A dataset of branch reflectance spectra for seven boreal and temperate tree species

This dataset is a part of the following publication titled "A spectral library of branches for seven boreal and temperate tree species" published in Data in Brief.

This dataset contains a novel spectral library capturing the hyperspectral reflectance of branches from seven boreal and temperate tree species. The reflectance spectra of branches were measured for coniferous and broadleaf tree species: European aspen (Populus tremula L.), goat willow (Salix caprea L.), grey alder (Alnus incana (L.) Moench), silver birch (Betula pendula Roth), Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst), and Siberian larch (Larix sibirica Ledeb.). The branch samples were collected in southern Finland between September and November 2024, and measured in laboratory conditions using a spectroradiometer (ASD FieldSpec 4 Standard-Res) coupled with a custom contact probe (Thorlabs Bifurcated 19-Fiber Bundle), an integrating sphere (Avantes Avasphere-30), and a light source (Ocean Optics HL-2000). In addition to the spectral measurements, auxiliary field measurements were conducted to describe the sampled branch and the tree it was detached from, e.g., tree height and branch length.

- The file "contact_probe_spectral_measurements.csv" contains conical-conical reflectance factor (CCRF) spectra of tree branches measured with a contact probe setup and a spectroradiometer.
- The file "integrating_sphere_spectral_measurements.csv" contains directional-hemispherical reflectance factor (HDRF) spectra of tree branches measured with an integrating sphere setup and a spectroradiometer.
- The file "sampled_tree_descriptions.csv" contains auxiliary data for each of the sampled trees.
- The file "sample_photos.pdf" shows photographs of the measured branch samples and the trees they were detached from.

Please refer to the Data in Brief publication for more details on sampling, spectral measurements, data processing, and how to interpret the files contained in this dataset.

If using this data, please cite this Mendeley Dataset and the accompanying Data in Brief publication:

- Juola, Jussi; Rautiainen, Miina; Hovi, Aarne (2025), "A spectral library of branches for seven boreal and temperate tree species", Data in Brief, 112255, doi: 10.1016/j.dib.2025.112255
- Juola, Jussi; Rautiainen, Miina; Hovi, Aarne (2025), "A dataset of branch reflectance spectra for seven boreal and temperate tree species", Mendeley Data, V2, doi: 10.17632/kvnx6vt8x9.2

Version history:

This is Version 2 of the dataset. Reference to the accompanying Data in Brief publication was added. Data are identical to Version 1.