Description:
This coniferous tree is 50-100' tall at maturity and its trunk is 2-5'
across. However, in the United States, this tree is usually smaller in
size than it is in Eurasia. In pine plantations and dense forests, the
trunk is tall and straight and the crown is relatively narrow
(typically ovoid-oblongoid in shape). Specimens that are grown in open
locations, however, have a shorter trunk and a wider ovoid crown that
may extend close to the ground. Upper branches of the crown are
ascending, while lower branches are widely spreading. The trunk bark is
gray or grayish brown, rather coarsely textured, and fissured, while
branches are gray and wrinkled. Twigs are terete, relatively stout,
gray or grayish brown, and rather prickly in appearance as a result of
detached fascicles (clusters) of needle-like leaves. The needle-like
leaves occur in fascicles of 2 along the twigs and shoots; they can
persist on a healthy tree for 3-7 years, creating a dense crown. The
leaves are narrowly linear in shape (1-2 mm. across), 3-6" long, dark
green, and sometimes slightly twisted or curved; they do not snap in
two readily when they are bent. Austrian Pine (
Pinus nigra) is
monoecious, producing separate male (staminate) and female (pistillate)
flowers on the same tree. The male flowers occur in catkins at (or
near) the tips of twigs; these catkins are up to ¾" long, yellow, and
cylindrical in shape.
The female flowers are conelets that develop at
(or near) the tips of twigs; they are either solitary or they occur in
groups of 2-3. The conelets are yellowish green to red, ovoid in shape,
and about ¼" long. The blooming period occurs during late spring or
early summer for about 1-2 weeks; cross-pollination occurs by wind.
Afterwards, the female flowers are replaced by immature seed-bearing
cones that are about ¾" long by the end of their first year of
development. The cones don't become mature until the end of the second
year of their development (during late summer or autumn), when they are
2–3½" long, broadly ovoid in shape (after the woody scales separate
from each other), and yellowish brown to brown. The woody
scales of each cone are oblanceolate in shape and slightly swollen
toward their tips; they often have solitary minute prickles (often
blunt, rather than pointed) on their
upper sides toward their tips. The winged seeds are released by the
cones and they are distributed by the wind. The bodies of individual
seeds are up to ¼" (6 mm.) in length and their membranous wings are up
to ¾" (20 mm.) in length. The woody root system is branched, widely
spreading, and relatively deep. This tree reproduces by reseeding
itself.
Cultivation:
The preference is full sun, mesic to dry conditions, and soil
containing loam, clay-loam, some rocky material, or sand. This pine
tolerates drought, but it dislikes the hot weather that is typical of
SE United States, preferring the cooler weather of NE United States and
the Great Lakes area. Individual trees begin to produce cones at 15-40
years of age. Austrian Pine is more tolerant of air pollution and road
salt than most pine species, and it is hardy to Zone 4. In the United
States, this pine is vulnerable to various disease organisms, including
Dothistroma Needle Blight (caused by
Dothistroma pini),
Lophodermium
Needle Cast (caused by
Lophodermium
pinastrii), and Diplodia Tip Blight
(caused by
Diplodia
pinea). As a result, this pine often suffers from
premature needle-drop and branch die-back, especially after it reaches
30 years of age. Many trees die prematurely as a result.
Range
& Habitat: Naturalized populations of Austrian
Pine are quite rare
in Illinois, occurring at Illinois Beach State Park in Lake County (see
Distribution
Map),
where it was planted more than 100 years ago.
However, this pine has managed to reproduce itself successfully at this
location, where it still persists. Austrian Pine is native to parts of
Europe, SW Asia, and North Africa. In North America, it is used
primarily as a landscape tree and for shelter belts. The habitat of
this pine in Illinois consists of pine plantations and sandy savannas
along Lake Michigan. In Eurasia and North Africa, it is often found in
hilly woodlands and mountainous areas. Most Austrian Pine trees in
North America derive from stock that originated from Austria and the
Balkan states of SE Europe.
Faunal Associations: In North
America, many kinds of insects are known to feed on the foliage, wood,
and other parts of Austrian Pine (
Pinus
nigra). These species include
Tomicus piniperda
(Common Pine Shoot Beetle),
Pilophorus
gracilis (a
plant bug) and other plant bugs,
Eulachnus
rileyi and other aphids,
Chionaspis pinifoliae
(Pine Needle Scale) and other armored scales, and
the larvae of
Dioryctria
zimmermani (Zimmerman Pine Moth) and other
moths (Cranshaw, 2004; Wheeler et al., 1983; Blackman & Eastop,
2013; ScaleNet, 2014). Other insects that feed on this and other pines
(
Pinus spp.)
include the larvae of long-horned beetles (Cerambycidae), weevils
(Curculionidae), stink bugs (Pentatomidae), spittle bugs (Cercopidae),
mealybugs (Pseudococcidae), larvae of sawflies (Diprionidae,
Pamphiliidae), and the larvae of a butterfly,
Callophrys niphon
(Eastern Pine Elfin). Some vertebrate animals use pines as a source of
food and shelter. The seeds of these trees are eaten by the Mourning
Dove, Black-capped Chickadee, Red Crossbill, Red-breasted Nuthatch,
Brown Creeper, Pine Siskin, Tufted Titmouse, Pine Warbler, and other
birds (see the
Bird Table for a
more complete list of these birds).
Among mammals, the Red Squirrel, other tree squirrels, and White-footed
Mouse eat pine seeds, while the White-tailed Deer and Elk occasionally
browse on the twigs and foliage of these trees (Martin et al.,
1951/1961). Sheep also browse on their lower twigs and leaves (personal
observation). Some birds also prefer pines as locations for the
construction of their nests; this includes the Yellow-throated Warbler
(
Dendroica dominica
dominica), Black-throated Green Warbler, Pine
Warbler, and Blue-headed Vireo (Pearson, 1917/1936; DeVore et al.,
2004). The Big-eared Owl and other owls often roost in pine trees
during the day, particularly during the winter, because of the shelter
and privacy that their evergreen foliage provides.
Photographic Location: The Arboretum of the University of
Illinois in
Urbana, Illinois.
Comments:
When it is healthy, the Austrian Pine (
Pinus nigra) can
become a relatively large tree with a dense crown of attractive
foliage. Unfortunately, it is vulnerable to various disease organisms
in North America that can cause premature drop of its needle-like
needles and die-back of branches. As result, this pine rarely achieves
its full potential as a landscape and plantation tree in North America.
Austrian Pine is similar in appearance to another introduced pine,
Scots Pine (
Pinus
sylvestris). This latter pine usually has shorter
needles that are often bluish green, instead of dark green, and the
bark of its upper trunk and branches often peels away to reveal
conspicuous patches of orange-red or red. Another species, the native
Red Pine (
Pinus resinosa),
is also somewhat similar in appearance to
Austrian Pine. Red Pine differs by having needles that break cleanly
when they are bent and its crown is usually less dense in appearance
because its needle-like leaves persist on the tree for no longer than 3
years. The needle-like leaves of Austrian Pine, in contrast, can
persist on the tree for 4-7 years, creating a more dense and leafy
crown. The mature cones of Red Pine are typically reddish brown or
brown and their scales lack prickles on the upper sides, while the
mature cones of Austrian Pine are yellowish brown or brown and their
scales usually have minute prickles (often blunt) on the upper sides.
Another common name of
Pinus
nigra is European Black Pine.