TY - JOUR T1 - Dynamics of marsh-mangrove ecotone since the mid-Holocene: A palynological study of mangrove encroachment and sea level rise in the Shark River Estuary, Florida JF - PLOS ONE Y1 - 2017 A1 - Yao, Qiang A1 - Liu, Kam-biu ED - Magar, Vanesa AB - Sea level rise and the associated inland shift of the marsh-mangrove ecotone in south Florida have raised many scientific and management concerns in recent years. Holocene paleoecological records can provide an important baseline to shed light on the long-term dynamics of vegetation changes across this ecotone in the past, which is needed to predict the future. In this study, we present palynological, X-ray fluorescence, and loss-on ignition data from four sedimentary cores recovered from a 20-km marine-to-freshwater transect along the Shark River Estuary, southwest Everglades, to document the patterns and processes of coastal vegetation changes in response to sea level rise since the mid-Holocene. Our record indicates that freshwater marsh progressively replaced marl prairies at the Shark River Estuary between 5700 and 4400 cal yr BP. As marine transgression continued, marine influence reached the threshold necessary for mangroves to establish at the current mouth of the Shark River Slough at 3800 cal yr BP. During the next 3000 years, although sea level rise in the Western North Atlantic slowed down to 0.4 mm/yr, a spatial and temporal gradient was evident as the marsh-mangrove ecotone shifted inland by 20 km from 3800 to 800 cal yr BP, accompanied by a gradual landward replacement of freshwater marsh by mangrove forest. If sea level continues to rise at 2.33 mm/yr in the 21st century in south Florida, it is possible that marine influence will reach the threshold for mangroves to establish in the central Everglades, and we could expect a much more aggressive mangrove encroachment toward the northern and interior parts of south Florida in the next few centuries. UR - https://doi.org/10.1371/journal.pone.0173670 ER - TY - JOUR T1 - Palynological reconstruction of environmental changes in coastal wetlands of the Florida Everglades since the mid-Holocene JF - Quaternary Research Y1 - 2015 A1 - Yao, Qiang A1 - Liu, Kam-biu A1 - Platt, William J. A1 - Rivera-Monroy, Victor H. AB - Palynological, loss-on-ignition, and X-ray fluorescence data from a 5.25 m sediment core from a mangrove forest at the mouth of the Shark River Estuary in the southwestern Everglades National Park, Florida were used to reconstruct changes occurring in coastal wetlands since the mid-Holocene. This multi-proxy record contains the longest paleoecological history to date in the southwestern Everglades. The Shark River Estuary basin was formed ~ 5700 cal yr BP in response to increasing precipitation. Initial wetlands were frequently-burned short-hydroperiod prairies, which transitioned into long-hydroperiod prairies with sloughs in which peat deposits began to accumulate continuously about 5250 cal yr BP. Our data suggest that mangrove communities started to appear after ~ 3800 cal yr BP; declines in the abundance of charcoal suggested gradual replacement of fire-dominated wetlands by mangrove forest over the following 2650 yr. By ~ 1150 cal yr BP, a dense Rhizophora mangle dominated mangrove forest had formed at the mouth of the Shark River. The mangrove-dominated coastal ecosystem here was established at least 2000 yr later than has been previously estimated. VL - 83 UR - http://www.sciencedirect.com/science/article/pii/S0033589415000290 IS - 3 JO - Palynological reconstruction of environmental changes in coastal wetlands of the Florida Everglades since the mid-Holocene ER -