The effect of fertilization on sap flux and canopy conductance in a Eucalyptus saligna experimental forest

摘要

Land devoted to plantation forestry (50 million ha) has been increasing worldwide and the genus Eucalyptus is a popular plantation species (14 million ha) for its rapid growth and ability to grow well on a wide range of sites. Fertilization is a common silvicultural tool to improve tree growth with potential effects on stand water use, but the relationship between wood growth and water use in response to fertilization remains poorly quantified. Our objectives in this study were to determine the extent, timing and longevity of fertilization effects on water use and wood growth in a non-water limited Eucalyptus saligna experimental forest near Hilo, HI. We evaluated the short- and long-term effects of fertilization on water use by measuring sap flux per unit sapwood area, canopy conductance, transpiration per unit leaf area and water-use efficiency in control and fertilized stands. Short-term effects were assessed by comparing sap flux before and after fertilizer application. Long-term effects were assessed by comparing control plots and plots that had received nutrient additions for 5 years.