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首页> 外文期刊>Environmental toxicology and chemistry >ROUNDUP~? AND AMPHIBIANS: THE IMPORTANCE OF CONCENTRATION,APPLICATION TIME, AND STRATIFICATION
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ROUNDUP~? AND AMPHIBIANS: THE IMPORTANCE OF CONCENTRATION,APPLICATION TIME, AND STRATIFICATION

机译：ROUNDUP〜？和两栖动物：浓度，施药时间和分层的重要性

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摘要

The widespread use of pesticides raises the possibility that non-target organisms might also be affected. To assess this, the traditional approach has been to conduct short-term laboratory experiments spanning a range of lethal concentrations and some longer-duration experiments at sublethal concentrations. While this approach has been very useful, less attention has been paid to the timing of exposure and the impacts of multiple, small exposures versus single, large exposures. We examined the role of application amount, timing, and frequency using outdoor mesocosm communities containing larval amphibians (Rana sylvatica and Bufo americanus) and using a commercial formulation of the herbicide glyphosate (Roundup Original MAX~?). Consistent with past studies, exposures of up to 3 mg acid equivalent (a.e.)/L caused substantial amphibian death. However, the amount of death was considerably higher when the herbicide was applied earlier in the experiment than later in the experiment. Single, large applications (at different times) had larger effects on tadpole mortality and growth than multiple, small applications (of the same total amount). The results may reflect an acclimation to the herbicide over time. In treatments with high tadpole mortality, there was no resulting increase in periphyton, suggesting that the reduction in tadpole herbivory might have been offset by direct negative impacts of the herbicide. We also discovered that temperature stratification caused herbicide stratification, with higher concentrations near the surface. Such stratification has important implications to the habitat choices of ectotherms that might prefer surface waters for thermoregulation or prefer deeper waters to avoid predators. Collectively, the present study demonstrates the importance of examining multiple applications times and frequencies to understand the impacts of pesticides on organisms.
机译：农药的广泛使用增加了非目标生物也可能受到影响的可能性。为了对此进行评估，传统的方法是进行涵盖一系列致死浓度的短期实验室实验和处于亚致死浓度的一些较长时间的实验。尽管此方法非常有用，但对曝光时间以及多次，多次曝光与一次，多次曝光的影响的关注较少。我们使用含有幼虫两栖动物的室外中观群落（林蛙和美洲蟾蜍），以及商业化的除草剂草甘膦制剂（Roundup Original MAX〜？），研究了施药量，施药时间和施药频率的作用。与过去的研究一致，最高3 mg酸当量（a.e。）/ L的暴露导致大量的两栖动物死亡。但是，在实验中较早地施用除草剂比在实验中后期施用的死亡量要高得多。单次大量施用（在不同时间）对multiple死亡率和生长的影响要大于多次次少量施用（相同总量）。结果可能反映了除草剂随着时间的推移逐渐适应。在with死亡率高的治疗方法中，周生植物没有增加，这表明t除草剂的减少可能已被除草剂的直接负面影响所抵消。我们还发现温度分层导致除草剂分层，在表面附近浓度更高。这种分层对等温线的生境选择具有重要意义，这些温湿度可能更喜欢地表水来进行温度调节，或者更深的水来避免捕食者。总体而言，本研究表明检查多种施用时间和频率以了解农药对生物的影响的重要性。

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  • 来源
    《Environmental toxicology and chemistry》 |2010年第9期|P.2016-2025|共10页
  • 作者

    Devin K. Jones; John I. Hammond; Rick A. Relyea;

  • 作者单位

    101 Clapp Hall, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA;

    rn101 Clapp Hall, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA;

    rn101 Clapp Hall, Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);美国《生物学医学文摘》(MEDLINE);美国《化学文摘》(CA);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    ecotoxicology; amphibian decline; polyethoxylated tallowamine; breakdown; oxygen;

    机译：生态毒理学两栖动物下降聚乙氧基牛油胺;分解;氧;

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