Terpenes are naturally occurring aromatic compounds found in many plants and are especially important components of natural tree resins. They contribute to the distinctive scents of resins, woods and conifers and play a role in the plant’s natural protective systems.
In fresh tree resin, terpenes are often among the more volatile components. As resin ages, dries or hardens, some of these compounds gradually evaporate or change, which can affect its aroma, texture and chemical composition.
How the Term is Used
When discussing natural tree resins, terpene generally refers to a family of compounds responsible for many of their characteristic aromatic qualities.
Common terpenes associated with resinous and aromatic plants include pinene, limonene and other compounds whose proportions vary according to plant species, growing conditions, resin type and age.
Terpenes in Natural Tree Resins
Trees produce resin as part of their natural defense and wound-response systems. Terpenes can help keep fresh resin fluid enough to move through resin ducts and across damaged tissue while also contributing to the strong aromatic environment surrounding the resin.
As the more volatile terpenes evaporate, the remaining resin generally becomes thicker and eventually hardens. This helps explain why freshly collected resin may smell and behave differently from older, dried resin.
Terpenes are only part of the chemistry of natural resin. Depending on the plant, a resin may also contain resin acids, terpenoids and other nonvolatile compounds that remain after much of the volatile fraction has dissipated.
Terpenes, Terpenoids & Volatile Oils
The terms terpene and terpenoid are often used loosely, but they are not chemically identical. Terpenes are hydrocarbons composed of carbon and hydrogen, while terpenoids are closely related compounds that have undergone chemical modification, often involving oxygen.
Terpenes may also occur in volatile oils, but a terpene is not itself the same thing as a volatile oil. Volatile oils are complex mixtures containing many different aromatic compounds.
Why Context Matters
The terpene composition of a natural resin can vary considerably between plant species and even between individual resin samples. Identifying a material as “terpene-rich” therefore does not describe one particular substance or effect; it simply tells us that compounds from this large chemical family are present.
Related Terms
Related concepts include Bioactive Compound and Volatile Oil. These terms may overlap when discussing aromatic plants and natural resins, but they are not interchangeable and each has its own meaning and context.
A Note on Wellness Language
Wellness terms can change over time and may be used differently across botanical, scientific, traditional, and commercial settings. Our goal is to explain them clearly and give enough context for you to make sense of the language you encounter.
A Note on Educational Information
The information in this glossary is provided for educational purposes only. It is intended to explain terminology and provide context, not to diagnose, treat, cure, or prevent disease, or replace advice from a qualified healthcare professional.
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Part of what gives natural resins their unmistakable aromatic character. 🌲