60
PROCEEDINGS OF THE OKLAHOMA
UPTAKE OF MINERALS BY TREES IN
SUCCESSIVE YEARS
JL I. PLICE, OkJalloma A. Hd JL College, Stillwater
The uptake of mineral material by plants, as shown by foliar analyses,
has been studied by many workers. Most of the studies in this connection
have involved cereal and grass plants, mostly annuals. Numerous determination. of the mineral constitution of tree leaves have also been made.
However, these studies reveal the mineral uptake by plants for a period
of one season only. It Is known that environment and heredity influence
plant nutrition. Blnce environment changes from place to place and heredity ceases at the death of a plant, the seeming inconsistencies in mineral
uptake by annual plants, as ~hown by foliar analyses, may be self-explanatory.
In view ot such tacts, It seems probable that more fundamental information regarding the innuence of ellmate on mineral metabolism of plants
could be obtained from tollar analyses by utlllzing tree leaves over a period
of successive years. A tree is a perennial plant whose heredity, for this
purpose at least, Is fixed. Its edaphic environment is also practically constant. The cUmate, then, is the most important variable. It is true that
dltferent trees react differently to both edaphic and climatic environment.
However, this is true, doubtleBS, for all plants.
The choice of tree leaves as a medium of study for mineral nutrition
as innuenced by climate seems to have several advantages over short-lived
plants, as follows:
(1) The ash content of plants can be Innuenced strongly by the growth
of preceding crops. This Is true qualitatively as well as quantitatively.
(2) Different soil physiological conditions are produced by dftferent
cultural operations.
(3) Analyses are not comparable from year to year when plants are
grown on different soUs.
Even should "standardized" plants be used to study mineral uptake,
I.e., plants of selected and flxed heredity, they should be grown in the
same spot in the soil each season in order for one to be able to draw valid
conclusions. Edaphic conditions vary within narrow and unpredictable
limits, even in small soU areas. Although much is known of the effect
of single factors in plant growth, the anabolism of any plant involves multiple factors. Changing the site only slightly sets in action a complication
of 8till different factors.
PRESENT STUDY
The present work was undertaken in order to learn more about the
effect of the weather on the mineral uptake of plants, using the ash contents of tree leaves as evidence. The study began with thirty-six trees,
representing twenty-four species, and ended with twenty-two trees of twenty
species. The remainder became victims of the axe, disease, insects, and
lightning. With the exception of one tree, a pecan, all trees grew on an
area of land leBS than a quarter-seeUon in extent. This land was originally
pratrie and Is fairly uniform In nature. The first five trees shown In the
tables grew nearly uniformly spaced on a plot of ground about flUy feet
square. They are reported to be of the same age, having been started In
a nursery and transplanted at the same time, whUe sapllngs about thirty
yean ago.
The leaves here reported were collected each autumn for five successive
seuonB. 1938 through 1942. They were taken mature and unweathered as
follows: trom the first eleven trees shown in Table II the leaves were
picked each autumn trom the same limbs and branches on approximately
ACADEMY OF SCIENCE FOR 1943
81
the bottom quarter of the tree when they were ready to abscise: from the
remaining eleven trees leaf cm.mples were collected dally after they fell
untU all leaves had fallen. In each Instance they were well mixed and
two-pound samples were saved. These were dried at 960 C. ground to paIS
through a sieve of halt-millimeter mesh and 200 grams were saved for
analysis. Determinations were made as shown In the tables. Weather data
were taken including temperature, precipitation, and evaporation from a
free water surface. Water-table levels were measured monthly.
PRESENTATION OF DATA
In Fig. I Is shown the average water levels, In feet, of eight wells In
the Stillwater Creek basin In which the trees studied are situated. In the
same figure Is also shown the cumulative departure from normal precipitation, in inches. for the period of time involved. Table I presents the
precipitation. temperature, and warm-season evaporation. In Table 11 are
given volume weighU of the ground leaf material, hydrogen-ion concentration expressed as pH, total nitrogen, crude ash, and eight ash constituents.
All determinations were made according to recognized methods and all results are averages of at least triplicate determinations. The data for the
first eleven trees shown in Table 11 are those for the hand-picked leaves.
Table III shows the yearly distribution, or arrangement, of the various
kinds of leaves accordingly as they were highest or lowest in the several
elements during the different years.
DISCUSSION OF METEOROLOGICAL DATA
As seen in Fig. 1, after several previous low-moisture seasons, there
was a sharp gain in precipitation from the beginning of 1938 until midsummer that year. Then began an Irregular drop that lasted until near
the end of 1940. At this time, and continuing through 1942, there was an
extremely large gain in moisture. Ground-water levels during the years
followed, quite comparably, the trends tor precipitation. The net gains for
moisture In 1941 and 1942 were large.
