Dynamic research on four main tree species decomposition of _weathered leaves from Huoditang area in Qinling moutains | 秦岭火地塘林区4种主要树种凋落叶分解动态研究

صينى. 研究秦岭火地塘林区4种主要树种的凋落叶分解动态，揭示森林生态系统的物质循环规律。以秦岭火地唐林区华山松(Pinus armandii)、油松(P. tabulaeformis)、锐齿栎(Quercus aliena var. acuteserrata)和华北落叶松(Larix principis-rupprechtii)凋落叶为研究对象，采用分解袋法于2005-11～2006-11对其分解过程中养分变化特征和热值的变化趋势进行研究。在分解过程中，4种树凋落叶的N、P含量呈上升趋势，分别增长了158.51%～125.20%和185.13%～125.85%。与分解前相比，油松、华山松、华北落叶松和锐齿栎凋落叶粗纤维含量分别上升为原来的104.64%，103.70%，121.85%和_110.46%，而粗脂肪、C含量和热值均呈下降的趋势，分别下降了32.93～24.10，26.30～68.50 g/kg和4.15～2.78 kJ/g；C/N呈降低趋势。在相似环境条件下，凋落叶的分解主要取决于凋落叶本身的性质。

إنجليزي. Weathered leaves dynamic decomposition of four kind of main tree species were studied in Huoditang Qinling mountain and materials recycle law of forest ecological system was revealed in this study. Weathered leaves of Pinus armandii, P. tabulaeformis, Quercus aliena var. acuteserrata and Larix principis-rupprechtii were selected from Huoditang in Qinling Mountains as study subjects, the experiment adopted the method of the decomposition-bags to study the characteristics of nutrition and tendency of thermal value in the process of decomposition from Nov, 2005 to Nov, 2006. The results indicated that the N and P content showed an increasing tendency at the early stage of decomposition, ranging from 158.51% to 125.20% and from 185.13% to 125.85% respectively. The crude fiber content, comparing to that before the decomposition, increased to 104.64%, 103.70%, 121.85% and 110.46% respectively, whereas the content of Crude fat, C and caloric value showed a declining tendency, with the decrease ratios from 32.93 to 24.10 g/kg, from 26.30 to 68.50 g/kg, and from to 4.15 to 2.78 kJ/g respectively. In similar environment condition, the decomposition of weathered leaves mainly depends on the properties of weathered leaves themselves.