Dataset - American beech sapling dominance: stand-scale insights from mobile laser scanning

This dataset is used in the article ' American beech sapling dominance: stand-scale insights from mobile laser scanning'.

We aimed to determine whether spatial relationships between beech saplings, mature beech trees, and canopy openness, previously observed among stands using discontinuous plot-based sampling, also applies within stands using continuous sampling of full stands. Because beech saplings are assumed to develop mainly through root suckering and that they respond strongly to increased light availability, we expected that (1) beech sapling cover would be positively related to mature beech basal area and canopy openness, and (2) the relationship between beech sapling cover and canopy openness would be strengthened by higher beech basal area.

To test our hypotheses, we created 3D-maps of 11 1-ha stands using mobile laser scanning (MLS) technology that allowed us to investigate the relationships between beech our variables at multiple spatial scales and to develop a new method for analyzing regeneration. Contrary to our expectations, we found very little to no effect between beech saplings and canopy openness, and a highly variable relationship with mature beech trees depending on the site.

Each site was divided into localized square pixels, with sizes ranging from 2 × 2 m to 16 × 16 m in 2 m increments. Various variables were averaged within these pixels to capture localized patterns. Additionally, some of these variables were calculated within circular radii plots centered on these pixels, with radii ranging from 5 m to 30 m, varying in steps depending on the variable. The variables analyzed in those plots included basal area measurements for different species and their conditions, such as beech trees, beech trees over 25 cm in DBH, and all trees, as well as their living, dead, or combined states. This multiscale approach allowed us to compare localized and broader spatial patterns and investigate their influence on sapling cover and other stand-level characteristics.

The complex and unorthodox method of calculation for all of these variables is explained in depth within the methodology section of the article. Custom algorithms were created and needed to treat raw LiDAR data and can be made available on request.

A separate excel file in this database, named 'variables_explanation' gives a list of all variables in the excel files with the explanation of what their name means.

All separate excel files are named by the name of the site (from 2 to 14, excluding 3, 7) and the pixel associated to the data (ranging from 2 to 16 in 2 m increments).

Any questions relating to the dataset that is not contained within the methodology section can be asked to the main author, Frédéric Moore, at the email address [e-mail].

Raw LiDAR point clouds of each site as well as the custom algorithms can be made available on request.