Land-use intensification (LUI) and biological invasions are two of the most important global change pressures driving biodiversity loss. However, their combined impacts on biological communities have been seldom explored, which may result in misleading ecological assessments or mitigation actions. Based on an extensive field survey of 445 paired invaded and control plots of coastal vegetation in SW Spain, we explored the joint effects of LUI (agricultural and urban intensification) and invasion on the taxonomic and functional richness, mean plant height and leaf area of native plants. Our survey covered five invasive species with contrasting functional similarity and competitive ability in relation to the native community. We modeled the response of native communities for the overall and invader-specific datasets, and determined if invader-native functional differences could influence the combined impacts of LUI and invasion. Overall, we found that urban intensification reduced taxonomic richness more strongly at invaded plots (synergistic interactive effects). In contrast, functional richness loss caused by urban intensification was less pronounced at invaded plots (antagonistic interactive effects). Overall models showed also that urban intensification led to reduced mean leaf area, while agriculture was linked to higher mean plant height. When exploring invader-specific models, we observed that the combined effects of agricultural and urban intensification with invasion were heterogeneous. At invaded plots, invader-native functional differences accounted for part of this variability. Our findings demonstrate the importance of considering the interactive effects of global change pressures for a better assessment and management of ecosystems.

中文翻译：

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土地利用集约化和植物入侵对土著社区的综合影响。

土地利用集约化（LUI）和生物入侵是驱动生物多样性丧失的最重要的全球变化压力中的两个。然而，很少探讨它们对生物群落的综合影响，这可能导致误导性的生态评估或减缓行动。基于对西班牙西南部445个沿海植被成对入侵和控制地块的广泛实地调查，我们探讨了LUI（农业和城市集约化）和入侵对原生植物的分类学和功能丰富度，平均植物高度和叶面积的共同影响。植物。我们的调查涵盖了五个入侵物种，它们相对于本地社区具有相似的功能相似性和竞争能力。我们为整个社区和特定于入侵者的数据集建模了本地社区的响应，并确定入侵者的功能差异是否会影响LUI和入侵的综合影响。总体而言，我们发现，城市集约化在入侵的土地上会更加强烈地降低分类学上的丰富度（协同相互作用）。相比之下，城市集约化导致的功能丰富度损失在被入侵的地块上不那么明显（拮抗作用）。总体模型还表明，城市集约化导致平均叶面积减少，而农业与更高的平均植物高度相关。在探索特定于入侵者的模型时，我们观察到农业和城市集约化与入侵的综合影响是异质的。在入侵地块，入侵者的功能差异是造成这种变异的部分原因。