中文摘要：

选取缙云山针阔混交林、常绿阔叶林、楠竹林和灌木林作为研究对象,对4种林分的凋落物储量和营养元素释放量等进行观测,并应用室内模拟酸雨实验对4种林分凋落物进行淋溶模拟。结果表明：缙云山各林分现存凋落物厚度为1.4～4.5 cm,具有明显的分层结构;林分未分解U层、半分解S层和分解D层现存凋落物量分别为1.97～8.59、2.84～10.18和3.58～17.43 t·hm-2,林分年凋落物量为2.17～9.86 t·hm-2·a-1,凋落物总储量为14.21～32.42 t·hm-2,凋落物分解常数为0.15～0.31,林下凋落物分解95%时所需时间针阔混交林和楠竹林均在10年以上,凋落物分解速率比较缓慢;林下凋落物层营养元素含量以Ca、N为主,Fe、K、Mg次之;凋落物总的营养元素释放率表现为常绿阔叶林（0.80）〉灌木林（0.72）〉针阔混交林（0.50）〉楠竹林（-0.17）;与叶片相比,凋落物中N、K、Mn 3种营养元素含量明显降低;为探明酸雨影响营养元素循环的作用机理,对模拟酸雨的离子含量与凋落物淋滤液盐基离子含量进行了分析,其相关性大小表现为楠竹林（相关系数0.895）〉针阔混交林（0.826）〉灌木（0.700）〉常绿阔叶林（0.699）,楠竹林凋落物营养元素的淋滤受酸雨影响最大,常绿阔叶林受其影响最弱;推测在这一过程中以凋落物的吸附作用为主。

英文摘要：

Abstract ： A field observation was made on the litterfall mass and nutrient release of four types of forest stand （mixed conifer and broad-leaved forest, evergreen broad-leaved forest, bamboo for- est, and shrub） in the Jinyun Mountains of China, and a simulated acid rain leaching experiment with the litters of the four forest stands was conducted in laboratory. The thickness of the existing litters in the four forest stands was 1.4-4.5 cm, and had an obvious hierarchical structure. Across the four forest stands, the litter reserve in un-decomposed layer （ U layer）, semi-de- composed layer （S layer）, and decomposed layer （D layer） was 1.97-8.59, 2.84-10. 18, and 3.58-17.43 t ~ hm-2, respectively, the annual litterfall mass was 2. 17-9.86 t ~ hm-2 ~ a-~ , the total litter reserve was 14.21 -32.42 t ~ hm-2, and the annual litter decomposition rate was 0.15-0.31. It needed more than 10 years to decompose 95% of the litters in mixed conifer and broad-leaved forest and bamboo forest, showing that the litter decomposition rate in the two forest stands was relatively slow. The main elements in litter layer were Ca and N, followed by Fe, K, and Mg. The release rate of nutrient elements in the litters of different forest stands was in the se- quence of evergreen broad-leaved forest （0.80） 〉 shrub （0.72） 〉 mixed conifer and broadleaved forest （0.50） 〉 bamboo forest （-0.17）. As compared with those in leaves, the N, K, and Mn contents in litter layer had an obvious decrease. In order to approach the action mecha- nisms of acid rain on the nutrient cycling, the ion contents in simulated acid rain and the base ion contents in litter leachates were analyzed, which showed that the correlation coefficient be- tween the contents of different elements in the simulated acid rain and in the litter leachates was in the order of bamboo forest （ r -- 0. 895 ） 〉 mixed conifer and broad-leaved forest （0. 826） 〉 shrub （0. 700） 〉 evergreen broad-leaved forest （0. 699 ）, suggestin