Data from: Scale-dependent responses to environmental fluctuations in tropical tree species’ crown temperatures
Data files
Jan 15, 2025 version files 483.99 KB
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Abiotic_Conditions_DRYAD.csv
298 B
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Crown_Temperatures_DRYAD.csv
443.19 KB
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Crown_Traits_DRYAD.csv
38.12 KB
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README.md
2.39 KB
Abstract
This dataset comprises tree crown temperature and tree crown trait data for four four canopy species in Laupahoehoe forest in Hawai'i, analyzed at a "crown" and "leaf" level, as defined in the manuscript methods. Climate data were collected from the climatological station at Laupāhoehoe Forest, and here we provide the average conditions at the 5 UAV flight times.
README: Hawaiian tree species’ crown temperatures and crown traits
https://doi.org/10.5061/dryad.kwh70rzfp
Description of the data and file structure
Data for the manuscript titled "Scale-dependent responses to environmental fluctuations in tropical tree species’ crown temperatures," by Bayliss et. al., for Communications Earth & Environment.
Files and variables
File: Abiotic_Conditions_DRYAD.csv
Description:
Variables
- DMY: Day, Month, and Year of Data Collection
- flight_time: Approximate Flight Times of Data Collection (Time marking beginning of UAV flight)
- Tair_Celcius: Air Temperature in degrees Celcius
- WS_mph: Wind Speed in miles per hour
- Rn_Wm-2: Net Radiation in Watts per meter squared
- VPD_Pa: Vapor Pressure Deficit in Pascals
File: Crown_Temperatures_DRYAD.csv
Description:
Variables
- species: Species names, coded as METPOL = Metrosideros polymorpha; ACAKOA = Acacia koa; CHETRI = Cheirodendron trigynum; COPRHY= Coprosma rhynchocarpa.
- UAV-flight-time: Approximate Flight Times of Data Collection (Time marking beginning of UAV flight)
- crown.reference: unique identifying crown identification number
- level-of-analysis: whether temperature averages (of pixels) were conducted at the "crown" or "leaf" level
- thermal.mean.Celcius: crown temperatures in degrees Celcius
- thermal.sd: crown temperatures standard deviation
- tdiff.mean: crown temperature deviations from air temperatures in degrees Celcius
- tdiff.sd: crown temperature deviations from air temperatures standard deviation
File: Crown_Traits_DRYAD.csv
Description:
Variables
- crown.reference: unique identifying crown identification number
- species: Species names, coded as METPOL = Metrosideros polymorpha; ACAKOA = Acacia koa; CHETRI = Cheirodendron trigynum; COPRHY= Coprosma rhynchocarpa.
- Z_mean_height_m: average crown height in meters
- rumple_index: measure of crown rugosity/roughness: crown rumple index value (no unit)
- leaf_clumping: coefficient of variation (CV) of crown height (the ratio of standard deviation to mean height)
- mean_density_voxels: crown densities (pts m-3) from 3D point densities from Lidar point clouds
Code/software
These data can be opened in Microsoft Excel, or any software that reads .csv files
Methods
Data here were derived from spatial orthomosaics from five UAV flights with a 20 cm2 pixel resolution were created for RGB, Thermal (°C), and lidar intensity with detailed methods described in the published manuscript.
Tree crown temperature data: 652 crowns or leaf clusters were identified to four species: 396 Metrosideros polymorpha (‘ōhi‘a lehua), 159 Acacia koa (koa), 51 Cheirodendron trigynum (ʻōlapa), and 46 Coprosma rhynchocarpa (pilo). Data were filtered to a "crown" and "leaf" level of analysis, described in detail in the manuscript, and thermal values from all remaining pixels were averaged to determine an average crown temperature at each flight time.
Tree crown trait data: For each tree crown, we extracted average height (m), calculated the coefficient of variation (CV) of crown height (the ratio of standard deviation to mean height) within each crown as a measure of leaf clumping. We used the R package “lidR” (1-3) and the function “voxel_metrics” to derive average crown densities (pts m-3) and the function “rumple_index” to calculate the rumple index (a measure of rugosity or roughness) for each crown.
1. R Core Team. (2023). R: A language and environment for statistical computing (Version 4.1.3). R Foundation for Statistical Computing. https://www.R-project.org/
2. J.R. Roussel, D. Auty, N.C. Coops, P. Tompalski, T.R.H. Goodbody, A. Sanchez Meador, J.F. Bourdon, F. De Boissieu, A. Achim, lidR: An R package for analysis of Airborne Laser Scanning (ALS) data. Remote Sensing of Environment 251, 112061 (2020). Doi:10.1016/j.rse.2020.112061
3. J.R. Roussel, D. Auty, Airborne LiDAR Data Manipulation and Visualization for Forestry Applications (2022). R package version 4.0.1. https://cran.r-project.org/package=lidR