Freshwater Macroinvertebrate Laboratory, Zoological Collection Dr. Eustorgio Mendez, Gorgas Memorial Institute for Health Studies (COZEM-ICGES), Panama City, Panama.
Doctoral Program in Natural Sciences with emphasis in Entomology, University of Panama, Panama City, Panama.
PLoS One. 2019 Aug 8;14(8):e0220528. doi: 10.1371/journal.pone.0220528. eCollection 2019.
Tropical forests are declining at unprecedented rates in favour of agriculture, and streams can be severely impacted due to effects of multiple stressors that have rarely been considered together in tropical studies. We studied the effects of multiple stressors associated with agricultural practices (pesticide toxicity, nutrient enrichment and habitat alteration-quantified as TUmax, soluble reactive phosphorus concentration and sedimentation, respectively) on macroinvertebrate communities in a tropical catchment in Panama (13 stream sites sampled in 20 occasions from 2015 to 2017, with 260 samples in total). We examined how macroinvertebrate abundance, taxonomic richness, community composition and biotic indices (SPEAR and BMWP/PAN, which were specifically designed to detect pesticide toxicity and nutrient enrichment, respectively) varied depending on the studied stressors, considering their single and combined effects. Our analyses revealed significant effects of the studied stressors on macroinvertebrate communities, with two particular results that merit further attention: (1) the fact that pesticide toxicity affected BMWP/PAN, but not SPEAR, possibly because the former had been adapted for local fauna; and (2) that most stressors showed antagonistic interactions (i.e., lower combined effects than expected from their individual effects). These results highlight the need for toxicity bioassays with tropical species that allow adaptations of biotic indices, and of observational and manipulative studies exploring the combined effects of multiple stressors on tropical macroinvertebrate communities and ecosystems, in order to predict and manage future anthropogenic impacts on tropical streams.
热带森林正以前所未有的速度减少，以利于农业发展，而溪流可能会受到多种胁迫因素的严重影响，这些因素在热带研究中很少被同时考虑。我们研究了与农业实践相关的多种胁迫因素（农药毒性、养分富化和栖息地改变——分别用 TUmax、可溶性反应性磷浓度和沉积来量化）对巴拿马热带流域（2015 年至 2017 年期间在 20 个场合对 13 个溪流站点进行了采样，共采集了 260 个样本）大型无脊椎动物群落的影响。我们考察了大型无脊椎动物的丰度、分类丰富度、群落组成和生物指数（SPEAR 和 BMWP/PAN，分别专门用于检测农药毒性和养分富化）如何根据所研究的胁迫因素而变化，同时考虑了它们的单一和综合效应。我们的分析显示，所研究的胁迫因素对大型无脊椎动物群落有显著影响，有两个特别值得关注的结果：（1）农药毒性影响了 BMWP/PAN，但不影响 SPEAR，这可能是因为前者已适应了当地的动物群；（2）大多数胁迫因素表现出拮抗作用（即，综合效应低于预期的个体效应之和）。这些结果强调了需要对热带物种进行毒性生物测定，以便对生物指数进行适应，并需要进行观察和操纵研究，以探索多种胁迫因素对热带大型无脊椎动物群落和生态系统的综合影响，从而预测和管理未来人为对热带溪流的影响。
