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Natural Regeneratlo.n of Balsam Poplar
Following Harvesting in the Susitna Valley, Alaska
by
J. C. Zasada\ L.A. VIereck\ M. J. Foote\
1
R. t-1. Parkenson 2, J. 0. Wolff 3, L. A. Lankford Jr.4
P. trichocarpa. Torr. & Gray); but there is little quantitative information regarding the course of natural regeneration
following harvesting of these species in Alaska.
The balsam poplarss, although covering less area than
birch and aspen, occupy floodplains in interior and southcentral Alaska, some of the most productive forest sites in
the State (Van Cleve eta/., 1971; Vierec~. 1970). Of the hardwoods in Alaska, we have t':e least information concerning
regeneration of mature balsam poplar floodplain forests
which originate through primary succession on newly formed alluvium.
In 1973, clearcutting began in a large, continuous stand
of poplar at the confluence of the Chulitna and Susitna
Rivers (Figs. 1 and 2). Harvesting was completed in 450ha in
the summer of 1975 and provided an opportunity to examine
the natural regeneration and plant community response to
harvesting. This report summarized observations made during the 4 years following harvesting.
Abstract
Regeneration of balsam poplar was studied following clearcut
logging with both chain saws and tractor-mounted shears in summer and winter. Logging with shears in beth summer and fall
resulted in the most surface disturbance and the greatest rate of
poplar regeneration. Stocking averaged 29% (range 4-62%) 4
years efter harvesting. Regeneration was from seeds, stump
sprouts, real suckers, dnd buried bra.. ~ es. RPgeneration in
summer-and winter-logged sites was primarily from root suckers,
but logging in the fall resulted in regeneration from buried bran·
ches. More \han 50% of the stumps produced sprouts the 1st and
2d years; but after 4 years, only 15% of the stumps in the areas log·
ged in summer still had live sprouts. Revegetation of clearcut areas
was rapid and dominated by grasses, horsetails, willows, alders,
and devil's club. Production of moose brm·vse was much greater in
the logged areas than in an unlogged control. Limiting clearcutting
to summer and encouraging disturbance of the surface could increase poplar regeneration.
I
I
Resume
Methods
On a etudu~ Ia regeneratton du pc~Jplier bat:mier etablte apres
coupe a blanc d'e!e et d'htver Les coupes or.t ete realtsees seton
deux techntques: a Ia scie a chaine d'une pa~t et au moyen d'une
CIS~l!ll~ motonsee, d'autre p~rt. La coupe a Ia ctsatlle latte l'ete au
l'hiver amene le meilleur bouleversement de Ia surlace du sol et
favonse Ia meilleure rheneratton de peuplier baum1er. Apres 4
ans, le stock vane entre 4 et 62% avec une moyenne de 29%. La
regeneratiOn du peuplier provient SOil a de graines. de rejets de
souches, de reJts de racines ou de branches enfouies dans le sol.
La regeneration sur les s1tes coupes e11 ete corr.rne en hiver provient d'abord des re1ets de racmes; cependant, Ia coupe d'automne
favonse Ia regeneratton ongmant de branches enfouies. Plus de
50% es souches ant donne des rejets au cours de Ia premtere et de
Ia deuxieme annee, mais apres 4 ans. 15% seulement des souches
de Ia coupe o ~te portatent des reJets vivants. Le repeuptement ae
I' aire de coupe a ete rap1de et fut domine par les h~rbes. 'es preles,
les sautes. les aulnes et le bois ptquant. La coupt: a blanc a favonse
un apport de v~getation plus Important, dans Ia strate de broutage
La coupe ablanc d'ete, avec bouleversement du sol, favonseratt la
regeneration du peuplier baumier.
This study began in August 1974. The nature of the stands
prior to logging was determined by examining adjacent uncut stands and by measuring stump diameters and densities
in the logged areas. Stands in the clearcut areas (lat. 62°
20'N., long. 150° 10'W.) ranged in age from about 100 to 200
years. In the uncut. adjacent stands, dominant trees were 30
to 35 m tall and 50·60 em clt-h. Stand density varied between
7 4 and 494 sterns per ha.
Regeneration was observed on permanent and temporary
plots in five areas. Time of harvest and method of felling for
thPse areas were:
Area No. Season harvested
1
2
Summer (June 27 ·July 1)
Summer (June 27-Juty 1)
Fall (September 1-10)
Winter (February)
Winter (January)
3
4
5
Year
Method of felltng
1973
shears
chain saw
shears
shears
chain saw
1973
1973
1973
1973
!
