Mathematic models for nutrient exportation estimate of Pinus taeda L. stands.

Abstract

This study aims at developing and assessing the usage of mathematical patterns to quantify the nutrient exportation in harvest of Pinus forests. This study to be carried out, in plantations of Pinus taeda with 4 ages, located in Guarapuava (PR) region. The samples were taken from the base, 1.0 m, 1.3 m, 2.0 m high, and from this point on, at each meter until it reached commercial height. Through these samples it was determinate the content of macronutrients, from the wood and the bark, being carried out at the Embrapa Floresta laboratory, in Colombo (PR). The random samples taken from Pinus taeda populations at different ages, in vegetative strata: dominant, co-dominant and suppressed), different management conditions and yield levels, allow to obtain estimation equations of nutrient accumulation with high levels of correlations and reliability. Obtaining samples in segments up to 4 m high allows determine the total amount of nutrients, without the need to have additional samples from segments of higher position in relation to the tree top. The determination of nitrogen content shows higher complexity and, basically, requires that others macronutrients be also determined, which implies in higher sampling and laboratory costs.