Dry-Matter Production In Immature
Balsam Fir Stands: Roots, Lesser
Vegetation, and Total Stand
BY
G. L. BASKERVILLE
Abstract. Data are presented on the dry weight per acre of tree roots and lesser vegetacian in stands oE 700, 1000, 1500,2000,3000 and 5000 stems per acre. The dry weightoftree
roots, above-ground tree stand, and total tree stand all inerease with increasing stand
density. The weight cf lesser vegetation decreases with increasing stand density, but is
insigniñcant in proportion to the whole stand.
IN 1962 a study of dry-matter production
was intiated in 40- to 50-year-old balsam
For detailed stand descriptions see
Baskerville 1965.' (See footnote 2, p. 52.)
fir stands in northwestern New' Brunswick. 1 ts aim was to estimate total stand-
Methods
ing erap and increment in six natural
stands of 700, 1000, 1500, 2000, 3000 and
5000 stems per acre. Dat'" on standing
crop and increment of the above-ground
portian oE the tree stand.c-are presented in
Baskerville 1965.' Tl:!,& present paper
reparts on tree roots and the vegetation
of the forest floor. Summaries of data for
the above-ground tree stand and for the
total stand are also presen ted.
The stands are dense mixtures of tir,
spruce and birch in the proportions .88,
.03, and .09. Such stands are common in
the area'4having developed {rom a advan ce gr6wth (about one foot in height)
that was released in 1913-19 by spruce
budworm destruction of overmature softwoods. The age from release is 43 years.
The average heights and diameters are
as follows:
No. stems
1Jer acre
Ave. ht.
(JI.)
700
1000
1500
2000
3000
36
32
31
32
32
27
5000
Ave. dbh
(in.)
5.6
4.8
4.4
4.4
3.8
3.2
Sampling was based on 18 plots, three
in each of the six densities. Plot size was
variable such that each plot contained
24 trees. For the study of above-ground
tree production, 140 trees were randomly
selected and analyzed in detail. Howevér,
for the study of roots it was impossible
to excavate the root systems oE these
randomly located trees. Instead all trees
were excavated on one plot in each
density.
On the plots to be exca vated aIl trees
were felled and the stumps tagged.
The surface litter was removed with a
tire hoe and the F and H layers were
removed with high water pressure directed
at a low angle. The mineral soil was
washed away using two hoses with high
volume and Iow pressure while a constant
lifting pressure was maintained with a
1 Baskerville, G. L.1965. Dry-matter production
in immature balsam fir stands. Forest Science
Monograph 9. 42pp.
The author is Research Officer, Dept. oE
Forestry oE Canada, Fredericton, N. B. Manuscript received Apr. 8, 1965.
vaZume 12, number 1,1966 /49
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large tripad and block and tackle. The
methad resulted in the lass af mast raats
less than 1/16-inch diameter. Excavatian
with these smaller roats intact proved
unfeasible. A total af 144 raat systems af
all species were raised. A number af these
were discarded because af damage in
excavation and others could nót be used
because they were invalved in grafted
unians. In the latter case it was usually
impassible ta determine haw much af the
total raat mass belanged ta each partner
oE the unían. Sorne 89 fir, two spruce,
seven birch and ane pin cherry singleunit raat systems, relatively free from
damage, were used in the present analysis.
These distributed by densities as fallaws:
1,'
'1
"
1
~
No.
01 roo! sys/cms
No. slcm! Balsam White
spruce
per acre
jir
700
1000
1500
2000
3000
5000
Total
White
bicrh
Pin
cherry
18
11
11
18
16
15
89
2
2
1
1
1
3
1
7
White birch:l ag lOW = .746 + 2.35 lag D
(n = 7, r = .96)
where W was the weight in paunds and
D was the diameter breast height in
inches. There was no systematic variatian af raat weight with density, hence
all values are cambined far each species.
The spruce data did nat permit calculation of a regression. Since the two values
for spruce were near the equation values
far lir the equation far lir has been used
far bath species.
