Site influence on 22-years-old Pinus taeda growth: 1. Soil physico-hydrical and chemical characteristics

Abstract

In order to evaluate the influence of site quality on pine tree growth, eight different sites were selected in a commercial Pinus taeda plantation belonging to Klabin, in Telêmaco Borba region, Parana State. Trees were 22 years old and sites were selected by soil type (Latosol and Cambisol), by soil texture (clayey and sandy) and by original vegetation (forest and grass). To characterize the sites, measurements of total height and DBH were taken from at least 50 trees at each site and soil samples were collected at three depths. Three average trees were selected from each site and DBH and total, sawing and cellulose heights were measured. The most important factor influencing tree growth, considering DBH increment, was the original vegetation phase. Original forest sites were the most productive of all. Cambissolo with loam texture and forest as original vegetation was the most productive site and the least productive site was a Cambissolo with loam texture and grass as original vegetation. The most productive site presented higher P and K contents, higher pH, higher base saturation and lower Al saturation percentage. This site presented lower total and macro porosities, higher bulk density and higher amount of available soil water, which was highly correlated to the growth variables.