Leaf Area Index (LAI) — GLBRC Biofuel Cropping System Experiment
Data in the KBS LTER core database may not be published without written permission of the lead investigator or project director Full terms of use
Leaf Area Index (LAI) measurements for all BCSE treatments (G1-G10) at KBS. From 2009 to 2013, LAI was measured with a Licor LAI-2000 meter and from 2013 to 2017 with an AccuPar LP-80 Ceptometer. Dual measurements using both meters were conducted in 2013 in order to compare results.
This datatable is part of the Leaf Area Index on the GLBRC Biofuel Cropping System Experiment dataset.
The leaf area index was measured to estimate the phenology and growth patterns of the different biofuel crops.
Note
| Experiment: | GLBRC Biofuel Cropping System Experiment |
| Data available from: | June 2009 to October 2017 |
| Dataset: | GLBRC148 |
| Datatable ID: | GLBRC082-007.4 |
| Repository link: | |
| Personnel: |
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| Last Updated | 2023-10-24 |
| Variate | Description | Units |
|---|---|---|
| sample datetime | date and time of measurement, the plus sign indicates the time relative to Universal Coordinated Time (UCT). | |
| local datetime | the time in the eastern time zone either standard time or daylight saving time depending on the date. | |
| treatment | experimental treatment | |
| replicate | replicate nested within treatment | |
| direction | direction and plant number | |
| lai | leaf area index | m^2/m^2 |
| sel | standard error of lai | m^2/m^2 |
| difn | fraction of sky visible | |
| mta | mean tilt angle | |
| sem | standard error of MTA | |
| smp | number of sample pairs used | |
| comments | notes about the data row | |
| instrument | the instrument used to measure LAI | |
| mean above par | mean PAR above the canopy in micromoles/(m^2 s) | |
| mean below par | mean PAR below the canopy in micromoles/(m^2 s) | |
| tau | ratio between the above and below canopy PAR | |
| chi | (leaf distribution parameter): ratio of the projected area of an average canopy element (a leaf, for example) on a horizontal plane to its projection on a vertical plane; the default value for χ is 1.0, which assumes the canopy angle distribution to be spherical. | |
| fb | (fractional beam radiation): ratio of direct beam radiation coming from the sun to radiation gathered from all ambient sources, like the atmosphere, or reflected from other surfaces | |
| zenith angle | angle between the point in the sky directly overhead vertical, called the zenith (0°), and the position of the sun. The angle is calculated based on the global position, time of day, and location |
Data Excerpt
| sample_datetime | local_datetime | treatment | replicate | direction | lai | sel | difn | mta | sem | smp | comments | instrument | mean_above_par | mean_below_par | tau | chi | fb | zenith_angle |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2017-10-27 12:52:00 +0000 | 2017-10-27 08:52:00 UTC | G8 | R1 | EP3 | 0.39 | LAI AccuPAR LP-80 Ceptometer | 11.2 | 8.1 | 0.719 | 1.0 | 0.02 | 83.0 | ||||||
| 2017-10-27 12:51:00 +0000 | 2017-10-27 08:51:00 UTC | G8 | R1 | EP1 | 0.67 | LAI AccuPAR LP-80 Ceptometer | 10.9 | 6.1 | 0.56 | 1.0 | 0.02 | 83.0 | ||||||
| 2017-10-27 12:51:00 +0000 | 2017-10-27 08:51:00 UTC | G8 | R1 | EP2 | 0.72 | LAI AccuPAR LP-80 Ceptometer | 11.0 | 6.0 | 0.542 | 1.0 | 0.02 | 83.0 | ||||||
| 2017-10-27 12:50:00 +0000 | 2017-10-27 08:50:00 UTC | G8 | R1 | WP3 | 0.79 | LAI AccuPAR LP-80 Ceptometer | 11.3 | 5.7 | 0.505 | 1.0 | 0.02 | 83.0 | ||||||
| 2017-10-27 12:48:00 +0000 | 2017-10-27 08:48:00 UTC | G8 | R1 | WP2 | 0.79 | LAI AccuPAR LP-80 Ceptometer | 12.1 | 6.2 | 0.51 | 1.0 | 0.02 | 84.0 |