This study is aimed to understand responses in growth rhythm to different climatic conditions of the widespread deciduous species Cedrela odorata. Our own research was conducted in Nova Iguaçu. Rio de Janeiro State, Brazil) and compared with literature data from Aripuanã. Mato Grosso State, Brazil), Manaus. Amazonas State, Brazil) and Barinas. Barinas State, Venezuela). Growth periodicity was evaluated through leaf phenological behavior and radial growth. In Nova Iguaçu, leaf phenology was monitored monthly and radial growth was evaluated by cambial histological analysis of samples collected in wet and dry seasons. In the other sites, the authors evaluated the growth rhythm by dendrometer bands. Growth always occurs in the wet season, even when there is no water deficit during the dry season. Thus, the species is considered conservative concerning the maintenance of growth seasonality. Nevertheless, C. odorata was able to change its growth period, following local seasonality of its different growth sites. Therefore we suggest caution when performing climate analysis from a chronology using trees that grow in different periods of the year.

Air pollution is considered to be one of the main causes of forest decline. The cambium is responsible for increase in tree girth, and its functioning is determined by environmental pressures. This study compared cambium histology of Ceiba speciosa (A. St.-Hil.) Ravenna (Malvaceae) in polluted and preserved sites in the Atlantic Rainforest domain. Samples were obtained during periods of cambial activity and dormancy and were processed and examined according to standard light microscopy techniques. In addition to differences typically observed in cambium during periods of activity and dormancy, the fusiform initials were shorter in trees of the polluted site. Furthermore, cambial rays were shorter, but larger, in the polluted site. It should be noted that all parameters related to cambial rays showed significant differences between the study sites. This is the first report of the effects of pollution on cambial activity in a South American species. The results suggest a tolerance of C. speciosa to pollution and reveal this species to be an important biomarker for environmental monitoring studies.

The lack of specific research on the sequence of events that determine plant growth from meristem until wood formation represents a gap in the knowledge of growth dynamics in woody species. In this work, we surveyed published studies concerning cambial activity of Brazilian native species aiming at allowing the comparison of applied methods and obtained results. The annual cambial seasonality was observed in all the investigated species. Nevertheless, we found high heterogeneity in the used methodologies. As a result from this analysis, our opinion points to the need for standardizing sampling protocols and for discussing the suitability of experimental designs. This will help to define with greater precision the factors that determine the radial growth in the different tropical ecosystems.

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Knowledge about growth rhythm and longevity of tropical trees is essential to understand life strategies of native species, and consequently, of forest remnants. This study aims to investigate the growth dynamics of Centrolobium robustum, a representative species from Atlantic Forest. For this purpose, radial growth was examined through tree rings and cambium analysis, from macroscopical, anatomical, and ultrastructural perspectives. The apical and radial stem growth was evaluated through leaf and cambium phenology, respectively. Leaf and cambium behaviors were associated with environmental seasonality. The results showed that the period of cell production and cambial development occurred in association with leaf expansion and during the wet, warm, and long-day season. Seasonality of cambial and leaf phenology in response to the environment determined the annual formation of tree rings, and it allowed to evaluate C. robustum growth rates and longevity. Species seasonality also responded to abnormal climatic events during the study period, which shows its sensitivity to environmental changes and represents a factor to be considered in the forest management programs.