GEDI4R: an R package for NASA's GEDI level 4 A data downloading, processing and visualization

Forest ecosystems' structure and biomass monitoring are crucial for understanding the contribution of forests to the global greenhouse gas balance. NASA's Global Ecosystem Dynamics Investigation (GEDI) mission collects waveform lidar data to estimate Above Ground Biomass Density (AGBD). While of great interest, GEDI data are challenging to download and pre-process and require coding expertise, limiting their usage. In this paper, we introduce GEDI4R, an open-source R package providing efficient methods for downloading, reading, clipping, visualizing, and exporting GEDI data. GEDI4R was tested over the whole of Italy, and more than 11 million GEDI pulses were downloaded in less than 10 hours. The GEDI pulse density in forests ranged between 132 per km2 (in the Friuli Venezia Giulia Italian administrative region) and 61 pulses per km2 (in Trentino Alto-Adige). A regional-level comparison between the official growing stock volume estimates reported in the last Italian forest inventory and the AGBD extracted from the GEDI data acquired over the forest revealed large correlations (r2 = 0.77). Our package facilitates the usage of GEDI AGBD data, which provides innovative information to monitor carbon cycle dynamics at the global scale.