Analysis of solar radiation and thermography data using tree crowns parameters for Norway spruce

Abstract

This study investigates how tree crown and forest canopy characteristics affect crown temperature and solar radiation in Norway spruce (Picea abies) stands, providing insights into forest health and the potential impacts of climate change. The research was conducted at the School Forest Enterprise near Kostelec nad Černými Lesy in the Czech Republic. Using a dataset from LiDAR and thermographic surveys, our research utilises the Point Cloud Solar Radiation Tool to model solar radiation. The voxel method was applied to the LiDAR data to calculate solar radiation. In addition, LiDAR data were used for crown segmentation and to assess individual tree parameters such as height, variability in crown height, crown area, canopy density index, the openness of the crown to gaps from south direction, area of forest gaps surrounding the tree. The findings indicate that the average crown temperature is significantly influenced by gaps area, the crown density, tree height, crown area, and crown openness to the south. For solar radiation, factors such as height of trees, crown density, and gaps area were found to be important. This research provides valuable insights for the development of effective forest management strategies, particularly for adapting to and mitigating the effects of climate change under the threat of bark beetle outbreaks.