BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Fraxinus nigra | Black Ash 



GENERAL BOTANICAL CHARACTERISTICS : 
Black ash is a small, native, deciduous tree ranging from 40 to 60 feet
(12-18 m) in height.  The tree has coarse ascending branches and a
slender, sometimes bent or leaning trunk which extends almost to the top
of a narrow crown.  The compound leaves are 10 to 16 inches (25-40 cm)
long.  Black ash is polygamous; its flowers are small and inconspicuous
[37].  The bark is shallowly fissured and divided into large irregular
plates with thin, soft, papery scales that rub off easily.  The fruit is
an elongated, winged, single-seeded samara that is borne in terminal or
axillary clusters.  Black ash has a shallow, wide-spreading root system
[8,9,21].



RAUNKIAER LIFE FORM : 
   Phanerophyte


REGENERATION PROCESSES : 
Black ash regenerates through sexual and vegetative reproduction.  Good
seed crops occur at 1- to 8-year intervals with most intervening years
having poor seed crops [13,34].

Germination: Black ash produces an abundance of seed [4].  The seed
contains a dormant embryo that requires stratification and a period of
cold temperatures for good germination.  Before embryos germinate, they
must grow from about one-half to two-thirds the length of the seed, so
most black ash seed do not germinate until the second spring after
seedfall.  Some seed may lie dormant in the litter for up to 8 years
[13].

Seedling development: Black ash seed is capable of germinating in
hardwood leaf litter or under 0.25- to 0.75-inch (0.6-1.8 cm) of soil;
however, grass, brush, and advance hardwood reproduction must be
controlled for successful black ash seedling establishment.  Germinants
are about 2 inches (5 cm) tall within 2 weeks.  Under the best
conditions they may average 6 inches (15 cm) in height by the end of
their first growing season [13].  Black ash seedlings often grow more
slowly than seedlings of associated species such as American elm and red
maple [37].

Vegetative Reproduction:  Black ash sprouts readily from stumps up to 12
inches (30 cm) in diameter.  Sprouts originate from adventitious buds on
the sides of the stump and at the root crown.  Stump sprouts can 
exhibit fast growth.  Black ash will also root sucker [13].



SITE CHARACTERISTICS : 
Black ash is most commonly found growing in moist to wet muck or shallow
organic soils.  It is found in swamps, along small streams in gullies,
and in small poorly drained depressions [25,37].  It also grows on fine
sands and loams underlain by clays and on other poorly drained sites
with high water tables.  In uplands black ash is restricted to sites
with impeded drainage, where it grows on wetter than normal mineral soils
[5,13].



SUCCESSIONAL STATUS : 
Facultative Seral Species

In the Great Lake States black ash is a pioneer.  It is also present but
not abundant in mature forests dominated by elm (Ulmus spp.), cedar
(Thuja spp.), larch (Larix spp.), spruce (Picea spp.), fir (Abies spp.),
and birch (Betula spp.) [1,10].  It is an invader species in sedge
meadows in southern Wisconsin [28].  In northeastern Minnesota, black
ash seedlings invade open areas in maple-beech forests [7].

Black ash is shade intolerant [37].



SEASONAL DEVELOPMENT : 
The flowers of black ash appear in May or June, concurrent with or just
before the leaves [37].  The fruits ripen from June to September and are
dispersed from July to October [34,35].

Related categories for Species: Fraxinus nigra | Black Ash