Remarks on Age and Growth Rate Determination of Amazonian Trees
Specific data and comments are given on age and growth rate determination in trees of the Brazilian Amazon basin, based on longterm observation and research of diameter increment, radiocarbon dating, microscopic wood structure, and gamma- and X-ray densitometry; special attention is given to species of the unflooded Terra Firrne forest. Annual dry seasons in eastern Amazonia provoke periodical cambial activity which may be measured as variation in girth increment and is recorded in the wood anatomy as well as its density. Gamma radiation densitometry is discouraged because of poor results. X-ray densitometry and the radiocarbon method are promising but must be refined. Irregular specific climatic events should be considered to be possible natural marks.