S T A T I O N PAPER NO 134
FOREST SERVICE
.
.
NORTHEASTERN FOREST EXPERIMENT S T A T I O N
U S DEPARTMENT O F AGRICULTLIRE
RALPH W. MARQUIS. DIRECTOR
.
.
1960
UPPER DARBY. PA
MUCH
of the s i l v i c a l information on our f o r e s t t r e e s i s widely s c a t t e r e d and sometimes d i f f i c u l t t o find. To make t h i s m a t e r i a l
more r e a d i l y a v a i l a b l e , t h e F o r e s t S e r v i c e i s
assembling information on t h e s i l v i c a l charact e r i s t i c s of a l l t h e i m p o r t a n t n a t i v e f o r e s t
t r e e s p e c i e s of t h e United S t a t e s . It i s e x pected t h a t t h i s information w i l l be published
a s a comprehensive s i l v i c s manual.
T h i s r e p o r t presents the s i l v i c a l charact e r i s t i c s of one species. It contains the essent i a l information t h a t w i l l appear i n the general
manual but has been w r i t t e n w i t h p a r t i c u l a r r e f erence t o the species i n the Northeast. S i m i l a r
r e p o r t s on o t h e r s p e c i e s a r e being prepared by
t h i s Experiment S t a t i o n , and by s e v e r a l o f t h e
o t h e r r e g i o n a l f o r e s t experiment s t a t i o n s .
A D R I A N M. GILBERT received h ~ sBachelor's degree in forestry
at the Univers~ty of Michigan in 1943. Joining the Northeastern Forest Experiment Station in 1946, he served in the
Forest Survey of the Northeast.
In 1948 he took a year's
advanced study at the Swiss Federal Institute of Technolo~y
at Zurich, Switzerland. More recently (1957-58) he has been
studying for a doctorate at the State University of New York
College of Forestry at Syracuse. Since 1952 he has conducted
research in the silviculture and management of northern hardwood forests. At present he is in charge of the Northeastern
Station's research center at Burlington, Vermont.
THE BIRCHES i n t h e Northeast,
t h e yellow b i r c h i s t h e
e l i t e s p e c i e s , by f a r t h e most v a l u a b l e a s a timber
tree.
More t h a n t h a t ,
i t is one o f t h e l a r g e s t deciduous
t r e e s o f n o r t h e a s t e r n America.
I t may reach 100 f e e t i n
h e i g h t and more than 3 f e e t i n diameter, and may l i v e t o 300
y e a r s o f age.
P i o n e e r s t o l d t a l e s o f t h e g i g a n t i c yellow
b i r c h e s they saw.
The yellow b i r c h ( B e t u l a ~ l l e ~ h a n i e n s i s ) t a k e s i t s
name from t h e c h a r a c t e r of i t s bark. ~ h e ' b a r k o f young
t r e e s i s l u s t r o u s s i l v e r y gray o r yellowish,
and i t p e e l s
back i n t o papery t h i n yellow c u r l s .
Yellow b i r c h is a t r e e o f t h e cool n o r t h and t h e
higher elevations.
From Newfoundland and t h e S t . Lawrence
country i t ranges westward through s o u t h e r n Quebec and
O n t a r i o t o t h e n o r t h s h o r e o f Lake S u p e r i o r and a s f a r west
I t i s found
a s Lake o f t h e Woods i n Minnesota ( f i g . 1 )
throughout t h e Great Lakes region, growing southward i n t o
and Pennsylvania.
Some i s found i n n o r t h e r n
Iowa, Ohio,
Delaware,
and southward along t h e h i g h e r e l e v a t i o n s of t h e
Appalachian Mountains a s f a r a s Georgia ( 2 2 ) .
'
The l a r g e s t c o n c e n t r a t i o n s of yellow b i r c h timber a r e
found i n e a s t e r n Canada,
n o r t h e r n New York and New England,
and t h e Upper P e n i n s u l a of Michigan.
I n terms of s t a n d i n g timber,
yellow b i r c h i s one o f
t h e most important hardwoods o f t h e Northeast. U.S. F o r e s t
S e r v i c e f o r e s t - s u r v e y d a t a show t h a t i n t o t a l volume i t
ranks f i r s t among a l l t h e hardwoods i n New Hampshire, second
i n Maine and Vermont, and t h i r d i n New York.
rdcr(,-zt&CLIMATIC
I n t h e areas where yellow b i r c h grows, p r e c i p i t a t i o n
averages about 45 inches a year i n t h e East, 30 inches i n
t h e Lake S t a t e s .
About h a l f of t h i s p r e c i p i t a t i o n occurs
during t h e growing season.
I n the northern a r e a s where t h e
l a r g e concentrations of yellow b i r c h timber a r e found, snowf a l l averages 80 t o 100 inches a year.
The average annual temperature i n t h e botanical range
of t h e species is about 45'F.
The July average i s about
70°, t h e January average about 20'.
However t h e temperature
The growing season
extremes range from 100° t o -40' ( 2 8 ) .
v a r i e s from 80 t o 140 days; t h e average i s about 120 days.
