black locust | skymeadows

black locust (Robinia pseudoacacia)

COMMON NAMES:
black locust
false acacia
yellow locust
white locust,
green locust
post locust

SCIENTIFIC SYNONYMS:
Robinia pseudoacacia var. rectissima (L.) Raber

CONFIRMATION STATUS: Confirmed.

TAXONOMY: The scientific name of black locust is Robinia
pseudoacacia L.

NATIVE STATUS: Native, United States; Introduced, Canada.

Black locust hybridizes with Kelsey locust (Robinia kelseyi), New Mexico
locust (Robinia neomexicana), clammy locust (Robinia viscosa), and bristly
locust (Robinia hispida). Several black locust cultivars are available.

GENERAL BOTANICAL DESCRIPTION: Black locust matures
to a medium-sized tree, generally 40 to 60 feet (12-18 m) in height and
12 to 30 inches (30-76 cm) in diameter. Trees in Michigan have reached
3 to 5 feet (0.9-1.5 m) in diameter, though smaller stems are more
common. Within its native range, black locust averaged 4 stems/
"rootstalk". Frequent frosts may result in crooked growth.

Young black locust bark is smooth and brown. Young trees are thorny. As
trees age, the bark becomes thick, deeply furrowed, scaly, and dark brown.
Black locust leaves are deciduous, alternate, and pinnately compound, with
7 to 19 leaflets on a central stalk that is 8 to 12 inches (20-30 cm) long.
Leaflets are 30 to 50 mm long. Black locust flowers are showy, white, and
fragrant, in drooping clusters about 6 inches (14 cm) long. Clusters arise
from leaf axils near the tip of new shoots. Black locust fruits are flat legumes
3 to 4 inches (7-10 cm) long. Seeds are dark, bean-like, 3 to 5 mm long, and
have a hard, impermeable coat. Each legume contains approximately 4 to 8
seeds.

Black locust trees develop extensive root systems. Radial root extent is
about 1 to 1.5 times tree height. Within black locust's native range, lateral
surface root extensions of 165 feet (50 m) were documented. In south-

eastern Ohio, no taproots were found within planted black locust stands,

but extensive lateral root systems were observed. The roots spread from

silty loam soil through loose shale and hard subsoil and below deep ravines

caused by gully erosion. On mined sites in eastern Kentucky, most of the

fine roots of black locust seedlings were found within the top 6 inches

(15 cm) of the soil.

While a number of sources state that black locust is commonly shallow-
rooted, the species occasionally develops deep roots. Vertical roots were
found at 20 to 25 feet (6.1-7.6 m) in the Southwest and 21 feet (6 m) in
the Oklahoma panhandle.

Root suckers form primarily where branch roots emerge from older roots.

Black locust is a nitrogen-fixing species. At the Coweeta Hydrologic
Laboratory in the Nantahala Mountains of North Carolina, regenerating
black locust stands had significantly higher concentrations of total nitrogen,
organic matter, and nitrates compared to mixed-oak-hardwood forest In
mixed-hardwood forests of the mid-Appalachian Mountains, black locust
contributed to elevated stream nitrate concentrations.

In early successional communities, black locust often grows in dense
thickets or clones due to the ability of individuals to root or stump sprout
following disturbance. Generally, the oldest trees are located in the
center and youngest trees on the edges of stands. In late successional
communities, black locust is generally an uncommon species, occurring
at low density.

In general, black locust trees are fast growing but short lived, living
approximately 90 years. Seedlings may have high survivorship. One
source suggests that early survival rates are usually high because wide-
spreading root systems support "vigorous" growth. Black locust had
the highest 6-year survival (69%) of all native and nonnative plants
studied on reclamation strip-mined land in Missouri, Kansas, and
Oklahoma.

Within its native range, black locust generally flowers from April to June,
though one source states it may flower as early as February in the South-

east.

In its nonnative range, flowering occurs mostly from May to June in the
Pacific Northwest, California, the Southwest, Northeast and Canada, and
Great Plains. Earlier flowering occurs from March to May in north-central
Texas, while later flowering occurs in some parts of New England, extend-

ing into July. In the uplands of the Adirondacks, flowering generally occurs

only in June. Fruit begins ripening as early as July in the Carolinas or August

in Arkansas, and ripening extends into November. In the Southwest, fruit
ripens from September to October. Black locust seeds persist through the

winter, though dispersal is described as occurring from September to April

in both its native and nonnative ranges.

