Li Hait-tao, Yu Gui-rui, Li Jia-yong, Liang Tao, Chen Yong-rui
Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Ying Yong Sheng Tai Xue Bao. 2007 Feb;18(2):233-40.
By using litter bag method, a 2-year experiment was made to study the dynamics of litter decomposition and phosphorous and potassium release of Castanopsis eyrei-dominated evergreen broad-leaved forest (EBF), Pinus taiwanensis, Cyclobalanopsis nubium and Castanopsisfabri coniferous and broad-leaved mixed forest (CBF) , and Rhododendron simiarum-dominated mountainous dwarf forest (MDF) in Jinggang Mountain region of Jiangxi Province, China. In each forest, litter bags were placed on soil surface (aboveground treatment, AG) and at the depth of 10 cm (below-ground treatment, BG). An inverse exponential relationship was found between litter decay rate and time for each of the three forests. The average value of the litter mass loss of AG and BG was 50.6% for EBF, 41. 7% for CBF, and 40. 13% for MDF by the end of first year, and 60.95% for EBF, 57. 06% for CBF, and 56. 60% for MDF by the end of second year, indicating that the litter decomposition of the forests was faster in first year than in second year. The annual litter loss decreased in the order of EBF > CBF > MDF, and that of AG was significantly higher than that of BG in first year but no significant difference was found in second year. According to the model simulation by Olson' s exponential function, it might take 6. 8-9. 9 years to reach 95% of decay (t095) for the forests investigated, compared with 8-17 years for warm temperate forests and 2 -8 years for south subtropical forests. The t0.95 value of the three test forests increased in the order of EBF < CBF < MDF. A net phospbhorus (P) immobilization was observed in the process of litter decomposition, with the intensity decreased in the order of MDF > CBF > EBF, which was related to the initial P content and C/P ratio of the litter. As for potassium ( K) , it was net release in most cases. By the end of the experiment, the release rate of P had little difference between AG and BG, while that of K was significantly higher in AG than in BG.
采用凋落物袋法，在江西省井冈山地区进行了为期2年的试验，研究以甜槠为主的常绿阔叶林（EBF）、黄山松、罗浮栲和栲树针阔混交林（CBF）以及以猴头杜鹃为主的山地矮林（MDF）凋落物分解动态及磷钾释放情况。在各森林中，将凋落物袋放置在土壤表面（地上处理，AG）和10厘米深度处（地下处理，BG）。发现三种森林中每种森林的凋落物分解速率与时间之间均呈负指数关系。到第一年年底，EBF的AG和BG凋落物质量损失平均值为50.6%，CBF为41.7%，MDF为40.13%；到第二年年底，EBF为60.95%，CBF为57.06%，MDF为56.60%，表明森林凋落物分解第一年比第二年快。年凋落物损失量排序为EBF＞CBF＞MDF，第一年AG的年凋落物损失量显著高于BG，但第二年无显著差异。根据奥尔森指数函数的模型模拟，所研究的森林达到95%分解率（t095）可能需要6.8 - 9.9年，而暖温带森林为8 - 17年，南亚热带森林为2 - 8年。三个试验森林的t0.95值排序为EBF＜CBF＜MDF。在凋落物分解过程中观察到净磷固定，强度排序为MDF＞CBF＞EBF，这与凋落物的初始磷含量和C/P比有关。至于钾（K），大多数情况下是净释放。到试验结束时，AG和BG之间的磷释放速率差异不大，而钾的释放速率AG显著高于BG。
