iES - Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Landau, Germany.
iES - Institute for Environmental Sciences, RPTU Kaiserslautern-Landau, Landau, Germany.
Sci Total Environ. 2024 Feb 25;913:169735. doi: 10.1016/j.scitotenv.2023.169735. Epub 2023 Dec 30.
The conservation and management of riparian ecosystems rely on understanding the ecological consequences of anthropogenic stressors that impact natural communities. In this context, studies investigating the effects of anthropogenic stressors require reliable methods capable of mapping the relationships between taxa occurrence or abundance and environmental predictors within a spatio-temporal framework. Here, we present an integrative approach using DNA metabarcoding and Hierarchical Modelling of Species Communities (HMSC) to unravel the intricate dynamics and resilience of chironomid communities exposed to Bacillus thuringiensis var. israelensis (Bti). Chironomid emergence was sampled from a total of 12 floodplain pond mesocosms, half of which received Bti treatment, during a 16-week period spanning spring and summer of 2020. Subsequently, we determined the community compositions of chironomids and examined their genus-specific responses to the Bti treatment, considering their phylogenetic affiliations and ecological traits of the larvae. Additionally, we investigated the impact of the Bti treatment on the body size distribution of emerging chironomids. Our study revealed consistent responses to Bti among different chironomid genera, indicating that neither phylogenetic affiliations nor larval feeding strategies significantly contributed to the observed patterns. Both taxonomic and genetic diversity were positively correlated with the number of emerged individuals. Furthermore, our findings demonstrated Bti-related effects on chironomid body size distribution, which could have relevant implications for size-selective terrestrial predators. Hence, our study highlights the value of employing a combination of DNA metabarcoding and HMSC to unravel the complex dynamics of Bti-related non-target effects on chironomid communities. The insights gained from this integrated framework contribute to our understanding of the ecological consequences of anthropogenic stressors and provide a foundation for informed decision-making regarding the conservation and management of riparian ecosystems.
河岸生态系统的保护和管理依赖于理解影响自然群落的人为压力源的生态后果。在这种情况下，研究人为压力源的影响需要可靠的方法，能够在时空框架内绘制分类单元出现或丰度与环境预测因子之间的关系。在这里，我们提出了一种综合方法，使用 DNA 宏条形码和物种群落的层次模型 (HMSC) 来揭示暴露于苏云金芽孢杆菌以色列变种 (Bti) 的摇蚊群落的复杂动态和恢复力。总共从 12 个洪泛平原池塘中采集了摇蚊的出现样本，其中一半接受了 Bti 处理，在 2020 年春季和夏季的 16 周内进行了采样。随后，我们确定了摇蚊的群落组成，并研究了它们对 Bti 处理的属特异性反应，考虑到它们的系统发育关系和幼虫的生态特征。此外，我们还研究了 Bti 处理对新出现的摇蚊的身体大小分布的影响。我们的研究表明，不同摇蚊属之间存在对 Bti 的一致反应，这表明系统发育关系或幼虫取食策略对观察到的模式没有显著贡献。分类和遗传多样性与出现的个体数量呈正相关。此外，我们的研究结果表明，Bti 与摇蚊身体大小分布有关，这可能对大小选择性的陆地捕食者产生相关影响。因此，我们的研究强调了结合使用 DNA 宏条形码和 HMSC 来揭示 Bti 对摇蚊群落的非目标影响的复杂动态的价值。从这个综合框架中获得的见解有助于我们理解人为压力源的生态后果，并为河岸生态系统的保护和管理提供有关决策的信息。
