Worldwide, invasive alien plant species (IAS) threaten the biodiversity and the functioning of ecosystems. Most invasion research so far has focused on the properties underlying species invasiveness and community invasibility, yet IAS impact and the underlying causal pathways remain largely unknown. Here we dealt with this knowledge gap by extending the traditional functional trait framework to spectral data, by using traits estimated from reflectance measurements obtained through proximal field spectroscopy, as a surrogate for conventionally measured traits. We focused on two functionally distinct species that are invasive in Belgium: the annual forb Impatiens glandulifera Royle, and the rhizomatous perennial forb Solidago gigantea Ait. By means of trait-based linear mixed models and structural equation models we studied their impact on six ecosystem functions involved in the cycling of carbon and nutrients, and the mechanisms mediating these changes. Analyses based on either conventionally or optically measured traits revealed similar results: the IAS altered aboveground biomass (decrease and increase under I. glandulifera and S. gigantea respectively), litter stabilization (decrease under both IAS) and soil available phosphorus (increase under both IAS) through mass ratio effects, rather than through decreasing the functional diversity of the community. Whereas S. gigantea did so by shifting the community towards more conservative traits, I. glandulifera achieved this by making the community taller and richer in leaf nutrients. The use of remote sensing through optically measured traits, is not only useful to advance our understanding of the mechanisms and consequences of plant invasion, but may also be valuable to the broader field linking plant community composition to ecosystem functioning. Its potential for studying larger spatial scales over time may contribute to even more comprehensive insights.

在世界范围内，外来入侵植物物种（IAS）威胁着生物多样性和生态系统的功能。到目前为止，大多数入侵研究都集中在物种入侵和社区入侵的潜在属性上，但是IAS的影响和潜在的致病途径仍是未知之数。在这里，我们通过将传统功能性状框架扩展到光谱数据来解决这一知识鸿沟，它使用通过近场光谱法获得的反射率测量值估算的性状作为常规测量性状的替代品。我们重点研究了在比利时入侵的两个功能不同的物种：一年生的一年生Impatiens glandulifera Royle刺和多年生的多年生长生菌Solidago gigantea天啊 通过基于特征的线性混合模型和结构方程模型，我们研究了它们对参与碳和养分循环的六个生态系统功能的影响，以及介导这些变化的机制。基于常规或光学测量的性状进行的分析显示了相似的结果：IAS改变了地上生物量（分别在I. glandulifera和S. gigantea下减少和增加），凋落物稳定性（在IAS下都减少）和土壤有效磷（在IAS下都增加了） ）是通过质量比率效应，而不是通过减少社区的功能多样性来实现的。巨大链球菌是通过将社区转变为更保守的特征来实现的。通过使社区的叶子营养更高，更丰富来实现这一目标。通过光学测量的特征进行遥感的使用，不仅有助于增进我们对植物入侵的机制和后果的理解，而且对于将植物群落组成与生态系统功能联系起来的更广阔的领域也可能是有价值的。随着时间的推移，它在研究更大的空间尺度方面的潜力可能有助于获得更全面的见解。