The objective of this study was to quantify the biomass and removal of nutrients in the first thinning of Pinus taeda stand at nine years of age in Cambará do Sul-RS. A forest inventory of the individuals that would be removed from the stand in the first thinning was done. The individuals were distributed in four diametric classes. Three individuals in each class were cut off and needles, live branches, dead branches, bark from the commercial wood, commercial wood, bark from the top wood and top wood were separated. These components were sampled and analyzed for contents of macro and micronutrients. The biomass resulting from the first thinning was 35.7 Mg ha-1, with the following magnitude distribution: commercial wood > live branches > bark in commercial wood > needles > top wood > dead branches > bark from the top wood. The needles presented the greatest concentration of macronutrients, which together with the bark from the top wood, also show the greatest amount of micronutrients. Harvest of bark and commercial wood in the first thinning resulted in the following removal of macronutrients: 46.2 kg ha-1 of N, 25.1 kg ha-1 of Ca, 15.2 kg ha-1 of K, 10.0 kg ha-1 of S, 6.7 kg ha-1 of Mg and 5.4 kg ha-1 of P, and for micronutrients, the values were: 2,641 g ha-1 of Mn, 1,026 g ha-1 of Fe, 240 g ha-1 of Zn, 234 g ha-1 of B and 66 g ha-1 of Cu.
Forest nutrition; forest exploration; Pinus taeda
