Sample size and cardinal orientation in cambial activity analysis: a case study

摘要

Radial growth dynamics of woody species is studied by different methods. The annual monitoring of cambial activity has been recommended as the method of greatest accuracy in research and appropriate for studies in protected areas for biological conservation, because it is largely nondestructive. Nevertheless, sampling protocols still need more standardization and precision. This study aims to investigate the influence of cardinal orientation on the number of cells in the cambial zone, and to evaluate the number of trees needed to conduct histological studies of cambial activity in Cedrela odorata, a tropical species with well-defined annual growth in the Atlantic Forest of South America' Brazil. Seventeen trees were evaluated during the period of intense cambial activity, with the sampling of four quadrants of the stem, according to cardinal orientation. The variance of cambial cell numbers was calculated for different numbers of trees. The results showed that radial growth variance was not related to cardinal orientation, but that at least 12 trees should be sampled for robust data on cambial dynamics.