Asynchronous leaf and cambial phenology in a tree species of the Congo Basin requires space–time conversion of wood traits.

Background and Aims Wood traits are increasingly being used to document tree performance. In the Congo Basin, however, weaker seasonality causes asynchrony of wood traits between trees. Here, we monitor growth and phenology data to date the formation of traits. Methods For two seasons, leaf and cambial phenology were monitored on four Terminalia superba trees (Mayombe) using cameras, cambial pinning and dendrometers. Subsequently, vessel lumen and parenchyma fractions as well as high-resolution isotopes (δ¹³C/δ¹⁸O) were quantified on the formed rings. All traits were dated and related to weather data. Key Results We observed between-tree differences in green-up of 45 d, with trees flushing before and after the rainy season. The lag between green-up and onset of xylem formation was 59 ± 21 d. The xylem growing season lasted 159 ± 17 d with between-tree differences of up to 53 d. Synchronized vessel, parenchyma and δ¹³C profiles were related to each other. Only parenchyma fraction and δ¹³C were correlated to weather variables, whereas the δ¹⁸O pattern showed no trend. Conclusions Asynchrony of leaf and cambial phenology complicates correct interpretation of environmental information recorded in wood. An integrated approach including high-resolution measurements of growth, stable isotopes and anatomical features allows exact dating of the formation of traits. This methodology offers a means to explore the asynchrony of growth in a rainforest and contribute to understanding this aspect of forest resilience. [ABSTRACT FROM AUTHOR]