Foliar and wood nutrient content of different eucalyptus clones under thinning or no thinning management

The genetic enhancement has contributed significantly to the increase of Eucalyptus productivity and the use of clones in the plantations is widespread nowadays. However, different clones can present different productivity as well variations on nutrient demand and cycling, becoming necessary studies to evaluate it under different forest management. In plantations with different eucalyptus genetic materials and managed with thinning or no thinning we evaluate the nutrient content of leaves and of the wood. The work was carried out in the County of Itatinga-SP, climate classified as Cwa. The experiment was conducted in a subdivided plot design composed of 8 clones and of a stallion planting of Eucalyptus grandis. Leaves sampling was performed for nutritional characterization of the plants. Wood samples were collected by the time of thinning and nutrient contents were determined in the core, sapwood and bark materials. Samples were dried, milled and submitted to nutrient analysis. There was small influence of the plant tissue (heartwood, sapwood or bark) on nutrient contents, which could be explained by the young age of plants with tissues presenting few structural differences. The sequence of nutrient content was: N>Ca>K>Mg>P. Thinning did not influence the decreasing sequence of nutrient contents in the leaves, which was similar to that observed in the wood tissues. But influenced the leaf content of Mg, which was higher under thinning in comparison with no thinning management.