Avaliação da sustentabilidade nutricional de plantios de Pinus taeda L. usando um balanço de entrada-saída de nutrientes

Abstract

DEDICATÓRIA A DEUS e aos meus pais Affonso e Hildaires pelo dom da vida e pelos valores pessoais que norteiam a minha caminhada. Aos meus irmãos, minha irmã e meus sobrinhos por serem a minha bela família e pelo apoio em todos os momentos. A Agnes que me trouxe a Beatrisse Que veio para trazer um novo sentido a vida.

Sustainability of Wood Productivity of Pinus TaedaBased on Nutrient Export and Stocks in the Biomass and in the Soil

“…Evaluating 26-year-old Pinus taeda, Oki (2002) found that wood accounted for roughly 75 % of the tree biomass, the branches 16 %, the needles 6 %, and bark, 3 %. The order of biomass distribution was: wood>root>dead branches>live branches>bark>needles, an order similar to that observed by Bizon (2005) for 25-year-old Pinus taeda in the same soil type.…”

“…Considering, for example, total N in the biomass, 31 % was found in the roots, 26 % in the litter, 18 % in the wood, 13 % in the needles, 9 % in the branches, and 6 % in the bark. Hence, the crown accounts for roughly 15 % of the biomass and stores 22 % of the total N. The relative nutrient contents accumulated in these components were similar in the results of Bizon (2005).…”

“…Although the largest components in biomass, namely wood and roots, showed higher nutrient stocks, there was no proportionality between biomass components and distribution of nutrients in the forest (Table 4). This is due to the difference in nutrient content in different components of the tree, as observed by Bizon (2005), who worked with the same soil type as used in this study. Considering, for example, total N in the biomass, 31 % was found in the roots, 26 % in the litter, 18 % in the wood, 13 % in the needles, 9 % in the branches, and 6 % in the bark.…”

“…The higher the correlation, the greater the efficiency in using assimilates. Forest productivity of P. taeda was studied by Bizon (2005) in different sites and attributed the difference in biomass allocation to the root component to the different productivity levels. (1) The depth of the primary coarser root (x, in m) is related to the total tree height (y, in m) according to equation: ŷ = 7.33 + 6.44 x (R 2 = 0.85; p<0.0001).…”

“…Several aspects are involved in the maintenance of forest productivity (Switzer and Nelson, 1972;Kimmins, 1994;Gonçalves et al, 1997;Santana et al, 2002;Bizon, 2005;Witschoreck, 2008) and litter plays an essential role in accumulating most nutrients extracted by the trees from the soil. The storage, inflow, and outflow of nutrients have a fundamental function in the nutritional management of P. taeda plantings (Poggiani et al, 1998).…”