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Introduction
Obse~vations
Hardwood forests In Alaska are a renewal;>!~ natural
resource whiGh have been little used for wood and fiber products. Because of increased urbanization and industrial
development In Alaska, predicted international shortages of
wood fiber and changing land owneiship patterns, the commercial potential of this resource is currently being
evaluated.
One important aspect of management of these forests is
regeneration following harvesting. Much is known from
other parts of North America and Europe about the
regeneration of c;spel" (Populus tremu/oides Michx.), birch
(Betula papyrifera Ma,_,,,) and poplar (P. balsamifera L. and
were confined to 2 to 3 hectares in each area.
1USDA Fores! Serv1ce. Fa,'banks. Alaska
2r-ormerly w1th UniVI"'!:ItY ol Alaska, Dept of Land Reso:~:ces. Fa•roanks. AlasKa, present·
iy Manage!, A:ask; P•an• MatellillS Center. Oepartme"t of Natural Resources, Palmer,
Atas~o.a
3Formerty W!lh USDA Forest Ser~·cc, Faubanks Alaska and Museum of Vertebrate
Zoology, Un•vetstty of Ca'tfom.a Berkeley, Cahforn•a, orec,e'l!IY D'lpartll'enl ol Biology,
Un1v of V•rgm•a, Cl'ar,ollesvllle Vugm1a
4Formetly W<l'l Alaska Dept of Natura! ReSOUiCJS D•v of Lands, Ancnorage. Alaska,
presen:ly .:or.;ull•no Forester. Westchlfe, Colomdo
:lf'alsam poplar {Populus balsamifera l.), black cottonwo.>d (P mchocarpa Torr, & Gray)
ana hybmls of the~e spectes make up the p.>plar complex 111 Alas!<~. Tl'e trees 1n the study
area appeared to be characlensttc of balsam poplar. but Viereck ana rt-ole (1970) in•
61cate that hybrids may occur here.
April 1981
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Area
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Figure 1. Study areas were located at the Junct:on of the
Chulitna and Susltna R1vers 1n souih-central
Alaska.
58
April 1981
The Forestry Chron•cle
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I wer ny pOtf.-t$ ·:~t=l t t:l~h;.!Urt:=.! :t:u ' • .. . • ~ ............... '" ... . • •.···" :~ unc~n !'.~ ... At each point a 1-m2 plot was used to
3 .."1tt ::.tt c > ·- · nd presence l f species: a 4-m2 plot
\
., ..
'" rt.... 1rmine f.tem der .slty Qf t~ll shrubs and
as. The point-quarter method was used to ·
, diameter, and basal area of the trees. In
:t ~"' additional 4-m2 plots were examined an~ sample size for balsam poplar stocking
.s 2, 3 and 4, 50 temporary 4-m2 plots were
..,
-#.
year for poplar stocking and density
1plar
seedlings and sprouts were counted
- t.•""t
1
ified as stocked !f it contained one or more
'6, the third growing season following
ldividual stems of balsam poplar regeneraated in areas 1, 3, and 5 to determine !h0;,
lling·s, root sucker, buried shoot, or stump
e production was measured m area 4;
"·~scribed in Wolff and Zasada {1979).
; Jf seedling establishment were made only
1e 1974 growing se;:son. These observations
)ng roads and skicl trails in both harvested
areas and natural stands. Paired plots of mineral soil and undisturbed organic surfaces were used in the logged areas.
On one of the skid trails the mineral soil surfaces were further subdivided ir:to sili and gravel.
Other regeneration observations are listed below
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Variable measured
Year
No. of observations
---------------------------------1. Seedling density and
197 4
450, 4-m2 plots
seedbed preference
2. Length and diameter of
buried shoots producing
sprouts
3. P Qduction of shoot~ u orr
1975, 1976
200 shoots
127"
490 root cutt.ngs
excised rool r.ut\1:1g-;
4. Sucker density ar.ci surf3ct i 2 'o
condition
5. Average diamett:>r oi m~ :; '~·75
producing .;hoots
300, 4·m2 plots
15:: roots
Laboratory stL. ...'!::!'~ Nal.: v)nducte:d · · 0 !lerrnine ;ne
capacity of root cu:1;ng~ t.:; yod,,ce sh~ots. Valiaoles v.Jerr:.
collection d~te, te:r.lpe·<!t rcl :.,,rl the lei'Jtn and dialt'et~( of
root cutting.;;. Ea.-;1: t. en · ~rt w&s ra~licated four !O six
times with stx to ci·/i' ; · ·: .~'"· .. :. rF.::·I;cation. RoC'',s were
collected from H ··vic~..~ .... !: ."'~ ,r: ,Ju!f and S!"Jtem!· er 197 4
and in Augus; 19?ti 1 .t.n&' .:/ etf:m (rees wc;re us·.:d.