SOILS
Yellow b i r c h i s found growing on s o i l s of t h e podzol,
brown podzolic,
and gray-brown podzolic s o i l groups ( 3 0 ) .
I n g l a c i a t e d p a r t s of i t s botanical range t h e s o i l s a r e
mostly derived from granites,
s c h i s t s , o r calcareous rocks;
elsewhere i n the range t h e s o i l s a r e derived from sandstones
o r shales.
Yellow b i r c h grows on well-arained,
.moderately welldrained,
and poorly-drained
loams and sandy loams.
On
poorly-drained areas t h e t r e e s a r e usually found on s l i g h t
e l e v a t i o n s above t h e ground l i n e , f o r example, on r o t t e d
stumps and windthrow hummocks.
The b e s t growth of yellow birch is found on moderatel y well-drained sandy loams within t h e podzol and brown podz o l i c s o i l s groups.
PHYSIOGRAPHIC
Yellow b i r c h t h r i v e s b e s t on f l a t s and lower slopes.
I n h i l l y mountainous t e r r a i n i t does b e t t e r on t h e cooler
northern and e a s t e r n slopes.
I n New York and New England
yellow b i r c h grows a t e l e v a t i o n s up t o 2,500 f e e t ; i n t h e
Lake S t a t e s i t grows up t o about t h e 1,600-foot elevation.
I n the southern Appalachians i t i s almost always found above
3,000 f e e t .
BIOTIC
Although yellow bii-ch may be present i n p r a c t i c a l l y
a l l s t a g e s of t h e f o r e s t succession,
i t i s found mostly i n
2
D I S T R I B U T I O N MAP B Y E L B E R T L .
LITTLE.
JR..
U.
S.
FOREST S E R V I C E .
Figure 1.--Re natural range of yellow birch. Shaded
areas show the commercial range, where heaviest concentrations of ye1 low birch timber are found.
climax associations; t h a t is, s r a t h e r permanent, self-perpetuating kind of f o r e s t as against the l e s s l a s t i n g kind
I t is found i n 21 of the
t h a t comes in, say, a f t e r f i r e .
cover types defined by the Society of American Foresters
The most important of these are:
(25).
Type
Type
Type
Type
Type
23
24
25
30
32
-- Hemlock
-- Hemlock-yellow birch
-- Sugar maple-beech-yellow
-- R e d spruceyellow birch
-- R e d spruce
birch
Yellow b i r c h i s a l s o found a s s o c i a t i n g with t h e paper b i r c h
and gray birch-red maple cover types, which a r e pioneer
types t h a t o f t e n f i l l i n on abandoned land.
Among t h e more common t r e e a s s o c i a t e s of yellow b i r c h
are:
American beech
Balsam f i r
Basswood
Bigtooth aspen
Black cherry
Eastern hemlock
Gray b i r c h
Paper b i r c h
P i n cherry
Quaking aspen
Red maple
Sugar maple
Red spruce
Sweet b i r c h
White ash
White pine
Fagus grandifo lia
Abies balsamea
Ti 1 ia aner icana
Popu Eus grandidentata
Prunus serotina
Tsuga canadensis
Betula populifolia
Betula papyrifera
Prunus pensy lvanica
Populus tremu loides
Acer rubrum
Acer saccharum
Picea rubens
Betula Eenta
Fraxinus americana
Pinus s trobus
The shrubs t h a t a r e commonly found
with yellow b l r c h include t h e following:
S t r i p e d maple
Mount s i n maple
A 1 t e r n a t e l e a f dogwood
Beaked hazelnut
Leatherwood
American f l y honeysuckle
Ground hemlock
Witch hobble
in
association
Acer pennsy lvanicum
Acer spicatum
Cornus alternifolia
Cory lus cornuta
Dirca palustris
Lonicera canadensis
Taxus canadensis
Viburnum a lni fo 1 ium
Of these,
t h e two maples,
t h e honeysuckle,
and t h e witch
hobble a r e t h e most common i n t h e Northeast. Ground hemlock
once was common, and s t i l l i s i n p a r t s of New England and
Canada; but where excessive deer populations have b u i l t up-as i n t h e Allegheny Plateau and over much of t h e Lake S t a t e s
region--this shrub may be v i r t u a l l y eliminated.
FLOWERING
&
FRUITING
A s with a l l hpecies i n t h e genus Betula, yellow b i r c h
i s monoecious; t h a t is, male and female flowers occur on t h e
same t r e e but i n s e p a r a t e c a t k i n s .
Although bi-sexual c a t k i n s have been found on some b i r c h e s , none have been r e p o r t ed f o r yellow b i r c h . l
However, t h e flowering c h a r a c t e r i s t i c s o f yellow b i r c h have n o t been s t u d i e d i n t e n s i v e l y .
The s t a m i n a t e c a t k i n s form i n l a t e summer o r f a l l .
They e l o n g a t e and become q u i t e conspicuous t h e following
s p r i n g (29). The p i s t i l l a t e flowers appear during t h e f i r s t
t h r e e weeks i n May,
about t h e same time t h e t r e e s begin t o
leaf.
