Variations in the foliar concentrations of macro and micro elements in a fast-growing tropical eucalypt

Summary The concentrations of N, P, K, Ca, Mg, Zn, Cu, Mn, Fe and B were measured in leaves of various ages in upper, mid and lower crown positions in Eucalyptus deglupta Blume during both wet and dry seasons. Based on coefficients of variation, the number of samples trees necessary for different levels of precision were calculated for each crown position.Least variation was found during the wet season for all elements except K. For all elements except Ca, fewest trees were needed when foliar material was collected from upper crown branches.The rate of leaf production in the upper crown was constant and it was possible to sample leaves of the same age by collecting from similar sampling positions; in contrast, that in the lower crowns was erratic and it was difficult to collect leaves of comparable age.The patterns of distribution and variation of foliar nutrients in the crown of E. deglupta are discussed. re]19750521