Background

Semi-natural plant communities such as field boundaries play an important ecological role in agricultural landscapes, e.g., provision of refuge for plant and other species, food web support or habitat connectivity. To prevent undesired effects of herbicide applications on these communities and their structure, the registration and application are regulated by risk assessment schemes in many industrialized countries. Standardized individual-level greenhouse experiments are conducted on a selection of crop and wild plant species to characterize the effects of herbicide loads potentially reaching off-field areas on non-target plants. Uncertainties regarding the protectiveness of such approaches to risk assessment might be addressed by assessment factors that are often under discussion. As an alternative approach, plant community models can be used to predict potential effects on plant communities of interest based on extrapolation of the individual-level effects measured in the standardized greenhouse experiments. In this study, we analyzed the reliability and adequacy of the plant community model IBC-grass (individual-based plant community model for grasslands) by comparing model predictions with empirically measured effects at the plant community level.

Results

We showed that the effects predicted by the model IBC-grass were in accordance with the empirical data. Based on the species-specific dose responses (calculated from empirical effects in monocultures measured 4 weeks after application), the model was able to realistically predict short-term herbicide impacts on communities when compared to empirical data.

Conclusion

The results presented in this study demonstrate an approach how the current standard greenhouse experiments—measuring herbicide impacts on individual-level—can be coupled with the model IBC-grass to estimate effects on plant community level. In this way, it can be used as a tool in ecological risk assessment.

中文翻译：

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模拟除草剂对植物群落的影响：将植物群落模型 IBC-grass 的模型预测与经验数据进行比较。

背景

田间边界等半自然植物群落在农业景观中发挥着重要的生态作用，例如为植物和其他物种提供庇护、食物网支持或栖息地连通性。为了防止除草剂的应用对这些群落及其结构产生不良影响，许多工业化国家的登记和应用受到风险评估计划的监管。对选定的农作物和野生植物物种进行标准化的个体水平温室实验，以表征可能到达场外区域的除草剂负荷对非目标植物的影响。这种风险评估方法的保护性的不确定性可以通过经常讨论的评估因素来解决。作为一种替代方法，植物群落模型可用于根据标准化温室实验中测量的个体水平影响的外推来预测对感兴趣的植物群落的潜在影响。在本研究中，我们通过将模型预测与植物群落水平的经验测量效果进行比较，分析了植物群落模型 IBC-grass（基于个体的草原植物群落模型）的可靠性和充分性。

结果

我们表明，IBC-grass 模型预测的效果与经验数据一致。根据物种特异性剂量反应（根据施用后 4 周测量的单一栽培的经验效应计算），与经验数据相比，该模型能够真实地预测除草剂对群落的短期影响。

结论

本研究中提出的结果展示了一种方法，如何将当前标准温室实验（测量除草剂对个体水平的影响）与 IBC 草模型结合起来，以估计对植物群落水平的影响。这样，它就可以作为生态风险评估的工具。