BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Betula populifolia | Gray Birch 



GENERAL BOTANICAL CHARACTERISTICS : 
Gray birch is a fast-growing, short-lived, deciduous tree commonly
attaining heights of 20 to 30 feet (6-9 m) [5].  Its short, slender,
contorted branches form a narrow pyramidal crown.  The alternate leaves
occur singly or in pairs on thin, gray twigs.  The leaves are long and
pointed with double-toothed margins.  The male flowers are borne on
yellow catkins hanging from the twigs.  The female catkins are erect on
the stems which develop into drooping, stalked cones with many small
nutlike winged seeds.  The trunk is dark, rough, and irregularly broken
by shallow fissures.  The roots are shallow [6,7,9,17].


RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Seed production and dissemination.  Gray birch reproduces mainly by
seed.  It begins producing seed at 8 years of age with abundant seed
crops every year.  The seed crops germinate readily.  The light, winged
seeds are dispersed by the wind and some seeds travel great distances
[1,10].  Gray birch is a prolific seed producer and will form a seed
bank in the soil [14,18].

Vegetative reproduction.  Gray birch sprouts from the stump when cut or
following fire.  Sprouting usually occurs when young trees have been cut
in the spring leaving stumps of about 2 inches (5 cm) in height [17].
Stump sprouts can be a valuable seed source since sprouts alone are
usually not numerous enough to adequately reproduce mature gray birch
stands [1,7].


SITE CHARACTERISTICS : 
Gray birch is found on a wide variety of sites.  It grows best on moist,
well-drained soil along streams, ponds, lakes, and swamps but also grows
on dry sandy or gravelly soil.  Gray birch grows on inorganic soils of
rocky slopes and hillsides, but its growth is usually retarded on these
sites [6,8,17].

Common tree associates of gray birch are blackgum (Nyssa sylvatica),
black oak (Quercus velutina), red oak (Q. borealis), eastern hophornbeam
(Ostrya virginiana), American holly (Ilex opaca), black cherry (Prunus
serotina), flowering dogwood (Cornus florida), and aspen (Populus
tremuloides).  Common understory associates include hobblebush (Viburnum
alnifolium), blueberry (Vaccinium spp.), witch hazel (Hamamelis
virginiana), bayberry (Myrica pensylvanica), and Canada serviceberry
(Amelanchier canadensis) [22,27,29,36].


SUCCESSIONAL STATUS : 
Obligate Initial Community Species.

Gray birch is a pioneer species.  It is an early seral species in
oldfield succession or following clearcutting in northern hardwood
forests.  Gray birch is shade intolerant and eventually gives way to a
fir-spruce (Abies spp.-Picea spp.) forest community [12,18].  On
undisturbed sites, climax succession is toward a maple-beech forest
community [18].


SEASONAL DEVELOPMENT : 
Gray birch flowers between April and May; the fruit ripens from
September to October.  The seed is dispersed from October through the
middle of winter [2].

Related categories for Species: Betula populifolia | Gray Birch