REGENERATION PROCESSES: Black locust reproduces both from
seed and by sprouting from the roots or stump. Sprouting is considered
more common than sexual reproduction. Limited seed dispersal, seed coat
impermeability, and high light requirements for germination all limit
reproduction by seed.

Black locust is insect pollinated. Flowers are also visited by hummingbirds.

Black locust begins producing seeds at about 6 years of age. Seed production
is best between 15 and 40 years of age and continues through approximately
age 60. Seeds are produced every year, but good crops are produced at
intervals of 1 to 2 or 2 to 3 years.

Black locust seeds are dispersed by gravity, wind, and potentially by birds.

Large size causes most black locust seeds to fall near the parent plant, and
black locust is generally considered to have a low dispersal rate. However,
long-distance dispersal is possible; black locust recruited by seed onto a
revegetating landfill site on Staten Island, New York. The closest seed
source was 397 feet (121 m) from the landfill.

Black locust seeds may persist in the soil for long periods of time. A
Michigan research study states that seeds may survive for more than 88
years in the soil. In a laboratory study, seed from 107 plant species was
buried up to 42 inches (107 cm) in soil. Black locust was 1 of 16 plant

species with more than 15% of seeds viable after 39 years. Other sources

state that seeds remain viable for more than 10 years or "many" years. In

mixed-oak and northern hardwood forests of western North Carolina, black

locust seeds remained viable in the soil for more than 1 year. Soil seed

densities were higher than seed rain, suggesting low annual seed mortality

and the presence of seeds from previous years.

Because black locust seeds are persistent, they may accumulate to great
levels in the seed bank. In contrast, in a mature mixed-oak-maple forest
in southwest Virginia, black locust seeds were found at a density of only
121 seeds/acre (300 seeds/ha). The authors suggested that the continuous
cover of mature forest would make it difficult for early-successional species
like black locust to produce a large quantity of seeds.

Black locust seeds require scarification and bare mineral soil for successful
germination. Though one source cites germination rates as high as 68% in
its native range, most sources suggest that seed germination is low due to
high seed coat impermeability and shade intolerance.

Black locust requires open conditions for establishment. Establishment is
often linked to natural and manmade disturbances. In its native range,
black locust grows rapidly following disturbances such as logging or mining.

Black locust is known for its rapid juvenile growth rate. The growth rate of
black locust seedlings is limited by plant density and insect infestations and
enhanced by light, moisture, and fertilization.

In regenerating hardwood forests in North Carolina, black locust seedlings
grew 26 feet (8 m) in 3 years. They grew faster than any other species for
10 to 20 years. Black locust had the second-tallest mean height of dominant
hardwood species 5 years after clearcut treatments in mixed-oak stands in
Virginia, with trees as tall as 8.6 feet (2.6 m).

Black locust growth rates are also high in its nonnative range. A review
states that black locust growth rates in plantations in the central states
could average as much as 42 feet (12.8 m) in 10 years, 68 feet (20.7 m)
in 25 years, and 84 feet (25.6 m) in 40 years.

Black locust may grow at high or low densities depending on local site
characteristics. Within its native range, seedling densities are variable.
There are often few seedlings under canopies containing mature black
locust.

Within mature forests of its native range, black locust usually occurs as
a canopy tree at low density.

Vegetative regeneration is important to the establishment, spread, and
persistence of black locust. It is thought to be a more common means
of reproduction than seed. Black locust commonly sprouts from roots
or the stump. Sprouting often occurs in response to stem or root damage
due to cutting , fire, wind, or disease. Root sprouting is also a common
means of reproduction following logging treatments and a means of
spread into revegetating reclamation sites and out of plantations and
into abandoned fields.

Root sprouting usually begins when plants are 4 to 5 years old and
increases rapidly in full sun, open areas, and particularly in sandy soils.
Though sprouting is a common response to disturbance, sprouts need
sufficient light to survive.

SITE CHARACTERISTICS: In its native range, black locust occurs in

a wide range of forest communities, as well as a variety of disturbed sites
such as old fields, and logged areas. It generally occurs at low density within
the forest interior but establishes well in forest openings, edges, and other
early-successional habitats.

