Diversified farming systems, for example those that incorporate agroforestry elements, have been proposed as a solution that could maintain and improve multiple ecosystem services. However, habitat diversification in and around arable fields has complex and inconsistent effects on invertebrate crop pests and their natural enemies. This hinders the development of policy recommendations to promote the adoption of such management strategies for the provision of natural pest control services. Here, for the first time, we conducted a trait-based approach to investigate the effect of farming system on plant, invertebrate herbivore, and invertebrate natural enemy communities. We then evaluated this approach by comparing the results to those generated using a traditional taxonomic approach. At each of three working farms, we sampled within an agroforestry field (a diverse farming system comprising alleys of arable crops separated by tree rows), and within a paired non-diversified area of the farm (arable control field). Each of 96 sample points was sampled between 8 and 10 times, yielding 393,318 invertebrate specimens from 344 taxonomic groups. Diet specialization or granivory, lack of a pupal stage, and wing traits in invertebrates, along with late flowering, short flowering duration, creeping habit, and perenniality in plants, were traits more strongly associated with agroforestry crop alleys than the arable control fields. We hypothesize that this is a result of reduced habitat disturbance and increased habitat complexity in the agroforestry system. Taxonomic richness and diversity were higher in the agroforestry crop alleys compared to the arable control fields, but these effects were stronger at lower trophic levels. However, functional trait diversity of natural enemies was significantly higher in the agroforestry crop alleys than the arable control fields, suggesting an improved level of biocontrol, which was not detected by traditional diversity metrics. Of eight key pest taxa, three were significantly suppressed in the agroforestry system, while two were more abundant, compared to the arable control fields. Trait-based approaches can provide a better mechanistic understanding of farming system effects on pests and their natural enemies, therefore we recommend their application and testing in future studies of diversified farming systems.

中文翻译：

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评估基于特征的方法来比较农林业与耕地系统中的天敌和害虫群落

多样化的耕作系统，例如包含农林业元素的耕作系统，已被提议作为一种可以维持和改善多种生态系统服务的解决方案。然而，耕地内外的栖息地多样化对无脊椎动物作物害虫及其天敌具有复杂且不一致的影响。这阻碍了制定政策建议以促进采用此类管理战略来提供天然害虫防治服务。在这里，我们首次采用基于特征的方法来研究农业系统对植物、无脊椎动物食草动物和无脊椎动物天敌群落的影响。然后，我们通过将结果与使用传统分类方法生成的结果进行比较来评估这种方法。在三个工作农场中的每一个，我们在农林场（一个多样化的农业系统，包括由树行分隔的可耕作物小巷）和农场的一对非多样化区域（耕地控制场）内进行采样。96 个样本点中的每一个都被采样 8 到 10 次，从 344 个分类群中产生了 393,318 个无脊椎动物标本。无脊椎动物的饮食专业化或食粮、缺乏蛹期和翅膀特征，以及植物的开花晚、开花持续时间短、匍匐习性和多年生性，这些特征与农林业作物小巷的相关性比耕地控制领域更密切。我们假设这是农林业系统中栖息地干扰减少和栖息地复杂性增加的结果。与耕地对照田相比，农林业作物小巷的分类丰富度和多样性更高，但这些影响在较低的营养水平下更强。然而，农林业作物小巷中天敌的功能性状多样性显着高于耕地对照田，这表明生物防治水平有所提高，而传统的多样性指标并未检测到这一点。在 8 个关键害虫类群中，3 个在农林业系统中受到显着抑制，而 2 个比耕地控制田更丰富。基于特征的方法可以更好地理解农业系统对害虫及其天敌的影响，因此我们建议在未来的多样化农业系统研究中应用和测试它们。但这些影响在较低的营养水平上更强。然而，农林业作物小巷中天敌的功能性状多样性显着高于耕地对照田，这表明生物防治水平有所提高，而传统的多样性指标并未检测到这一点。在 8 个关键害虫类群中，3 个在农林业系统中受到显着抑制，而 2 个比耕地控制田更丰富。基于特征的方法可以更好地理解农业系统对害虫及其天敌的影响，因此我们建议在未来的多样化农业系统研究中应用和测试它们。但这些影响在较低的营养水平上更强。然而，农林业作物小巷中天敌的功能性状多样性显着高于耕地对照田，这表明生物防治水平有所提高，而传统的多样性指标并未检测到这一点。在 8 个关键害虫类群中，3 个在农林业系统中受到显着抑制，而 2 个比耕地控制田更丰富。基于特征的方法可以更好地理解农业系统对害虫及其天敌的影响，因此我们建议在未来的多样化农业系统研究中应用和测试它们。表明生物防治水平有所提高，这是传统多样性指标未检测到的。在 8 个关键害虫类群中，3 个在农林业系统中受到显着抑制，而 2 个比耕地控制田更丰富。基于特征的方法可以更好地理解农业系统对害虫及其天敌的影响，因此我们建议在未来的多样化农业系统研究中应用和测试它们。表明生物防治水平有所提高，这是传统多样性指标未检测到的。在 8 个关键害虫类群中，3 个在农林业系统中受到显着抑制，而 2 个比耕地控制田更丰富。基于特征的方法可以更好地理解农业系统对害虫及其天敌的影响，因此我们建议在未来的多样化农业系统研究中应用和测试它们。