Long-term Variation of Litter Fall, Canopy Leaf Area and Flowering in a Eucalyptus maculata Forest on the South Coast of New South Wales

Abstract

Litter fall, canopy leaf area and environmental conditions were monitored in a regrowth stand of Eucalyptus maculata Hook. in Kioloa State Forest on the south coast of New South Wales, from spring 1977 to winter 1992. Litter fall during the first half of the study period was strongly influenced by two of the most serious droughts that had occurred in 100 years. Canopy renewal and, hence, leaf fall and changes of leaf area index (LAI), were also influenced by the flowering phenology of E. maculata. Total annual litter fall (including bark shed from lower boles) averaged 5.7 t ha^-1 and ranged from 3.1 up to 7.5 t ha^-1. The respective means (plus absolute ranges) of annual leaf, twig and bark fall were 2.8 (1.5–4.2), 0.9 (0.3–1.4) and 1.6 (0.5–3.1) t ha^-1. Forest LAI varied between 0.7 and 5 m² m^-2. Leaves comprised 50% of the average annual litter fall; bark shed from lower boles of E. maculata contributed 0.63 t ha^-1 to average annual bark fall. Flower buds were produced by a proportion of overstorey trees of E. maculata about every second year. Synchronous production and flowering of buds on all trees was observed only once in 15 years. Less than 15% of flower buds (overall) produced fruit.