They a r e terminal on s h o r t b r a n c h l e t s . The f r u i t , a
winged n u t l e t l o c a t e d i n t h e s c a l e s o f t h e s t r o b i l e s , r i p e n s
i n l a t e J u l y o r August ( f i g . 2 ) .
SEED
PRODUCTION
Seed production of yellow b i r c h begins a t about 40
years, when t r e e s i n t h e main crown canopy may average about
5 inches i n diameter a t b r e a s t h e i g h t .
The b e s t seed proa t which time t h e t r e e s may
d u c t i o n o c c u r s a f t e r 70 years,
be 8 o r 9 inches i n diameter. Good seed c r o p s a r e r e p o r t e d
The germinative c a p a c i t y
t o occur every 1 o r 2 y e a r s (29).
averages 27 percent, with a range from 6 t o 48 p e r c e n t .
Heavy seed f a l l begins with c o l d weather i n October
(2).
M i l l i o n s of seeds may be discharged p e r a c r e .
They
a r e d i s p e r s e d by wind.
When a hard snow cover i s present,
s e e d may be blown along t h e s u r f a c e o r picked up i n wind
c u r r e n t s and moved hundreds of f e e t from t h e i r source. Event u a l l y , many of such migrant seeds may c o l l e c t i n small
pockets i n t h e snow and subsequently s e t t l e t o t h e ground a t
t h e s e s p o t s when t h e snow m e l t s .
I n d i c a t i o n s a r e t h a t t h e seeds o f h i g h e s t germination
c a p a c i t y a r e t h o s e t h a t f a l l f i r s t when t h e c a t k i n s begin t o
dry (14).
The s e e d s have i n t e r n a l dormancy and, i f n o t autumnsown, should be s t r a t i f i e d i n moist sand o r p e a t a t 40° F.
f o r a t l e a s t one month b e f o r e sowing ( 1 4 , 29).
'personal communication from Dr. F. U. Klaehn, a s s i s t a n t p r o f e s s o r o f s i l v i c u l t u r e , S t a t e U n i v e r s i t y o f New York College o f F o r e s t r y , Syracuse, N. Y.
PHENOLOGY
Phenological observations (average d a t e s ) recorded a t
a r e tabulated
B a r t l e t t , N. H., Kane, Pa., and Dukes, Mich.,
below:
art let t
Kane
Dukes
Leaf bud swell
Begins t o l e a f
Full leaf
Flowering
Seed ripening
Seed f a l l begins
Seed f a l l ends
Leaf f a l l begins
Leaf f a l l ends
S t a r t of height growth
End of height growth
A p r i l 16
May 5
May 1
Oct. 5
Feb
Sept. 20
Oct. 15
.
May 8
May 12
May 21
May 21
July 30
Aug. 10
Aug. 17
Oct. 8
Oct. 23
May 6
May 19
June 11
May 12
Aug. 20
Sept. 1 8
--
Sept.
Oct.
May
Aug.
Figure 2. --The flowers and seed of yellow birch.
A, flowers, staminate catkins pendant. B, strobi le
(cone).
C, bract, or strobi le scale. D, fruit, a
winged nut let.
24
17
16
10
Figure 3. --Ye 1 low birch
seedlings tend t o deve lop a shallow, spreading root system rather
than a taproot.
VEGETATIVE
PROPAGATION
Yellow b i r c h w i l l s p r o u t from stumps, e s p e c i a l l y from
younger t r e e s .
S e e d l i n g s p r o u t s a p p a r e n t l y develop a s well
a s seedlings.
Since n e i t h e r f o r e s t e r s nor h o r t i c u l t u r i s t s
have had much r e a s o n t o Propagate t h e s p e c i e s by c u t t i n g s o r
by g r a f t i n g ,
l i t t l e i s known o f i t s a d a p t a b i l i t y t o t h e s e
methods.
SEEDLING
DEVELOPMENT
Normally,
germination t a k e s p l a c e i n t h e s p r i n g f o l lowing s e e d d i s p e r s a l ( 2 0 )
But according t o o n e r e p o r t ,
seed t h a t had l a i n o v e r u n t i l t h e second y e a r produced vigorous seedlings ( 2 ) .
.
Yellow b i r c h r e g e n e r a t e s very poorly i n t h e r e l a t i v e Though l a r g e
l y t h i c k l i t t e r o f an u n d i s t u r b e d f o r e s t (5)
numbers o f s e e d s may germinate,
t h e i r r o o t s a r e t o o weak t o
p i e r c e t h e l i t t e r ( f i g . 3). Drying of t h e l i t t e r d u r i n g t h e
If
growing season i s u s u a l l y l e t h a l t o t h e puny s e e d l i n g s .
.
p a r t i a l l y p r o t e c t e d from sun and wind, e i t h e r humus s o i l s o r
s t r a i g h t mineral s o i l a r e good seedbeds.
E x c e l l e n t seedbed
c o n d i t i o n s a r e c r e a t e d by such d i s t u r b a n c e s a s logging,
f i r e , and windthrow. I n a managed f o r e s t , t h e a r e a o f favora b l e seedbed and t h e amount o f yellow b i r c h r e g e n e r a t i o n can
be i n c r e a s e d by mechanical s c a r i f i c a t i o n o f t h e s i t e a f t e r
logging ( 1 2 , 1 3 ) .
