Ektvedt Tone Marie, Evans Michael N, Falk Donald A, Sheppard Paul R
Department of Geography, University of Bergen, Fosswinchelsgate 6, 5020 Bergen, Norway.
Laboratory of Tree-Ring Research, University of Arizona, Bryant Bannister Tree-Ring Building, 1215 E. Lowell Street, Tucson, AZ 85721, USA.
Plants (Basel). 2025 Jun 3;14(11):1704. doi: 10.3390/plants14111704.
Tropical trees represent an important potential archive of climate and ecological information, but their dendrochronology based on conventional techniques has been challenging. We conducted a pilot study of the wood anatomy and dendroclimatological potential of Diels (Juglandaceae), an IUCN Red List species, using 225 radii sampled from 57 trees in Piura (4°55' S, 79° 56' W), northern Peru. A total of 112 radii from 40 trees passed quality control and are included in the tree-ring width chronology for this species. has demonstrably annual rings, and results are consistent with reports that the species has a dormant period during the dry season, which locally is approximately June-November. Local precipitation is correlated ( = 0.10, 1-tailed test) with tree-ring growth, lagged by one year, consistent with other studies of tropical tree species. The age distribution of the sample collection of is young and invariant, probably because of selective cutting by local villagers. To supplement ring-width analysis, we conducted the first oxygen isotopic (δO) and radiocarbon (∆C) analysis for this species on radii from two individuals; results are preliminary given sample size limitations, but consistent with dendrochronological dating, within uncertainties, in all three chronometric analyses. A two-sample composite annually-averaged δO anomaly data series is correlated significantly with gridded regional growing season (December-May) precipitation (1973/74-2005/06). Qualitatively consistent with simulation of ring width and δ18O, responses to El Niño events are manifested in positive ring-growth anomalies and negative isotopic anomalies following known event years. The combination of tree-ring, radiocarbon, stable isotopic analyses, and the application of sensor and chronological modeling provides a degree of confidence in the results that would not have been possible by relying on any single approach and indicates the potential for further investigation of this and other tropical tree species with uncertain ring boundaries.
热带树木是气候和生态信息的重要潜在档案库，但基于传统技术的树木年代学研究一直具有挑战性。我们对国际自然保护联盟红色名录物种迪尔斯胡桃（胡桃科）的木材解剖结构和树木气候学潜力进行了一项试点研究，使用了从秘鲁北部皮斯科（南纬4°55′，西经79°56′）的57棵树中采集的225个半径样本。来自40棵树的总共112个半径样本通过了质量控制，并被纳入该物种的年轮宽度年表。迪尔斯胡桃有明显的年轮，结果与该物种在旱季有休眠期的报道一致，当地旱季大约是6月至11月。当地降水量与年轮生长呈正相关（r = 0.10，单尾检验），滞后一年，这与其他热带树种的研究结果一致。迪尔斯胡桃样本采集的年龄分布年轻且不变，可能是因为当地村民的选择性砍伐。为了补充年轮宽度分析，我们对两个个体的半径样本进行了该物种的首次氧同位素（δO）和放射性碳（∆C）分析；由于样本量有限，结果是初步的，但在所有三种年代测定分析的不确定性范围内，与树木年代学测定结果一致。一个双样本复合年平均δO异常数据系列与网格化的区域生长季节（12月至5月）降水量（1973/74 - 2005/06）显著相关。在定性上与年轮宽度和δ18O的模拟结果一致，对厄尔尼诺事件的响应表现为在已知事件年份之后出现正的年轮生长异常和负的同位素异常。树木年轮、放射性碳、稳定同位素分析的结合，以及传感器和年代学模型的应用，为结果提供了一定程度的可信度，这是仅依靠任何单一方法都无法实现的，并表明了对年轮边界不确定的该物种和其他热带树种进行进一步研究的潜力。
