Canopy Photosynthesis Study

Data

• hf059-01: photosynthesis data

Overview

• Lead: Susan Bassow, Fakhri Bazzaz
• Investigators:
• Contact: Emery Boose
• Start date: 1991-01-01
• End date: 1992-12-31
• Location: Prospect Hill Tract (Harvard Forest)
• Latitude: +42.54
• Longitude: -72.17
• Elevation: 340 meters
• Taxa: Acer rubrum (red maple), Betula alleghaniensis (yellow birch), Betula papyrifera (white birch), Quercus rubra (red oak)
• Research topic: atmosphere
• Study type: short-term measurement
• LTER core area: primary production
• Keywords: canopy, photosynthesis, physiology
• Release date: 1999
• EML version: knb-lter-hfr.59.8
• Revisions:
• Related links:
• Abstract:

  Measurements were made from 2 canopy access towers in a time period between July 1991-October 1992. Four species were observed: Oak - red oak (Quercus rubra); RM - red maple (Acer rubrum); WB - white birch (Betula papyrifera); YB- yellow birch (Betula alleghaniensis). There are 1950 records; each represents a single measurement of a leaf in the canopy.

• Methods:
• Use:

  This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement. For more information on LTER Network data access and use policies, please see: http://www.lternet.edu/data/netpolicy.html.

• Citation:

  Bassow S, Bazzaz F. 1999. Canopy Photosynthesis Study. Harvard Forest Data Archive: HF059.

Detailed Metadata

hf059-01: photosynthesis data

1. date: date
   • 1: 16 July 1991
   • 2: 22 August 1991
   • 3: 28 September 1991
   • 4: 12 June 1992
   • 5: 10 July 1992
   • 6: 21 August 1992
   • 7: 3 October 1992
2. month: month in which the measurement was made (MM)
3. year: year
   • yr1: 1991
   • yr2: 1992
4. TOWER: refers to the Canopy Access Tower from which measurement was made
   • 1: Tower 1
   • 2: Tower 2
5. HEIGHT: refers to either the top of the canopy (T) or the sub-canopy (L) heights. The sub-canopy height was the lowest height where there were sufficient leaves accessible form the towers on the canopy trees.
   • L: sub-canopy heights
   • T: top of the canopy heights
6. SPECIES: species observed
   • OAK: red oak (Quercus rubra)
   • RM: red maple (Acer rubrum)
   • WB: white birch (Betula papyrifera)
   • YB: yellow birch (Betula alleghaniensis)
7. REP: at least 5 replicate leaves of each tree were measured in a given 2 hour time period on each observation date. October 3, 1992 has only a limited set of data.
8. hour: corresponds to hour of day, EST, hours fractional (hh)
9. PSN: in situ photosynthetic rate of the leaf (micromolesPerMeterSquaredPerSecond )
10. Cond: in situ conductance rate of the leaf (micromolesPerMeterSquaredPerSecond )
11. PAR: photosynthetically active radiation (light levels) (micromolesPerMeterSquaredPerSecond )
12. LPAR: ln transformed PAR levels (number )
13. CO2: CO2 concentration in the leaf chamber during the measurement in units of ppm (dimensionless )
14. Ci: calculated internal CO2 concentration in units of ppm (dimensionless )
15. E: calculated transpiration rates (micromolesPerMeterSquaredPerSecond )
16. Ci/Ca: ratio of Ci to CO2 concentration (dimensionless )
17. Tleaf: leaf temperature measured by a leaf thermocouple touching theunderside of the leaf when enclosed in the leaf cuvette (celsius )
18. Tair: air temperature measured in the cuvette during the measurement (celsius )
19. RH: relative humidity (%) measured in the cuvette during the measurement (dimensionless )
20. esleaf(kPa): calculated vapor pressure of the leaf (kilopascal )
21. eair(kPa): calculated vapor pressure of the air in the cuvette during the measurement (kilopascal )
22. vpd (kPa): vapor pressure deficit (kilopascal )