Stem CO2 Efflux measurements from Manaus, Brazil, 2017

Author(s): Jardine K; Cobello L

Site ID: BR-Ma2

Site Name: Manaus - ZF2 K34

Variables: Other

Date Range: Oct. 11, 2020 - Oct. 17, 2020

Description: This data was collected in order to test the effects of temperatures on the autotrophic respiratory process in the tropics. This data package contains raw real-time stem carbon dioxide (CO2) efflux files during the night and day from 3 different species near the K34 in Manaus during the day and the night. Raw and derived data files are included in the format of .csv and .xlsx and information about the canopy trees and temperatures recorded can be found in the field event log using microsoft excel. The data was collected from three canopy dominant trees in the central Amazon near the K34 tower. Real-time stem CO2 efflux was determined using a Li7000 gas analyzer configured in differential mode and connected to a dynamic stem chamber secured to the stem at breast height using straps to generate a reasonable seal. Ambient air was continuously pumped into the stem chamber and CO2 concentrations of the air entering and exiting the chamber were continuously monitored. CO2 efflux was calculated based on the CO2 concentration difference between ambient and stem chambers, the flow rate of air through the chamber, and the area of the enclosed stem. Additional auxiliary data, including sap flow and crown temperature were also measured. No data processing or QA/QC was done on the raw data packages.

QA/QC: None

Methods Description: This field experiment was carried out 60km NW of Manaus/Brazil at the Experimental Station of Tropical Forestry. Three canopy trees were monitored from June to October 2017 during the driest months of the year in order to test the effects of temperatures on autotrophic respiratory process in the tropics. A dynamic stem CO2 efflux (Es) gas-exchange system was used by attaching a stem chamber to the sample trees at 1.3 m height. A dual channel infrared gas analyzer (Li7000) was used to monitor the difference in CO2 while air entered and exited another chamber. Ambient air was continuously delivered to a dynamic stem enclosure and the concentration of CO2 entering and exiting the enclosure were continuously monitored using the Li7000 in differential mode. A heat ratio sap flow sensor was used to monitor sap velocity every 15 minutes in order to understand the relationships of respiration and transpiration. Crown temperature was also monitored; these measurements were made with infrared radiometer sensors installed on the tower less than 7 m away and pointed at the crowns of the sample trees. Thermocouples were also positioned on the leaves of the crowns to record leaf temperature every 15 seconds. Vapor pressure deficit was calculated by data collection of air temperature and humidity with a thermohydrometer. Air temperature and humidity was provided by outside sources.

Access Level: Public

Originating Institution(s): National Institute for Amazon Research and Lawrence Berkeley National Laboratory

Sponsor Organization(s): None

Contact: Jardine, Kolby - Lawrence Berkeley National Laboratory (kjjardine@lbl.gov)

Version: 1.0

Dataset Citation: Jardine K; Cobello L (2022): Stem CO2 Efflux measurements from Manaus, Brazil, 2017. 1.0. NGEE Tropics Data Collection. (dataset). http://dx.doi.org/10.15486/ngt/1804760

Acknowledgement: This material is based upon work supported as part of the Next Generation Ecosystem Experiments-Tropics (NGEE-Tropics) funded by the U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research`s Terrestrial Ecosystem Science Program through contract No. DE-AC02-05CH11231 to Lawrence Berkeley National Laboratory.

Data Link: Download Dataset

Jardine K, Cobello L, Gimenez B, Higuchi N, Chambers J (2020) Diurnal suppression of basal stem CO2 efflux associated with enhanced transpiration in canopy dominant trees in the central Amazon, in prep.