A Cedrela odorata tree ring width chronology spanning from 1786 to 2016 was developed in the quasi-equatorial eastern Amazon Basin. Annual calendar dates were assigned using dendrochronological techniques at the Federal University of Lavras, Brazil. Due to its strategic location at the edge of the Equator (approximately 0°57′S), an independent confirmation of the annual periodicity of this century-long chronology would be of great value, allowing its future use for climate reconstruction and for filling gaps in upcoming atmospheric radiocarbon (¹⁴C) compilations. For reconstruction of atmospheric ¹⁴C, high reliability of the dendrochronological calendar dates is a requirement. Here, we used high-precision ¹⁴C bomb pulse dating (BPD) of selected C. odorata tree rings as a robust independent method to validate the dendrochronological dates. Eight calendar years from across the pre-to post-bomb period were tested through ¹⁴C analysis of α-cellulose extracts (19 targets in total were produced from those 8 calendar years). All dendrochronologically dated tree rings measured produced ¹⁴C values in perfect alignment with the Southern Hemisphere ¹⁴C bomb curve, further confirming the annual growth of this important record. Extraction of α-cellulose was attained by a recently implemented procedure at the Lamont-Doherty Earth Observatory (LDEO). The method was ¹⁴C assessed by high-precision measurements at the Keck Carbon Cycle Accelerator Mass Spectrometer (KCCAMS) at the University of California, Irvine (UCI) by measuring reference materials and unknown samples. High reproducibility of reference materials (within uncertainties) showed that the novel 150-funnel system and protocol developed at LDEO is reliable and can potentially expedite cellulose extractions for ¹⁴C analysis.

在准赤道的亚马逊东部盆地开发了一种从1786年到2016年的香雪松年轮宽度年表。年度日历日期是使用巴西联邦拉夫拉斯联邦大学的树轮年代学技术分配的。由于它位于赤道边缘（大约0°57′S）的战略位置，因此对本世纪以来的年表的年度周期性进行独立确认将具有重要价值，从而使其将来可用于气候重建和填补空白在即将到来的大气放射性碳（¹⁴ C）汇编中。为了重建大气¹⁴ C，需要树轮年代日历日期的高可靠性。在这里，我们使用了高精度¹⁴选定的香茅树年轮的C炸弹脉冲定年（BPD）作为验证树轮年代学日期的可靠的独立方法。通过对¹⁴种α-纤维素提取物进行¹⁴ C分析，测试了炸弹爆炸前后的8个日历年（从这8个日历年中总共产生了19个目标）。测得的所有按年代顺序排列的树木年轮都产生了¹⁴ C值，与南半球¹⁴ C炸弹曲线完全吻合，进一步证实了这一重要记录的年度增长。通过最近在Lamont-Doherty地球观测站（LDEO）实施的程序可以提取α-纤维素。方法是¹⁴在加利福尼亚大学欧文分校（UCI）的凯克碳循环加速器质谱仪（KCCAMS）上通过高精度测量，通过测量参考物质和未知样品来评估C。标准物质的高可重复性（在不确定性范围内）表明，LDEO开发的新型150漏斗系统和方案是可靠的，并且可以加快纤维素提取的速度，以进行¹⁴ C分析。