Abstract
The establishment of technologies for large-scale afforestation in arid lands for carbon fixation is expected. This technology is one of the countermeasures for reduction of carbon dioxide that is the main cause gas of global warming. Arid lands can provide only small amount of water for plant growth, so highly effective water use is required. The objective of this study is the establishment of a method to estimate the amount of water required for tree growth on the basis of nutrion flow in a tree. Therefore, detailed examination on the effects of various factors on the behavior of nutrions is necessary. In this report, the behavior of nutrions in a sap was examined by changing pressure for sap extraction, height of a tree, distance from tree bottom, and time in a day for Eucalyptus camaldulensis, one of the typical species in the research area near Leonora, Western Australia. As results, the pressure for extraction of a sap from a tree had remarkable influence on the nutrion concentration which approached a value with increased pressure. The daily variation in the nutrion concentration was also found to exist. Effects of other factors on the behaviors of nutrions in a sap were not found.
