Fertilizer effects on LAI and growth of four Eucalyptus nitens plantations

Leaf area index (LAI) is a key driver of water and nutrient use, carbon balance, and the rate of growth of plantation forests, but these interactions can be environment-dependent. Our aim was to determine the relationship between LAI and stem growth in four 5-8-year-old Eucalyptus nitens plantations and its dependence on site and fertilization. Fertilizers were applied at various intervals between planting and age 6 years at cumulative rates that ranged from 0 to 1600 kg N ha(-1) and 0 to 700 kg P ha(-1). Stem growth and LAI were monitored for 2 years. Values of LAI ranged from 1.4 to 9.6, and temporal variations in LAI were small. Fertilization increased LAI by up to 3.1 units. There was a strong relationship across all sites and treatments between initial LAI and growth, and predictions using LAI were more precise than those using basal area as the independent variable. (C) 2002 Elsevier Science B.V. All rights reserved.