Without some d i s t u r b a n c e of t h e f o r e s t f l o o r , yellow
b i r c h r e g e n e r a t i o n i s r e s t r i c t e d mostly t o c r a c k s i n bould e r s and t o r o t t e d l o g s and stumps. A s t u d y i n Pennsylvania
showed t h a t 38 p e r c e n t of t h e yellow b i r c h grew on such
r o t t e d wood ( 1 1 ) . These r e g e n e r a t i o n h a b i t s of yellow b i r c h
e x p l a i n t h e f r e q u e n t s t i l t - r o o t i n g of t h e s p e c i e s .
I n Quebec, w i t h a r t i f i c i a l s e e d i n g s under f o r e s t conditions,
f i r s t - y e a r germination was h i g h e s t under p a r t i a l
shade,
b u t much lower i n
almost a s high under f u l l canopy,
t h e open ( 1 6 )
On t h e o t h e r hand, s e e d l i n g s u r v i v a l on mini n p e r c e n t of t o t a l germination,
e r a l s o i l a f t e r 2 years,
was h i g h e s t i n t h e open and n e x t under p a r t i a l shade.
.
S u c c e s s f u l s u r v i v a l depends upon a p a r t i c u l a r combin a t i o n of temperature, moisture, and l i g h t .
The s e e d l i n g s
need overhead l i g h t , b u t a cool, moist seedbed.
Nursery-grown s e e d l i n g s i n t h e Lake S t a t e s , grown a t
about 1 5 p e r s q u a r e f o o t a f t e r 1 year,
averaged 3.6 i n c h e s
i n h e i g h t and 6 . 1 i n c h e s i n r o o t d e p t h ; and a f t e r 3 y e a r s ,
20.5 i n c h e s i n h e i g h t and 12.6 inches i n r o o t depth ( 2 6 ) .
r e g e n e r a t i o n o f yellow b i r c h
After harvest cuttings,
i n small openings ( p a t c h e s ) o f 0.1- t o
0.5-acre i n s i z e . I n t h e Lake S t a t e s , 0.1-acre openings a r e
considered b e s t ( t i ) . I n t h e Northeast, where annual p r e c i p i t a t i o n i s h i g h e r , t h e openings may be l a r g e r . A s t h e openi n g s i n c r e a s e i n s i z e , yellow b i r c h s e e d l i n g s tend t o become
more p l e n t i f u l along t h e edges than i n t h e c e n t e r .
i s most s u c c e s s f u l
The s u p e r i o r i t y of patch c u t t i n g s i n n o r t h e r n hardWoods f o r r e g e n e r a t i n g yellow b i r c h ,
as compared t o o t h e r
i s shown below by d a t a taken i n a New
c u t t i n g methods,
Hampshire s t u d y 1 0 t o 15 y e a r s a f t e r t h e c u t t i n g s were made
(15).
Wethod o f cutting
1/3-acre p a t c h e s
Clear-cut
Tree s e l e c t i o n
Mi l a c r e s s t o c k e d
w i t h ,ye1 low b i r c h
(percent)
Stocked milacres were those on which t h e s a p l i n g of g r e a t e s t
apparent p o t e n t i a l f o r a f u t u r e crop t r e e was a yellow b i r c h .
Most of t h e o t h e r quadrats, of course, were stocked with
o t h e r species.
SAPLING
STAGE
TO
MATURITY
Growth
Given overhead l i g h t , young yellow b i r c h makes modera t e l y r a p i d height growth. I n c l e a r - c u t openings l e s s than
1 a c r e i n area,
made i n a mature stand o f t h e birch-beechmaple type on an average s i t e i n t h e White Mountains of New
Hampshire, t h e o r d e r of r e l a t i v e h e i g h t s of 6-year-old sapl i n g s , beginning. with t h e t a l l e s t species,
was a s follows :
p i n cherry, b i g t o o t h aspen,
paper birch, white ash, yellow
birch, sugar maple, American beech.
The yellow b i r c h were 8 t o 10 f e e t t a l l a t 6 years.
A t 23 years t h e p o s i t i o n s were about t h e same, except t h a t
most of t h e p i n cherry had disappeared.
Yellow b i r c h then
aver aged about 30 f e e t
.
I n t h e Adirondack Mountains of New York, yellow b i r c h
s a p l i n g s i n a northern hardwood stand t h a t followed a burn
averaged 6 f e e t a t 6 years, 12 f e e t a t 10 years, and 22 f e e t
a t 14 years (18).
I n t h e same region,
stem analyses were made of an
almost pure 60-year stand of yellow b i r c h t h a t had followed
a charcoal c u t t i n g ( 1 8 ) .
Age
(years)
Total height
(feet)
D. b.h.
(inches)
The average annual diameter increment of yellow b i r c h
poletimber and sawtimber is small i n r e l a t i o n t o i t s s a p l i n g
height growth.
