科尔沁沙地优势固沙灌木叶片凋落物分解的主场效应

在气候变化和人类活动的影响下，科尔沁沙质草地中灌木植物种增加，导致沙质草地逐渐向灌木地转变。选取该地区优势固沙灌木差不嘎蒿（Artemisia halodendron）和小叶锦鸡儿叶（Caragana microphylla）凋落物及其混合凋落物开展交互移置培养试验，分析了培养过程中CO₂释放和干物质损失量以及混合凋落物CO₂释放量实测值与预测值的差异，辨析主场效应产生的原因及其驱动机制，以期为将主场效应纳入到凋落物分解模型提供理论基础。结果表明：与高质量的小叶锦鸡儿叶凋落物相比，质量较低的差不嘎蒿叶凋落物分解具有更强的主场效应；其次，引起叶凋落物分解的主场效应归因于土壤微生物的特化作用，而不是土壤动物的搬运或贮藏行为。此外，混合凋落物主场效应与其分解生境中长期输入的凋落物的质量相似性紧密相关，质量相似性越大，主场效应越强，这也是本研究中混合凋落物分解在差不嘎蒿灌丛土壤下具有较强主场效应的原因。

Home-field Effects of Leaf Litter Decomposition of Dominate Sand-fixing Shrubs in the Horqin Sandy Land

Under the influence of climate change and human activities, sandy grassland in Horqin gradually degenerates into shrubs. In this study, we collected leaf litters of two dominant sand-fixing shrubs,Caraganamicrophylla and Artemisia halodendron,to carry out the interactive transplantation experiments by placing single litter and mixed litter to "home" or "away" environment.wedescirbed CO₂ release and dry matter loss and also compared the difference between measured and predicted CO₂ emissions from mixed litter. We studied the causes of home-field effect and its driving mechanism. Hence, it can provide a theoretical basis for incorporating the home field effect into the litter decomposition model. The results showed that compared with the high-quality leaf litters of C.microphylla, the decomposition of A.halodendron litter had a stronger home field effect. Also, the special effects of soil microbes rather than the transport or storage behavior of soil animals lead to thehome field effect of leaf litter decomposition. In addition, the home field effect of mixed litter is closely related to the similarity of quality of long-term input litter in the decomposing habitat. The greater the quality similarity, the stronger of the home field effect. This study provides a theoretical basis for incorporating the main field effect into the litter decomposition model and improving the simulation accuracy.