Black locust thrives best on moist slopes of the eastern mountains below
3,400 feet (1,040 m). It occurs below 300 feet (90 m) in parts of Kentucky
and Tennessee and above 4,000 feet (1,200 m) in Great Smoky Mountains
National Park.

Black locust occurs in a variety of soil types within its native range.
Numerous sources associate black locust with limestone, sandstone, chert,
and mica-gneiss substrates. Soils tend to be loams, or sandy loams. Other
soil characteristics associated with black locust include "rich", deep,
well-drained , and moist. Black locust may not grow well on very sandy,
very acid, or wet soils. It is sensitive to soil conditions that produce either
minimal or excessive aeration and drainage. Black locust growth is limited
by water-logged soils or soil compaction.

Black locust is often found on slope forests within its native range. In the
Monongahela National Forest in central West Virginia, black locust occurred
on slopes of 45% to 55%. Black locust has been found on northwestern
slopes in eastern West Virginia and southerly slopes in North Carolina and
Tennessee.

Black locust is also found on valley floors, bottomlands, floodplains, ridges,
rolling uplands, and loess hills.

Climate conditions in black locust's native range are humid, though it has
been successfully introduced into many parts of the world where climate
conditions vary widely.

Outside of its native range, black locust thrives in disturbed, or "waste"
areas. Specific examples of disturbed areas include roadsides, railroad
right-of-ways, constructed wetland edges, disturbed hammock margins,
man-made sandflats, and channel levees.

Many disturbed black locust sites are also associated with human habitation
and agricultural operations. Black locust occurs in fencerows and hedgerows,
abandoned agricultural fields and pastures, and near old home or farm sites.
Black locust spreads from disturbed sites into areas such as forests, forest
edges, woodlands, woodland openings, thickets, or prairies and other
grasslands. Black locust often establishes in riparian areas such as stream-
and riverbanks and floodplain forests throughout its nonnative range,
including locations in the Southeast, Northeast, Great Lakes, Northern
Great Plains, Northern and Central Rockies Northwest, Southwest, and
California.

In its nonnative range, black locust is found at a wide range of elevations.
Black locust may occur anywhere from 30 to 6,500 feet (10-2,000 m) in
its nonnative range.

In its nonnative range, black locust is found in a wider range of soil
conditions than within its native range. An association with limestone
or calcareous soil is noted in the Southwest, the Northeast, and Canada.
In contrast to its native range, a strong association with sandy soils is
found in the Northern Great Plains, north-central Texas , Illinois, the
Northeast, Maryland, and California. Many of these locations are either
sand dunes or sand prairies, or stream or river deposits. Black locust was
found on fertile loam near the Sacramento River in California, Richfield
silty loam in the high plains regions of the Oklahoma panhandle, silty-clay
loam in eastern Nebraska, well-drained loams in eastern Washington and
northern Idaho.

A preference for moist sites is noted in the Northern Great Plains,
northern United States and southern Canada, and Hungary. Black locust's
deep rooting ability may allow it to grow in locations much drier than in
its native range. Black locust was one of the most abundant trees
establishing in dense stands on "poor", dry soils on man-made sandflats
along the Hudson River in eastern New York. Several sources suggest
that as in its native range, black locust does best on well-drained sites.
One source states that black locust prefers deep soils in the Southwest,
it may grow well on shallow soils in the Northeast. Black locust is found
on sites that range from low to intermediate and high soil fertility in its
nonnative range. The ability of black locust to establish and persist in
areas with low soil nutrient levels (like the pitch pine-scrub oak forest
type in New York or dry grasslands in Europe is highly problematic to
land managers.

Black locust has been planted on soils with a wide range of pH and
tolerates extremely acidic soils, particularly in strip-mine reclamation
sites.

Black locust is commonly found on slopes across its native and nonnative
ranges. In southwestern Michigan, it occurred on the south slope of a
large moraine.

Black locust is highly susceptible to frost and cold weather damage, which
may limit expansion of its range. Black locusts planted in Ontario were
limited by hard winter frosts that killed new growth. Low precipitation
may also limit black locust persistence or range expansion.

SUCCESSIONAL STATUS: Black locust is a shade-intolerant species.
Its ability to tolerate shade improves on fertile sites. It establishes well
in early-successional stands, particularly following disturbance,though
its dominance is usually temporary. Pure, persistent stands of black
locust occur very rarely within its native range and are usually associated
with planting, land abandonment, fire, or other severe disturbances. In
later-successional forest communities, black locust generally occurs at
low density and is considered uncommon.

