【摘要】 为探究凋落物添加对土壤养分及化学计量比的影响，本研究采用梅森瓶室外培养法，探求凋落物添加种类及添加量对蒿类荒漠草地0～10 cm土壤有机碳(SOC)、全氮(TN)、全磷(TP)及其化学计量比的影响，发现茎叶混合促进了凋落物分解，但同一添加物各添加量间分解速率无显著差异。添加5 g和7.5 g叶后土壤SOC较对照分别增加10.4%,15.2%(P<0.05)。土壤TN随叶添加量增加呈上升趋势，较CK增加11.9%～18.4%(P<0.05),而茎、茎叶混合依次仅在5 g、7.5 g添加量时显著减少7.9%、增加37.8%(P<0.05)。2.5 g茎叶、5 g茎和7.5 g叶添加后土壤TP较CK依次增加9.8%,14.4%,7.2%(P<0.05)。凋落物添加后土壤C∶N,C∶P,N∶P分别为2.46～3.63,12.40～16.17,3.47～5.60,且SOC与C∶P、TN与N∶P均呈正相关，而TN与C∶N除添加叶外均呈显著负相关。因此，凋落物分解有利于蒿类荒漠土壤养分的恢复，尤其是叶凋落物的分解是其土壤碳氮短期补充的重要来源。更多还原

【Abstract】 In order to investigate the effects of litter additions on soil nutrients and stoichiometric ratios, the effects of litter additions on soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP),and their stoichiometric ratios in Sagebrush desert grassland from 0 to 10 cm were studied by using the method of outdoor incubation in Mason jars. The results showed that stem and leaf mixing promoted litter decomposition, but there was no significant difference in decomposition rates among different amount of the same additives. Soil SOC increased by 10.4% and 15.2%(P<0.05) with the addition of 5 g and 7.5 g of leaves, respectively, compared with the control(CK). Soil TN showed an increasing trend with leaf addition, increasing by 11.9% to 18.4%(P<0.05) compared with CK,while stem and stem-leaf mixing significantly decreased by 7.9% and increased by 37.8%(P<0.05) only at 5 g and 7.5 g additions, respectively. Soil TP increased by 9.8%,14.4%,7.2%,and 7.5%(P<0.05) after 2.5 g of stem and leaf, 5 g of stem, and 7.5 g of leaf additions, respectively, compared with CK. 7.2%(P<0.05). Soil C∶N,C∶P,and N∶P were 2.46～3.63,12.40～16.17,and 3.47～5.60,respectively, after the addition of litter, and SOC was positively correlated with C∶P,and TN was positively correlated with N∶P,whereas TN was significantly negatively correlated with C∶N,except for the addition of leaves. Therefore, decomposition of litter is beneficial to soil nutrient recovery in Sagebrush desert, especially leaf litter decomposition is an important source of short-term carbon and nitrogen supplementation in soil.更多还原