Different site quality in a plantation of Populus deltoides cv Catfish 2 located in the low delta of the Parana River (Argentina)

摘要

In this work we studied the quality of forest site in a 12 years olds commercial plantation of Populus deltoides cv catfish 2, located in Paraná delta’s lowlands surrounded and protected by dams, using direct and indirect methods. In direct method we considered the mean dominant height through the development of height - age curves in which the site index was calculated as the dominant height to an age of 9 years old considered as base age. The Logistic model presented the best fit. The selected function sowed the following values: Dominant height = SI*(1+exp(2.78–0.504*9))/(1+exp(2.78–0.504*age). We studied the vegetation in relation to the height of dominant trees and the soil as indirect method. The greatest productivity (519 m3/ha), basal area (44 m2/ha), and height of dominant tree (30,10 m) were detected in high lands with high phosphorus contest in superficial stratum. The lowest productivity (79,2 m3/ha), basal area (9 m2/ha) and height of dominant trees (23,45 m) were detected in low relief lands, characterised by low assimilable phosphorus contest in superficial stratum. We registered a great number of fallen down trees by the wind during the vegetative period in low lands where it was carried out a bad water management. According to the results obtained from multivariate analysis (DCA) of vegetation we could identify vegetation species as indicators of site quality.