On average s i t e s , t h e annual increment i s
about 0.1 inch ( 9 ) ; on poor s i t e s , about 0.05 inch.
Crown lengths and widths of yellow b i r c h generally
a r e a l i t t l e l e s s than those of sugar maple and beech ( 8 ) .
Crown l e n g t h s a r e normally about 40 percent of t o t a l height.
Figure 4.--A mature yellow b i r c h i n a beech-birch-maple
f o r e s t i n New England.
One o f t h e l a r g e s t deciduous
t r e e s , y e l l o w b i r c h ma,y grow 100 f e e t t a l l and 3 f e e t
i n diameter.
Crown widths f o r s e v e r a l diameter c l a s s e s ,
t h e Lake S t a t e s , a r e a s follows:
Diameter
class
(inches)
6
12
18
24
a s measured i n
Average crown
width
(feet)
12
20
27
34
Mature yellow b i r c h on average s i t e s may b e 90 t o 100
f e e t t a l l and more t h a n 30 inches i n diameter at 200 y e a r s .
I n n o r t h e r n New England, such t r e e s have a form c l a s s o f
about 80 and a c l e a r l e n g t h o f 40 t o 46 f e e t ( f i g . 4).
To l e r a n c e
The s p e c i e s i s t h e most t o l e r a n t o f t h e b i r c h e s nat i v e t o e a s t e r n North America; i t needs l e s s d i r e c t overhead
l i g h t than t h e o t h e r b i r c h e s and i s found i n s m a l l e r openings.
S t i l l , i n comparison with o t h e r t r e e s o f a l l kinds,
yellow b i r c h g e n e r a l l y i s r a t e d a s i n t e r m e d i a t e i n t o l e r ance.
And although i t is w e l l r e p r e s e n t e d i n many climax
types o f n o r t h e r n f o r e s t s , i t tends t o g i v e way with age t o
more t o l e r a n t s p e c i e s , e s p e c i a l l y on t h e l e s s moist s i t e s .
Pruning
I n dense s t a n d s yellow b i r c h prunes i t s e l f f a i r l y
well.
Yet when such t r e e s a r e exposed by c a r e l e s s c u t t i n g
o r m o r t a l i t y i n t h e stand, they commonly develop a p r o f u s i o n
o f epicormic branches from dormant buds (16), t h u s n u l l i f y ing the e f f e c t s of e a r l i e r self-pruning.
Favorable r e s u l t s have been r e p o r t e d i n a study of
a r t i f i c i a l pruning on 20-year-old yellow b i r c h i n Michigan.
The pruned t r e e s were i n a n o r t h e r n hardwood s t a n d of about
1,400 t r e e s p e r a c r e ; no t h i n n i n g o r o t h e r c u t t i n g was done
on t h e study a r e a .
Eleven y e a r s a f t e r pruning t o 1 8 feet-about h a l f of t o t a l t r e e height--examination of t h e s t a n d
showed t h a t n e i t h e r h e i g h t nor diameter growth had been reduced.
Boles c l e a r e d by pruning had remained c l e a r . A few
epicormic branches had appeared a f t e r t h e pruning, b u t a l l
d i e d w i t h i n 3 years.
Wounds from f l u s h pruning up t o 2
inches i n diameter healed over i n 6 t o 8 y e a r s without decay
o r o t h e r d e f e c t ; i n l a r g e r wounds t h e r e was some a s s o c i a t e d
d e f e c t b u t no i n f e c t i o n o f h e a r t r o t ( 2 4 ) .
Weaknesses
The t h i n bark of young yellow b i r c h ( f i g . 5) i s hight h e f o r e s t types
l y inflammable ( l o ) , although normally
c o n t a i n i n g yellow b i r c h a r e not very s u s c e p t i b l e t o f i r e .
Butt
But should i t occur, yellow b i r c h i s e a s i l y i n j u r e d .
r o t may follow f i r e damage.
Figure 5.--The bark o f yellow birch, a distinguishing
On young trees the bark is lustrous
characteristic.
silvery gray or yellowish, peeling back into papery
thin ye1 low curls.
Yellow b i r c h t r e e s u s u a l l y develop a shallow, widespreading r o o t system; t h i s s u b j e c t s them t o windthrow.
Trees t h a t have become e s t a b l i s h e d on boulders and those
t h a t a r e s t i l t - r o o t e d a f t e r having s t a r t e d on l o g s o r stumps
a r e e s p e c i a l l y v u l n e r a b l e t o t o p p l i n g by wind ( f i g . 6 and 7).
Insects & Diseases
When s t a n d s a r e opened up e x c e s s i v e l y by c u t t i n g , t h e
change i n environment may cause a d e c l i n e i n yellow b i r c h
t h a t i s commonly r e f e r r e d t o a s post-logging decadence.
Birch i n undisturbed stands, however, may undergo a s i m i l a r
Figure 6. --This ye 1 low
birch, which apparent ly
began life as a seedling
taking root in the crack
of a boulder, has accommodated itself to the
boulder by sending roots
down around it
.
Figure 7.--Stilt rooting. This tree probably began as
a seedling growing atop a stump, which rotted
away
and left the tree standing on stilt roots.
