Format: ORAL

Veronica Angyalossy1, Andr C. Lima2, Lui Agostinho Teixeira1, Marcelo R. Pace3, Carmen R. Marcati2, Ray F. Evert4

1 Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil 2 Departamento de Ciência Florestal, Solos e Ambiente, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, Brazil 3 Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad de México, Mexico 4 Department of Botany, University of Wisconsin, Madison, USA

The vascular cambium typically has a seasonal activity, both in trees and lianas, either in the tropics or in temperate regions. This seasonal activity is generally annual for both habits. Photoperiod is one of the main triggers of the resume of cambial activity after dormancy, but this is in concert to a rise in temperatures in the temperate regions and the end of the dry season in the tropics. Both the onset and offset of cambial activity occur within the favorable growing season, i.e., summer in the temperate region and rainy season in the tropics, indicating that cambial rhythm anticipates the seasons that come ahead. However, lianas typically have a much larger inter-specific variation than trees. Within a study under the same conditions, some lianas had only 2 months activity, others 5 month and others yet had the cambial activity throughout the year. We explore here the best methods to detect cambial activity, the most reliable initial and terminal growth rings markers, specificities in growth ring formation in lianas and how vascular variants of lianas may also greatly influence cambial activity.