We live in a time of rapidly changing biodiversity and ecosystem functioning with vast consequences for the sustainability of human civilization. Management of ecosystems for sustainability to meet the goals and targets of the UN Kunming Montreal Global Biodiversity Framework is critical to conserving species, lineages and their interactions that are critical to the functioning of our life support systems. A key aspect of management is monitoring and assessing the status and trends of biodiversity and ecosystems to inform decision-making. We present a multi-pronged and multi-scale vision for how spectral information and remote sensing tools can be scaled to link plant collections, vegetation plots, plant traits and satellite detection of biodiversity and ecosystem functioning towards this end. We address the potential for and challenges to adding spectral information to herbarium specimen databases in tandem with digitization efforts to predict the functional traits of species past, present and future. These efforts coupled with species distribution models can contribute to mapping plant functional traits globally as a means to validate functional trait predictions from forthcoming satellites, such as NASA’s Surface Biology and Geology mission. Combined approaches across scales from biodiversity collections to spaceborne observatories are a means to help monitor changing plant diversity and will play a critical role in a global biodiversity monitoring system.