Author(s): Pivovaroff A; McDowell N; Davies S; Detto M; Wolfe B; Wright J; Zambrano A
Site ID: PA-SLZ
Site Name: Bosque Protector San Lorenzo (Fort Sherman)
Variables: Air Temperature; Relative humidity; Sapflow; Solar Radiation
Date Range: Jan. 1, 2020 - June 1, 2020
Description: This data package contains sap flow data from the NGEE Tropics site in San Lorenzo, Panama (PA-SLZ) from 01 January 2020 to 01 June 2020. Sap flow measurements quantify plant-level transpiration, which varies across spatial and temporal scales. It is a key trait in understanding plant hydraulic functioning. Here sap flow was measured using ‘Granier-type’ thermal dissipation probes. Raw data downloaded from the data logger is in the 'Raw data' folder as a CSV file. The data was processed using the AquaFlux package in R. R code for preparing the data for use in AquaFlux is in the 'R code for pre-processing data folder'; it is saved as a text file that can be copy and pasted into R. Each core sap flow tree has two sensors. The data was processed for each sensor as well as for each tree. These processed data files are in the 'Processed data' folder as CSV files. Documentation for the Granier sensors and AquaFlux package is in the ‘Manuals’ folder as PDF files.
QA/QC: Full QA-QC
Methods Description: The data was processed using the AquaFlux package in R. AquaFlux can autoselect ’Tmax’ points (the maximum temperature difference when sap flux = 0) based on vapor pressure deficit (VPD), which requires associated meteorological data (downloaded from the Smithsonian Tropical Research Institute ‘Physical Monitoring’ site). While the AquaFlux documentation says it can use "spline interpolation to make the VPD data have the same timestamps as the dT {temperature difference between probes} data," in practice this is not the case. To make the sap flow timestamps match the meteorological data timestamps, the 5-minute sap flow measurements were averaged for every 15-minutes. In addition, the sap flow timestamps were shifted by 15 minutes, because the sap flow timestamps represent the START of the measurement, while the meteorological data timestamps represent the END of the measurement. Shifting the sap flow timestamps allowed the actual time intervals over which measurements were taken to now overlap. Manuals for the sap flow sensors and AquaFlux are in the 'Manuals' folder.' R code for preparing the data for use in AquaFlux is in the 'R code for pre-processing data folder'; it is saved as a text file that can be copy and pasted into R. The processed data is in the 'Processed data' folder. Each core sap flow tree has 2 sensors. The data was processed for each sensor as well as for each tree by simply taking the mean for the two sensors in each tree. See the documentation 'AquaFlux_README.pdf' section 'Chapter 5: Process dt Data - QAQC' for additional details about QAQC.
Access Level: Public
Originating Institution(s): Pacific Northwest National Laboratory (PNNL) & Smithsonian Tropical Research Institute (STRI)
Sponsor Organization(s): None
Contact: Pivovaroff, Alexandria - Pacific Northwest National Laboratory (alexandria.pivovaroff@pnnl.gov)
Version: 1.0
Dataset Citation: Pivovaroff A; McDowell N; Davies S; Detto M; Wolfe B; Wright J; Zambrano A (2020): Sap flow data from San Lorenzo, Panama (PA-SLZ) from January - June 2020. 1.0. NGEE Tropics Data Collection. (dataset). https://doi.org/10.15486/ngt/1678733
Acknowledgement: Funding for NGEE-Tropics data resources was provided by the U.S. Department of Energy Office of Science, Office of Biological and Environmental Research.
Data Link: Download Dataset