The numb~! O! stu;n )S ...,-,ti ~h sprouts was recortJed each
year on 150 io · 8 ~-tum~-<:> ir eacl-1 '1f the fivE' treatment
Figu~e 2. -:-;,., :untrol r1'~::a was a star .. of mc·t.~c
areas. T1l'-': ·~ .ump sprout perc:enta'Jes •H , e comparet!
analysis •"'i variance w;lh method of harvest (chain Sit
shears) aqd time of harvest {:.ummer. fell, and winter'
indeper·dr nt variables.
•
Reic··~t~
.:;H_: Discussion
;.. • ;, , stocking 6 was 29% (range 4·62%) 4 yea·
har'.'El- .t1• ;. Change in stockir? i?.vel during the 4 y:
obsuv& ~n was relatively sr.ail. Areas where tre:
bee
•·: ..2red tended to ha\~ .. ;g~:~r stocking pe1ce·
tha.· · ~:r:: wnere trees wer d -..>ll~d cy c~1am saw. Tt
,...,..:::>s . .ent in the areas lcyg-·~ ~ i. .;• •mr er and coulu
tribu , ~ · increased sudacc 1 il'tU b· nco calAsed by
shea1 , -:..1uipment and ;r.~· ·~t.l< of .:movV protection. P--e
avera~::-3 • '• sity on stockeCl 1-~ ·: r ;r:ts .raried fron: 2 to :: 4
stems
;;SIOCI<ll'(j b~s
'!Q•••vilten• !':l a
p-
1v
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o.
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!~!ley
Table 1. Perco~•t stocking and density of na' .Jra'~; !''.-:!t'"~ · .... ,._. '' ····-.
haiYe::Stlng' matnods
Area
·n ..
Harvesting ... ·•" :..
surr~
·.
sh:.:l .. rs
--------------------
• I.
following different
1977
~
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1
4
2
._ 5
,,
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ocp':: adja<" :nt to the IO'JJ'3d arr.; 1. Large1
r.r d 30-3::5 ,n in height a·-,,1 ~o-er ~-;·, in ~;3m:
orear.t height.
c..?
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. The source of regeneration determined 3 years after loggmg, varied among units. In units 1 and 5, logged in the sum·
·l mer and winter respectively, root suckers comprised 85 and
70% of the stocking. Stump sprouts accounted for 8% of
the stocking in the summer logged area and 22% in the
·•·~ter log':ied area. In the fall harvested area, the predomi·
t sour.~e of new plants .(63%) was brancn segments
broken from the crown and buried during harvesting. The re·
mainder of the stoc~dng in ,the fall harvested unit was ac·
counted for by suck.ers (27%) and stump sprouts (10%).
Seedling reproduction was observed in the summer logged
area only, it's contribution to stocking was 8%.
'..l.,
Stump aprouts. More than 50% of tho stumps in each area
produced sprouts the first or second growing season after
cutting. In the areas logged in fall and winter,-survival of
stump sprouts was .good 4 years after harvesting {T~ble 2}.
Mortality had reduced the number of stumps with sprouts in
summer-logged areas to less than 15%.
During the first grow!ng season following harvest, 50% or
more or the stumps produced more than 25 sprouts (Table
3). The oflly exception to this occurred in area 1, an area log·
ged in' summer, where the majority of stumps produced less
than 10 sprouts. By 1977. area 3, logged in the fall, had
equal numbers of stumps with less than 10, 10-25, and
greater than 25 sprouts; sprouting in the other areas was
predominantly in the lower two classes.
Stump sprouts originated from two sources - dormant
bllds and callus. The percentage of stumps producing
sprouts from dormant buds in the 2 wmter logged areas was
51% while the 3 areas logged during the growing season
has only 6% of the stumps producing sprouts of this type.
The percentage of stumps producing callus sprouts was
more consistent between areas varying from 85 to 100%.
Most frequently, callus sprouts originated at the top of the
stump from callus which had proliferated at the bark·wood
,1; ·face. In area 1 (summer logged with shears}, however,
·<!"..:.,us sprouts occurred on the side of the stump where bark
had been removed dunng shearing (Fig. 3). Sprout production from callus has been reported for Populus (Kozlowski,
f}
1971).