Corresponding with the gain in moisture there was a definite decrease
in temperature tor the period. This is related to the decrease In evaporation from 1939 through 1942. It Is possible that air movement is as great
a factor in evaporation as temperature. Although complete data on wind
mileage is not available and is not here presented, there was a very noUcea.ble let-up in wind movement during the last few years.
During the period of the present work a complementary study of drainage water from the soil was made by use of lysimeters. From a battery of
forty-eight of these the leachings of meteorological water through four
fallow-soU cores were measured and averaged, and samples analyzed. The
soil in these lysimeters, fine sandy loam in texture, consisted of undisturbed,
natural, cylindrical cores, two and one-halt by tour and one-half teet In
dimensions, and weighed nearly two tons each. The average amount of
leachate through each core for the years 1938 through 1942 was respectively
20, 16, 134, 274, and 287 liters. The concentration of total bases In the drainage water was fairly constant regardless of the total amount of leaching:
thus, the more leaching the more bases lost. Nitrates seemed to form to
the greatest extent during the fall and winter. Llxiviatlng rains early In
the spring cause the nitrates to pour out in the drainage water particularly
from fallow soils. All of these conditions seem to be closely related to
local and general weather patterns and these, in turn, appear to be closely
related to crop yields (Bean 1942).
Conditions causing the loss of nitrates were quite noticeable during
the present study. Nitrate formation was especially favored In FebruarY
and March. 1938, but the following rainy May caused severe nitrate 101&e8
and tree leaves were yellowlsh-colored until late Bummer. The only drain-
83
PROCEEDINGS OJ' THE OKLAHOMA
FIGURE L
1'$9
1938
1M!
1NO
1M2
-'11, 1, 2, S, ., 7, 11, 15, .ad 17
_t.r 1.....1 aboy. a.1UIIed datu
.~.
~
11
10
9
8
'1
f
+.
-.
O\D.llath'. departure tJ'Oll anne.
preo1pltatiOD dnoe Jan. 19U
~
0
-8
-12
-1e
-20
-u
-28
-S2
11_ own_a)" ot
lna
lUt
Mr. E. W. B.eees
_ v.S.O.s.
1941
1M2
1 Volaae wellbt wu detenlllDed b1 w~ the erouod leaf IIl&terl&l III & four-ounce
h1rtJaDD offtclal welabt-per-buahel uaID tester and comp&l'lq thIa welabt with the wellht
wbk!Ia the ecale bucket eouId hold. Kaeh Tolume weicht MOwn Is the &Tenp of
01
wa.
ft"MPUa&e~
+0.8
+1.3
-0.6
-0.4
-0.5
Jan.
-6.0
+3.8
+5.9
-13.4
+4.7
+1.3
1937
1938
1939
1940
1941
1942
Year
1937
1938
1939
1940
1941
1942
°
Jan.
Year
+0.7
+5.4
-2.1
-t-O. 4
+0.6
+2.2
-1.3
-t-1.2
-1.0
-3.7
+2.6
-3.8
-1.0
-0.4
-0.9
-t-2.1
+0.3
+7.3
-0.1
+0.5
+1.5
+0.6
+0.7
-t-5.6
June
-0.8
-0.2
-1.2
-0.3
-1.6
-1.5
July
+0.2
-0.9
-0.3
+2.5
-0.4
+6.1
Aug.
+0.1
-1.3
-2.8
-2.5
+1.5
+1.1
Sept.
-t-O.6
-0.9
-0.5
--4.0
-t-7.2
+3.2
+1.6
-4.1
+2.2
-0.4
-2.4
-1.2
-2.0
+9.2
+0.8
-_.
+2.6
+0.5
+2.7
-0.2
+3.4
-t-O.6
°
+1.3
-0.2
-t-1.4
-1.4
-2.6
+2.4
+0.5
+2.5
-0.8
+0.7
+0.5
May
June
July
---_._-_._._._-----
-t-3.6
+2.9
+0.7
-3.3
+1.0
-1.6
Aug.
+0.3
-t-1.3
+5.7
-2.0
+1.4
-2.2
Sept.
-0.6
+6.5
+4.1
+6.1
-t-4.1
+0.7
Oct.
61.7
--
Total
1937
7.2
6.7
9.1
12.8
13.6
6.8
6.6
April
May
June
July
August
September
OCtober
Month
60.3
--
5.5
6.8
8.0
12.4
13.1
7.4
7.1
1938
68.4
--
6.4
8.1
8.8
13.1
11.8
11.9
8.3
1939
65.0
--
7.2
8.2
8.3
10.7
7.7
6.5
6."
1940
Nov.
Dec.
1942
-2.9
-1.1
-1.1
-3.0
+1.6
+3.9
Nov.
45.5
--
"3."
--
"-8
7.7
7.9
8.0
6.8
6.1
3.1
-4.0
+0.8
--6.9
-1.8
+9.9
+11.4
Net
tor year
-1.3
-3.3
-t- 2.1 +27.0
-t-5.3 +27.8
+4.7 -11.3
+6.7 +18.3
+2.6 +14.4
Dec.
