Cambium phenology and dendrochronology of the endangered tropical tree Ocotea catharinensis Mez

Abstract

Ocotea catharinensis occurs mainly in the Brazilian Atlantic Forest and is highly threatened by timber logging, forest fragmentation, and habitat loss. The remnant populations of this species are genetically rich, which may be related to the presence of long-lived trees, and so it is imperative to understand their growth and age. In this study, we analyzed trees of O. catharinensis from dense ombrophylous forest, its dendrochronological potential, the period of cambial activity and dormancy, and the influence of climate on annual growth. The species showed distinct annually-formed tree-rings, with cambial activity during summer and autumn, and cambial dormancy during winter and spring. A tree-ring width chronology was built from 1852–2015. The estimated age of the sampled trees varied from 40 to 164 years. O. catharinensis in our study site does not show a strong age–diameter relationship, hence similar diameters at breast height resulted in differences in ages by as much as 50 years. The resulting tree-ring width chronology is positively correlated with March precipitation, the transition month between rainy and dry seasons. This study brings valuable contributions to the understanding of the growth of O. catharinensis, which is a novelty for this species and important to the maintenance of these long-lived trees in natural forests.