Sprout productivity differences are the result at many
variables, some of which are accounted for by comparing
study areas by season and method of felling. Others cannot
be adequately accounted for. For example, in almost all
· C.:if(S, the fall-and winter-cut stumps were the most prolific
(i
sprouters. These differences can be ascribed to iQ~,"ler
nutrient reserves during early, summer and to significant
physical damage to stumps in the summer-sheared area
where cambial growth was occuring and the bark easily
damaged (Fig/3). ·Tree age, vigor/and genetic ability to
sprout variables that could not be accounteti for, could have
influenced results.
\
Root suckers. Root suckers were most common where the
organic layer had been removed and silt was exposed. Production of root suckers aftei 3 years was a main contributor
to stocking in areas 1, and 5. However, based on previous
experience with balsam poplar (Day and Vogel, 1944;
Fowells, 1965) and aspen, the suckering response was less
than expected. When gravel rather -than silt was the surface
soil, suckering was reduced. The following comparison
shows this relationship
Frequancy of occurencg
Surface condition
Loamy sand
Gravel
Organic matter
(%)
No. of plots
57
13
4
100
100
100
111 order to assess the potential of balsam poplar to produce suckers. root cuttings were collected in 197 4 and 1975
for growth under controlled conditions. The percentage c.f
fall collected cuttings, incubated at 25°G, which produced
roots averaged 41% (range 21·58). Suckers were produced from callus formed at the ends of cuttings and from buds ••
along the root. Suckers of bud origin accounted for 50% of
the suckers produced. Nheteen percent of the cuttings produced suckers of both origkls. New roots were initiated from
pre-existing primordia and from callus: cuttings producing
new roots varied from 6 to 90%. In cases where roots were
incubated over a range of temperatures (25,20, 15 °) suckering was generally reduced at lower temperatures; however,
these tests were limite(i and the results were not c( · ·.iusive.
The results of this study were similar to those of Schier and
Campbell (1976) who conduGted a study of suckering in
balsam poplar and three other Populus species in Utah.
Shoots produced by roots were excavated in the field in
1975.
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Table 2. Occurrence of balsam poplar stump sprouting success over a 4-y~ar period following harvesting.
Harva~Ung
Area
method
.,
A'.!9.
Ave.
stlimp stump
ht.
dla.
-em-
1S7'5
s~routs
1976
1977
n1
_o/o---··
1
summer
shears
26 '
51
60b,c2
22C
15b
gb
156
.
2
summer
ch:lin saw
24
27
54C
41b,c
2Qb
14b
154
f
3
fall
shears
43
56
0
7oa
66a
54 a
152
1
4
winter
shears
36
41
a1a
71a
61a
59 a
158
winter
cham saw
5
1 n :: total
numbet
81
ot stumps exammed m eclch area
2v. .ues m columns With same letter not Slgn,ltcantly d1fferent at p = 05
60
% with
1974
·(
April 1981
The Forestry Chronicle
59
7sa.b
s5a,b
58 a
498
i
150
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Table 3. NumbeF of sprouts per stump. and percent of stumps examined In 1974 and 1977, 1 and 4 years after harv9stlng.
.
t'
/
Number per stump
,.,......."
-
28
44
20
0
60
9
26
92
8
8
66
0
53
13
1975
1977
22
32
23
32
55
36
74
69
1974
13
35
20
67
51
14
75
65
49
2
80
48
Year
1
summer
shears
1974
1977
52
56
2
summer
chain saw
1974
1977
3
fall
shears
4
winter
shears
5
1n
n1
Harvesting thne
and method
..,
l
>25
Are•
-
1977
winter
chain saw
=total number ol stumps examtned
tn
10·~5
~10
% of stumps -
1974
~6
25
1977
67
31
each area
Most suckers grew from roots within the upper 2 em of scil.
Suckers sprouting from exposed roots were often observed.
The average diameter of roots producing suckers was 1.1
em (n = ·~ 00). Broken roots with suckers were frequently
observed. This was particularly common in the vicinity of log
decks wher,'3 soil disturbance was severe. The broken root
segments (n = 50) averaged 1.1-cm diameter and 68-cm
length. Each produced an average of. six suckers (0.09
suckers/em); 87% had produced new roots. No callus
development was observed, and all shoots appeared to
have been produced from pre-existing primordia. This Nas in
contrast to the laboratory tests where shoots of callus origin
were common on roat cuttings.
Although production of suckers is determined by a host of
internal and external factom, soil temperature requires particular attention because it is known to affect sucver production in Populus, (Maini, 1968; Zasada and Schier 1973): and
because temperature may be the factor most easily altered
by harvesting and subsequent cultural practices.