-0.1
-1.0
-0.6
-1.0
-0.2
-0.8
Net
tor year
aeuOD
~~
Net lur
_--~-
-3.4
-1.3
--6.1
--6.6
-t-10.6
+12.3
Net for
srowing
HUon
°
+6.7
-t-"."
+6.2
+16.8
+20.0
----
-_ ..- - - - - - _..
-0.4
+0.2
-0.6
-t-2.7
-0.9
-1.7
------_.-
4.7
6.7
6.4
9.9
8.6
7.1
3.1
1941
Warm seaBOn evaporation-free water surface-inches
+1.8
+4.2
°
Apr.
Oct.
-_.----------,-
Temperature departure from normal--degrees F
May
Allr.
Precipitation---41eparture from normal-inches
Mar.
0
+2.0
-0.4
-2.1
-1.6
-1.5
-1.0
+3.1
+0.3
+2.4
+0.7
+0.3
Feb.
Mar.
Feb.
TABLE I
Weath,-,' data
=
t
~
...
~
t!'!J
C':l
~
...rt5
~
0
I
1938
1939
194()
1941
1942
1938
1939
1940
1941
1942
1938
1939
1940
1941
1942
1942
No.2,
5.0
5.1
5.3
5.0
5.0
m4Xima
Quercus
borealis
Northern
red oak,
Quercw
palwtris
.')1,7
.255
.240
.250
.270
0.88
1.19
0.85
0.74
0.66
6.11
5.17
5.02
5.35
7.20
1.25
1.80
1.28
0.99
0.95
5.0
5.0
4.9
4.5
4.9
.258
.255
.252
.260
.2M
Pin oak
No. 2,
6.02
5.69
5.05
5.55
7.10
1.05
1.38
1.01
0.86
0.79
6.~
5.85
5.70
5.56
5.75
16.00
18.40
5.0
4.9
4.8
4.7
4.8
n.n
15.65
14.76
14.30
12.90
11.96
14.80
17.60
%
ash
Crude
1.85
2.16
1.78
1.37
1.27
2.05
2.13
2.02
1.23
1.12
'lot.
N. %
5.6
5.7
5.3
6.5
6.5
.250
.252
.263
.255
.257
.238
.236
.212
.196
.226
5.8
5.9
5.5
6.7
7.1
pH
Quercw
palustris
Pin oak
No.1,
glabra
TitUs
Ba&8wood
1938
.220
.189
1939
1940
1941
1!H2
.215
Tiilu,
No.1,
1939
1940
1941
.230
.228
Vol.
wt.
glabra
Baa.wood
1938
Tree
lpeclea
Year
0.69
0.67
0.65
0.66
0.74
0.37
0.30
0.43
0.52
0.60
0.41
0.37
0.54
0.49
0.60
1.97
1.88
2.05
2.22
2.28
1.88
1.62
1.47
1.90
2.07
%
SIO,
0.05
0.05
0.09
0.06
0.05
0.06
0.03
0.05
0.05
0.07
0.10
0.05
0.09
0.05
0.05
0.09
0.07
0.09
0.07
0.07
0.09
0.07
0.08
0.09
0.09
%
1"810,
le(Jf)~f)en-drJI
TABLE II
Compo8ition of
0.20
0.11
0.33
0.15
0.18
0.21
0.22
0.12
0.09
0.19
0.16
0.18
0.20
0.10
0.16
0.19
0.12
0.24
0.23
0.19
0.21
0.16
0.16
0.17
0.11
%
AhO.
ba.ri.t
1.98
1.61
1.26
1.57
1.90
1.30
1.95
2.20
0.51
0.55
0.50
0.65
0.61
0.75
0.78
0.74
0.85
0.79
1.83
1.42
0.77
0.70
0.54
0.80
0.69
1.33
1.07
1.31
1.26
1.35
1.24
1.14
1.32
1.35
1.49
MIO
%
1.74
1.62
1.31
1.90
2.03
5.41
4.75
4.55
5.00
6.60
4.90
4.18
3.56
5.00
6.05
%
CaO
0.07
0.07
0.08
0.10
0.09
0.08
0.10
0.12
0.14
0.12
0.16
0.16
0.18
0.22
0.2n
0.05
0.04
O.M
0.03
0.03
0-02
0.02
0.02
0.03
0.03
%
Ku,O.
