The trophic network (TN) has been well stablished, and recently knowledge concerning non‐trophic relationships (NTRs) is receiving increasing attention. Although NTRs can influence trophic ones, network models, including both types of interactions (multi‐interaction network, IN) and changes in the role of nodes when NTRs are added to TN, are scarce. To evaluate the role of NTRs in freshwater shallow ecosystems, where these interactions are relevant mainly in the benthic habitat, we constructed, from the same communities, the two mentioned networks and compared them focusing on the nodes’ topological roles. Our approach is based on empirical data from a mesocosm experiment where aquatic communities inhabited coupled habitats (pelagic, within‐meadow and benthic) under three environmental scenarios: warming, increased ultraviolet radiation, plus control conditions. The experiment allowed us to assess: the topological roles of the nodes from different habitats when NTRs were added to the TN, and the relative impact of adding NTRs according to environmental scenarios. We calculated a set of node indices by considering both direct and indirect connections up to an ecologically meaningful number of steps. Our results highlight significant differences in the nodes’ roles between both network versions. When NTRs were added: 1) pelagic nodes lost relevance in the network; 2) the number of within‐meadow relevant nodes increased and 3) the large benthic consumers in TN were substituted by charophytes, plus a chain of small within‐meadow predators/preys, as the most relevant to the IN. Furthermore, the scenarios modulated changes in the nodes’ roles when including NTRs. The warming scenario promotes the central position of some nodes (e.g. charophytes) and harms others (e.g. benthic cladocerans), and UVR modulates changes in benthic filamentous primary producers’ roles. Therefore, the inclusion of NTRs in ecological models seems crucial to better understand the functioning of complex communities and their response to environmental disturbances.

中文翻译：

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水生生态系统中非营养性关键参与者：中观实验

营养网络（TN）的建立已十分完善，最近有关非营养关系（NTR）的知识也越来越受到关注。尽管NTR可能会影响营养性，但缺乏网络模型，包括两种类型的交互（多重交互网络，IN）以及将NTR添加到TN时节点角色的变化。为了评估NTR在淡水浅层生态系统中的作用，这些相互作用主要与底栖生境有关，我们从相同的社区构建了上述两个网络，并比较了它们在节点的拓扑作用方面的作用。我们的方法基于中观实验的经验数据，在该实验中，水生社区在以下三种环境情景下居住于耦合生境（中上层，草甸内和底栖生物）：变暖，紫外线辐射增加，加上控制条件。通过实验，我们可以评估：将NTR添加到TN时，来自不同栖息地的节点的拓扑角色，以及根据环境场景添加NTR的相对影响。我们通过考虑直接连接和间接连接以及对生态有意义的步骤数来计算一组节点索引。我们的结果强调了两个网络版本之间节点角色的显着差异。添加NTR时：1）远洋节点在网络中失去相关性；2）草甸内相关节点的数量增加，3）TN中的大型底栖动物被藻类取代，加上一串小的草甸内捕食者/猎物，与IN最为相关。此外，当包含NTR时，方案会调制节点角色的更改。变暖的情景促进了某些节（例如藻类）的中心位置而伤害了其他节（例如底栖的锁骨），而UVR调节底栖丝状初级生产者角色的变化。因此，将NTR纳入生态模型似乎对于更好地了解复杂社区的功能及其对环境干扰的响应至关重要。