MODEL FOR ESTIMATING OF SOME SHOOTS BIOMETRIC PARAMETERS IN THE CASE OF WOODY SPECIES

Abstract

The present study evaluated the relationship between dimensional parameters of annual growth of shoots in woody species. The biological material was represented by the species Tilia cordata L., from the area of the Cenad Forest Protected Area, Timis County, Romania. The length of the internodes (IL) and the diameter of the internodes (ID) were determined in relation to the position of the internodes on the shoot (IP). The length of the internodes (IL), in relation to their position on the shoot, was described by a polynomial equation of degree 3, in statistical safety conditions, according to R2 = 0.832, p = 0.00014. The diameter of the internodes (ID), in relation to their position on the shoot (IP), was described by a polynomial equation of degree 2, in statistical safety conditions, according to R2 = 0.982, p <0.001. Within PCA, PC1 explained 63.002% of variance, and PC2 explained 36.998% of variance. Cluster Analysis led to the grouping of internodes based on Euclidean distances, in relation to the values of IL and ID parameters, in statistical safety conditions (Coph. Corr = 0.913). The highest degree of similarity was found in the case of internodes I7 and I8, in which case SDI = 0.2786. The regression analysis facilitated the obtaining of an equation that described the variation of the internode diameter (ID) in relation to the internode position (IP) and internode length (IL) analyzed simultaneously, in statistical safety conditions according to R2 = 0.995, p <0.001. 3D and isoquant models were obtained to represent the ID variation in relation to IP and IL. From the comparative analysis of the real data and the graphical representation of the models from the obtained equations, deviations of the ID values were found in the case of internodes I6, I7, I8 and I9 from the theoretical model. This can be associated with certain stress conditions generated by vegetation factors during the formation of the respective internodes. The approach can be extended to other arboreal or fruit species of economic interest.