Optical traits perform equally well as directly-measured functional traits in explaining the impact of an invasive plant on litter decomposition

1. Functional traits can help elucidate and predict the impact of invasive plant species on ecosystem functioning. Yet, this approach requires comprehensive and labor-intensive trait collection campaigns, covering intraspecific trait variation of both the invader and native species in the invaded community. One potential way to overcome these logistic constraints is using hyperspectral remote sensing technology to efficiently quantify functional trait values. Although such spectrally derived or ‘optical’ traits are known to closely link to directly-measured functional traits, little research has explored how well these optical traits perform in assessing invader-induced ecosystem impact. 2. Here, we explored the trait-mediated impact of the invasive Rosa rugosa on litter decomposition and evaluated whether optical traits perform equally well as directly-measured traits in predicting litter decomposition variation. We collected data on species-specific functional traits, leaf hyperspectr...