The organic layer is of major importance in the. regulation
of soil temperature in the forests of interior Alaska. Soil
temperature monitored at four depths over a 3-day period in
late June 1974 indicated that in areas where orgamc layers
were removed, temperatures we:e higher than where they
were intact (Fig. 4). Because the organic layer had been
removed, temperatures at the measured depths in the
winter-harvested area increased an average of 10°0. In the
summer-harvested areas, the organic layers had been
removed only 10 days prior to the mea~mrement of soil
temperature. Temperatures, however, had responded quickly as even the 50-cm depth showed an increase of 3°0.
Although these data are limited, they do suggest-that roots
in the mineral soil and within 5 em of the surface are in a
more favorable temperature environment than those at
greater depths in mineral soil.
Rooting oq buried branches. Regenera :on from buried
branches was not important in the summer-and winterlogged areas. In araas logged in the summer, dormant buds
were not present at the lime of harvest. In winter-logged
areas, dormant buds were present; but, the frozen soil surface and snow cover prevented burial of broken branches.
In the fall-harvested unit, 63% of the shoots observed in the
stocking survey conducted in 1976 had originated from
branches that were broken from the crown and buried durWinter harvest
9
25 ·~·
•1·2
_ 20 1"..
0
1.1 ·,.
0
~
+ Organic layer removed
---:.:~ Organic layer intact
-+
Summer harvest
·---""' -· Organic layer removed
0
. I
. t t
"'-----"
rgantc ayer tn ac
o"'"'"""" ::> Uncut Stand
Values at each data point
.3 are standard errors.
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20
5
10
50
SoU depth
Figure 4. Soil temperature in lat~ June in an uncut balsam
poplar stand and in areas logged in winter and
summer.
April 1981
SPIM;
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Figure 3. A stump from an area logged with shears in the
summer. Callus sprouts occur on the side of the
trunk where the bark has been .cmoved by shearing.
',+7
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The Forestry Chronic:e
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61
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· ··
The majority
·
~t 1 iiie-~e·~ b;a.nches
were.~ompletely burled in a generally horizontal position. Of
th~ shoots examined, 97% had initiated ·adventitious roots
With an average of 2.2 roots per shoot. The diameter of
b~rled branches producing shoots va_ ried fn:>m less than 1 to
A 1. Seve~tY·!ive percent of the branch sections were less
~ -~1 3 em m dtameter. Branch length varied from 6 to 300
em. Seventy percent of the branches were between 11 and
50 em. D~v~lopment of new shoots from buried branches
appeared tQ be from dormant buds In all cases.
'fne rooting Q~pacity of stem cuttings for other Populus
species, particularly those in sections Tacamahaca and
AigeHros, is well known and widely used for asexual
reproduction.
Seed regeneration. At the end of !he 1974 growing season
we found no seedlings on organic and gravel surfaces.
Mineral soil seedbeds ala~ a road under the uncut stands
averaged 28 seedlings/m with 100% frequency. These
areas had the highest seedling density and provided an indication of the 1st-year seedling potential under conditions
of maximum seedfall.
Seedling density in the cut area was three to five seedlingstm2 and the frequency of occurrence on the 1-m2 plots
was 80-85-%. Seedling density was reduced five to nine
times at distances of 100 and 200 meters from the seed
source.
The amount of mineral soil exposed during harvesting
varied with the season of the harvest. Frequency of mineral
soli on the 1-m2 plots after summer and fall harvesting was
50 and 68% respectively. Mineral soil covered 48 and i 9%
of the same plots. Winter harvesting resulted in only 5% of
the area with exposed mineral soil. By 1977, 4 years after
harvest, there was no exposed mineral soil on any of the
harvested sites.
Q) .ure11ce of other vascuiar plants. The cover and fre<(u'eney of occurence of heruacE:ous plants increased
significantly from 197 4 to 1977 (Table 4) .. Swe~t-scented
bedstraw (Ga/ium tritlorum Michx.) and horsetail (Equisetum
arvense L.) were the most common plants in both the
summer-and winter-logged areas (area 1 and 5).
Wintergreen (Pyrola asarifo/ia Michx.) red bRneberry (Ac·
Figure 5. Area 5, a site logged in winter.
A. Quadrat (m2) in 1974 showing logging debris.
62
April 1981
The Forestry Chronicle
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taea rubra (Ait.) Wild.) and fireweed (Epi/obium angustlfollum
L.) were most common In the sommar·logge'd area. Bluejolnt
(Calamagrostis canadensis (Michx.) Beauv.), although not as
common as the -above species, formed relatively dense, tall
clumps causing it to appeai to dominate the areas where it
occured. By the end of the fourth summer, these herbs
formed a dense and continuous cover about a meter in
height.