0.18
0.35
0.13
0.140.16
0.20
0.24
0.13
0.10
0.19
0.22
0.27
0.140.15
0.28
0.29
0.35
0.26
0.28
0.38
0.25
0.30
0.28
0.17
0.25
%
P,O,
%
1.11
1.28
0.81
1.15
0.95
0.72
0.70
0.43
0.59
0.55
0.64
0.68
0.47
0.66
0.60
1.05
1.00
0.60
0.87
0.78
1.10
1.16
0.90
1.24
0.98
KIO
~
~
~
0
~
~
0
m
Q
Z.
t:1
I
:
Tree
5.1
5.1
5.2
6.0
6.9
.401
4.7
4.8
5.0
4.9
5.0
.319
.316
.315
.264.333
.347
.320
.337
.351
.368
1938
1939
1940
1941
1942
1938
1939
1940
1941
1942
6.0
6.1
6.2
6.9
6.3
.387
Carra
illinoensi.s
Pecan,
Brouuonetia
papyri/era
Paper mw·
berry,
alba
Monu
While mul·
beay,
6.0
6.1
6.6
6.1
6.3
.335
.341
.374
.349
5.5
5.5
5.5
6.3
5.8
pH
2!J1
.319
.351
.2Zl
.323
wt•
Vol.
.351
.340
.M2
.341
Maclura
pomijera
Hedgeapple
(Oaage orange),
pumila
Asiatic
elm,
UlmlU
• peel.
1938
1939
1940
194-1
1942
1938
1939
1940
1941
1942
1939
1940
1941
1942
1938
Year
0.02
0.07
0.09
0.14
0.05
0.09
0.16
0.13
0.23
0.11
0.06
0.05
0.09
0.10
0.05
7.85
9.20
10.10
11.90
11.98
3.15
7.20
8.55
9.15
8.92
1.43
1.91
1.42
1.30
1.37
19.21
21.02
23.4421.50
22.85
16.30
20.43
22.25
22.45
22.62
9.60
7.69
8.70
9.80
10.58
0.90
1.09
0.95
1.68
1.39
2.11
1.35
1.01
1.62
0.92
0.85
1.03
1.51
1.50
1.48
0.05
0.05
0.09
0.05
0.<11
2.45
2.57
2.61
2.95
3.99
16.97
16.50
16.17
16.61
23.48
0.92
1.23
0.95
1.63
1.19
0.11
0.05
0.09
0.18
0.06
%
FezO,
8.10
8.33
7.67
9.10
8.95
%
810z
15.75
16.25
16.20
16.3418.25
%
am
leave.~ven-d,."
0.85
1.16
1.20
1.27
1.25
Tot.
N. %
Crude
CompoBltion 01
TABLE II
(continued)
0.27
0.09
0.15
0.10
0.35
0.10
0.13
0.15
0.14
0.30
0.26
0.58
0.84
0.50
0.45
0.84
0.58
0.40
0.44
0.72
0.30
0.21
0.09
0.21
0.24
AbO,
%
bari8
2.49
1.88
2.15
2.72
2.75
4.32
5.50
5.40
6.20
5.85
5.10
5.15
4.85
4.60
4.42
5.545.62
5.77
5.66
6.94
2.86
2.95
2.47
3.18
3.03
%
CaO
0.93
1.12
0.73
1.07
0.98
1.12
1.43
1.55
1.541.27
0.88
0.80
0.82
0.87
0.67
0.68
0.75
0.81
1.31
0.89
0.68
0.80
0.74
0.90
0.91
MIlO
%
0.12
0.10
0.09
0.10
0.11
0.01
0.02
0.01
0.03
0.02
0.03
0.02
0.01
0.02
0.02
0.02
0.02
0.01
0.02
0.03
0.02
0.01
0.01
0.02
0.01
Kn,O.
%
0.33
0.23
0.25
0.35
0.35
0.41
0.29
0.20
0.32
0.30
0.28
0.37
0.69
0.50
0.51
0.26
0.405
0.40
0.49
0.61
0.31
0.35
0.37
0.25
0.32
%
PzO,
"
0.80
0.69
0.71
0.90
0.71
1.37
1.31
1.51
1.65
2.96
2.68
1.62
2.67
1.90
1.48
0.96
1.15
1.03
1.04
2.10
1.02
1.10
2.03
2.36
2.M
LO
j
S'0
'Ill
0
m
~
I
~
.-•
Tree
.197
.219
.227
.223
FTUlCrocarptZ
Loblolly
taeda
1941
1942
1938
1939
1940
1941
1M2
.336
.337
poplar,
Pop~
tleltoida
1940
1941
194.2
.325
.337
.335
Carolina
.24S
.322
.290
2n
1938
1939
Pinus
pin~
Quercus
1940
0.65
0.82
0.62
1.04
0.95
5.0
5.1
5.2
5.1
5.1
1.28
1.40
1.041.13
0.99
2.30
2.90
2.38
3.61.
