These days I deal mostly with quantitative genetics and wood properties. However, trees are much more than wood and one of our PhD students at the School of Forestry, University of Canterbury had a look at production of Eucalypts essential oils, particularly cineole.
One can easily see the seasonality of production (peak in Spring & Summer) and the difference between juvenile and mature foliage. Details available at:
Chamira Rajapaksha, Luis A. Apiolaza, Marie A. Squire and Clemens Altaner. 2023. Seasonal variation of yield and composition in extracts from immature and mature Eucalyptus bosistoana leaves. Flavour and Fragrance Journal 38(4): 293-300. Open Access at https://doi.org/10.1002/ffj.3742
