Napora Katharine G, Lecher Alanna L, Cherkinsky Alexander, Horan Robert, Jacobs Craig, Tyler Blaine, Thompson Victor D
Florida Atlantic University, Department of Anthropology, Boca Raton, FL 33431.
Environmental Science & Policy, College of Arts & Sciences, Lynn University, Boca Raton, FL 33431.
Proc Natl Acad Sci U S A. 2025 Jun 17;122(24):e2421181122. doi: 10.1073/pnas.2421181122. Epub 2025 Jun 9.
Bald cypress () is the longest-lived tree species in Eastern North America, but coastal cypress forests are vulnerable to a range of environmental factors [D. W. Stahle ., , 1-15 (2012)]. Here, we present analyses of bald cypress trees from a subfossil deposit at the mouth of the Altamaha River on the Georgia Coast, United States. Shifts in tree lifespans and growth rates correspond temporally to the onset of the Vandal Minimum environmental downturn, c. 500 CE. Trees that sprouted after c. 500 CE had significantly shorter lifespans on average (<200 y) than those that sprouted before this point in time (>470 y). Trees sprouting after c. 500 CE also grew significantly faster than those that sprouted before this point. Bald cypress lifespans at the Altamaha River mouth never recovered to pre-Vandal Minimum levels and, in fact, continued to decrease significantly over time. The last long-lived trees retrieved from the deposit died at the beginning of the Little Ice Age, another major climatic shift. This study suggests the enduring, localized impacts of climatic downturns and indicates the vulnerability to climate change of coastal cypress forests of the Southeast. These conclusions pertain to this location and, perhaps, other near-coastal forests. In remaining pockets of old-growth forest with bald cypress in the Southeast, 800 to 2600-y-old trees are still proven to be alive [D. W. Stahle ., . , 1-15 (2012); D. W. Stahle ., , 1002 (2019)].
落羽杉（）是北美东部寿命最长的树种，但沿海的落羽杉林易受一系列环境因素的影响[D. W. 斯塔赫尔等人，《美国国家科学院院刊》，109卷，第1期，1 - 15页（2012年）]。在此，我们展示了对来自美国佐治亚州海岸阿尔塔马哈河河口一个亚化石沉积物中的落羽杉树的分析。树木寿命和生长速率的变化在时间上与公元500年左右的汪达尔极小期环境衰退的开始相对应。公元500年之后发芽的树木平均寿命（<200年）明显短于在此之前发芽的树木（>470年）。公元500年之后发芽的树木生长速度也明显快于在此之前发芽的树木。阿尔塔马哈河河口的落羽杉寿命从未恢复到汪达尔极小期之前的水平，事实上，随着时间的推移还继续显著下降。从沉积物中获取的最后一批长寿树木在小冰期开始时死亡，这是另一次重大的气候转变。这项研究表明了气候衰退的持久局部影响，并指出了东南部沿海落羽杉林对气候变化的脆弱性。这些结论适用于这个地点，或许也适用于其他近岸森林。在东南部仍有落羽杉的老龄森林残余区域，已证实树龄在800至2600年的树木仍然存活[D. W. 斯塔赫尔等人，《美国国家科学院院刊》，109卷，第1期，1 - 15页（2012年）；D. W. 斯塔赫尔等人，《公共科学图书馆·综合》，14卷，第10期，e0223534（2019年）]。
