| dc.description.abstract | The objectives of this study were to establish some mensurational relationships in a tropical secondary forest located in Turrialba, Costa Rica, in the "Very humid premontane tropical forest" lif zone according to the Holdridge classification system. A study of the diameter class distribution in the forest, applying the data obtained in the complete inventory method of plots, revealed that there are 1012 trees with a dbh of more than 20 cm and 1005 trees with a dbh between 10-20 cm present in 123 plots, 10 x 50 m in size. The number of trees per hectare (NA) decreased rapidly with increase in dbh. The equation which represent best the distribution of trees is a geometric mathematical model, NA = 657.6 x 10 exponent -0.034082 dbh with an R exponent 2 = 0.9797. The species Rollinia microsephala Standley, Simarouba amara Aubl., Cordia spp. and species of the Lauraceae family were represented in the volumetric composition of the forest with 13.08, 1.66, 7.99, 2.88 and 10.54 per cent respectively. Relationships between dbh/total height and dbh/commercial height were determined for the forest as a whole and the species Rollinia microsephala Standley, Simarouba amara Aubl., Cordia spp., Virola spp. as well as for species of the (family) Lauraceae. For the entire forest and the species mentioned the logarithmic equation Y = b subindex o . X exponent bl and the quadratic equation Y = b subindex o + b subindex1X - X exponent 2 resulted in the same adjustment coefficients. Applying the logarithmic, quadratic, linear and geometric models in establishing the relationship between dbh/commercial height the determination coefficient was always less than 0.21 for all equations, and all species, which proves that this relationship is quite fragile in secondary tropical forests. The same mathematical models were applied to establish the relationship between total height/commercial height. It was determined that the linear model is most closely adjusted to this relationship. | es_ES |
