Growth Index of Indigenous Tree Species in Urban Planting

Abstract

Growths can be quantified by various vegetative parameters such as collar diameter, girth, diameter at breast height (dbh), crown diameter, total photosynthetically active leaf area (TPALA), live-crown ratio (LCR), and total height (TH). These are useful growth indicators for tree species. For forestry purposes, top height, first branch height, and diameter at breast height are the indicators of growth and yield. However, there is yet to have a formula to comprehensively quantify the overall growth parameters of the tree species for environmental and ornamental plantings. The dbh, TPALA, LCR, TH, basal area (BA), and volume (V) are parameters that describe the health and vegetative growth and yield of the tree. Hence, this study aims to propose a growth index (GI) to quantitatively capture the overall growth of the tree. The formula that would capture the overall growth of the tree in the planting is proposed to be GI= dbh*LCR*NPALA*TH or GI=BA*LCR*NPALA*V. The ranking of their GI can be objectively carried out for each species. Hence, this study proposes that GI be used as an index for ranking the growth performance of tree species for ornamental and environmental plantings.