4.07
4..71
5.83
5.44
15.95
16.30
16.59
11.90
12.16
2.30
5.02
3.03
3.29
2.50
0.97
1.15
3.03
3.02
2.64
8.50
9.20
9.65
0.05
0.10
0.05
O.al
0.14
0.10
0.07
0.14
0.07
0.11
0.03
0.05
0.09
0.05
0.05
7.6IJ
9.84
3.35
1.56
1.6IJ
1.75
1.70
0.05
0.12
0.07
0.04
0.05
%
FezO,
0.03
0.05
0.05
0.03
0.05
0.47
0.50
0.66
0.26
0.43
%
810z
0.28
0.11
0.05
O.2D
0.33
0.18
0.22
0.06
0.29
0.09
0.19
0.29
0.28
0.34
0.14
0.12
0.09
0.140.12
0.15
0.22
0.20
0.21
0.08
0.11
AlzO,
%
leaves-oven-drll basis
0.45
0.38
0.44
0.30
0.59
10.15
8.47
7.36
7.70
10.50
2.85
3.2h
0.58
0.75
0.6IJ
0.72
0.47
5.0
5.1
5.1
5.1
5.1
.337
.253
Burr oak
(Mossy-cup oak).
Albizzia
juLibrissin
10.50
9.71
9.52
10.20
9.65
0/0
Crude
ash
01
1.45
1.90
1.52
1.50
1.50
0/0
Tot.
N.
4.3
4..4
4.5
4.4
4.5
5.5
5.4
5.2
5.2
5.6
.335
.326
.323
.291
.317
.286
.293
.291
Mimosa,
.307
Robinea
p.seudo.
acacia
5.0
5.1
5.4
5.4
5.4
pH
.314-
Vol.
wt.
Black
locust,
species
1938
1939
1938
1939
1940
1941
1942
1938
1939
1940
1941
1942
Year
Composition
TABLE II
(continued)
4..15
3.70
3.86
3.2h
2.59
0.58
0.63
0.53
0.61
0.66
1.80
1.95
2.10
2.00
2.68
3.11
2.91
2.06
2.70
2.97
3.61
2.70
3.24
3.72
3.10
%
CaO
0.92
1.20
1.32
1.05
0.81
0.24
0.27
0.29
0.32
0.30
0.63
0.86
0.89
1.02
0.82
0.55
0.68
0.32
0.58
0.45
0.81
0.75
0.80
1.02
0.70
MiO
%
0.03
0.02
0.03
0.01
0.02
0.02
0.01
0.01
0.01
0.02
0.07
0.05
0.10
0.05
0.07
0.01
0.01
0.01
0.01
0.01
0.01
0.02
0.02
0.01
0.01
%
Mna04
0.21
• 0.2D
0.13
0.16
0.13
0.07
0.09
0.09
O.M
0.17
0.23
0.21
0.18
0.20
0.21
0.37
0.36
0.35
0.25
0.30
0.26
0.17
0.18
0.14-
0.2D
%
PzO.
1.96
1.56
3.80
1.55
1.45
0.45
0.33
0.21
0.28
0.29
1.18
0.66
0.80
0.87
0.54
1.79
1.42
1.51
1.10
1.72
1.23
1.55
1.50
0.76
1.15
%
KzO
=
Ca1
~
:!
...
::
~
c
~
t-I
~
~
0
!
%
1.28
0.97
1.05
1.19
1.09
1.07
1.03
4.5
4.6
5.4
5.0
5.1
.330
.300
.3401
.332
.411
occidentali,
Apricot,
PrU1SlU
annenUzcQ
1938
1939
19400
19401
1942
19401
19412
.230
.243
.zJ.7
.239
Plattmus
1940
2.12
2.10
0.97
0.65
0.62
. 0.76
0.60
0.32
10.22
9.96
11.45
10.05
9.30
TABLE III
1.49
1.30
%
810.
9.82
10.70
11.28
10.20
8.01
%
Crude
uh
0.06
0.13
0.25
0.09
0.06
0.05
0.07
0.05
0.05
O.~
%
1'0.0.
0.26
0.14
0.340
0.32
0.12
0.15
0.09
0.06
0.10
0.15
%
AltOs
0.84
0.76
0.88
0.62
0.57
1.66
1.52
2.02
2.18
1.40
0.63
0.75
0.52
0.66
0.65
T
3.29
2.50
2.37
2.60
2.15
%
e.0
0.02
0.01
0.02
0.02
0.02
0.03
0.02
0.02
0.01
0.01
%
IIIb04
Year
1938
1939
1940
19401
19402
1
15
4
2
High
10
1
2
4
5
Low
Ash
2
2
4
2
12
High
4
8
3
3
4
Low
Stllell
2
14
1
5
14
6
2
Tot. N.
High
Low
4
13
5
4
4
4
10
Calcium
High
Low
2
3
5
9
3
7
6
3
6
Magnesium
High
Low
5
7
2
1
7
2
7
3
1
9
PhOllphorus
High
Low
12
3
3
4
2
5
11
1
3
Potaaaium
Low
Hlah
DutnbuUon 01 trees with regartJ to highest ana lowest content 01 the vanou leaf element, for the at1!erent 'Vears. For example, fifteen trees had their highest ash content ."
1942 while ten haa thetr lowest in 1940.
1.()6
0.87
1.14
5.0
5.1
5.3
5.5
5.0
.243
'~
Sycamore,
Tot.