To obtain per acre estimates of Qvendry raat weight the diameter af each tree
nat used in establishing the carrelation
was substituted in the abave equations.
This was done for the 18 plats by calculating the weight of each roat system and
, then summing far the plot.
Because the loss af rootIets resulted
in an underestimation of total root weight,
an attempt was made to estimate the
1
amaunt of these small raots. Two pits
each 2 X 2 feet,:"ere dug in each densi ty.
AlI material Frij¡n each pit was sifted and
the roots less '::han 1/16-inch in diameter
1
separated .. These roots were oven-dried,
and their 'tIry weigh ts expanded ta per
acre estimates.
The extracted raat systems were
washed and allawed ta dry far several
days. They were then weighed an either
a dynamometer or a butcher's heam de-
i~
pending an their size. Immediately after
weighing, samples including material
from the full range af sizes were cut from
each raat system and weighed in the
labaratary. The samples were aven-dried
far 24 haurs at 1050 C. and reweighed.
The aven-dry weight af each raat system
was estimated by multiplying the total
greeri weight by the ratio af oven dry /
green weight abtained far the carrespanding sample.
The aven-dry weight af the raat system was carrelated ta stem dbh as
fallaws:
,;'1
q
Balsam lir: lag 10W
I '1"
1[,
1
1~:I
'Ir
!,I,',
[1
1li!
,il'
,'I!'
Itil
50 / For ..t Science
=
+
.618
2.45 lag D
(n = 89, r = .96)
The weight of vegetation an the forest
Roor was estimated from six 3 x 3-foot
samples (2 from each af 3 plats) in each
density. A 3 x 3-foat frame was dropped
randaml y a-nd all vegeta tion inside the
frame was collected. Sample locatians
were rejected if they had been disturbed
by previous tree layer sampling. Vegetation fram each sample was sorted and
aven-dried far 24 hours at 1050 C. The
oven-dry weights were then expanded ta
per acre estimates.
Resu/t. ami Discussion
The total dry weight af lir root systems
increasedfram 11.9 tons at 700 stems per
acre to 19.5 tons at 5000 stems per acre
(Table 1). The proportians af spruce and
birch in the stands were variable across
TABLE 1. Dry weight
Tre.
700
Component
1000
of the tree stand by density
and free componen/o
Number of 800ms per acre
2000
3000
5000
700
1000
1500
(oven-dry tons per acre)
1500
2000
(percent)
3000
5000
Balsom Fir
Folinge
Branch wood
Branch bark
Canes
SOOm wood
Stem bark
Total aboye
ground
Root9
Total
7.07
7.07
7.49
4.26
3.19
.25
8.03
4.14
7.77
3.71
2.98
S.23
3.03
.20
43.02
12.8
S.O
5.7
.4
44.S
6.5
58,47
64.28
17.82
19.48
83.76
12.5
7.6
5.4
11.6
44.1
7.5
••
6.6
4.9
.4
45.5
5.7
11.0
5.7
4.4
.4
48.4
6.9
10.2
4.7
3.9
.4
49.7
7.5
9.S
4.5
3.5
.2
51.4
7.2
78.3
21.7
77.7
22.3
75.7
24.3
76.8
23.2
76.6
23.4
76.7
100
100
100
100
100
100
3.76
4.38
3.12
.25
24.63
3.65
4.27
3.06
.33
24.92
43.10
11.91
43.87
48.87
55.95
12.58
15.68
16.92
55.01
56.45
64.55
72.87
76,29
.55
.48
.32
. OS
).0'
.03
.0•
.02
.02
.04
.4.
2.48
.28
.25
.02
.22
.02
.31
4.22
1.31
.42
.12
.32
.09
5.53
.54
.41
.4.
