1. The Web Page Development Team predicted that stomata would demonstrate
a daily cycle of opening and closure, evident as changes in their stomatal
area measured from superglue leaf impressions.
2. The team anticipated that increases in the area of stomatal openings
would be reflected by decreases in the resistance of the stomata
to the exit of gasses from the leaves, if measurements were made using
a porometer at the same times that superglue slide data were collected.
The data support both hypotheses advanced by the Web Page
Development Group:
1. Stomatal area rose and fell in a cyclical manner, as indicated by SCION
analysis of the superglue molds. Two daily peaks were observed in
the aperture of stomata. The first was more dramatic and occurred around
10:00 AM. There was a second, less pronounced occurance between 4:00
and 6:00 PM.
2. As expected, there was a clear, inverse relationship between the values
obtained from the porometer and the computed stomatal aperture area.
Since the porometer yields greater resistance values as stomatal
flow decreases, larger porometer values should be accompanied by smaller
measurements of the openings through which the gasses must flow.
This indeed was the case.
The group concluded that stomatal aperture calculations prepared from superglue
molds are a reliable indication of the rate of gas exchange between leaves
and the atmosphere, at least for Princeton holley plants in mid-July.
