Longevity, climate sensitivity, and conservation status of wetland trees at Black River, North Carolina

Abstract

Bald cypress trees over 2,000-years old have been discovered in the forested wetlands along Black River using dendrochronology and radiocarbon dating. The oldest bald cypress yet documented is at least 2,624-years old, making Taxodium distichum the oldest-known wetland tree species, the oldest living trees in eastern North America, and the fifth oldest known non-clonal tree species on earth. The annual ring-width chronology developed from the ancient Black River bald cypress trees is positively correlated with growing season precipitation totals over the southeastern United States and with atmospheric circulation over the Northern Hemisphere, providing the longest exactly-dated climate proxy yet developed in eastern North America. The Nature Conservancy owns 6,400 ha in their Black River Preserve and the North Carolina legislature is considering establishment of a Black River State Park, but ancient forested wetlands are found along most of this 106 km stream and remain threatened by logging, water pollution, and sea level rise.

On tree longevity

“…Despite the relatively narrow range of latitudes, forests harboring the oldest trees are environmentally and structurally quite diverse (Fig. 2), ranging from sea‐level swamps dominated by Taxodium (Stahle et al ., 2019) to the subalpine and timberline zones occupied by Pinus in the Great Basin and Rocky Mountains (Currey, 1965; Brunstein & Yamaguchi, 1992) and by Juniperus in Tibet (Liu et al ., 2019). Somewhere in between are foggy coastal areas and mountains with a Mediterranean‐type climate where one finds the gigantic Sequoia and Sequoiadendron in the northern hemisphere (Douglass, 1919; Stephenson & Demetry, 1995; Carroll et al ., 2014), and the similarly majestic Fitzroya in the southern hemisphere (Lara & Villalba, 1993; Premoli et al ., 2003).…”

Epigenomic patterns reflect irrigation and grafting in the grapevine clone ‘Chambourcin’

“…One group in which the ability to respond to environmental variation is particularly important is long-lived (perennial), woody plants. Perennial, woody plants must withstand environmental variation occurring over days, weeks, years, decades, centuries (Quercus rubra L.), and even millennia (Taxodium distichum; Stahle et al, 2019) . Phenotypic plasticity is an important mechanism enabling long-lived plants to respond to changes in environmental conditions.…”

A Paleo Perspective of Alabama and Florida (USA) Interstate Streamflow

“…(bald cypress; Table 3). As the longest-lived tree species in eastern North America, T. distichum has been shown to provide a valuable annual archive of multi-millennial paleo-hydroclimate conditions [3,8,9,14,29,31], and thus is ideal for developing these long reconstructions. Three TRCs were retained in the Choctawhatchee (Newton), Conecuh and Escambia River models, and two were retained by the Choctawhatchee (Bruce) and Perdido River models.…”

“…Most streamflow gage data for rivers unimpaired by human activity consist of 60 years of data or fewer, which fails to capture the full range of climate variability, therefore limiting the reliability of the overall modeled streamflow. Tree-ring chronologies (TRCs) often date back centuries and are used as a surrogate for hydroclimate data reconstruction to provide further historical insight [4][5][6][7][8][9], as certain tree species are sensitive to the moisture signal of the region and serve as robust proxies for streamflow reconstruction [2,[8][9][10][11][12][13][14][15].…”

“…While dendrochronological reconstructions of hydroclimate, including streamflow, have been widely utilized in the western United States (US) due to the arid, moisturelimited environment [6,7,[16][17][18][19][20][21][22][23][24][25][26][27][28], until recently, similar studies have been relatively limited in the southeastern US [3,8,14,[29][30][31][32][33][34]. However, Crockett et al [2] established TRCs to be useful and statistically significant proxies even in the humid subtropical climate of northern Florida.…”