Immediately after harvesting, devil's club (Oplopanax horridum (Sm.) Miq.) was the dominant shrub on the winterlogged site; high bust, cranberry (Viburnum edule (Michx.~
Raf.) and prickly rose (Rosa acicularis Lind!.) dominated the
summer-logged sites. At the end of the fourth growing
season, these three species plus currant (Ribes triste Pall.)
had frequencies of more than 50% on both sites. Stem density' increased to varying degrees for all shrubs while percent cover both increased and decreased depending on the
site and species. Figures 5 to 8 show representative suface
conditions in the winter-and summer-logged areas after the
first and fifth growing seasons.
\
Available moose browse. Logging improved moose
browse conditions. In the logged areas, woody browse was
not available above snowline until the 2nd to 4th year after
logging when it increased from 5.3 to 15.9 kg/ha (Table 5).
The only woody browse available to moose during the second and third consisted of cottonwood twigs
sproutings from cut stumps. The density of stumps was only
104/ha, however each stump had a mean ,of 37 twigs/stump
at 4 years. Four years after the harvest, alder, willow, and
highbush cranberry were tall enough (over 1m) to be ln- .
eluded in the browse survey. Alder made up 9% of the
available browse at 4 years. The unlogged cottonwood •
stand had 112 stems/ha, none of which produced browse.
Alder and hlghbush cranberry were scat,ered in the
understory and contributed less than 1 kg/ha of browse
(Table 5). Two; 3 and 4 years after logging, browsing intensities in the logged areas were 38, 18 and go;,. During the
second and third winters, poplar was the only browse
species available above snowline. Of the four browse
species available during the fourth winter, a preference was
shown for cottonwood and feltleaf willow over highbush
cranberry and ald&r (Table 5). No moose browsing was
recorded in the unlogged balsam poplar stand.
KC~!l,;:J. '?-a\
,
B. Same quadrat in 1978 showing dense growth :'
of devil's club, ferns, and other herbs.
I
'_j
.. .
~---·--
~-
1...,.
.-
~--.
_,..____ __ ...
,
.
-
,.,.~-------~----....-....-----------
......-._....._
_______.__
--~---....-·~--'-~·
\
~
~
"'
t
Table 4. Frequency of occurranca ana percent cover of common vucular plants and stem denalty of common woody plants on sum·
mer and winter logged balsam poplar clearcuts end an uncut atand'ln the upper Sualtna Valley at tha end of the first and
~ fourth growing seasona. (Frequency and cover ba*ed- on 20 permanent plot1 h1 each area) · ·
Area 1 (aummw togged)
Area 5 (vlii1ter logged)
Uncut Control
Specie•
Year
Freq.covar
Dentlty
Freq.covar
Density
Freq.co\,er
Oentlty
(stems
(atema
(stems
' .•
(%)
(%)
/ha)
(%)
(%)
/ha)
(%)
(%)
/ha)
HE.RBS
Equisetum arvense
t
Gallum triflorum
4
Actaea rubra
~
Pyro/a asarifolia
Epilobfum angustifolium
Streptopus amplexifolius
Calamagrostis canadensis
Dryopterus dilatata
Mertensia
paniculata
t
SHRUBS
Op/opanax horridum
Viburnum edule
Rosa acicularis
~
i''·.
i
11
0)
Ribes tristes
Rubus idaeus
Alnus tenuifolia
& A. crispr
Salix barc:dyi
TREES
Populus balsflmifera
~
(
I
'•
I
I
Betula papyritera
'
Picea glauca
1974
1977
1974
1977
1974
1977
1974
1977
. 1974
1977
1974
1977
1974
1977
1974
1977
1974
1977
70
100
45
100
35.
95
55
80
5
75
0
45
5
40
10
25
0.8
46
0.7
4
0.4
4
0.6
2
1.0
6
0
0.8
1
100
45
95
65
100
20
30
20
20
0
30
75
45
10
50
40
35
0
20
8
5
3
6
0.2
0.7
2
6
0
0.8
2
1
1974.
1977
1974.