13
d e c l i n e ; here t h e malady i s c a l l e d b i r c h dieback. This cond i t i o n i s prevalent i n t h e Maritime Provinces of Canada and
i n northern New England.
No c a u s a t i v e pathogen has been
found.
Theories have been advanced t h a t t h e dieback,
like
post-logging decadence, i s a r e a c t i o n t o changed environment
--specifically,
t o t h e gradual warming of t h e c l i m a t e t h a t
has been occurring over t h e p a s t s e v e r a l decades.
The symptoms of post-logging decadence and dieback
a r e very s i m i l a r . A t f i r s t , t h e leaves c u r l and turn yellowi s h . Then t h e twigs d i e back from t h e t i p s . Eventually a l l
o r a considerable p a r t of t h e crown d i e s (20).
I n some
cases t h e r e may be p r o l i f i c epicormic branching along t h e
stem.
Some t r e e s d i e while o t h e r s recover by growing a new
crown, but r o t may e n t e r t h e stem from t h e dead limbs.
Very l i t t l e i s known about what t r i g g e r s b i r c h dieback.
According t o a study i n New Brunswick, Canada (21),
t h e r o o t system of yellow b i r c h i s extremely s e n s i t i v e t o
high s o i l temperatures. An i n c r e a s e of summer s o i l temperat u r e of 3.6' F. increased r o o t l e t m o r t a l i t y tenfold,
from 6
t o 60 percent.
However, a t Chalk River, Ontario, a 10' inc r e a s e i n s o i l temperature from one year t o t h e next was accompanied by no n o t i c e a b l e change i n t h e h e a l t h of t h e t r e e s
(7).
Discrepancies i n r e s u l t s may be due t o t h e r e l a t i v e l y
b r i e f d u r a t i o n of t h e s t u d i e s , d i f f e r e n c e s i n s i t e , o r i n
methodology.
A recent study of yellow b i r c h dieback i n r e l a t i o n t o
growth p a t t e r n s and climate, coupled with a c a r e f u l examinat i o n of t h e h i s t o r y of t h e disease, c a s t s considerable doubt
on t h e o r i e s t h a t dieback i s some s o r t of purely physiologiI t i s shown t h a t t h e malady has spread i n
c a l disturbance.
t h e manner of an i n f e c t i o u s d i s e a s e from t h e l o c a l i t y of i t s
f i r s t recognized appearance i n c e n t r a l New Brunswick i n 1932.
I t was found t h a t t h e growth behavior of unaffected t r e e s
during drought d i f f e r s from t h a t of t r e e s a f f l i c t e d with
dieback: during drought, high-vigor t r e e s s u f f e r l e s s growth
reduction than low-vigor ones, whereas during e a r l y y e a r s of
dieback t h e more vigorous t r e e s s u f f e r t h e g r e a t e r growth
reduction. I t i s pointed o u t t h a t a g r e a t e r show of symptoms
i n p l a n t s of high vigor i s c h a r a c t e r i s t i c of v i r u s infections.
The sum of t h e evidence adduced i n t h i s study supp o r t s a hypothesis t h a t b i r c h dieback i s an i n f e c t i o u s d i s ease caused by a v i r u s (3).
Birches a r e s u b j e c t t o i n f e s t a t i o n by t h e bronze
b i r c h borer, A g r i l u s a n x i u s .
Apparently t h e i n s e c t s r a r e l y
complete t h e c y c l e from egg t o a d u l t on normal, healthy
t r e e s . However, on dying t r e e s o r those showing t h e symptoms
o f b i r c h dieback, they can complete t h e c y c l e ,
The t u n n e l i n g s o f t h e b o r e r weaken t h e t r e e and may c a u s e d e a t h .
Yellow b i r c h i s an o c c a s i o n a l h o s t t o two l e a f feede r s : t h e b i r c h s k e l e t o n i z e r , B u c c u l a t r i x c a n a d e n s i s e l l a ; and
t h e gypsy moth, P o r t h e t r i a d i s p a r .
The b i r c h leaf-mining
c a n s t r i p e n t i r e trees, b u t i t
Sawfly, Phy I lo torna nernorada,
is rarely f a t a l (4).
Y e l l o w birch is o f t e n infected with h e a r t r o t s .
The
f a l s e t i n d e r fungus, Fomes i g n a r i u s , i s very common on b i r c h .
Fomes fomentarius, t h e t i n d e r fungus, i s most common on dead
b i r c h , b u t o c c a s i o n a l l y a t t a c k s l i v i n g trees ( 2 3 ) .
Less
common on y e l l o w b i r c h i s Fornes app l a n a t u s .
,
The stem canker, Nec t r i a ga 11igena i s common on y e l low b i r c h ( I ) . I t r e d u c e s t h e q u a l i t y o f t h e main stem, i n c r e a s e s t h e chances o f wind breakage, and p r o v i d e s a f o o t i n g
f o r other diseases.
Two s p e c i e s o f P o r i a a r e found on y e l l o w b i r c h : P o r i a
l a e v i g a t a and P o r i a o b l i q u a ( 2 7 ) .
