Last updated: August 29, 2025
Article
U.S. Federal Forest Type Definitions Differ from Those in Scientific Discourse
Lack of alignment between how forest types are defined could make widespread acceptance of new definitions elusive.
By the editors of Park Science magazine
About this article
This article was originally published in the "Research Roundup" section of Park Science magazine, Volume 39, Number 2, Summer 2025 (August 29, 2025).
Image credit: NPS / Billy Flynn
Scientists place a lot of value on consistent definitions. But one area where there’s a lack of scientific agreement is when using terms like “mature” and “old growth” to describe forests. This has implications for how people manage forests.
In a January 2025 paper in the Journal of Forestry, researchers tell how they examined scientific publication titles, definitions, and sampling methods where scientists used terms like “mature” to describe forests. The researchers wanted to know how recent U.S. federal agency forest definitions differed from those used in the scientific literature.
The federal definitions were developed by quantifying the structural features of a forest. The developers used attributes like age, density, and tree diameter. But the Journal of Forestry paper authors found that outside of federal agencies, scientific views of these terms were developed differently. Definition of terms such as “old growth” evolved through conversations and debate, with varying results. The authors think this could make it less likely that non-federal forest scientists will widely adopt the new federal definitions.
Frye and others. 2025. Scientific Definitions and Measurements of Second-Growth, Mature, and Old-Growth Forests. Journal of Forestry 123: 23–39.