BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Pinus strobus | Eastern White Pine 



GENERAL BOTANICAL CHARACTERISTICS : 
Eastern white pine is a large, native, evergreen conifer.  It grows
rapidly and in 40 years can be 60 feet (18.3 m) tall and 8 to 10 inches
(20-25 cm) in d.b.h. [7].  Individuals of 150 feet (46 m) and 40 inches
(102 cm) in d.b.h. were common in virgin forests.  Eastern white pine
commonly reaches 200 years of age and may exceed 450 years [68].  In
closed stands, boles are free of branches for over two-thirds of their
length.  Needles are 2.5 to 5.0 inches (6-13 cm) long, and the winged
seeds are about 0.8 inches (2 cm) long.  The roots are widespreading and
moderately deep without a distinct taproot [20].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Eastern white pine begins producing cones when 5 to 10 years old, but
good seed production does not occur until trees are at least 20 to 30
years old [26].  Good seed years occur every 3 to 5 years, with some
seed produced in intervening years [7].

Seeds are dispersed primarily by wind.  Seeds travel 200 feet (60 m)
within a stand and more than 700 feet (210 m) in the open.  Animals also
disperse seeds.  Gray squirrel seed caches were responsible for white
pine reproduction under red oak (Quercus rubra) stands in southern New
Hampshire [68].  White-footed mice and red-backed voles bury caches
containing 20 to 30 eastern white pine seeds beneath the litter but on
top of the mineral soil.  Caches that escape revisitation and decimation
produce seedlings [1].

Favorable seedbeds include moist mineral soil, mosses (Polytrichum
spp.), and short grass cover of light to medium density.  Dry mineral
soil, pine litter, lichen, and very thin or very thick grass covers are
poor seedbeds in full light but adequate in shade [68].  Eastern white
pine shows very limited delayed emergence the second year after seed
fall, and none after 3 years [57].

Eastern white pine colonizes disturbed sites, but a nurse crop of aspen
(Populus spp.), birch (Betula spp.), or other pioneer species promotes
best regeneration [7].  When colonizing oldfields, eastern white pine is
more likely to become established in openings than under herbs.  Even
though seedling emergence and survivorship are higher under herbs, so
too is seed and seedling predation by rodents [14].

Eastern white pine seedlings require at least 20 percent of full light
for survival.  They achieve maximum height growth in 45 percent of full
light [51].  Early growth is slow, but between 10 and 20 years of age,
the average annual height growth is about 16 inches (40 cm) per year
[68].

Eastern white pine does not reproduce vegetatively [68].


SITE CHARACTERISTICS : 
Eastern white pine occurs on a variety of sites along the full moisture
gradient from wet bogs and moist streambottoms to xeric sand plains and
rocky ridges [7,67].  In Maine and New Brunswick, eastern white pine
occurs in well0drained, raised bogs [8]; in Michigan, it occurs on sand
dunes [42].  In the southern Appalachian Mountains and in Pennsylvania,
pure stands mainly occur on northerly aspects, in coves, and on
streambottoms [11].  Eastern white pine is common on the east shore of
lakes where blowdowns create openings for regeneration [28].

In New England, eastern white pine usually occurs between sea level and
2,000 feet (610 m) in elevation; on Catamount Mountain in the Adirondack
Mountains of New York, it occurs up to 3,168 feet (966 m).  In the
southern Appalachian Mountains, it occurs between 1,200 and 3,500 feet
(370-1,070 m) [11,28]

Eastern white pine grows on nearly all soil types within its range.  It
is most competitive on fairly infertile sandy soils, such as
well-drained outwash soils.  On clay or poorly drained soils, eastern
white pine occurs only as individuals or in small groups.  It grows on
fine sandy loams and silty loams on disturbed sites if there is little
hardwood competition [68].

Eastern white pine is the characteristic oldfield species in New
England.  Nearly pure stands develop on oldfields where seed is ample
and sod is intact [53].  In the Hudson River valley, eastern white pine
dominates the finer textured, less rocky oldfield sites, whereas oak
communities dominated the coarser textured, rockier sites [15].

Tree associates of eastern white pine not mentioned in Distribution and
Occurrence include sweet birch (Betula lenta), bigtooth aspen (Populus
grandidentata), quaking aspen (P. tremuloides), black cherry (Prunus
serotina), and black oak (Quercus velutina) [11].  

Understory species are scarce in pure stands of eastern white pine.  On
dry sites, associates include blueberries (Vaccinium spp.), wintergreen
(Gaultheria procumbens), dwarf bush-honeysuckle (Diervilla lonicera),
sweetfern (Comptonia peregrina), bracken fern (Pteridium aquilinum),
clubmosses (Lycopodium spp,), and broomsedge (Andropogon virginicus).
On moist, rich sites associates include wood sorrel (Oxalis spp.),
partridgeberry (Mitchella repens), wild sarsaparilla (Aralia
nudicaulis), jack-in-the-pulpit (Arisaema triphyllum), and hay-scented
fern (Dennstaedtia punctilobula).  Other associates include bigleaf
aster (Aster macrophyllus), Canada mayflower (Maianthemum canadense),
and bunchberry (Cornus canadensis) [11,41,25].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Eastern white pine is intermediate in shade tolerance [2] and is present
in all successional stages.  It is a pioneer species on oldfields and
other disturbed sites, a long-lived successional species, and a
physiographic climax species on dry, sandy soils [53,68].  Eastern white
pine is sometimes a component of climax forests on certain sites such as
steep slopes and ridge tops where windfall provides regeneration
opportunities [54].

Eastern white pine forests frequently establish after disturbance and
are even-aged.  However, uneven-aged forests also occur.  Eastern white
pine has dominated an uneven-aged old-growth forest in southern Ontario
for at least 700 years.  In this forest, canopy gaps created by the
death of individual trees from surface fire or windthrow enable eastern
white pine to regenerate [44].

Eastern white pine succeeds aspen postdisturbance forests.  The diffuse
aspen canopy allows enough light for eastern white pine to regenerate
[52].  Bigtooth aspen colonized and was the early dominant on a burn in
northern Michigan, but 53 years after the fire, eastern white pine and
red maple (Acer rubrum) were dominant [49].

More shade-tolerant species succeed eastern white pine.  In the Boundary
Waters Canoe Area in Minnesota, it begins to be replaced by white spruce
(Picea glauca), eastern white-cedar (Thuja occidentalis), balsam fir
(Abies balsamea), and paper birch (Betula papyrifera) about 360 years
after fire [16].


SEASONAL DEVELOPMENT : 
Eastern white pine male strobili open and shed pollen in April through
June, depending on latitude.  Fertilization occurs 13 months after
pollination.  Cones ripen and seeds are dispersed August through
September, about 2 years after cone initiation [7,26].  Seeds germinate
in the spring [7].  Terminal shoot growth is usually completed by the
end of June [68].

Related categories for Species: Pinus strobus | Eastern White Pine