Data for testing the assumption of fractal scaling in canopy surfaces across a diverse range of forest types

This is a collection of scripts and research data for a study on whether canopy surfaces follow fractal scaling laws across a diverse range of forest types. As data, we use canopy height models (CHMs) from 9 Australian research sites belonging to the Terrestrial Ecosystem Research Network (TERN). Their extent is 5 km x 5 km throughout. The underlying data can be found here: https://portal.tern.org.au/metadata/TERN/4ff0b4c9-cfa0-4d09-9520-b5402adc583f. Climatic data are extracted from the CHELSA climatology 1981-2010 (Brun et al. 2022: Global climate-related predictors at kilometer resolution for the past and future. Earth System Science Data, 14(12), 5573–5603. https://doi.org/10.5194/essd-14-5573-2022; Karger et al. 2017: Climatologies at high resolution for the earth's land surface areas. Scientific Data, 4(1), 170122. https://doi.org/10.1038/sdata.2017.122). Each uploaded zip-file corresponds to a folder within a common repository. To reproduce our analysis, unpack into the same folder, upholding naming conventions and overall structure. Please note that some parts of the analysis require external software, e.g., GRASS GIS for the generation of simulated fractal surfaces. Paths need to be reset accordingly. rscripts.zip: the overall R script ("areforestsfractals_v3.R") used to generate fractal surfaces, calculate fractal statistics from CHMs and simulated surfaces, and to carry out the analysis various summary statistics saved both as RData and csv files TERN.zip: data within this folder are ordered by site name for each site, we include several CHMs, their corresponding DSMs (digital surface models) and DTMs (digital terrain models), as well as ancillary layers (pulse densities of laser scans) for each site and each CHM/DSM, we also save the fractal scaling properties in separate csv files TERNtrees.zip: data within this folder are ordered by site name for each site, we include manual delineations of the largest trees per 1 km x 1 km square (25 in total) for each site, we include subplots of the CHM (200 m x 200 m) centred around the largest tree climate.zip: climate layers from CHELSA for precipitation and site water balance terrain_fractal.zip: simulated fractal surfaces, based on different generating algorithms fractal scaling properties of simulated fractal surfaces in separate csv files sites_coordinates.csv lon/lat coordinates of each site