N. %
1938
1939
pH
Tree
Year
Vol.
wt.
TABLE II
(continued)
OomporiUon of leavu-oven-d,.., 00ria
%
3.00
4.17
8.40
0.51
0.72
3.52
3.63
0.940 .
1.69
1.67
1.52
8.14
E.O
0.36
0.52
0.44
0.23
0.24
0.19
0.30
0.25
%
PIO.
!
~
i
~
~
I
=
ACADEMY OF SCIENCE FOR 19"
age that oecuned In 1938 took place during that month.
Favorable rains,
whieh did not cause leaching, then caused strong accumulation of nitrates
for the season of 1939 and the foliage that year had an extremely blackilhgreen color. Nearly all the leaves had their highest nitrogen contents In
1939. From then on. rains, whieh caused leaching Just at the nitrateforming periods, caused a eumulative decrease of this nutrient and foliage
beeame continually more yellowish untll, all during 1942, xanthophyll al·
most dominated chlorophyll In coloration effect.
DISCUSSION OF ANALYTICAL DATA-TABLE II
Vol.me weight. The figures for this determination tended, somewhat
inconsistently, to Increase with larger ash content. Probably the most outstanding discrepancies in this connection occurred in the eases of the apricot, sycamore, black loeust, and loblolly pine in the fall of 1942. The leaves
of these trees fell three weeks earlier than the others that year and their
ash weights are lower and their volume weights are higher than for the
preceding year. It has been found that volume weight, or apparent apecitic
gravity, of ground leaf material is as highly correlated with the physical
nature of the leaf as with its ash content. Early-fa111ng, greenish-colored
leaves, when finely ground give a more flaky and leBS fibrous product
than ground ripe leaves--the latter being quite "nutty" in comparison, thus
occupying a larger volume per unit of weight.
Aciditt/. The hydrogen-ion concentration tended, somewhat inconslst·
ently, to decrease (increase in pH) with larger ash content. It ia Quite
generally presumed that the more total bases a plant material contains
the lower is its resulting acidity. However. substantial data in another
connection, not herewith presented, show that some tree leaves with high
base content have strong acidities; conversely, some leaves with low base
content show comparatively weak acidities. It seems certain that this
feature is not necessarily a base-content characteristic; instead, it leems
to be more closely related to anion hook·up. Anion contents vary as greatly
as and more diversely than those of cations.
Total nitrogen. The data show a gradual but general decrease In
nitrogen contents since 1939. This is especially true for the hand·picked
samples. The explanation of this seems to be the continual lOBS of nitrates
in drainage waters since that year. In the field ot horticulture it is known
that, for vegetable crops, at least, the more nitrogen plant tissue contains,
the less mineral matter and fiber it contains, relatively. The same thing
seems to be true for tree leaves, as the ash and mineral figures indicate
herein.
Of all the trees studied, two-thirds contained their highest nitrogen
values in 1939; the other third was scattered somewhat unequally through
the other seasons. In 1942, two-thirds of the trees had their lowest nitrogen
contents, the rest having theirs mainly in 1938 (see Table III). It has already been mentioned that 1939 was the year most favorable to nitrate
accumulation.
Orv.de ash. With few exceptions, the ash contents of the leaves were
on a downgrade from 1938 through 1940. From that time onward there
was an almost exaggerated increase in this material. This variation seems
to be directly correlated with moisture conditions. The precipitation curve
(cumulative departure from normal) In Fig. 1 shows the moisture drop
from 1938 through 1940 with the 8ubsequent 81m greater rise from then
through 1942. A curve for the ash contents would appear much the eame.
There eeems to be lOme doubt as to whether mineral uptake by trees
fa comparable to that by small plante sa shown by foliar analylis. It 18
P«l8aible that the feeding propensities of the latter may differ from tho8e
of th~ fonner owing to the seeming disparity in the natures of their ra-
10
PROCEEDINGS 01' THE OKLAHOMA
IJ)eCtlve root BJ'ltema. It II quite generally known that lmall plants, such
.. grauee. have shalJow root systems but it is not generally recognized
that, in comparison with lize, the feeding zone of tree roots il mostly
Quite .hallow.
It may be expedient to mention here that ash analyses are often mieunderltood and consequently misinterpreted. That fs, attempts are otten
made to compare the sum of the bases determined with the amount of ash
obtained. A balance between the two Is seldom obtainable and wide diecrepancles are common. This is due to several reasons. If ashing is done
carefully at a low temperature, in order to prevent volatllization of some
of the constituents, some carbon Is always left unburned)! The amounts
of such residue may be as high as 15 or 20 percent of the total ash, depending on the proportion of certain mineral elements present-particularly
soda. potasli, and smca. Further, seldom are any but the so-called most
Important elements determined; anions in particular are unaccounted for.
