HOW TO MEASURE GROWTH DYNAMICS IN TROPICAL TREES - A REVIEW

Cambial dormancy and annual rings in tropical trees are induced by ann ually occurring dry periods or flooding, Growth periodicity is indicat ed by the leaf fall behaviour and is connected with an annual periodic ity of shoot elongation. Changes in stem diameter are measured with a dendrometer or by measurable differences in the electrical resistance of the cambium. Dendrochronological methods applied to carefully prepa red samples can serve as proof of the annual periodicity of growth zon es. For this purpose the following methods have been used: cambial wou nding, radiocarbon dating, pointer year detection and regression analy ses of ring width and climate data. Although X-ray densitometry and th e analysis of stable isotopes in rings of tropical trees promise to pr ovide interesting climatological information, the use of these methods remains difficult.