Vulnerability of xylem to embolism is an important trait related to drought resistance of plants. Methods continue to be developed and debated for measuring embolism. We tested three methods (benchtop dehydration/hydraulic, micro-computed tomography (microCT) and optical) for assessing the vulnerability to embolism of a native California oak species (Quercus douglasii Hook. & Arn.), including an analysis of three different stem ages. All three methods were found to significantly differ in their estimates, with a greater resistance to embolism as follows: microCT > optical > hydraulic. Careful testing was conducted for the hydraulic method to evaluate multiple known potential artifacts, and none was found. One-year-old stems were more resistant than older stems using microCT and optical methods, but not hydraulic methods. Divergence between the microCT and optical methods from the standard hydraulic method was consistent with predictions based on known errors when estimating theoretical losses in hydraulic function in both microCT and optical methods. When the goal of a study is to describe or predict losses in hydraulic conductivity, neither the microCT nor optical methods are reliable for accurately constructing vulnerability curves of stems; nevertheless, these methods may be useful if the goal of a study is to identify embolism events irrespective of hydraulic conductivity or hydraulic function.

中文翻译：

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加利福尼亚橡木树种（Quercus douglasii）的不同陈年茎的抗栓塞性：光学和microCT方法不同于台式脱水标准。

木质部对栓塞的脆弱性是与植物抗旱性有关的重要特征。继续开发和讨论测量栓塞的方法。我们测试了三种方法（台式脱水/液压，微型计算机断层扫描（microCT）和光学方法），以评估加利福尼亚本地橡树种（Quercus douglasii Hook。＆Arn。）对栓塞的脆弱性，包括对三种不同茎年龄的分析。 。发现这三种方法的估计值均存在显着差异，并且对栓塞的抵抗力较大，如下所示：microCT>光学>水力。对液压方法进行了仔细的测试，以评估多个已知的潜在工件，但没有发现。使用microCT和光学方法（而非水力方法），一岁的茎比老茎更具抗性。在估算microCT和光学方法的液压功能理论损失时，microCT和光学方法与标准液压方法之间的差异与基于已知误差的预测一致。当研究的目的是描述或预测水力传导率的损失时，microCT和光学方法均无法可靠地构建茎的脆弱性曲线。但是，如果研究的目的是识别栓塞事件而与水力传导率或水力功能无关，则这些方法可能有用。当研究的目的是描述或预测水力传导率的损失时，microCT和光学方法均无法可靠地构建茎的脆弱性曲线。但是，如果研究的目的是识别栓塞事件而与水力传导率或水力功能无关，则这些方法可能有用。当研究的目的是描述或预测水力传导率的损失时，microCT和光学方法均无法可靠地构建茎的脆弱性曲线。但是，如果研究的目的是识别栓塞事件而与水力传导率或水力功能无关，则这些方法可能会有用。