.02
.05
.02
.08
.20
.05
.05
.l~
.0
.08
. 08
.03
.09
.14
.04
.11
.21
.00
3.7
11.1
3.7
3.8
9 .•
2.4
3.4
8.2
2.0
7.1
7.1
2.0
3.7
5.7
LO
4.3
8.2
2.3
.28
.04
1.14
.17
.81
.42
.12
1.64 ''V
.44 }
.54
4.22
29.36
4.31
3.18
.30
35.25
5.05
.2S
37,91
5.76
6.04
23.3
White Spruce
Foliage
Branch wood
Branch bark
Cones
Stem wood
Stem ba.rk
Total aboye
ground
Roo,"
Total
.42
.15
.12
11.9
14.8
8.7
5.8
7.4
5.5
9.8
4.9
4.'
8.7
5.5
4.3
16.3
.16
8.5
5.9
14.9
5.7
4.2
.04
1.67
.17
1.28
.16
44.8
5.1
46.3
3.7
53.5
4.9
67.4
8.7
61.8
6.3
45.4
.44
.02
2.67
.03
2.14
.68
76.3
23.7
77.S
22.2
7S.0
22.0
95.6
4.4
9S.S
1.2
75.9
24.1
2.70
2.S2
.03
.02
.23
100
100
100
100
100
5.7
100
White Birch
Foliage
Branch wood
Branch bark
Cones
Stem wood
8tem bark
Total aboye
ground
Roots
Total
.58
.10
1.43
.11
.12
.34
.19
1.56
.25
51.9
7.4
54.8
8.2
55.6
7.5
51.4
8.8
58.1
7.7
60.9
9.8
.87
.2.
I.S9
.57
2.19
.37
77.8
22.2
78.8
21.2
76.7
23.3
77.0
23.0
76.8
23.2
85.5
14.5
2.08
1.46
1.13
2.46
2.56
7.75
4.92
3.46
.25
27.39
3.97
7.23
4.51
3.14
.33
26.31
4.41
7.58
4.40
3.24
. 26
30.39
4.44
8.15
4.25
3.23
.30
36.14
5.19
8.30
4.14
3.18
.28
41.01
6.12
8.76
4.13
3.21
.20
45.S6
6.45
12.7
8.1
5.7
.4
44.S
6.5
47.74
13.34
45.93
13.14
50.31
l6.U
57.26
17.10
63.03
IS.42
68.61
20.53
78.2
21.S
61.0S
59.07
66.42
74.46
81.45
89.14
!"
100
100
100
100
100
100
All Spccics
Foliage
Branch wood
Branch bark
Cones
Btem wood
Btem bark
Total aboye.
ground ~f
Roots
Total
100
12.2
7.0
5.3
11.4
•••
44.5
7.5
••
4.9
.4
45.S
•. 7
77.8
22.2
75.S
24.2
100
100
]0.9
5.7
4.3
9.9
4.7
48.6
'7.0
10.2
5.1
'.9
.3
SO.4
7.5
.2
51.4
7.2
76.9
23.1
77.4
22.6
77.0
23.0
••
100
100
•••
100
the range of density, eonsequently there
is no definable trend in the root weights
of these species. When these two speeies
are included total weight of all tree roots
inereased from 17.3 tons per acre at 700
stems to 20.5 tons per acre at 5000 stems
per acre. Data for the above-ground portion of the tree stand are reprodueed in
Table 1 to indieate the proportion of the
tree stand eomprised of roots.
the smal! pits are as follows:
The oven-dry weights of roots less than
1/16-ineh in diameter as estimated from
Beeause of the smal! number of samples
and the high variability, no trend 18
No. slems
per acre
Sample 1
700
1000
1500
2000
3000
5000
2.19
1.95
5.76
1.86
1. 74
3.63
Tons per acre
Sample 2 Áverage
1.67
2.11
.89
1.65
5.21
1.63
1.93
2.03
3.32
1. 75
3.48
2.63
volume 12, number 1, 1966 /51
.""
TdBLE 2. Dry weight o/lesser vegetation by density (stems per acre) and genus.
700
Species
1000
1500
2000
3000
5000
o.d. weight lbs./ ac.
