A1 Refereed original research article in a scientific journal
Quantifying changes in forest structural complexity using bi-temporal airborne laser scanning
Authors: Cimdins, Reinis; Yrttimaa, Tuomas; Hyyppä, Juha; Vastaranta, Mikko; Kankare, Ville
Publisher: Taylor & Francis
Publication year: 2024
Journal: European Journal of Remote Sensing
Journal name in source: European Journal of Remote Sensing
Article number: 2417905
Volume: 57
Issue: 1
eISSN: 2279-7254
DOI: https://doi.org/10.1080/22797254.2024.2417905(external)
Web address : https://doi.org/10.1080/22797254.2024.2417905(external)
Self-archived copy’s web address: https://research.utu.fi/converis/portal/detail/Publication/458882567(external)
Structural complexity is an important forest characteristic for habitat assessment, forest management
and planning. However, monitoring how forest structural complexity evolves over
time in various forest types has not been widely explored. In this study we investigate the
feasibility of bi-temporal low-density airborne laser scanning (ALS) for the assessment of
changes in light availability conditions within forest canopy, considered to imply changes in
forest structural complexity. We used ALS data acquired in 2012 and 2019 to generate canopy
vertical profiles by slicing the point clouds into 4 × 4 ×1 m voxels which were then rasterized
and reclassified into four light availability categories. To understand structural development
over time in different forest types we used field-measured tree heights and tree species
information to stratify sample plots in different stand complexity categories. Stands with higher
structural complexity represented increased proportions of space occupied by vegetation as
well as decreased proportions of empty space below the canopy. The experiments showed the
ability of low-density ALS to characterize the dynamics in canopy layering structure, implying
changes in forest structural complexity. The presented methodology could potentially be
upscaled and applied in the landscape-level monitoring of the development of boreal forest
structural characteristics.
Downloadable publication This is an electronic reprint of the original article. |
Funding information in the publication:
This research was funded by the Research Council of Finland and European Union (NextGenerationEU) through project “Capturing structural and functional diversity of trees and tree communities for supporting sustainable use of forests” (Diversity4Forests, 348643), and by Flagship “Forest-human-machine interplay – building resilience, redefining value networks and enabling meaningful experiences” (UNITE, 337127, 357906).