Fungal biodiversity across the Middle Miocene Climate Optimum

O'KEEFE JENNIFER M. K.; POUND MATTHEW; NUÑEZ OTAÑO N.B.; WARNY SOPHIE; ROMERO C. INGRID; GIBSON E. MARTHA; PILIÉ M.R; SPEARS M. TYLER; FAIRCHILD JOLENE C.; JONES SAVANNAH; LENNEX-STONE JE; TARLTON LAIKIN

Congreso; 53rd AASP-TPS Annual Meeting at LSU; 2021

The palynological society

Fungi are key components of ecosystems, although often overlooked in deep-time palynological preparations. Elucidating their distribution and diversity in ancient ecosystems has become a vital endeavor, as much-needed large-scale, long-term predictive models for fungal behavior during warming climates cannot be built with relatively short-term modern datasets. Likewise, it is currently impossible to use existing datasets of fossil fungal palynomorphs because the relationship between fossil-named taxa and their nearest living relatives is rarely defined. The Fungi in a Warmer World (FiaWW) project is targeting both problems by developing a global dataset of fungal diversity and distributions from X early-middle Miocene sites worldwide using, where possible, modern taxonomic assignments to family, and frequently, genus. The fungal assemblages are then directly compared to modern assemblages, yielding snapshots of community ecosystem dynamics through time. Each site contains sediments deposited during the middle Miocene Climate Optimum and was chosen to take advantage of existing paleobotanical, palynological, and/or geochemical paleoecologic and paleoclimatic studies. Unlike pollen, fungal remains in the terrestrial environment are generally deposited very close to their origin. While many are cosmopolitan, others have very narrow substrate such as sedges, bamboos, and palms (the pollen of which may be under- or not at all represented in palynological preparations), temperature, and rainfall tolerances, many others have obligate associations (as mutualists, such as with mycorrhizae, and/or as a biotrophs) with specific plant taxa. The identification of individual fossil fungal palynomorphs and the correlation of fossil fungi assemblages with modern fungal assemblages? ecological traits should allow to refine existing paleoecologic and paleoclimate records and to trace fungal assemblage responses to climate change. This project, the first of its kind, is facilitated by intensive cross-training of and collaboration among an international team of palynologists, mycologists, and climate modelers, which has been called for since at least the 1970?s.