There is a frequent energy flow connection between streams and riparian zones. However, riparian communities have been limited in studies of stream ecosystems. To understand the significance of riparian communities in the energy flow of stream ecosystems, we compared two trophic models in a small forest tributary (the Feifong Stream) and the mainstream (the Houlong Stream) that possessed high and low biomasses of riparian vegetation and arthropods, respectively. There were 25 functional groups classified into 3 integer trophic levels in the two trophic models. Arthropods, mostly insects, were the main carrier of the energy flow between aquatic and riparian habitats. The feeding connections were more extensive and intensive in the tributary than in the mainstream, as riparian arthropods were more abundant in the tributary. When including the riparian community in the tributary, the trophic model became more mature, as the values of system omnivory index and trophic transfer efficiency and the ascendency: capacity ratio were higher, but the connectance index value and overhead: capacity ratio were lower in the model with riparian groups than in the model without riparian groups. In the tributary, the ecotrophic efficiency (EE) values of aquatic insect groups increased largely if the riparian community was included in the model. In the mainstream, however, most of the ecosystem attributes and the EE values of aquatic insect groups did not obviously change if the model included the riparian community. This study highlights the significance of riparian communities in the energy flow of subtropical stream ecosystems. Aquatic and riparian systems should be considered together as a mature ecosystem for the planning of stream conservation. The loss or degradation of one habitat may have more detrimental effects on the other community than we have previously recognized, particularly in a small forest stream.

溪流和河岸带之间存在频繁的能量流连接。然而，河岸群落在河流生态系统的研究中受到限制。为了了解河岸群落在河流生态系统能量流中的重要性，我们比较了森林小支流（飞凤溪）和干流（后龙溪）的两种营养模式，它们具有高和低的河岸植被和节肢动物生物量，分别。两种营养模型共有25个功能组，分为3个整数营养级。节肢动物，主要是昆虫，是水生和河岸生境之间能量流动的主要载体。与干流相比，支流的摄食联系更为广泛和密集，因为支流中的河岸节肢动物更为丰富。将河岸群落纳入支流后，营养模型更加成熟，系统杂食性指标、营养转移效率和优势：容量比值较高，但连通性指标值和开销：容量比值较低。有河岸群的模型比没有河岸群的模型要好。在支流中，如果模型中包括河岸群落，则水生昆虫群的生态营养效率（EE）值会大大增加。然而，在主流中，如果模型包括河岸群落，大部分生态系统属性和水生昆虫群的 EE 值没有明显变化。本研究强调了河岸群落在亚热带河流生态系统能量流中的重要性。应将水生系统和河岸系统一起视为规划河流保护的成熟生态系统。一个栖息地的丧失或退化对另一个群落的不利影响可能比我们以前认识到的要大，尤其是在小森林溪流中。