The chemical analysis of tree rings has attracted the interest of researchers in the past five decades in view of the possibility of exploiting this biological indicator as a widely available, high-resolution environmental archive. Information regarding the surrounding environment can be derived either by directly measuring environmental variables (nutrient availability, presence of pollutants, etc.) or by exploiting proxies (e.g. paleoclimatic and paleoenvironmental reconstructions). This review systematically covers the topic and provides a critical view on the reliability of dendrochemical information. First, we introduce the determinable chemical species, such as major elements, trace metals, isotopic ratios, and organic compounds, together with a brief description of their uptake mechanisms and functions in trees. Subsequently, we present the possibilities offered by analytical techniques in the field of tree ring analysis, focusing on direct methods and recent developments. The latter strongly improved the details of the accessible information, enabling the investigation of complex phenomena associated with plant life and encouraging the direct analysis of new analytes, particularly minor organic compounds. With regard to their applications, dendrochemical proxies have been used to trace several processes, such as environmental contamination, paleoclimate reconstruction, global environmental changes, tree physiology, extreme events, ecological trends, and dendroprovenance. Several case studies are discussed for each proposed application, with special emphasis on the reliability of tracing each process.

Starting from the reviewed literature data, the second part of the paper is devoted to the critical assessment of the reliability of tree ring proxies. We provide an overview of the current knowledge, discuss the limitations of the inferences that may be drawn from the dendrochemical data, and provide recommendations for the best practices to be used for their validation. Finally, we present the future perspectives related to the advancements in analytical instrumentation and further extension of application fields.

鉴于过去有可能将这种生物指示剂用作广泛使用的高分辨率环境档案，对树木年轮的化学分析吸引了研究人员的兴趣。有关周围环境的信息可以通过直接测量环境变量（营养素可用性，污染物的存在等）或通过利用代理（例如古气候和古环境重建）来获得。这篇综述系统地涵盖了该主题，并提供了有关树状化学信息可靠性的批判性观点。首先，我们介绍可确定的化学物种，例如主要元素，痕量金属，同位素比和有机化合物，并简要描述它们在树木中的吸收机理和功能。后来，我们介绍了树木年轮分析领域中分析技术提供的可能性，重点是直接方法和最新发展。后者极大地改善了可访问信息的详细信息，从而能够调查与植物生命相关的复杂现象，并鼓励直接分析新的分析物，尤其是次要的有机化合物。就其应用而言，树状化学代理已被用来追踪多个过程，例如环境污染，古气候重建，全球环境变化，树木生理，极端事件，生态趋势和树露。针对每种拟议的应用讨论了几个案例研究，其中特别强调了跟踪每个过程的可靠性。

从回顾的文献数据开始，本文的第二部分致力于对树环代理可靠性的严格评估。我们提供了当前知识的概述，讨论了可从树状化学数据中得出的推论的局限性，并提供了用于验证的最佳实践的建议。最后，我们介绍了与分析仪器的进步以及应用领域的进一步扩展有关的未来观点。