Effects of nitrogen and phosphorus fertilization on litterfall production and nutrient dynamics in a Schima superba forest in Zhejiang Province of East China

In 2011, an investigation was made on the litterfall production and nutrient dynamics in a phosphorus-limited subtropical evergreen broadleaved forest dominated by Schima superba in Tian- tong, Zhejiang Province of East China under different levels of nitrogen (N) and phosphorous (P) fertilization. After the N and P fertilization, the annual litterfall production ranged from 6.82 to 8.30 t·hm^-2·a^-1, with three peaks in May or June, August, and October, respectively. Under fertilization, the annual average N and P concentrations of the litterfall (except the annual average N concentration under P fertilization) increased, and had a seasonal variation. There were no significant differences in the nitrogen return amount (60.05-71.47 kg·hm^-2·a^-1) and phosphorus return amount (2.94-3.93 kg·hm^-2 ·a^-1) of the litterfall among different treatments. As compared to the control, the N:P ratio of the litterfall under fertilization was higher at the beginning of the experiment (spring, 2011), but lower in the winter, 2011, indicating that nitrogen and phosphorus fertilization could alter the original nitrogen and phosphorus limited conditions of the studied forest ecosystem.