宝天曼自然保护区锐齿栎林生态系统营养元素循环

对河南内乡宝天曼自然保护区内 35年生的天然次生锐齿栎林生态系统的营养元素循环进行研究 ,结果表明 :所测定系统中的 N、P、K、Ca、Mg、Fe、Na、Mn、Zn、Cu1 0种营养元素积累总量为 1 0 387.894kg·hm- 2 ,土壤库贮量 8880 .70 9kg·hm- 2 ,占 85 .49% ;植物体贮量 1 5 0 7.1 82 kg·hm- 2 ,占 1 4.5 1 % ,其中活植物体占 90 .5 6% ,凋落物占 9.44%。系统中 1 0种营养元素年吸收量 2 0 7.5 4 5 kg· hm- 2 ,年存留量1 0 5 .2 85 kg· hm- 2 ,年归还量 1 0 1 .65 1 kg·hm- 2 ,年积累速率为 77.8986kg·hm- 2 ;年归还量占年吸收量48.98% ,表明系统中营养元素的循环处于良好的平衡状态。 1 0种营养元素的平均利用系数为 0 .1 85 ,平均周转期为 9.98a。其中 P、N、Mg、Na、Mn的周转期较短为 4～ 8a,K、Ca、Fe、Cu周转期较长为 1 0～ 1 6a,Zn的周转期最长为 1 7.4a。

Study on element cycle of Quercus acutidentata forest ecosystem in Baotianman Natural Reserve

This paper studied the element cycle of a 35-year-old %Quercus acutidentata% (Fagaceae) forest in Baotianman Natural Reserve, Neixiang county, He'nan Province. The forest is a secondary vegetation type in the northern deciduous forest region. Investigations were carried out in a 20×20 m2 plot in which trees were measured and ranked according to Kraft (1884) method during 1993~1995. The stand biomass was determined and the element contents of N, P, K, Ca, Mg, Fe, Na, Mn, Cu and Zn were analyzed in trees, shr...