Other undetermined items, including titanium and the rare earths, may
often amount to as much as five percent of the total ash. In addition,
the ash consists mostly of a mixture of oxides and carbonates which, with
Intcatea and unknown acid radicals, does not permit close calculation. In
the present work the ash is, in every instance, saturated with carbon
dioxide but contains indefinite amounts ot unburned carbon. No determinations of uncommon elements were made.
Bilka. In general, this material seems to correspond directly to the
amount of ash present. Twelve trees had their highest sllica contents in
1942, the other highest ones being distributed fairly uniformly throughout
the years. The largest number of trees had their lowest silica contents in
1939. This, it Is remembered, is the year in which available nitrogen was
present in greatest amounts. Further, as already mentioned, ash constitu·
ents (particularly silica) diminish as succulence increases.
Oalclum. This element Is present even more nearly proportional to
ash than Is slUca; It generally constitutes about one-third of the ash con·
tent. Thirteen of the trees had their highest lime content in 1942, the
rest being nearly equally divided between 1938 and 1941. Ten trees had
their lowest contents in 1940, the others being equally divided between 1938.
1939, and 1942.
Calcium is an element the avaUabillty of which is generally believed
to be closely related-{)ther things being equal-to the presence of hydrogen
fons in the soil. Further, it fs commonly believed that an Increase in
BOll moisture generally results in an increase in pH, or a decrease in
acldlty. In the beginning of the present study the acidity ot all soils involved ranged between pH 6.2 and 6.5. At the close no significant changes
fn this respect could be detected. A slight callche concentration underlies
this entire area at varying depths of several teet but in no instance was
it observed to be in close contact with the feeding-root zones of the trees
involved.
Complete agreement does not exist among workers regarding the relationship of the mineral uptake by plants to the kind of season they l1nder·
go. Other data trom this statton indicate that, for cereals and grasses,
phosphorus and potassium are taken up more abundantly by plants in wet
years (Murphy and Danfel 1936 and Daniel.and Harper 1936). On the
other hand, calcium is taken up to a greater extent in drier years. The
present data, tor trees, seem not to agree entirely with this. The difference
In depths of root lones Is a probable explanation.
Mopelf,.,n and pAo.tpAortU. It fs difficult to deduce any clear-cut
reason for the various distributions of these elements in the different years.
• 'l'bIa amounl He" to be eoutaJlt for the aame aample of matertal. With full aeeeto alr, UIq lUIle \elDlMratul'e and tlIIle for lpltlOD, aoocl cbecb are replarly obt&lJled.
ACADEMY 011' SCIENCE FOR 19U
It is possible that some unobserved or undetected factor. or factors, is responsible for the seeming diversities in use of these elements by the trees.
This is possibly true to a somewhat lesser extent for some of the other
elements also. Further, it is true that sUght increases or decreases In elemental amounts, in some instances, would have shifted the distribution
standings.
Potassium. Slightly more than half of the trees contained their highest
amounts of this element in 1938 and exactly half of them contained their
lowest amounts in 1940. For tlle latter, this Is in agreement with the idea
of little potassium in dry years but not a single tree contained its highest
potassium content in 1942. A possible explanation for this seeming im.
passe might be that, in the soils involved, potassium does not rapidly be-.
come available, particularly in dry seasons. The year of 1936 was quite
dry; 1937 was somewhat more favorable In this respect. Then, in the early
part of 1938, the weather was abnormally warm and plenty of moisture was
received. Owing to this combination of favorable circumstances and to
the probable small take-up of potassium during the immediately preceding
years, a larger-than-ordinary amount of this element may have been avallable.
Of all the elements given in the analysis, iron and aluminum seem to
show the least relationship to possible weather influences. Manganese is
only slightly more clear in this connection. Such characteristics as high
ash for hackberry, low ash for pine, and high manganese content for pin
oak, etc., are species peculiarities and do not come within the purview ot
this study.
A further study of the chemical data shows a seemingly greater con·
sistency and agreement of elemental uptake with weather conditions tor
the hand-picked leaves than for the nonpicked leaves.s The probable explanation of this is connected with the growth of succulent foliage, or
water-sprout leaves. It was noticed that the formation of such leaves occurred each year and varied greatly in amount from tree to tree and from
season to season. This condition seems to occur mainly in the top halt ot
trees and may be restricted to a few limbs or be scattered irregularly
over many limbs and branches. These succulent leaves were always higher
in nitrogen and lower in ash than the normal leaves.. It is here believed
that the tendency toward water-sprout formation on trees Is greater in
subhumid than in humid areas.
The question of differences in ash content of leaves from the bottom,
middle, or top part of the tree may be apropos here. European studies tn
this connection are mostly of old vintage (Fliche and Grandeau 1876,
Schroeder 1878, and WolU 1880) and give confiictfng results. Serex (1917)
in the United States, believed that this unproved phenomenon was a species
proprium; some of the trees in his study were higher in ash in top leave.
and lower in the bottom leaves while other trees were the reverse. However, his data is not extensive enough to be significant. In the present
work an attempt was made to answer this question. It was found that
variations occurred in a few instances but were entirely inconsistent from
tree to tree and year to year. As already mentioned, the prevalence of
water-sprout leaves seemed to offer the most plausible explanation of these
inconsistencies.
