A dependent and independent growth distance model was fitted to evaluate how competition variables may account for the variation of periodic diameter increment of 132 Cedrela odorata trees. Using a Potential Relative Increment (PRI), the relative diameter increment (IRd) was estimated from the multiplication of maximum diameter growth (potential increment) by modified function (portion of the reduced growth due to competition by light and growth space). The significance of the reduced fitted model demonstrated the influence of asymmetric competition variables on diameter growth, explaining 71% of the total variation as well as indicated that competition responses were not constant, but it varied among the different size classes of trees.
diameter periodic increment; morphometric indices; competition indices
