NUTRIENTS CONTENT AND ALLOCATION IN Platanus x acerifolia (Aiton) Willd. PLANTATIONS IN DOM FELICIANO, RIO GRANDE DO SUL STATE

Abstract

http://dx.doi.org/10.5902/1980509812350This study had as objective to evaluate nutrients content and allocation pattern in different biomasscomponents of Platanus x acerifolia, in a 5.5 year stand, located in Dom Feliciano, Rio Grande do Sul state.Twenty-four trees were sampled, based on diametric amplitude, with biomass determination in the followingcomponents: leaves, fruits, stem bark, wood and roots. To study the variation of nutrients concentration,wood and bark samples were collected in different positions along the stem. Nutrients stock estimation, ineach component, was based on biomass average values and nutrients content, by the number of trees perdiametric classes per hectare. Nutrients content variation along the stem, in bark and in wood was studiedbased on regression equations adjustment, correlating nutrients concentration and the point of collection.Considering all biomass components, the following sequence according to nutrients concentration was: N> Ca > K > Mg > P > S > Fe > Mn > B > Zn > Cu. The highest contents, for most nutrients, were observedin leaves and the lowest, for all nutrients, were observed in the wood. Total nutrients stock in Platanus xacerifolia biomass was 574.72 kg ha-1, according to the following allocation order, among the components:wood ~ branches > roots ~ leaves > bark > fruits. Regarding to nutrients, the accumulation sequence was feasfollows: N > K > Ca > Mg > S > P > Fe > Mn > B > Zn > Cu, where N, K and Ca represent 82.9% fromthe total. It was verified a great variance in nutrient concentration along the stem, bark and wood, withdistinction of basic patterns: growing, decreasing and invariable, from the base of the tree towards to thetop.

Keywords

• ciclagem de nutriente
• estoque de nutriente
• amostragem de biomassa