PRELIMINARY RESULTS FROM POLLEN AND FUNGAL SPORES IN HOLOCENE TERRACE DEPOSITS: EVIDENCE FOR ECOSYSTEM CHANGE FOLLOWING THE MEDIEVAL WARM PERIOD

Paleoecological information about the 600-year span from the end of the Warm Period, through the Little Ice Age, into the modern period is scarce in the central Appalachians and no comparison exists with similar settings in the southern hemisphere. Existing studies on plant distributions, often used in paleoecological and paleoclimatic reconstructions are, however, incomplete. Fungi are important drivers of carbon cycling and can be significant ecological indicators because a correlation exists between fungal community richness and the local flora, as well as with temperature, moisture, and topography. Worldwide their study is an increasingly important component of paleoecological studies. We present the preliminary results of the first comparative study of fungal palynomorphs recovered from similar latitudes in the southern and northern hemisphere: the eastern Entre Ríos province in Argentina and eastern Kentucky in the United States. While climatically similar, the two settings do contain different plant groups, and likewise somewhat different fungal spectra were recovered. Of note, several taxa that occur in Argentina do not occur in the Kentucky samples, including Potamomyces spp.; likewise, the fern and lycophte flora recovered from Entre Ríos is more varied than that recovered in Kentucky. Previous work in eastern Kentucky has indicated that significant environmental changes are correlative to major historical land-use changes during this period; this is again observed at new sites to the southeast of the original study. Fungi from these sites indicate a rich and varied community of mycorrhizae, saprophytes, and parasites, including taxa routinely used to estimate presence/absence of vertebrate taxa. Variations in fungal taxa present track with land-cover changes.