Abstract: The measurements on the litter production and its nutrient fluxes in an age sequence of Eucalyptus grandis×E. urophyllas plantations were studied in Zhangzhou, Fujian Province. The results showed that the annual litter production of 2, 3, 4, 5, and 6year old E. grandis×E. urophyllas plantations was 279665, 309810, 4489.13, 4200.72, and 3692.40 kg·hm^-2, respectively, showing an increase with stand age at early stage, but slightly decline after 4yearold. The litter production of 3and 4yearold stands and that of 6yearold stand showed a single peak in early summer (June) and in midspring (April), respectively, while that of 2 and 5yearold stands exhibited one peak in midspring (April) and another peak in summer (June). In the litters, fallen leaves occupied the greatest proportion (84.86%-90.04%), followed by miscellaneous materials (501%-6.70%), branches (2.95%-4.52%), barks (2.64%-3.62%), and fruits (0.30%-0.55%). The nutrient contents in the litters were N>Ca>K>Mg>P, and their annual fluxes in the 2, 3, 4, 5, and 6year old E. grandis×E. urophyllas plantations were 86.01, 90.51, 133.20, 124.98, and 97.56 kg·hm^-2, respectively.

Key words: Photosynthesis, Eco-physiology, Urban forest