1977
1974
1977
1974
1977
1974
1977
1974
1977
1974
1977
35
50
50
70
40
60
25
60
0
10
20
10
0
15
0.7
0.7
0.9
5
2
7
0.2
3
0
0.2
0.3
0.8
0
0.2
875
2 375
1 500
16 000
1 000
19 250
0
27 125
0
625
875
625
0
375
100
85
55
60
20
20
50
80
5
30
15
15
11
4
0.3
0.6
0.5
"l(}
5
0.1
1974
1977
1974
1977
1974
5
50
0
30
0
0.1
500
22 875
0
1 375
0
20
15
0
5
0
0
1
0
0.3
0
""
'
5
5
5
0
0
85
7
20
0
0
100
65
0
0
1
6 750
21 125
3 000
13 875
1 875
2 500
0
28125
0
10 125
750
3 625
625
750
0
3 375
0.4
0.2
0
0.5
0
3 250
500
0
125
0
95 1
40
100
0
0
0
60
s
39
4
'Tree data tn the central was oblamed by the pomt..quarter method.
~~~
30
13
3
t5
0.8
35
5
0
3
~
·~
20
3
10
4
5
70
11
3
6
0
0.4
0.1
0.2
0
0.2
:
24 125
10
0.2
500
5
0.2
125
45
2
10
0.2
20
0,9
0
500
1.4
-··
d
,,
_.
i
"
Figure 6. Areas 5, a site logged In winter.
A. Logging debris and white spruce left atter logging in 1974.
B. In 1978, the same area shows dense herbs arid
shrub cover.
..
,
April 1981
The ·Forestry ChroniCle . 63~
I
..
\
... ',.:·
:~
•..'\".
~
...
"'
,
.
"'·
... ·
\
B. Same quadrat in 1978 showing development of
herbs, pnmarily fireweed, and grass.
Figure 7. Area 1, a site logged in summer.
A. Quadrat (m2) showing logging debris.
Figure 8. Area 1, a te logg
in summer.
A Logging debris and white spruce left after logging in 1974,
B. In 1978, this area ·shows dense herbs and
shrub cover.
Table 5. Browse production and moose utilization by plant species In a balsam poplar cutover, two, three and four years after cut·
tlng. Numbers In ( ) are standard deviations
2
Available Browse Browse Browsln~ Preference lndex
Years
Den~lty
cons. lntonslty determined by
since
(stems (twigs
twigs biomass
&terns
(%)
/shrubs) (g/shrub) (kgn1a) (kg/ha)
hfllrvest
/ha)
Species
38
2.0
5.3
104(15) 21.4(1.3) 50.5
2
Balsam poplar
18
9.0
196
104(15) 36.6(2.7) 86.4
3
Balsam poplar
Balsam poplar
~ FeiUeaf willow
·Highbush cranberry
Alder
Uncut Stand
Balsam poplar
4
4
4
4
156
27
2'>0
282
112(17)
37.2(7.1)
8.7(3.2)
7.3(0.5)
7 6{0.6)
0 .
87.8
73
2.3
5.2
0
0.2
9
43
34
1.5
0.0
0
0
0
0
1~.7
12
0.2
0.5
O.i
1Brt7Hse ccnsuml.d + available browse
2tndex deftr."".:: as P1b/P1s where Ptb tS the proport1on of the tlh senes 1n the dtet and P1s ts the proportion olthal spec.es
64
April 1981
tn
3.5
1.3
1.8
0.4
0
0.5
1 '1
0
0.9
5·.4
4.3
0
the stand
The Forestry Chronicle
'_j
·~.·
Management Implications
I
··~
•
bances. Increased surface disturbance could be ac·
complished by concentrating logging during snow-fme
· periods and/or post harvest site preparation.
The fourth means of regeneration, stump sprouting, did
not result in tree for tree replacement. Dormant season
harvesting appeared to be most desirable if maximum
sprQt,Jt production is desired.
Balsam poplar is the most versatile, iP terms of the means
/ available for. regeneration, species in Alaska. Seed
regeneration was best on mineral soil, and ro0t sucker production benefited from removal of the forest floor. Broken
branch segments must be b~.,;ried during harvesting to produce new t1ees .. Thus the probability of regeneration by
these means appe:~~s to be increased by surface distur/
··~
References
.
Viereck, L.A. 1970. Forest succession and soil develop-
Day, M.W., and F.H. Vogel. 1944. ~ilviculture ;:md utiliza~
tion of balsam poplar. J. For. 42: t~12-514.
Fowell&, H.A. 1965. Silvics of forest trees of the United
States. USDA For. Serv. Agric. Handb. No. 271. 762 p.
Kozlowski, T.T. 1971. Growth and development of trees.
ment adjacent to the Chana River in interior Alaska,
Arct. and Alp. 2(1 ): 1-26.
