Anthropogenic activities such as mining, industry, urban waste production, and the overuse of agricultural inputs may result in the contamination of the environment by heavy metals, which are toxic to organisms mainly due to their potential to accumulate in tissues. This contamination causes the simplification of aquatic and edaphic food webs, which show impaired structure and function. We investigated whether soil contamination with heavy metal at the permitted concentrations affects the structural or functional properties of a terrestrial food web of insects living in the aboveground parts of a plant. As study models we used lead (Pb) and kale-associated insects. Kale plants (Brassica oleracea var. acephala) were grown in soil experimentally contaminated with four lead nitrate concentrations: 0 (control), 144 (T1), 360 (T2), and 600 (T3) mg/kg of soil. The experiment was conducted in an open greenhouse for natural insect colonization. The insects were collected twice in the field using trap bags attached to the plant leaf and by direct removal. In general, we observed a simplification of the food web as the Pb concentrations increased, resulting in visually smaller food webs. The food web metrics decreased from the T2 treatment (the Pb limit for agricultural soils). Structurally, the Number of Species (whose values were highly positively correlated to the Number of Links and Link Density values) decreased with increasing contamination, while Connectance increased. Functionally, the Predator/Prey Ratio and Trophic Vulnerability and Generality became lower. This study shows that soil contamination by Pb can simplify insect food webs in the aboveground parts of plants, negatively affecting the structure and function of the webs, even at permitted concentrations.

采矿、工业、城市废物生产和过度使用农业投入等人为活动可能导致重金属对环境的污染，重金属对生物体有毒，主要是因为它们可能在组织中积累。这种污染导致水生和土壤食物网的简化，显示结构和功能受损。我们调查了允许浓度的重金属污染土壤是否会影响生活在植物地上部分的昆虫陆生食物网的结构或功能特性。作为研究模型，我们使用了铅 (Pb) 和羽衣甘蓝相关的昆虫。羽衣甘蓝植物 ( Brassica oleracea var. acephala) 生长在受四种硝酸铅浓度实验污染的土壤中：0（对照）、144（T1）、360（T2）和 600（T3）mg/kg 土壤。实验在开放式温室中进行，用于自然昆虫定植。使用附在植物叶子上的诱捕袋和直接移除昆虫，在田间收集了两次昆虫。总的来说，我们观察到食物网随着 Pb 浓度的增加而简化，导致食物网在视觉上变小。食物网指标从 T2 处理（农业土壤的 Pb 限制）开始下降。在结构上，物种数量（其值与链接数量和链接密度值高度正相关）随着污染的增加而减少，而连接度增加。在功能上，捕食者/猎物比率和营养脆弱性和普遍性变得更低。这项研究表明，铅污染的土壤可以简化植物地上部分的昆虫食物网，对网的结构和功能产生负面影响，即使在允许的浓度下也是如此。