Detecting long-term functional changes in biodiversity: boosting analyses of herbarium specimens using spectroscopic methods
Biodiversity change is a key challenge for science and society, yet available studies are limited with respect to time scales covered, as well as facets of biodiversity considered. We propose to address change in nutrition availability / plant nutrient content over decadal to even centennial time-scales by revisiting herbaria as large archives of biological material. Standard wet-lab measurements have shown the potential of this approach, but fall short of unlocking the full wealth of material kept as they are destructive and resource-intensive. Building on pilot studies of our teams in both field and herbaria, we propose to use spectroscopic methods coupled with standard calibration procedures to measure plant nitrogen and phosphorus content. Considering feasibility within the framework of a PhD project, we decided to focus on herbarium collections of the regional flora that are well represented in iDiv-associated partner herbaria. The project has three work packages namely method establishment and testing, revisiting extant populations of selected species sampled in the past, and a species pool approach covering characteristic species of arable fields and mesic meadows. We thus intend to establish the method and provide proof of concept for two fields of questions, with the overarching goal to open up a new avenue for larger scale research on plant nutrition building on the vast herbaria in Germany and globally.