Tree-ring measurements are a primary quantitative tool used in numerous scientific disciplines. Some species, however, exhibit morphological complexities leading to significant uncertainty in these measurements. Hawaiian Sandalwood (Santalum paniculatum) stems, for example, often develop asymmetric growth features that hinder tree-ring measurements. These features include faint-ring boundaries and wedging rings which disappear in portions of the cross-section. In this work we a use a novel two-dimensional transect methodology and our own open-source software, svg-dendro, to analyze particularly difficult cross-sections. Our method accomplishes this by first tracing all rings by hand and automatically generating a user-specified number of transects. On average, these traced measurements had more sensitivity to tree-ring variability without losing important equivalencies with the traditional binocular stereomicroscope technique (e.g., radii, skewness) as indicated by greater mean variance for ring number, mean tree-ring width, and standard deviation. All S. paniculatum samples had ring wedging, where certain sides of the stem had many locally absent tree rings but to different intensities. The new technique allows us to analyze the shift from complete rings with little to no wedging to rings with more wedging starting between the 19th and 40th ring, where deep stem lobes begin forming. The new method also reveals the difficulty in measuring these trees, as the wedging creates multiple lobes with different visible ring counts. This research suggests that this two-dimensional methodology would be best applied to non-circular trees with fewer incomplete rings, supporting the importance of species and population selection. Overall, we have developed an efficient and flexible means to measure otherwise unmeasurable growth features in tree samples through representing tree-ring boundaries as curves and developing software to sort and map transects.

树木年轮测量是许多科学学科中使用的主要定量工具。但是，某些物种会表现出形态复杂性，从而导致这些测量结果存在明显的不确定性。例如，夏威夷檀香（Santalum paniculatum）茎通常会形成不对称的生长特征，从而阻碍了树木年轮的测量。这些特征包括微弱的环边界和楔形环，这些楔形环在横截面的一部分中消失了。在这项工作中，我们使用新颖的二维断面方法和我们自己的开源软件svg-dendro，以分析特别困难的横截面。我们的方法通过首先手动跟踪所有环并自动生成用户指定数量的样线来实现此目的。平均而言，这些跟踪的测量对树环变异性具有更高的敏感性，而又不会失去传统双目立体显微镜技术（例如，半径，偏度）的重要等效性，这通过对环数，平均树环宽度和标准偏差的较大平均方差来表示。所有沙门氏菌样品有环楔，茎的某些侧面有许多局部不存在的树环，但强度不同。新技术使我们能够分析从第19到第40环之间开始形成完整茎环的过程，该过程从几乎没有楔入到没有楔入的完全过渡到向更多楔入的过渡。新的方法还揭示了测量这些树的困难，因为楔形创建了具有不同可见环数的多个裂片。这项研究表明，这种二维方法最适用于具有较少不完整环的非圆形树，这支持了物种和种群选择的重要性。全面的，