DOI: 10.25573/data.14417933
title: Surface elevation models and associated canopy height change models for the 50-ha plot on Barro Colorado Island, Panama, for 2014-2019

description: 1-m surface elevation models and associated canopy height change models for the 50-ha Smithsonian ForestGEO plot on Barro Colorado Island, Panama, for 47 dates between 2 October 2014 and 28 November 2019. Surface elevation models were produced from photogrammetry processing of drone-acquired imagery using Agisoft Metashape (previously Agisoft Photoscan) software. We horizontally aligned all orthomosaics and canopy surface elevation models to the first set (2 October 2014) using the centers of Attalea palms as manual control points to produce the initial DEMs with horizontal resolutions of 18-25 cm. We clipped the elevation models using the polygon of the 50 ha plot plus an extension of 25 m to produce clipped DEMs (DEM_clip_2014 to DEM_clip_2019). We then resampled elevation models to 1 m horizontal resolution (DEM_clip_1m.zip). Finally, we differenced surface elevation models for successive dates to obtain a raster of the canopy height changes for the associated intervals. We assumed that the true median change in elevation between successive dates was zero and that any nonzero median elevation change for successive dates reflected systematic error in the vertical coordinates on one or both dates. We thus corrected rasters of canopy height changes for vertical positioning errors by subtracting the median observed elevation model difference (DEM_dif_cor.zip)<br>These data are licensed under CC BY, meaning use of the data is allowed so long as attribution is given via citation. These data should be cited either as an individual dataset or as part of the larger collection: Garcia, Milton, Jonathan P. Dandois, Raquel F. Araujo, Samuel Grubinger, and Helene C. Muller-Landau. 2021. Surface elevation models and associated canopy height change models for the 50-ha plot on Barro Colorado Island, Panama, for 2014-2019. Smithsonian Figshare. DOI: 10.25573/data.14417933orAraujo, Raquel F., Samuel Grubinger, Milton Garcia, Jonathan P. Dandois, and Helene C. Muller-Landau. 2021. Collection of datasets: Strong temporal variation in treefall and branchfall rates in a tropical forest is related to extreme rainfall: results from 5 years of monthly drone data for a 50-ha plot. Smithsonian Figshare. DOI: 10.25573/data.c.5389043<br>These datasets were used in the following peer-reviewed journal article:Araujo, R. F., S. Grubinger, C. H. S. Celes, R. I. Negrón-Juárez, M. Garcia, J. P. Dandois, and H. C. Muller-Landau. 2021. Strong temporal variation in treefall and branchfall rates in a tropical forest is related to extreme rainfall: results from 5 years of monthly drone data for a 50-ha plot. Biogeosciences.<br><br>The code used to analyze these data for this article are available in GitHub, at https://github.com/Raquel-Araujo/gap_dynamics_BCI50ha<br><br>Author contribution for datasets for 2014-2015: Helene C. Muller-Landau conceived the research, wrote the grant proposal that funded the research, and designed data collection. Jonathan Dandois constructed the drones, led drone data collection, performed photogrammetry processing, and did preliminary horizontal alignment. Samuel Grubinger finalized horizontal and vertical alignment and identified canopy disturbances. Raquel F. Araujo revised canopy disturbances and classified them as branchfalls, treefalls, or standing dead trees. Author contribution for datasets for 2016-2019: Helene C. Muller-Landau conceived the research and designed the data collection. Milton Garcia led drone data collection and processed drone imagery. Raquel F. Araujo performed horizontal and vertical alignment, identified canopy disturbances, and classified disturbances as branchfalls, treefalls, or standing dead trees. Acknowledgments: We thank Marino Ramirez, Pablo Ramos, Paulino Villareal and others for assistance with drone data collection; and Milton Solano for assistance with data processing and organization. We gratefully acknowledge the financial support of the Smithsonian Institution Competitive Grants Program for Science; the Next Generation Ecosystem Experiments-Tropics, funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research; and the Smithsonian Tropical Research Institute fellowship program. Kristina Anderson-Teixeira, Stephanie Bolman, Richard Condit, Stuart Davies, Matteo Detto, Jefferson Hall, Patrick Jansen, Stefan Schnitzer, Edmund Tanner, and S. Joseph Wright were co-PIs on the original Smithsonian proposal, and we thank them for their contributions to the proposal and input on the research. <br>