BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Pinus sylvestris | Scots Pine 



GENERAL BOTANICAL CHARACTERISTICS : 
Scots pine is an exotic, medium-sized, two-needle pine.  Height at
maturity usually ranges from 50 to 100 feet (15-30 m) [18,42].  The
crown is open and spreading.  Needles range from 1.8 to 3.6 inches
(4.5-9.0 cm) in length [57].  The bark is relatively thin [18,57].  A
taproot is frequently developed on sandy soils, but is not a universal
trait for Scots pine.  The depth of the taproot ranges from 4.9 to 9.8
feet (1.5-3.0 m), but most of the roots are horizontal and within 7.8
inches (20 cm) of the soil surface [42].  A population of middle-aged
Scots pine in Finland had numerous root grafts between neighboring
trees in networks of up to ten trees.  Water and nutrients are
transferred from one tree to another through the grafts (Yli-Vakkuri in
[9]).

Scots pine is long-lived; individuals of nearly 1,000 years of age
occur in northern Sweden [59].  Ages of 200 and 400 years are common in
Scandinavia [22].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Scots pine reproduces by seed.  Sexual maturity can be reached as early
as 5 to 8 years of age; the usual range is from 10 to 15 years of age.
Scots pine continues to produce viable seed for up to 200 years.  Good
seed crops are produced every 3 to 6 years, with light crops in
intervening years.  Seed cones require alternating wet and dry weather
to open; seeds can be retained until early spring.  Seed dispersal
distances range from 164 to 328 feet (50-100 m) from the parent, though
the maximum distance is greater than 0.6 mile (1 km) [42].  Seed quality,
germination, and establishment decrease with distance from the parent
plant [52].

Scots pine seedling establishment occurs on bare mineral soil.  In
England, however, where Scots pine is invading heather (Calluna
vulgaris)-bracken fern (Pteridium aquilinum) heaths, Scots pine
seedlings were found even in dense stands of bracken fern; the limiting
factor on these sites appears to be proximity to seed source, rather
than density of ground vegetation [33].

Moisture stress, in the form of repeated cycles of wetting and drying,
has a pronounced negative effect on Scots pine seed germination [40].
Seedlings establish best with adequate moisture and some shade [42].
Survival is best when seedlings are planted on microsites close to the
tops of hills, and lowest in overly moist depressions [19].

There is no naturally occurring vegetative reproduction [42].


SITE CHARACTERISTICS : 
Scots pine is found from sea level to 8,000 feet (2,440 m) elevation,
and grows on a wide variety of soils including peat, though growth on
peat usually results in stunted trees [42].  Growth is best on
well-drained soils [29].  Soil pH ranges from 4.0 to 7.0, but growth is
best between 4.5 and 6.0 [42,56].

Where it is naturalized in northern New York, Scots pine is associated
with black cherry (Prunus serotina), red maple (Acer rubrum), sugar
maple (A. saccharum), American beech (Fagus grandifolia), quaking aspen
(Populus tremuloides), and eastern white pine [42].


SUCCESSIONAL STATUS : 
Facultative Seral Species

Scots pine is intolerant of shade [42].  High mortality rates occur for
Scots pine growing under canopy.  Few trees survive more than 50 years
under suppression; most do not survive even 7 years of shade [44,47].
Scots pine is not very responsive to release from suppression; trees
under 20 years old show a modest response [44,47].  Scots pine stands
are usually even-aged, or are uneven-aged with distinct age classes.  In
Scandinavia, 50 to 70 percent of the trees in a stand commonly belong to
one age class, with the rest of the trees in the neighboring age classes
[22].

Scots pine usually regenerates in gaps (forming even-aged clumps) or
after stand-replacing disturbances [44,47,50].  In Sweden, most Scots
pine dominated-forests are maintained by fire.  In the absence of fire,
Scots pine is usually replaced by Norway spruce (Picea abies).  On some
sites, however, uneven-aged Scots pine stands are self maintaining in
the absence of fire.  Regeneration peaks on these sites occurred at long
intervals and appear to be more related to favorable climatic conditions
than to any disturbances.  The ability of Scots pine to reproduce
without disturbance is attributed to the thin humus and litter layers of
these poor sites [44].

The percentage of pine pollen increased after disturbances in soil core
samples dated from 1,430 years BP to present, in an area where Scots
pine is usually present [4].


SEASONAL DEVELOPMENT : 
Scots pine pollen cones open from late May to early June.  Pollination
occurs in early summer and is followed by fertilization 12 months later.
Seeds mature and cones ripen from September to October.  Seed dispersal
occurs from December to March [27,42].

Related categories for Species: Pinus sylvestris | Scots Pine