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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。
Select the mixed forest of coniferous and broadleaf, the evergreen broad-leaved forest, the bamboo forest and the shrub forest in Jinyun Mountain as the research object, and observe the litterfall and the amount of nutrient release of the four forest types. Applying simulated indoor acid rain experiment, Litter litter simulation. The results showed that the existing litter of individual forest in Jinyun Mountain was 1.4 ~ 4.5 cm in thickness with obvious stratification structure. The litterfalls of undegraded U layer, semi-decomposed S layer and decomposed D layer were 1.97 ~ 8.59 and 2.84 ~ 10.18 and 3.58 ~ 17.43 t · hm-2, respectively. The annual litterfall volume was 2.17 ~ 9.86 t · hm-2 · a-1, the total litterfall was 14.21 ~ 32.42 t · hm-2 and the litter decomposition rate was 0.15 ~ 0.31, the time needed for forest litter to decompose 95% was more than 10 years for both coniferous-broadleaved forest and Phoebe bournei forest, and the decomposition rate of litter was relatively slow. The content of nutrient elements in litter layer was Ca, N, Fe , Followed by K and Mg. The total nutrient release rate of litter showed as follows: broadleaved forest (0.80)> shrub (0.72)> conifer-broadleaved forest (0.50) Compared with the control, the content of N, K and Mn in litter significantly decreased. In order to find out the mechanism of acid rain influencing nutrient cycling, the ion content of simulated acid rain and the content of salt ions in litter were analyzed. The correlations were as follows: bamboo forest (correlation coefficient 0.895)> mixed coniferous and broad-leaved forest (0.826)> shrub (0.700)> evergreen broad-leaved forest (0.699) Nutrient leaching is affected by acid rain maximum litter, evergreen broad-leaved forests affected weakest; presumed to adsorption litter mainly in the process.