ABSTRACT Drying protocols might alter the isotopic signatures of plant samples given that high temperatures can volatilize various organic compounds or delay the halting of physiological processes at lower drying temperatures. We thus evaluated the effect of four drying protocols on the carbon and nitrogen isotopic signatures for 23 species of plants. In particular, leaves were either freeze-dried, placed in a herbarium drying stove (ca. 50°C), in a gravity convection oven (80°C), or microwaved (900 W) in 2-minute pulses, until constant weight. For each species, neither treatment led to significantly different δ13C values, which ranged from −31.7 to −12.4‰. The δ15N values of 21 of the species considered were not affected by the drying protocols, ranging from −11.6 to −8.8‰. For Tillandsia makoyana, significant differences were observed between the freeze dried and the microwaved samples and between the freeze dried samples and those dried at 50°C for Macroptilium gibbosifolium.

中文翻译：

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干燥方案不会改变植物 δ13C 和 δ15N：生态研究的基线调查

摘要 干燥方案可能会改变植物样品的同位素特征，因为高温会挥发各种有机化合物或在较低的干燥温度下延迟生理过程的停止。因此，我们评估了四种干燥方案对 23 种植物的碳和氮同位素特征的影响。具体而言，将叶子冷冻干燥，置于植物标本干燥炉（约 50°C）、重力对流烘箱（80°C）中，或以 2 分钟脉冲微波（900 W），直至恒重. 对于每个物种，两种处理都导致 δ13C 值显着不同，范围从 -31.7 到 -12.4‰。所考虑的 21 个物种的 δ15N 值不受干燥方案的影响，范围从 -11.6 到 -8.8‰。对于铁兰 makoyana，