# Accuracy of Increment Core Method for Measuring Basic Wood Density and Moisture Content in Three Catalpa Species

## TL;DR

This study shows that using incremental cores to measure wood density and moisture in Catalpa trees can be inaccurate and suggests using species-specific calibrations for better results.

## Contribution

The study identifies species-specific biases in the incremental core method and proposes a practical calibration solution for ecological research.

## Key findings

- Incremental cores overestimated wood density by 12.31–27.31% in three Catalpa species.
- The method underestimated moisture content by 5.61–30.51% across the species.
- Species-specific linear calibration models are recommended to improve accuracy.

## Abstract

Assessing wood moisture and density is essential to understanding ecological processes such as tree growth and wood formation. This study compared basic density and moisture content estimates for three Catalpa species (Catalpa ovata G. Don, Catalpa bungei C. A. Mey, and Catalpa fargesii Bureau) using three sampling methods (incremental cores, wood chips, and standard wood blocks). While strong correlations (r2 ≥ 0.99) were observed among all methods, the incremental core approach exhibited significant species-specific biases—overestimating density by 27.31–12.31% on average while underestimating moisture content by 5.61–30.51%. Despite its cost-effectiveness and minimal sample collection requirements, the method’s systematic deviations limit its applicability to multiple tree species. Consequently, we recommend developing species-specific linear calibration models that incorporate baseline data from standard wood block measurements to substantially improve estimation accuracy. This approach offers a practical, theory-supported solution for optimizing field sampling strategies in ecological research.