IMAR-CMA Department of Life Sciences, University of Coimbra, Apartado 3046, 3001-401 Coimbra, Portugal.
Ecotoxicol Environ Saf. 2011 Oct;74(7):2002-12. doi: 10.1016/j.ecoenv.2011.07.015. Epub 2011 Aug 24.
This work intends to implement the use of native soil nematode communities in ecotoxicological tests using a model pesticide and two geographically nematode communities (Mediterranean and sub-tropical) in order to obtain new perspectives on the evaluation of the toxic potential of chemical substances. The environmental condition of the nematode communities was described using a trait-based approach (grouping the organisms according to their feeding traits) and a traditional taxonomic method (identification to family level). Effects on total nematode abundance, number of families and abundance of nematode feeding groups as well as potential shifts in both trophic and family structure were assessed. Agricultural soils from Curitiba (Brazil) and Coimbra (Portugal) were sampled and the corresponding nematode communities were extracted. Part of the collected soil was defaunated and spiked with four doses of a carbofuran commercial formulation. Afterwards each of the replicates was inoculated with a nematode suspension containing ≈200 or 300 nematodes. After 14 and 28 d of exposure the nematodes were extracted, counted and identified at family level and separately classified according to their feeding traits. The patterns of nematode responses revealed a decrease in the total abundance and a reduction in the number of families. Despite the similar effects observed for both communities, statistically significant toxic effects were only found within the Portuguese community. The total nematode abundance was significantly reduced at the highest carbofuran concentrations and significant shifts in the family structure were detected. However, the trophic structure, i.e., the contribution of each feeding group for the overall community structure, did not significantly change along the contamination gradient. Results showed that using such a trait-based approach may increase the ecological relevance of toxicity data, by establishing communalities in the response to a chemical from two different taxonomic communities, although with potential loss of information on biodiversity of the communities.
本研究旨在利用模型农药和两个地理上不同的线虫群落（地中海和亚热带）中的本地土壤线虫群落，进行生态毒理学测试，以期为评估化学物质的毒性潜力提供新的视角。采用基于特征的方法（根据摄食特征对生物体进行分组）和传统的分类学方法（鉴定到科水平）来描述线虫群落的环境状况。评估了对线虫总丰度、科数和摄食类群丰度的影响，以及两者在营养和科结构上的潜在变化。从巴西库里蒂巴和葡萄牙科英布拉采集农业土壤，并提取相应的线虫群落。采集的部分土壤进行除虫处理，并添加四个剂量的呋喃丹商业制剂。然后，将每个重复接种含有约 200 或 300 条线虫的线虫悬浮液。暴露 14 和 28 天后，提取、计数并按科水平鉴定线虫，然后根据摄食特征分别分类。线虫响应模式显示总丰度减少，科数减少。尽管两个群落观察到的影响相似，但仅在葡萄牙群落中发现了统计学上的毒性效应。在最高浓度的呋喃丹下，线虫总丰度显著减少，并且检测到科结构的显著变化。然而，摄食结构，即每个摄食类群对整个群落结构的贡献，并没有沿着污染梯度显著变化。结果表明，采用基于特征的方法可能会增加毒性数据的生态相关性，通过在两个不同分类学群落对化学物质的反应中建立共性，尽管存在群落生物多样性信息损失的潜在风险。
