growthTrendR R package: A comprehensive toolkit for data processing, quality assessment and statistical analysis of tree-ring data

We present growthTrendR, a new R package designed to streamline the processing, quality assessment, and statistical analysis of tree-ring data. The package offers tools for data formatting, identification of measurement anomalies, and classification of data quality using spatial comparisons and cross-correlation techniques. It integrates flexible detrending and climate–growth modeling through Generalized Additive Mixed Models (GAMMs), enabling robust analyses of non-linear trends and autocorrelated data. growthTrendR also supports standardized visual reporting, including summaries of data completeness, quality diagnostics, and model performance. Compatible with the widely used .rwl file format and tailored for the Canadian Forest Service Tree-Ring Data (CFS-TRenD) repository, growthTrendR provides a comprehensive and adaptable framework for dendrochronologists working with large and complex datasets.