“优先路径”是指土壤中植物根系穿插而产生的根孔、动物的运动通道和居穴、由于土壤膨胀收缩形成的裂隙，以及因湿润锋不稳定所形成的指状渗透通道等。通过在长江三峡曲溪小流域花岗岩林地坡面开挖土壤剖面，测定了“优先路径”在剖面的分布状况，并采取土壤样品，对土壤的物理特性用筛分法进行了室内测定。结果表明：剖面中距地表以下82～110cm范围内，土壤密度最小，其毛管孔隙度也较小，显示出其土壤中存在有较多非毛管孔隙构成的“优先路径”。“优先路径”在距地表以下80～100cm范围内，分布比较集中。该范围内含有较多粗颗粒物质，有利于“优先路径”的形成。“优先路径”的存在，使该层土壤稳渗速率较其他土层得以大幅度提高，土层内快速运动的水流，又加速了“优先路径”的形成与发展。“优先路径”的存在，影响着土壤物理特性，而土壤物理性质，对“优先路径”的形成与发展，也有较大影响。

通过对三峡库区三种森林类型（松栎混交林、栓皮栎纯林、马尾松纯林）林下苔藓储量调查分析及其持水特性试验，得到不同森林类型林下苔藓储量、最大持水量、吸水速率等水文特征参数。结果表明，马尾松纯林林下苔藓储量最大（12.93t/hm2），松栎混交林和栓皮栎纯林林下苔藓储量相同 (9.47 t/hm2)。松栎混交林林下苔藓最大持水量为5.36mm，栓皮栎纯林为5.73mm，马尾松纯林为6.26mm。研究结果还表明，三峡库区林下苔藓持水量随时间变化过程与森林类型无关。在只有苔藓覆盖情况下，不同森林类型林内不产生水分下渗和地表径流时的最大降雨量和最大降雨雨强分别为：松栎混交林林地5.36mm，5.820mm/h；马尾松纯林林地6.26mm，7.420mm/h；栓皮栎纯林林地5.73mm，6.060mm/h。

该文通过对三峡库区3种森林类型(松栎混交林、栓皮栎纯林、马尾松纯林)林下枯落物储量调查分析及其持水特性试验，得到不同森林类型林下枯落物储量、最大持水量、吸水速率等水文特征参数。结果表明，栓皮栎纯林林下枯落物储量最大(10.7t/hm)，其后依次为松栎混交林(10.1t/hm2)、马尾松纯林(5.8t/hm2)。松栎混交林林下枯落物未分解层最大持水量为3.09mm，栓皮栎纯林为2.95mm，马尾松纯林为1.46mm。松栎混交林林下枯落物半分解层最大持水量为3.03mm，栓皮栎纯林为2.37mm，马尾松纯林为0.99mm。研究结果还表明，在同为中龄林条件下，三峡库区针阔混交林林下枯落物持水能力大于阔叶树纯林或针叶树纯林林下枯落物持水能力。在只有林下枯落物覆盖情况下，不同森林类型林内不产生水分下渗和地表径流时的最大降雨量和最大雨强分别为：松栎混交林林地6.12mm，7.000mm/h；马尾松纯林林地2.45mm，1.760mm/h；栓皮栎纯林林地5.32mm，6.200mm/h。

通过对三峡库区3种森林类型(松栎混交林、栓皮栎纯林、马尾松纯林)林下地被物调查及其持水试验，分别得到3种森林类型林下地被物最大储水量、吸水速率等水文特征参数。结果表明，栓皮栎纯林林下苔藓层储水量最大，为其风干重的303.1%，松栎混交林林下的为283.8%，马尾松纯林林下的为242.3%。松栎混交林林下枯落物最大储水量为其风干重的282.2%，栓皮栎纯林林下的为262.5%，马尾松纯林林下的为239.3%。经分析拟合，得到林下苔藓层、林下枯落物吸水速率与浸泡时间之间关系式为S=ktn。在同为中龄林条件下，3种森林类型林下苔藓层储水量均高于林下枯落物储水量，而林下地被物储水量随时间变化过程与森林类型无关。

To study the characteristics of the distribution of the preferential paths and the affecting factors in the Three Gorges area, four soil profiles were dug to observe the distribution of preferential paths in the Quxi watershed in the Yangtze River basin. The Morisita exponential test method was used to examine the distribution type of preferential paths. The physical properties and infiltration characteristics of the soil were also measured to evaluate their relationship to preferential paths. The results showed that in this area, preferential paths clustered and mainly distributed in the 80-100 cm soil layer, and along the interface between the weathered layer and semi-weathered layer. There were more non-capillary pores in the 83-110 cm layer than in the other layers. It can be derived that most non-capillary pores in this layer were preferential paths caused by geological processes and rotten plant roots. The percentage of coarse soil particles increased with the depth of the soil layer. In the deeper soil layer, the coarse soil particles helped the formation of preferential paths. The fastest steady infiltration rate was observed in the of 83-110 cm layer, which is inferred to be due to the greater number of preferential paths.