. Bulletins of American paleontology. 50 Bulletin 361 1998-f Q < to. 120 125 130 135 140 Annual Precipitation (cm) 145 Text-figure 5.—Annual rainfall (9 point smoothing) for Ever- glades, 1895-1998. Vertical line indicates 1895-1998 average. Based on precipitation data for Florida region 5 obtained from NOAA at and Dineen, 1994), and the reduced water depths re- corded in sediments from site 1 after 1960 illustrates the impact of that hydrologic change. The increased abundance of cattail pollen at site 2 after 1960 is cor- related with increase
. Bulletins of American paleontology. 50 Bulletin 361 1998-f Q < to. 120 125 130 135 140 Annual Precipitation (cm) 145 Text-figure 5.—Annual rainfall (9 point smoothing) for Ever- glades, 1895-1998. Vertical line indicates 1895-1998 average. Based on precipitation data for Florida region 5 obtained from NOAA at and Dineen, 1994), and the reduced water depths re- corded in sediments from site 1 after 1960 illustrates the impact of that hydrologic change. The increased abundance of cattail pollen at site 2 after 1960 is cor- related with increased levels of phosphorus in both sediments and pore water from cores (Orem et al., 1999). After 1960, agricultural activities in the EAA expanded rapidly: the subsequent increased phospho- rus concentrations and cattail abundance recorded in sediments at site 2 appears to be tied to greater nutrient runoff from the EAA after that time. VEGETATIONAL HISTORY: SOUTHERN EVERGLADES SITES Pre-20™ Century Vegetation The impact of climatic changes on hydrology and salinity in the southern Everglades is illustrated in four cores collected in Taylor Slough and near Florida Bay (Sites 5-8. Text-fig. 1). From about 0 to 1200 , fresh-water marshes, analogous to sawgrass marshes and wet prairies found in the southern Ever- glades today, dominated the four sites (Text-figs. 6-9). Even at the southernmost site near Florida Bay (site 8), mollusc assemblages of this interval consist exclu- sively of terrestrial and fresh-water taxa (Text-fig. 9). The first occurrence of brackish mollusc and benthic foraminifer taxa there in the late 13''' century coincides with a decreased abundance of pollen typical of fresh- water marshes. By the 16"' century, vegetation at that site fluctuated between wet prairies and brackish marshes, indicating periodically shallower water and, possibly, salt-water intrusion. The last occurrence of terrestrial and fresh-water molluscs and algae was in the 17
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