Field Notes

When: Apr 18, 2002
Where: Tonzi/Vaira Ranches
Who: Liukang Xu

Weather: Sky clear in the early morning, sunny in the am, and increasing patchy cumulus clouds in pm. Temperature in the early morning was 2-3 ^oC and in the pm was around 17-20 ^oC in the pm. Mild west wind.

4:10 am arrived at Tonzi ranch for predawn water potential measurement. I took these leaves as near ground as possible and also as close to the main stem as possible! Finished in 1 hr 40 min.

Shortly after sun rose, I noticed that heavy dew on the grass in the open space, much light dew under the trees.

Soil moisture point sensor reading

Soil moisture loss much fast at Vaira ranch than at Tonzi ranch.

Dendrometer reading

By comparing the two previous reading, the trees are still expanding, even though the tree leaves out a couple of weeks ago. This might be due to cold weather recently and plenty of soil moisture.

Floor flux system:

Gillsonic program was running, fence working, sonic sn 000021 and li-Cor sn 0035

C: drive 2.98 GB free space. All the dataloggers (CR10X2, CR10X4, CR10X5, CR23X3, CR23X6) are communicating with PC. CR23X6.dat are not breaking the file into each individual day.

After download data, reboot PC, gillsonic flux program outputs are;

Fence battery voltage 12.3V, watchdog battery voltage 14.02 V. It is too high, Ted ????

PV reading: 13.2V, 6.9A, and 2.0A. Battery fully charged !

Mr. Tonzi’s granddaughter-in-law’s dog got zappered by electric fence.

Tower flux system:

Fence working, its battery voltage 12.55 V. Gillsonic flux program was running. Download data. From d1050730 to d1060430 gillsonic not running, I need look the radiation data to see whether this was caused by low sunlight or caused by the same unknown problems we had last summer. 4.06 GB free space on C:. swapped li-cor sn 0065 came off and sn 0041 went on. Sonic sn 000022. PV reading; 14.4, 17.9, 1.8A, and battery fully charged. Reboot pc, gillsonic output as follows;

10:40 arrived at Vaira ranch: no cow around for the whole day.

Grass head out, just start senescence, grass leaves not as green as last week.

Finished 2 A/Ci curves on clove leaves and one curve on annual grass. The Amax for grass is pretty high from li-cor 6400.

Fence working. PV reading 12.7, 4.0 and 2.7A, battery charge low, red light flashing.

Sonic sn 000028; Flux program was running download data. And swapped li-cor sn 0042 came off and sn 0073 went on, reboot pc and found output of q and CO2 was 5.00 V. Check all the connections and reboot pc again could not solve the problem, so I reinstalled li-Cor sn 0042 again on the system.

Gillsonic outputs;

Soil moisture point sensor reading, see above for results.

Took 3 LAI samples and grass height measurement (n=30, m=29.9 cm, std=8.9 cm)

4:15 return to Tonzi site to drop off tool box and point moisture meter.

Took 3 LAI samples and grass height measurement. (n=30, m=5.3cm, std=4.0).

Took some oak leaves from 6 trees.

Final check the two flux systems and found the flux program at floor was frozen. The program was run only two hr after I download data in the morning. Reboot the pc, everything seems OK.