The green leaves of land plants st Belle
ow
\
i
were selected to show the trend of activity
in terrestrial vegetation.
Figure 16 shows
the decline of individual plate values as a
scatter diagrem upon which are superimposed
the calculated regression line of slope -1.63
from Table 1, and a curve fitted by inspection to the crosses representing the arith-
metic means of values of radioactivity
.
NA
“
]
grouped by logarithmically equal intervals
of time.
The latter curve resembles the trend
noted for Halimeda at Belle, in that it
$
et te
Fig. 16
increases in steepness at first, and then
It differs in being
steepest at 20,
instead of 100,
7
days as with Hal imeda.
/
Over the 150 to
600-day period the slopes
averaged -.54.
4
iWi
and Table 12.
Ota
/
scatter of the decline values
TREE CC awES
4
Belle is complicated by the
OC. 8
/
tee
Comparison of decay with
Gecline for leaves taken at
in the pertod from 150 to 600
days.
Slopes of 13 decay
curves appear in Figure 17
4
decreases.
ae
“eee
RaQ Oact. te
Sete Nee ee
Jand plants
Decline for this period
lies between the slope of the
regression line, -1.63, and the
slope (~0.45) of the curved
line of Pigure 16 between 150
and 600 days.
’
00
Since the decay rate of
i
170M Omega
and is only slightly greater
than the minimum of -0.45,
the rate of decline is considered to exceed the rate of
decay.
,
+~“Boo
14 1994
Pig. 17
-0.54 falls far short of the
maxinrum decline rate of -1.63,
we hh
J
)
Cutves:
1000
Cars av CR wav
Teble 18.
Desey rates of samples of green lcavee from
land >lante at Belle.
Curve Plate
num
ber
1
nweber
6348
2
3
Lagso
10819
s
10680
‘4
S7
10818
Species
Kind of Bomth
Year
Seacvole
young
¥
°
eprout
apiece)
°
epical
old
and day
collested,
1066
Mey 15
Segt. ?
?
°
?
sev. 30
600 aeye
1.
36
250
6
9
LEE
Loges
Beesoregumidig epteal
sprout Sept. 7?
»
~60
ides
Pieris
vude
0
S|
ims
Portwulec
leaves
,
ai
lwre
"aeenu
leaves
°
e
108s?
340
1aees
©
aa
. as
Seerhagote
leaves
ole
leaves
.
7
’
°
7
.@
-
62
a
1.90