Spectral Library of Arctic Plants

This is a collection of over 350 reflectance spectra of mostly plant material, measured during various fieldwork programmes, between 2002 and 2017, at locations in the European subarctic. These were located at and around either the Abisko field station in Sweden, or the Khibiny field station on the Kola Peninsula, Russia. The fieldwork programmes were part of a long-running collaboration between the Geography Faculty of Moscow State University, and the Scott Polar Research Institute, University of Cambridge. The authors acknowledge with gratitude the assistance of students of both institutions, as well as the staff of the field stations, in acquiring these data. We also acknowledge the support of the UK Natural Environment Research Council and the EU Interact Transnational Access scheme in supporting this work. Spectra were acquired using ASD Fieldspec Pro spectroradiometers, and encompassed both natural and anthropogenically disturbed, and moist and dry, environments. The data are presented as absolute reflectances at wavelengths in 1-nm intervals from 350 to 2500 nm. Reflectances were calibrated against ‘Spectralon’ standards, which had in turn been calibrated at the UK National Physical Laboratory. Some spectra were measured using artificial light sources as illuminants, while others (the majority) used natural daylight. In the latter case next to no illumination was present in certain wavelength ranges, because of strong absorption of the incident solar radiation by atmospheric water vapour, and as a consequence the calculated reflectances are extremely noisy and in practice meaningless. While these values have not been filtered out from the presented dataset, they are easy to recognise. The affected ranges of wavelength, where they occur, are roughly 1350-1410 nm, 1810-1950 nm and 2475-2500 nm. Data are described by two files. One is a text file containing all the spectra. The first row contains spectrum numbers (1-356) and the first column contains wavelengths in nanometres (350-2500). Reflectances are absolute, i.e. multiply them by 100 to get %ages. The second document is a spreadsheet identifying each spectrum by acquisition date (in European day-month-year format), type, condition, genus and (sometimes) species, and collection location - basically, northern Sweden or northern Russia. Some of the data presented here have been published: W.G. Rees, O.V. Tutubalina, E.I. Golubeva (2004). Reflectance spectra of subarctic lichens between 400 and 2400 nm. Remote Sensing of Environment, 90 (3), 281-292, https://doi.org/10.1016/j.rse.2003.12.009. Rees, W. G., Golubeva, E. I., Tutubalina, O. V., Zimin, M. V., & Derkacheva, A. A. (2020). Relation between leaf area index and NDVI for subarctic deciduous vegetation. International Journal of Remote Sensing, 41(22), 8573–8589. https://doi.org/10.1080/01431161.2020.1782505