The establishment of technologies for large-scale afforestation in arid lands for carbon fixation is important. However, arid lands can provide only small amounts of water for plant growth; therefore, effective water use is likewise a very important issue. The objective of this study, conducted near Leonora, Western Australia, was to establish a method for estimating the amount of water required for tree growth. This method is based on the nutrient flow in a tree, and it is accordingly necessary to examine the effects of various factors on the distribution of nutrients for the estimation of representative nutrients concentration in tree organ. In this report, the distribution of nutrients in tree organs was examined in Eucalyptus camaldulensis, one of the typical tree species in the area. The distribution of nutrients in tree organs was considered to be influenced by various factors, including organ type (leaf, branch, trunk, or bark), distance above ground of the sampling point, orientation of the tree, and height of the tree. However, it was clear that the nutrient concentrations of and biomass allocation to each organ are important factors for the estimation of representative nutrients concentration in tree organ. Further, it was shown that the calcium concentration clearly decreased, whereas the potassium concentration increased, with increasing vertical distance from the base of the trunk.