The taxonomy-based response pattern of macroinvertebrates to pollution gradient is well established, with tolerant taxa increasing in impacted conditions, while sensitive taxa increase with decreasing deterioration, typical of rural pollution. This study identified rural indicator and sensitive traits of Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa by examining their trait distribution pattern in relation to rural pollution. Physicochemical parameters and EPT were sampled seasonally from August 2016 to April 2017. Eight sites were selected and categorised into three site groups. Site group 1 served as the least impacted site group and Site group 2 as the moderately influenced, whereas Site group 3 was the most impacted. Seven traits were selected and categorised into 27 trait modalities. The response of EPT traits to physicochemical parameters was analysed using the simultaneous analysis of the information contained in three tables: R (environmental characteristics of samples), L (taxa distribution across samples) and Q (species traits) (RLQ) and confirmed with fourth-corner analysis. Three trait attributes, large (10–20 mm), swimming, shredding, streamlined body shape and large body size (≥ 10–20), were considered tolerant signature traits of semi-urban pollution. These trait attributes were associated with the influenced Site group 3 and indicated a significant positive affinity with at least one physicochemical indicator of increasing semi-urban pollution (NH₄-N, NO₃-N, NO₂-N, PO₄-P, EC, turbidity, temperature and pH). Conversely, small body size (< 10 mm), operculate gills, spherical body shape and a preference for sediments were correlated with the least influenced Site group 1 and were considered sensitive traits of semi-urban disturbance. Overall, this study provided critical insights into EPT responses to disturbance, revealing that semi-urban activities influenced EPT traits differently in the Tsitsa River.

建立了基于分类的大型无脊椎动物对污染梯度的响应模式，在受影响的条件下，宽容的分类单元增加，而敏感分类单元则随着农村污染的典型恶化而增加。这项研究通过检查与农村污染相关的特征分布模式，确定了星翅目，鞘翅目和毛鳞翅目（EPT）类群的农村指标和敏感特征。从2016年8月至2017年4月按季节取样理化参数和EPT。选择了八个站点并将其分为三个站点组。站点组1是受影响最小的站点组，站点组2是中等影响的站点，而站点组3是受影响最大的站点。选择了七个特质，并将其分为27个特质形式。R（样品的环境特征），L（样品的类群分布）和Q（物种性状）（RLQ），并通过第四角分析进行了确认。三种特质属性（大（10–20 mm），游泳，切碎，流线型的身体形状和大体形（≥10–20））被认为是半城市污染的耐受特征。这些性状属性与受影响的位点组3相关，并表明与至少一种增加半城市污染的物理化学指标（NH ₄ -N，NO ₃ -N，NO ₂ -N，PO _4）具有显着的正亲和力。-P，EC，浊度，温度和pH）。相反，较小的体型（<10 mm），可操作的腮，球形的体型和对沉积物的偏好与受影响最小的站点组1相关，并被认为是半城市干扰的敏感特征。总的来说，这项研究对EPT对干扰的反应提供了重要的见解，揭示了半城市活动对Tsitsa河中EPT特性的影响不同。