Overview of Tree-Ring Analysis in Tropical Regions

Although tree-ring analysis is a rapidly developing area of study, tropical regions have been largely neglected until recently by dendrochronologists. Research in these regions had mainly consisted of phenological, anatomical, and other studies by ecologists, foresters and anatomists. Many dendrochronologists felt that the tropics, due to a general lack of seasonality, were difficult if not impossible regions to apply their science. Many species do not form distinct rings and in many cases where rings are formed they often are not annual in nature. Increasing concern over tropical forests is focusing greater interest on tropical tree-ring analysis. In northern Australia, India, northern Argentina, central America, Brazil, West Africa and Kenya there are initially promising results. The key to the results is seasonality of some environmental conditions that induce dormancy and/or genetic tendency for growing identifiable rings in a cyclical manner. All techniques including densitometry and isotopic analysis as well as conventional ring analysis must be employed to maximise future results. The importance of tree-ring analysis for forestry and ecology relates to better information about factors influencing growth rates, wood production and quality, rotation times, and replacement rates. This information should find uses ranging from harvest and plantation planning to maintenance of natural forests. In addition, longer time series of tropical tree growth are important to studies of climatic change.