Black locust's prevalence in early-successional stands has important
consequences for plant community development in its native range.
Several authors discuss black locust in terms of facilitating successional
plant species, particularly because of its ability to fix nitrogen, and
stabilize the soil. In a North Carolina oak- hickory-yellow-poplar forest,
high biomass and net primary production of black locust in large forest
openings created from logging increased soil nitrogen and accelerated
growth rates of cooccurring plant species. Because black locust is short
lived, shade-tolerant species in the understory often release after its death.

Historically, disturbances such as fire, drought, insect and disease outbreaks,
windfall, lightning, ice storms, and landslides played an important role in
shaping plant community dynamics within black locust's native range. After
settlement by Europeans, disturbances such as logging, fire exclusion,
burning and clearing land for settlement and agriculture, grazing, gypsy
moth outbreaks, loss of American chestnut, pollution, and the presence
of introduced species also became important within the native range of
black locust. In general, black locust is abundant in logged stands. It
responds favorably to logging, often responding immediately through
vigorous sprouting, rapid growth , and increased abundance compared
to pretreatment levels. In some instances, black locust dominates
regeneration, though this dominance is often short lived. For example,
in mixed-oak forests in Virginia, black locust was the clear dominant
in the tree stratum 4 and 5 years after clearcutting. Other trees surpassed
black locust in dominance in years 6 and 7, but it was still one of the most
abundant species. Black locust establishes on open surfaces created by
mining operations. It was an abundant tree species in revegetating
abandoned mine land in West Virginia, Maryland, and Tennessee.

Black locust may thrive in canopy gaps within its native range, though this
response is not consistent and may depend on gap size. Black locust
responded favorably to logging treatments that simulated natural canopy
gap formation. Other research suggests that canopy gaps have little or no
effect on black locust abundance. In a North Carolina mixed-oak forest,
black locust rarely established in single-tree canopy gaps and was not
found in multitree canopy gaps.

Black locust was 1 of the 4 most important species regenerating 10 years
after debris avalanches in a Virginia mixed-hardwood forest. It was not
present or present at a very low density in adjacent undisturbed plots.

While disturbances often favor the establishment of black locust, some
disturbances also lead to direct mortality of or damage to established
trees. For example, drought can led to high levels of black locust
mortality Black locust also sustains high levels of wind damage.

SEASONAL DEVELOPMENT: Within its native range, black locust
generally flowers from April to June, though one source states it may
flower as early as February in the Southeast.

Fruit begins ripening as early as July in the Carolinas or August in Arkansas,
and ripening extends into November. In the Southwest, fruit ripens from
September to October. Black locust seeds persist through the winter,
though dispersal is described as occurring from September to April in both
its native and nonnative ranges.

GENERAL DISTRIBUTION: Black locust is native to the United
States, though the extent of its original range is not accurately known.
It is thought that black locust was originally found in 2 regions. The
eastern region was centered in the Appalachian Mountains and ranged
from central Pennsylvania and southern Ohio south to northeastern
Alabama, northern Georgia, and northwestern South Carolina. The
western region included the Ozark Plateau of southern Missouri, northern
Arkansas, and northeastern Oklahoma and the Ouachita Mountains of
central Arkansas and southeastern Oklahoma. It is thought that
outlying native populations existed in southern Indiana and Illinois,
Kentucky, Alabama, and Georgia.

Black locust inhabits a broad range of forest types and conditions within
its native range, though it develops and grows best in the cove or mixed-
mesophytic forests of the central and southern Appalachian region.

In western Maryland and northern Virginia, black locust is a relatively
common species in disturbed forests, occurring with basswood, chestnut
oak, flowering dogwood, eastern hophornbeam (Ostrya virginiana), red
maple, northern red oak, sugar maple, and white ash in the transitional
hardwood forest, and with black tupelo, black oak (Quercus velutina), chest-
nut oak, red maple, flowering dogwood, pignut hickory (Carya glabra),
northern red oak, white oak, eastern white pine (Pinus strobus), mockernut
hickory, Virginia pine (Pinus virginiana), and white ash in the oak forest
types. In a valley in northwestern Virginia, black locust occurred with river
birch, yellow birch (Betula alleghaniensis), striped maple (Acer pensylvan-
icum), northern red oak, pignut hickory, basswood, and sugar maple. In this
same region, it also occurred in an area dominated by pitch pine (Pinus
rigida) and chestnut oak. In western Virginia, black locust was a minor
overstory and understory component in high-elevation northern red oak
and river birch stands.

