Understanding how the biological invasion is driven by environmental factors will improve model prediction and advance early detection, especially in the context of accelerating anthropogenic ecological changes. Although a large body of studies has examined how favorable environments promote biological invasions, a more comprehensive and mechanistic understanding of invasive species response to unfavorable/stressful conditions is still developing. Grass invasion has been problematic across the globe; in particular, C₄ grass invaders, with high drought tolerance, adaptations to high temperatures, and high water use efficiency, could become more severe. Here, we conducted a rigorous microcosm experiment, with one of the most damaging invasive C₄ grass, cogongrass (Imperata cylindrica), to explore how cogongrass responds to soil water and nutrient stress. We further integrated the results of the microcosm study with a species distribution model to (1) corroborate greenhouse results with field observations and (2) validate the robustness of our findings at subcontinental scales. Both the microcosm experiments and species distribution model agreed that soil water stress had a stronger impact on cogongrass than the nutrient one. New vegetative growth of cogongrass continued to be inhibited by the prior water stress. The significant water effect on cogongrass total biomass was supported by the finding that both allometric and biochemical traits of cogongrass did not show significant responses to the changes in water treatment. Different to the conventional wisdom that nutrient enrichment plays a bigger role in facilitating biological invasions, this study highlighted the possibility that water conditions may have a more substantial effect on some aggressive invaders. Therefore, an important implication of this study on biological conservation is that field managers might take advantage of the negative effect of global drought on some invasive species to increase the efficiency of their controlling efforts because invasive species may become more vulnerable under drought effect.

中文翻译：

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将草入侵的实验应力响应扩大到大陆级范围适宜性的预测

了解环境因素如何驱动生物入侵将改进模型预测并推进早期检测，尤其是在人为生态变化加速的背景下。尽管大量研究已经研究了有利的环境如何促进生物入侵，但对入侵物种对不利/压力条件的反应的更全面和机械的理解仍在发展中。草入侵在全球范围内都存在问题。特别是，耐旱性强、适应高温、水分利用效率高的C ₄草入侵者可能会变得更加严重。在这里，我们进行了一项严格的微观实验，使用最具破坏性的侵入性 C ₄草之一，白茅（白茅)，探索白茅对土壤水分和养分胁迫的反应。我们进一步将微观世界研究的结果与物种分布模型相结合，以 (1) 用实地观察证实温室结果，以及 (2) 验证我们的研究结果在次大陆尺度上的稳健性。微观实验和物种分布模型都同意土壤水分胁迫对白茅的影响比养分影响更大。之前的水分胁迫继续抑制白茅的新营养生长。白茅的异速生长和生化特性对水处理的变化没有显着响应，这一发现支持了水对白茅总生物量的显着影响。与营养丰富在促进生物入侵方面发挥更大作用的传统观点不同，这项研究强调了水条件可能对一些侵略性入侵者产生更实质性影响的可能性。因此，这项研究对生物保护的一个重要意义是，田间管理人员可能会利用全球干旱对某些入侵物种的负面影响来提高其控制工作的效率，因为入侵物种在干旱影响下可能变得更加脆弱。