Collection of the Sphagnum moss samples and measurements of their reflectance spectra are described in detail in Salko, S.-S., Juola, J., Burdun, I., Vasander, H., Rautiainen, M. (2023). Intra- and interspecific variation in spectral properties of dominant Sphagnum moss species in boreal peatlands. Ecology and Evolution. DOI: 10.1002/ece3.10197. The dataset consists of biconical reflectance factors of nine Sphagnum moss species collected from southern Finland. The samples were collected in May 2022, and the nadir-view reflectance factors were measured in a dark laboratory using an ASD FieldSpec 4 spectroradiometer (serial number 18641). The spectral range of measurements was 350-2500 nm, and spectral resolution was 3 nm at 700 nm and 10 nm at 1400 and 2100 nm. During the measurement, the sample was illuminated with a 12 V 50 W Quartz Tungsten Halogen lamp, with an illumination angle of 40º. The spectra of nine species are reported, with 10 samples for each species. The size of each sample was 21,7 * 21,5 cm, and they were measured four times: as fresh (0h, within four to six hours after initial collection), after one day (24h), after two days (48h) and after one week (1w) of the sample collection. Between the spectral measurements, the samples were stored in open containers in a semi-dark room with no direct sunlight and standard temperature (average 20.5 ºC) and air humidity (average 29 %). Example photographs of the fresh sampled species can be found from the file Data_description.pdf. The spectra are reported in two versions: as raw data (“_raw”) and as smoothed with Savitzky-Golay filter with 25 nm window (”_smoothed”). The first three rows in the data contain information for citing and reading the data. After that, the first column indicates the species and ID number of the sample, as well as the time of measurement (0h, 24h, 48h or 1w). The second column indicates simply the species of the sample, the third column indicates the within-species sample ID, the fourth column indicates the time of measurement and the fifth indicates the location of the sampling site (peatland name_municipality). The subsequent columns (wl350-wl2500) indicate the measured reflectance value at that wavelength. The encoding of the csv file is UTF-8. List of Sphagnum species measured: Sphagnum angustifolium Sphagnum capillifolium Sphagnum centrale Sphagnum cuspidatum Sphagnum fallax Sphagnum fuscum Sphagnum girgensohnii Sphagnum riparium Sphagnum rubellum If you use this dataset, please cite: 1) Salko, S.-S., Juola, J., Burdun, I., Vasander, H., Rautiainen, M. (2023). Intra- and interspecific variation in spectral properties of dominant Sphagnum moss species in boreal peatlands. Ecology and Evolution, DOI: 10.1002/ece3.10197. 2) Salko, S.-S., Juola, J., Burdun, I., Vasander, H., Hovi, A., Rautiainen, M. (2023). Reflectance spectra of nine boreal Sphagnum moss species. Mendeley Data, V1, DOI: 10.17632/wm5fcxdmzd.1.

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