P. l a e v i g a t a h a s charact e r i s t i c bark-covered c a n k e r s on mature b i r c h ; P . o b l i q u a i s
common on t h e f a c e o f o l d N e c t r i a cankers,
and i t s s t e r i l e
conks a r e found on branch s t u b s o r t r u n k wounds. Both i n d i c a t e e x t e n s i v e ,decay.
Yellow b i r c h may b e g i r d l e d by mice,
rabbits,
and
porcupines.
I t i s a f a v o r i t e browse o f d e e r .
Grouse f e e d
on i t s buds, c a t k i n s , and s e e d ; s o n g b i r d s e a t t h e seeds, t o o .
I n g e n e r a l , yellow b i r c h may be d e s c r i b e d a s a v e r y
sensitive tree.
I t i s a t t a c k e d h e a v i l y by i n s e c t s and d i s eases.
I t a d a p t s v e r y p o o r l y t o changes i n environment.
Although yellow b i r c h s e e d s o f t e n and p r o l i f i c a l l y ,
it is
d i f f i c u l t t o b r i n g i t through t h e s e e d l i n g s t a g e and on t o
maturity.
Yellow b i r c h r a n k s h i g h among t h e hardwoods used i n
f u r n i t u r e manufacture i n t h e United S t a t e s ( 1 9 ) .
I n the
q u a l i t i e s t h a t s u i t i t well f o r furniture, i t is s i m i l a r t o
h a r d maple and b l a c k c h e r r y .
dense.
The wood o f yellow b i r c h is heavy, hard, s t r o n g , and
tinged with
The heartwood i s l i g h t brown i n c o l o r ,
r e d ; t h e sapwood i s nearly white. The wood machines well and
takes f i n i s h b e a u t i f u l l y .
Yellow b i r c h i s a l s o used f o r f l o o r i n g and lumber.
Large l o g s a r e sought by veneer makers, f o r manufacture i n t o
f i n e plywood and such items a s modern f l u s h doors.
Wintergreen o i l i s p r e s e n t i n t h e inner bark of t h e
stem and roots, but i n much smaller q u a n t i t i e s than i n sweet
birch.
No r a c i a l t e s t s of yellow b i r c h have been reported.
One n a t u r a l hybrid has been found, B e t u l a x p u r p u s i i , a c r o s s
between yellow b i r c h and B e t u l a p u m i l a var. g l a n d u l i f e r a , a
shrub. I t occurs i n t h e Lake S t a t e s (17).
(1)
Boyce, John S .
1938. F o r e s t p a t h o l o g y .
600 pp. New York and London.
(2)
Burton, D. H., and L e s l i e , A. P .
1953. Some s i l v i c a l c h a r a c t e r i s t i c s o f b i r c h .
Canada Dept. Agr. F o r e s t Biology Div. Symposium on b i r c h
d i e b a c k : 57-58.
Ottawa.
(3)
C l a r k , J., and B a r t e r , G. W.
1958. Growth and c l i m a t e i n r e l a t i o n t o die-back
birch.
F o r e s t S c i . 4 ( 4 ) : 343-364.
(4)
Craighead, Frank C.
1950. I n s e c t enemies o f e a s t e r n f o r e s t s .
U.S. Dept. Agr. Misc. Pub. 657. 679 PP.,
of
illus.
yellow
(5)
Cunningham, G. C.
1953. Research i n t o l e r a n t hardwoods.
Canada Dept. Agr.
F o r e s t Biology Div. Symposium on b i r c h
d i e b a c k : 52-56.
Ottawa.
(6)
Eyre, F. H., and Z i l l g i t t , W. M.
1953. P a r t i a l c u t t i n g s i n n o r t h e r n hardwoods o f t h e Lake S t a t e s .
U.S. Dept. Agr. Tech. B u l l . 1076. 124 pp., i l l u s .
(7)
F r a s e r , D. A.
1957. Annual and s e a s o n a l march o f s o i l t e m p e r a t u r e on s e v e r a l
s i t e s under a hardwood s t a n d .
Canada Dept. Northern Aff a i r s and Nat. Resources, F o r e s t Res. Div. Tech. Note 56,
15 pp., i l l u s .
(8)
Frothingham, E. H.
1915. The n o r t h e r n hardwood f o r e s t .
I t s composition,
growth,
and management.
U.S. Dept. Agr. Bul. 285. 80 pp., i l l u s .
(9)
Gilbert,
1955.
Wilson, Robert W., Jr., and Hutnik, R u s s e l l J.
Adrian M.,
Growth b e h a v i o r o f n o r t h e r n hardwoods a f t e r a p a r t i a l
c u t t i n g . J o u r . F o r e s t r y 53: 488-492.
(10)
Harlow, W i l l i a m M., and H a r r a r , Ellwood S .
1950. Textbook o f dendrology.
Ed. 3, 555 pp., i l l u s . New York.
(11)
Hough, A. F., and Forbes, R. D.
1943. The ecology and s i l v i c s o f f o r e s t s i n t h e h i g h p l a t e a u s
o f P e n n s y l v a n i a . Ecol. Monog. 13: 299-320.
