Comparative growth performance of eight tropical tree species on sites of varying altitudinal gradients in Lantapan

Introduced on sits of varying altitudes, the growth response of 21-month-old plots of Acacia mangium, Albizia lebbekoides, Eucalyptus robusta, Rucalyptus torilliana, Gmelina arborea, Paraserianthes falcataria, Pterocarpus indicus and Swientenia macrophylla was investigated and determined. At each site and across sites, species differed significantly in height and diameter growth. These differences were an indication of genotype x environment interaction which was reflective of magnitude of species-site specificity. Altitude influenced species performance significantly through its effect on the nutrient availability and temperature of experimental sites. The quantities of Calcium, Magnesium, Phosphors and Potassium decreased with increased altitude, and percent Nitrogen, organic carbon and organic matter increased with increased altitude.