Invasive plants cause changes to native plant communities and nutrient cycling, and by doing so, may alter the amount and quality of habitat available for animals at multiple trophic levels, including arthropods. Arthropods are generally abundant, diverse, and contribute to energy flow and nutrient cycling and are, therefore, an important group to study as a way of determining the effects of changes to ecosystem functioning. Spotted knapweed (Centaurea stoebe L.), a perennial forb native to Eastern Europe, is considered one of the most ecologically harmful invasive species in Western North America. Here, we test if spotted knapweed alters plant community, ground litter and ground temperature, and arthropod functional group structure and biomass in grassland habitats in British Columbia, Canada. Pitfall traps, installed at 20 sites that differed in spotted knapweed density, were sorted into herbivores, omnivores, predators, detritivores, and parasites. Decreases in herbivore and detritivore biomass was associated with increasing spotted knapweed density. The first two coordinates of a Principle Coordinates Analysis explained a cumulative 60% of the variation, and herbivores were separated from predators on both axes. The results suggest that spotted knapweed density may affect arthropod functional groups through changes in plant community composition, and surface soil temperatures. The results suggest that in terms of relative abundance and biomass, increasing knapweed density had positive effects on some arthropod functional groups, neutral effects on others, and negative effects on others. Thus, not all arthropod functional groups responded equally to knapweed invasion, and knapweed invasion does not necessarily decrease arthropod functional group diversity

外来入侵植物引起原生植物群落的变化和养分循环，并且这样做可能会改变多种营养级别（包括节肢动物）可为动物提供的栖息地的数量和质量。节肢动物通常数量众多，种类繁多，并有助于能量流动和养分循环，因此，是确定作为对生态系统功能变化影响的一种重要研究对象。斑点的矢车菊（矢车菊L.）是东欧原产的多年生植物，被认为是北美西部最具生态危害的入侵物种之一。在这里，我们测试斑节菜是否改变了加拿大不列颠哥伦比亚省草地栖息地的植物群落，地垫和地面温度以及节肢动物的功能群结构和生物量。陷阱陷阱安装在20个地点，地点斑点斑点的密度各不相同，被分类为草食动物，杂食动物，捕食者，碎屑动物和寄生虫。草食动物和有害生物量的减少与斑点状海藻密度的增加有关。主坐标分析的前两个坐标解释了累积的60％的变化，并且食草动物在两个轴上都与掠食者分开。结果表明，斑节植物的密度可能通过改变植物群落组成和地表土壤温度来影响节肢动物的功能群。结果表明，就相对丰度和生物量而言，节肢动物密度的增加对节肢动物的某些功能组具有积极影响，对其他节肢动物功能组具有中性影响，而对其他节肢动物则具有负面影响。因此，并非所有节肢动物功能组均对节肢动物入侵有同样的反应，而节肢动物入侵并不一定会降低节肢动物功能组的多样性