TRACKING SEA LEVEL CHANGES USING A NEWLY DISCOVERED PALYNOMORPHIC FINGERPRINT TO DETECT THE PRESENCE OF HIGH-LEVEL SALT MARSH SEDIMENTS WITH DEPTH

Juncus roemerianus is the plant that occurs at the highest level of saltwater influence in much of the high-level salt marsh in the southeastern United States. Marsh and Cohen (2006) have recently shown that it is possible to distinguish high-level salt marsh (dominated by Juncus roemerianus) from either low-level salt marsh (dominated by Spartina alterniflora) or salt panne (dominated by Salicornia virginica) using a newly discovered palynomorphic fingerprint. This fingerprint can be recognized in surface sediments underlying Juncus marshes by: 1) a palynomorph abundance that is nearly double that present in the other salt marshes; 2) a palynomorph diversity nearly double that of the other types); 3) the presence of “Fungal Spore Type A” in quantities equal to or exceeding 10 % of the total palynomorph count; and, 4) the presence, in nearly any concentration, of Atrotorquata lineata, a fungal type that is found exclusively in sediments beneath Juncus marshes. This follow-up study examines core sediments from current salt marshes in the vicinity of James Island, SC, to test the fingerprint concept with depth. The J. roemerianus palynomorphic fingerprint was readily identified in these cores, indicating that it is now possible to trace past expansion or contraction of Juncus roemerianus marshes along coastlines and, thus, to track sea level rise and fall over time.