Mountain ecosystems offer a unique opportunity to investigate organism responses to different climatic patterns. In this study, we aimed to test the hypothesis that the usnic acid (UA) content per mass unit and the total extract yield of Usnea amblyoclada (Müll. Arg.) Zahlbr. would increase in exposed microsites (i.e., northern and flat microsites) and at higher elevations (i.e., 1800 m.a.s.l. and 2100 m.a.s.l.). A total of 27 U. amblyoclada extract samples were analyzed to assess UA concentration and total extraction yield. Generalized linear models revealed a significant difference in UA concentration among elevations (p > 0.01). Tukey’s post hoc test indicated that UA concentration was significantly lower at higher elevations (i.e., between 900 and 2100 m.a.s.l.), with no significant differences observed between the 1800 and 900 m.a.s.l. elevations, nor between the 1800 and 2100 m.a.s.l. elevations. In conclusion, our study provides insights into the relationship between UA content, elevation, and temperature in U. amblyoclada. These findings highlight the importance of considering temperature as the primary driver of UA concentration variations in this species, shedding light on the responses of organisms to distinct climatic patterns in mountain ecosystems.

Graphical abstract

中文翻译：

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松萝酸对海拔和微场地条件的定量变化：预测气候变化影响的化学计量模型

山区生态系统为研究生物体对不同气候模式的反应提供了独特的机会。在本研究中，我们旨在检验紫松萝 (Müll. Arg.) Zahlbr 的每质量单位松萝酸 (UA) 含量和总提取物产量的假设。在暴露的微地点（即北部和平坦的微地点）和海拔较高的地区（即海拔 1800 米和海拔 2100 米），水温会增加。对总共 27 个U. amlyoclada提取物样品进行了分析，以评估 UA 浓度和总提取率。广义线性模型揭示了不同海拔地区 UA 浓度的显着差异 ( p> 0.01）。Tukey 的事后测试表明，UA 浓度在较高海拔（即 900 和 2100 masl 之间）显着较低，在 1800 和 900 masl 海拔之间以及 1800 和 2100 masl 海拔之间没有观察到显着差异。总之，我们的研究为U. amlyoclada的 UA 含量、海拔和温度之间的关系提供了见解。这些发现强调了将温度视为该物种尿酸浓度变化的主要驱动因素的重要性，揭示了生物体对山地生态系统中不同气候模式的反应。

图形概要