Viereck, L.A. and M.J. Foote. 1970. The status of Populus
balsamifera and P. trichocarpa in Alaska. Can. Field Nat.
84: 169-173.
Wolff, J.O. and J.C. Zazada. 1979. Moose habitat ana
forest succession on the Tanana River floodplain and
Yukon-Tanana upland. Proc. N. Am. Moose Conf. and
Workshop No. 15:213·244.
Zasada, J.C. and G.A. Sch!er. 19i3 Aspen root suckering
in Alaska: effect of clone, collection date and
temperature. Northwest Sci. 47 (2): 100-104.
Zasada, J.C. and L.A. VIereck. 1975. The effect of
temperature and stratification on germination in selected
members of the Salicaceae in interior Alaska. Can .. J. For.
. Res. 5: 333-337. ·
Vol. 1, Seed germination, ontogeny, and shoot growth.
Academic Press, New York. 443 p.
Mainl, J.S. 1968. Silvics and ecology of Populus in Canada.
p. 20-69. In Malni, J. S. and J.H. Cayford. (Ed.) Growth
and utilization of Poplars in Canada. Can. Dep. Forest.
and RL:ral Develop. Forest. Branch, Publ. No. 1205.
Schier, G.A. and R.B. Campbell. 197~. Difference among
Populus species in suckering from root segments and
rooting of sucker cuttings. Can. J. For. Res. 6: 253-261.
Van Cleve, K., L.A. Viereck, and R. Schlentner. 1971. Accumulation of nitrogen in alder (Alnus) .ecosystems near
Fairbanks, Alaska. Arct. and Alp. Res. 3 {2): 101-1 ~ 4.
0
Survival and Growth of Bullet, Styroplug and
Bateroot Seedlings on Mid-Elevation Sites in
Coastal British Columbia
by
J.T. Arnott1
Abstract
b) semts 1·0 cyltiVE~s dans les contenants en "Styrc.blocks" du
BC/CFS et
c) semts traditionnels 2·0, utilises a racines nues du Pseudotsuga
menzeisu et de Tsuga heterophyl/a.
Cmq ans apres Ia plantation, les taux de survte rnoyens pour le
Pseudotsuga furent pour a) 77%, b) 84% etc) 81 % landis que pour
Tsuga, ceux·cl furent pour a) 69%, b) 87% etc) 63%. La hauteur
moyenne quinquennale sur ces sites d'elevatton moyanne fut de a)
51 em: b) 62 em etc) 72 em pour Pseuclotsuga eta) 63 em; b) 67 em
et c) 57 em pour Tsuga Ces resullats mdiquent clat:ement qu'on
obltent un metlleur rendement sur le terrain en utllisant des semis
1-0 issus de contenants en "Styroblocks" pour Tsuga heterophylla
plutO! que de prendre les semis tradtttonnels 2·0 a racines nues.
Cependant de telles ,fltfferences ne furent pas aus:::; c:videntes pour
le Pseudotsuga menziesli.
.
f, trial was established over 2 successive years at two mid-
elevation locations on southern Vancouver Island to assess and
compare the field performance of a) 1-0 seedlings grown in
Walters' bullets, b) 1-0 plug seedlings grown in BC/CFS Styrobtocks.
and c) conventional 2-0 bareroot stock of Pseudotsuga menzie:;ti
and Tsuga heterophyl/a.
Five years after planting, average survival rates for P. menziesti
were a) 77, b) 84 and c) 81 %, and for T. hel·9fophylla, a} 69, b) 87
and c) 63%. Avar~ge fifth year height on thes·e mid-elevation sites
was a) 51, b) 62 and c) 72 em for P. menzies//, and a) 63, b) 67 and c)
57 em for T. heterophylla. The results indicate that significantly better field performance can be obtained using 1-0 styroptug seedlings
for T. heterophyl/a rather than conventional 2-0 bareroot stock.
Such statistically significant differences were not evident for P.
menzlesli.
Introduction
Resume
Field trials of container reforestation systems have been
made in British Columbia since 1967 (Arnott 1973). Initial in-
Un test tut etabli et poursuivi durant 2 annees consecuttves sur
deux sites d'elevatlon moyenne au sud de Pile de Vancouver pour
etabllr et comparer le rendement sur le terrain des:
a} semls 1·0 cultlves dans les douilles du type Walter;
TPii'Coii'CF'Orest Research Centre, Canadian Forestry Servtce, 506 W, Burnstdo Ad. Vic·
tor•a. B.C. VSZ 1MS
April 1981
112
.. CIA
sa
.:e
The Forestry Chronicle
n ••sua ••
&
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65 .
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