Ahies (seedlings)
Oxalis
Coptis
Dryopteris
;~ Lycopodium
Callierognella
.8
3.6
65.2
343.3
Dicranum
96.7
27.7
2.1
Polytrichum
Hylocomium
567.8
Total
.2
1.4
.6
1.4
.3
2.7
.9
.2
.8
13.5
1.4
.6
83.2
.9
9.7
69.8
.2
.6
29.2
181. 6
2.2
19.3
103.6
.1
1.9
525.0
127.1
87.2
96.5
225.0
32.8
117.1
.1
401.2
11.7
ti
TdBLE 3. Dry weight
and vegetation layer.
of total standing crop
Species
700
(including roots) by density (stems per acre)
1000
1500
2000
3000
5000
72.87
.46
1.13
74.46
76.29
2.70
2.46
81.45
83.76
2.82
2.56
89.14
o.d. weight /ons/ac.
Tree layer
Balsam fir
Whi te spruce
White birch
AH species
Shrub layer
Forest floor
Total
1
l
.54
61.08
56.45
.54
2.08
59.07
64.55
.41
1.46
66.42
.28
.26
.06
.04
.05
.11
61.36
59.33
66.48
74.50
81.50
89.25
55.01
5.53
•
Less than .01 ton per acre.
evident. The average estimate for all 12
samples is 2.52 tons per acre. Since this
value would only add a constant to the
amounts given in Table 1 no correction
has been made for the loss of the rootlets.
Roots accounted for 21.7 per cent of
the fir stand at 700 stems per acre and
23.3 percent at 5000 stems per acre. This
trend results from the fact that roots
represent a slightly larger proportion of
small fir trees than they do of large trees
(Baskerville 1965'). The corresponding
percentages for spruce do not indicate a
trend because of the small number of
52 / Forest Saience
trees involved and the consequent in-
creased influence of tree size. With changing density the proportion of the birch
stand comprised in roots appears te
remain constant at about 23 percent.
However, because of the high proportion
of the total stand in fir the percentage of
the total stand in roots tends to increase
with increasing density.
2 Baskerville, G. L. 1965. Estimating of dry
weight oE tree components and standing crop
in conjfer stands. Ecology (in press).
No satisfactory method of estimating
current annual net and gross increments of
roots was devised. As a result the only
estimate of increment available is on a
mean annua! basis (root weight divided
by age). Such a procedure would indicate
increasing increment with increasing density as was found for the aboye ground
portion of the stand.
The total shrub stand consisting of one
smal! Ame!anchier on a 700 stem per acre
plot had a dry weight less than 0.01 tons
per acre and has not been recorded.
The oven-dry weight of vegetatian on
the forest /loor proved highly variable.
However, there was a lagical tendency
towards decreased weight with increasing
density of the tree stand (Table 2). The
vegetation consisted 0[:
Abies balsamea (seedlings)
Oxalis montana
Coptis groenlandica
,
Dryopteris spinulosa
Lycopodium lucidulum
Calliergone!la schreberi.
Dicranumjuscesens . . ~
Po!ytrichum commune.'.
Hylocomium umbratum (traces of H.
splendens)
Hypnum crista-castrensis (traces)
The data given in Table 2 include both
tops and roots. The six samples contributing tú each of the averages shown were
highly variable both as ta weight and the
presence or absence cf given species.
Estimates of total standing crap including taps and roots are given by
vegetation layer in Table 3. Dry weight
of standing crop increases form 61.4
tons per acre at 700 stems ta 98.2 tons
per acre at 5000 stems per acre. The lesser
vegetation forros an insignificant portian
of the total stand.
Conclusion
The oven-dry weight of total standing
crop in these 43-year-old fir-spruce-birch
stands increases with íncreasing stand
density.
The total weight of tree roots increases
with increasing density as does the weight
uf the aboye ground tree stand. Roots
form a slightly greater propartion of the
tota! stand in the denser stands.
Shrubs were present only in the 700
stem per acre density and there in negligible amounts.
The dry weight of vegetation on the
forest /loor tended to decrease with increasing density but the total weight
involved was insignificant in comparison
to the total tree stand.
tt-
volume12, number 1, 1966 / 53