Black locust has been widely planted and frequently escapes cultivation.
As of 2009, it occurred throughout the conterminous United States and
a number of Canadian provinces. Black locust also occurs in parts of South
America, Europe, Asia, Africa, and Australia.

SKY MEADOWS DISTRIBUTION:

Tree specimens can be found on trails marked in red.

       Bleak House
       Appalachian Trail/Old Trail
       South Ridge/North Ridge
       Gap Run
       Snowden
       Woodpecker Lane

       Sherman's Mill
       Rolling Meadows/ Lost Mountain
     Fish Pond

HABITAT TYPES AND PLANT COMMUNITIES: Black locust
inhabits a broad range of forest types and conditions within its native
range, though it develops and grows best in the cove or mixed-meso-
phytic forests of the central and southern Appalachian region. Plant
community descriptions are given for forests, regenerating old fields,
and naturally revegetating reclamation sites. Black locust is rarely a
canopy dominant in the communities described except in some early
successional or disturbed communities.

In a valley in northwestern Virginia, black locust occurred with river
birch, yellow birch (Betula alleghaniensis), striped maple (Acer pensylvan-
icum), northern red oak, pignut hickory, basswood, and sugar maple. In this
same region, it also occurred in an area dominated by pitch pine (Pinus
rigida) and chestnut oak. In western Virginia, black locust was a minor
overstory and understory component in high-elevation northern red oak
and river birch stands.

Black locust was a minor component in an old-growth forest remnant in
western Maryland. Overstory species included chestnut oak, northern red
oak, sweet birch, and red maple. Black locust was listed in the yellow-poplar
forest association found adjacent to or on bottomlands. This forest associa-
tion contained red maple, flowering dogwood (Cornus florida), Virginia
creeper (Parthenocissus quinquefolia), black tupelo, white oak, sassafras,
black cherry, grapes (Vitis spp.), mockernut hickory (Carya tomentosa),
southern arrowwood (Viburnum dentatum), and Japanese honeysuckle
(Lonicera japonica).

In western Maryland and northern Virginia, black locust was a relatively
common species in disturbed forests, occurring with basswood, chestnut
oak, flowering dogwood, eastern hophornbeam (Ostrya virginiana), red
maple, northern red oak, sugar maple, and white ash in the transitional
hardwood forest, and with black tupelo, black oak (Quercus velutina),
chestnut oak, red maple, flowering dogwood, pignut hickory (Carya glabra),
northern red oak, white oak, eastern white pine (Pinus strobus), mockernut
hickory, Virginia pine (Pinus virginiana), and white ash in the oak forest
types.

In the Monongahela National Forest in eastern West Virginia, black locust
was a minor component of valley floor and northwest slope forests. On
valley floors, it occurred with dominant species such as white oak (Quercus
alba), sugar maple, pines (Pinus spp.), basswood (Tilia americana), and
eastern hemlock (Tsuga canadensis). On northwestern slopes, it occurred
with chestnut oak (Quercus prinus), white oak, and pines. In the Mononga-
hela National Forest in central West Virginia, black locust was a minor
component of a mixed-mesophytic community dominated by northern red
oak, sugar maple, basswood, and white ash (Fraxinus americana).

IMPORTANCE AND USES: Black locust is a food item for many wild-
life species. White-tailed deer heavily browse black locust in North Carolina,
Georgia, and Arkansas, though one study found a lack of white-tailed deer
herbivory on black locust in Maryland and West Virginia. Mule deer browse
black locust in Washington, California, and New Mexico. Rabbits browse on
stems. Ruffed grouse eat black locust leaves. Squirrels, doves, California
quail, northern bobwhite, chukar, pheasants, ruffed grouse, and other game
birds eat black locust seeds.

Invertebrate species also consume black locust. Freshly fallen black locust
leaves were palatable to millipedes in laboratory studies. Black locust was
a host to the Lepidopteran species the silver-spotted skipper and the three-
staff underwing in the southeastern United States, and it is widely visited
by bees for its nectar throughout its native and nonnative ranges.

