies, we found that 5) various Suillus species access different nitrogen sources 5) in burned soil, Suillus americanus (sibericus) inoculation increased seedling biomass 61%, leaf nitrogen content 25%, and lowered δ15N. Suillus americanus was used to inoculate pines for several large restoration projects on burns involving thousands of nursery-generated whitebark pine seedlings in Canada and Montana; results will be discussed. MON 6 Prescribed fire reorganizes fungal communities and alters microbial decomposition in the long-leaf pine savanna of North America Tatiana Semenova-Nelsen1, William Platt2, Taylor Patterson1,3, Jean Huffman2, Benjamin Sikes1 1University of Kansas, Lawrence, USA. 2Louisiana State University, Baton Rouge, USA. 3State University of New York, Syracuse, USA Abstract Frequent fires sustain pyrogenic ecosystems. In many of these systems, recurrent fires maintain a tree-grassland “matrix” and generate heterogeneous microhabitats that support high species diversity. Aboveground responses to fire in pyrogenic systems have been well-studied, but responses of belowground communities, such as fungi, remain poorly known. We assessed fire effects on fungal communities and decomposition rates in a pyrogenic pine savanna in North America. Fungal communities in litter and soil substrates were sampled in recently burned and unburned microhabitats located near or away from pines. Soil properties and vegetation composition were sampled to assess drivers