(12)
J a r v i s , J. M.
1956. An e c o l o g i c a l approach t o t o l e r a n t hardwood s i l v i c u l t u r e .
Forest
Canada Dept N o r t h e r n A f f a i r s and Nat Resources,
Res. Div. Tech. Note 43. 43 pp., i l l u s .
.
.
(13)
J a r v i s , J. M.
1957. C u t t i n g and seedbed p r e p a r a t i o n t o r e g e n e r a t e yellow
b i r c h . Canada Dept. N o r t h e r n A f f a i r s and Nat. Resources,
F o r e s t Res. Div. Tech. Note 53.
17 pp., i l l u s .
(14)
Joseph, H i l d a C.
1929. Germination and v i t a l i t y o f b i r c h s e e d s .
Bot. Gaz. 87: 127-151.
(15)
Leak, William B., and Wilson, Robert W., Jr.
1958. R e g e n e r a t i o n a f t e r c u t t i n g of old-growth n o r t h e r n hardwoods i n New Hampshire.
U. S. F o r e s t S e r v . N o r t h e a s t .
F o r e s t Expt. S t a . , S t a . P a p e r 103. 8 pp.
(16)
L i n t e a u , Andre.
1948. F a c t o r s a f f e c t i n g g e r m i n a t i o n and e a r l y s u r v i v a l o f y e l low b i r c h i n Quebec.
F o r e s t r y Chron. 24: 27-86.
(17)
L i t t l e , E l b e r t L., Jr.
1953. Check l i s t o f n a t i v e and n a t u r a l i z e d t r e e s o f t h e United
U. S. Dept. Agr. Handbook 41.
S t a t e s ( i n c l u d i n g Alaska).
472 pp.
(18)
McCarthy, Edward F., and Belyea, Harold C.
1920. Yellow b i r c h and i t s r e l a t i o n t o t h e Adirondack F o r e s t .
N.Y. S t a t e C o l l . F o r e s t r y Tech. Pub. 12.
50 PP., i l l u s .
(19)
Merrick, Gordon C.
1951. Wood u s e d i n manufacture--1948.
U.S. F o r e s t S e r v . Resource Rpt. 2 .
66 pp.
(20)
and Duda, Edward J.
Nash, Robley W.,
1951. S t u d i e s o n e x t e n s i v e dying,
r e g e n e r a t i o n , and management
o f b i r c h . Maine F o r e s t Serv. Bul. 15. 82 pp., i l l u s .
(21)
Redmond, D. R.
1955. R o o t l e t s , mycorrhiza,
and s o i l t e m p e r a t u r e s i n r e l a t i o n
t o b i r c h die-back.
Canad. J o u r . Bot. 33: 595-627.
(22)
S a r g e n t , C h a r l e s S.
1933. Manual o f t h e t r e e s o f North America.
Ed. 2, 910 pp., Boston and New York.
(23)
S i l v e r b o r g , Save1 B.
1954. N o r t h e r n hardwoods c u l l manual.
S t a t e Univ. N.Y. 12011. F o r e s t r y B u l . 31.-
45 pp.,
(24)
S k i l l i n g , D a r r o l l D.
1959. Response o f yellow b i r c h t o a r t i f i c i a l p r u n i n g .
J o u r . F o r e s t r y 57: 429-432.
(25)
S o c i e t y o f American F o r e s t e r s .
1954. F o r e s t c o v e r t y p e s o f N o r t h America.
69 pp., Washington.
(26)
S t o e c k e l e r , J. H., and Jones, G. W.
1957. F o r e s t n u r s e r y p r a c t i c e i n t h e Lake S t a t e s .
U.S. Dept. Agr. Handbook 110. 124 pp-., i l l u s .
(27)
True, R. P., Tryon, E. H., and King, J. F.
1955. Cankers and decays o f b i r c h a s s o c i a t e d
s p e c i e s . Jour. F o r e s t r y 53: 412-415.
(28)
(29)
.
U n i t e d S t a t e s Department of A g r i c u l t u r e .
1941. C l i m a t e and man.
U.S. Dept. Agr. Yearbook.
1,248 pp.,
w i t h two P o r i a
illus.
---------1938.
(30)
illus.
S o i l s and men.
U.S. Dept. Agr. Yearbook.
1,232 pp.,
United S t a t e s F o r e s t S e r v i c e .
1948. Woody p l a n t s e e d manual.
U.S. Dept. Agr. Misc. Pub. 654.
illus.
416 pp.,
illus.
,
.
This is one of a s e r i e s of 15 s i l v i c a l , i p a p e r s to be
published by the Northeastern Forest bper&nt S t a t i o n .
The s e r i e s w i l l include papers on the f o l l o v i d specses:
I
reen en' ash .. .
*White ash
&ch
.
Paper birch
*Sweet birch
*kellow. birch
BEack cherry
-
-6
:E
<
Red maple
f i r j- *Red sprucc"~
'Eastern h&ock
'Eastern white pine
* P i t c h pine
*Virginia pink
*Atlantic white-cedar
rBalsam