辽东栎叶片凋落物在不同气候带下的分解及其主要元素释放的比较

应用分解网袋法对辽东栎（Quercus liaotungensis Koize)叶片凋落物分别在暖温带的东灵山，亚热带的神农架，热带的西双版纳为期1-2年的分解和K，Ca,Mg,Fe,P,Cu,Mn等营养元素释放动态进行比较研究。三个气候带下辽东栎叶片凋落物质量损失基本符合Olson的指数模型。但降解速率有很大的差别。气候条件对凋落物的分解和营养元素的释放影响很大，降水量增多，年均温增高，凋落物分解速率相应加快，研究还发现影响营养元素释放的因素除公认的土壤生物（土壤动物和土壤微生物）作用外。对于Fe,Mn等元素遵循的是“化学因素主导”模式。特征在于由于化学螯合作用。其释放过程和凋落物本身失重呈显著负相关。另外，对不同因素占主导的各种分解模式进行了归纳总结。

Comparison of Major Nutrient Release Patterns of Quercus liaotungensis Leaf Litter Decomposition in Different Climatic Zones

Leaf litter decomposition of liaotong oak (Quercus liaotungensis Koize) under temperate, subtropical and tropical forests was examined using a litter bag technique. Decomposition rates and release dynamics of nutrients Ca, Cu, Fe, K, Mg, Mn and P were observed separately at all three sites for 1 to 2 a periods. The leaf litter mass loss of liaotong oak was simulated with Olson's exponential model. Significant differences of leaf litter mass loss were found in forests of all three climate zones. Litter decomposition was accelerated with the increase of both annual mean precipitation and temperature. Our results agreed with other studies demonstrating that litter decomposition processes were greatly affected not only by soil organisms (including soil fauna and microorganisms), but also by chemical factors. These chemical factors were important for controlling the release of nutrients, especially elements of Fe and Mn. We also found that Fe and Mn content increased in semi-decayed leaf litter as litter mass decreased. This result was presumably due to chelating process which accumulated soil Fe and Mn ions into the decomposing litter. In conclusion, our study allowed us to determine the classification of the characteristics of different nutrient release patterns.