In connection with leaf analysts, in general, it bas been noticed that
the nitrogen content of various tree species growing west of the 95th meridian Is significantly higher than for the same species growing east ot this
• The seemtnc irregularities In the chemical contenLl of the .1lppel'1 and Aalatte tlJIl
leues In 1942 may possibly be partly due to the fact that the bottom limbe were pruned
~ these trees durlng the sUDlJIIer aDd the leaf nmpJes were conaequently taken from
_er up than before.
1.
Jill..
PBOCDDINGS OJ' THE OKLAHOMA
The l&IDe appean to be true, aJ8o, for calcium bat lees cons1etently
10 (PUce. JlS).
The IUmmer of 1943 was different from other sammers involved in the
.tudy In that, whUe it was droughty enough to injure pastures and crops
b841y, .afficient molature from 1942 remained In the subsurface and subIOU to permit the trees to grow luurlantly all season. Consequently. leaf
I&lIlple. from all the trees were collected again in the fall of 1943 and
wUJ be analyzed as betore. Increment borings in the trees will also be
taken to ascertain whether there is any correlation between annual increment of wood and the chemical content of the leaves.
Note. Since completion of the above material an article was uncovered
in an old German publication (Stahl-Schroeder 1904) in which the follow·
ing interesting data are given. In one experiment with oats, using potted
.oill with moisture content increasing gradually trom 36 up to 96 percent
ot thefr water-holding capacity, It was found that as the moisture content
of the soU Increased there was a continuous increase In the ash, stlica, and
pholphorus content ot the oat grain. At the same time there was a conltant decrease in total nitrogen, reaching a minimum at 90 percent. At
this point, however, nitrogen began to increase and continued to do so up
to 95 percent ot the water-holding capacity ot the soU.
SUMMARY
In an ettort to study mineral uptake by plants so' that climate would
be the only (or main) variant, analyses were made of tresh mature leaves
ot twenty-two trees ot twenty species tor tive successive years. From half
of the trees the leaves were picked trom approximately the bottom quarter
of the trees as they were just ready to abscise; trom the others the leaves
were collected as they tell. Weather and other data taken consisted of precipitation, evaporation, temperature, water table levels, and drainage from
natural sol1 lysimeters.
In the early spring of 1938, after several years of droughty weather,
heavy rains put soil moisture to a temporary high level. Decreased precipitation then reduced soil moisture until late 'in 1940. Then began greater
than average rainfall and soil moisture rose to the highest levels ever
measured In the SUllwater Creek basin.
Chemical analyses ot the leaves show that mineral uptake seems to
follow trends of solI moisture. With few exceptions, the ash materials,
particularly slUca and calcium, decreased from 1938 through 1940 and
gradUally increased to new high levels trom then through 1942. Total
nitrogen Increased with decreasing soU moisture and vice versa; vegetation In general was quite yellowish in color all during the summer of 1942.
Magnesium and manganese varied somewhat irregularly and iron and alumInum entirely 10. Acidity decreased somewhat irregularly with increasing
1011 moisture. Volume weight Increased irregulat'IY with increasing ash
content. Moat trees had their highest potash content in 1938 and their
lowest in 1940.
LITERATURE CITED
Bean. L. H. 1942. Crop yields and weather. Misc. Publ. U. S. Dept. Agric.
471.
Daniel, H. A., and H. J. Harper. 1936. The relation between total calcium
and phosphorus in alfalfa and prairie hay. J. Am. Soc. Agron. %1:
6....62.
I'Uche, P., and L. Grandeaa. 1876. Recherches eh1mIQues
tion des teulUes d'age et d'ee~ dltterenta.
Ann. Chim. et Phya.. Ser. G. 11 :261-309.
III1ll'
1& composi-
ACADJDIY OF SCIENCE FOR 19t1
Murphy, H. F., and H. A. Daniel. 1936. The composition ot BOme ot the
Great Plains gra8888 and the tnfiuence of rainfall on plant composition. Proe.' Okla. Acad. Be. 26: 87..0.
PlIce. M. J. MS. Unpublished data.
Schroeder, J. 1878. Forstchemiache und pfianzenphystologlache Untersuchungen. Dresden.
Serex. P. 1917. The plant food materials in the leaves of forest tree,.
J. Am. Chem. Soc. 39: 1286-1296.
Stahl-Schroeder, M. 1904. Kann die Pflanzenanalyse uns AufschluS8 ueber
den Gehalt an assimllierbaren Naehrstoffen im Boden geben?
J. Landw. 52: 31-96.
Woltt, E.
1880.
Producten.
Aschen-Analysen von land- und forstwirthschattlichen
Berlin.