Reliability of Annual Growth Rings in Age Determination of Rosewood (Pterocarpus Erinaceus) from Bali Local Government Area of Taraba State, Nigeria

Abstract

A study was undertaken to determine if Rosewood (Pterocarpus erinaceus) produce distinct growth rings and to determine the reliability of the annual nature of the tree age determination and finally the relationship between the number of growth rings and age of the tree and stem diameter. Thirty-two (32) stem sections were used for the study; sixteen (16) each from Medium (M) and Large (L) sample trees. Macroscopic and Microscopic investigation of annual growth rings in stem sections shows that growth rings were visible and growth ring boundaries were reasonably distinct in all the selected sample stems. The result showed a significant difference between girth, DBH and age (P=0.05) P<0.05. The pattern of ring development provides a basis for the use of ring counts in determining the age of P. erinaceus. The results can therefore be used in forest management studies in the woodlands of Bali local government area of Taraba State, Nigeria as tree-ring analysis gives information on the real age of a tree and the lifetime growth rates. However, the phenomenon of missing growth rings suggests that the influence of environment in the use of growth rings in age determination needs to be considered in areas that experience droughts.