Numerous accounts describe parts of the black locust as poisonous to live-
stock including mules, horses, cattle, and domestic sheep due to the pres-
ence of the poison robotin. Poisonous plant parts include the roots, young
shoots, seeds, twigs, leaves, and bark. In some cases, poisoning may be
fatal to livestock, though one author asserts that fatality from poisoning
is rare. In livestock, symptoms of black locust poisoning may include re-
duced hearing, stupor, vomiting, and purging.

Some people eat fried or cooked black locust flowers. Tea can be made from
the flowers. However, black locust is poisonous to humans. In some cases,
poisoning may be fatal. Symptoms of black locust poisoning include dilated
pupils, feeble pulse, severe vomiting, and a death-like pallor. Humans may
get dermatitis from exposure to black locust wood.

Black locust is an important cover species for wildlife, providing nesting,
roosting, and thermal cover. The persistent nature of black locust stems
after plant death makes it an important resource for cavity-dependent
wildlife species. A disproportionate number of snags were identified as
black locust in a Maryland old-growth forest remnant, a 24- to 64-year-
old yellow-poplar-red maple stands in southeast Ohio, and second- and
old-growth mixed-hardwood forests in eastern Kentucky. Compared to
urrounding forest, a disproportionate number of cavities were found in
black locust trees in mixed-hardwood and oak-hickory forests in West
Virginia.

Black locust cavities are used for nesting and roosting by bats and birds.
Black locust cavities were used as maternity roosts for long-eared bats in
West Virginia and the endangered Indiana bat in the Champlain Valley,
and as day roosts for male northern bats in West Virginia. In its native
range, black locust provides nesting cavities for birds such as the hairy
woodpecker, downy woodpecker, northern flicker and red-bellied wood-
pecker. In Kentucky, eastern screech-owls roosted in black locust cavities
in the winter.

Black locust cover is also important to birds. Black locust was positively
associated with red-eyed vireo habitat in southwestern Virginia and
rufous-sided towhee habitat in Maryland. In a mixture of small decid-
uous woodlots and thickets interspersed with old fields in Kentucky,
adult and juvenile eastern screech-owls used black locust stands for
roosting in the postfledging period.

Outside of the native range of black locust, birds that nest in black locust
foliage include the black-billed magpie, western kingbird, Baltimore oriole,
and Swainson's hawk in eastern Washington, the long-eared owl and logger-
head shrike in Idaho, and the dickcissel in central Oklahoma. Near Cape
Cod, Massachusetts, black locust stands provided suitable cover for north-
ern bobwhite and American woodcock. In south-central Kansas, 62 breed-
ing bird species were detected in shelterbelts containing black locust, and
black locust was highly recommended for planting as wildlife habitat in the
Northern Great Plains region.

Black locust occurring in small to large patches in the Palouse prairie region
of eastern Washington and northern Idaho provided winter thermal, loafing,
and hiding cover for 7 mammal species (moose, white-tail deer, coyote,
North American porcupine, striped skunk, house cat, and mountain cotton-
tail), 23 avian species (including gray partridge, ring-necked pheasant, red-
tailed hawk, rough-legged hawk, great-horned owl, and short-eared owl),
and 1 reptile (garter snake).

The wood of black locust is heavy, strong, and durable and shrinks little
upon drying. Its strength is due to high lignin content. Consequently, the
wood of black locust is valuable for a variety of uses, such as fenceposts,
railroad ties, insulator pins, mine timbers, shipbuilding, furniture, handles,
barrel staves, boxes and crates, pulp, and fuelwood.

Black locust has been widely planted for windbreaks and shelterbelts, as
woody biomass for energy production, and as a street or ornamental tree.
It has also been widely planted for honey production. One author claims
that black locust plantations provide the basis for Hungary's commercial
honey industry.

The nitrogen-fixing abilities of black locust have prompted its planting in
nurseries and plantations to assist the growth of other desired trees. Black
walnut, southern catalpa (Catalpa bignoides), and hardwoods in Indiana
have shown improved growth when planted with black locust. In Canada,
black walnuts interplanted with black locust had higher foliar nitrogen con-
tent than those not planted with black locust. However, the wide-spreading
crown and prolific root sprouts of black locust may suppress or kill slow-
developing interplanted tree seedlings in some plantation settings.

Black locust was once a favored tree for restoration or rehabilitation
because its extensive root system holds and stabilizes the soil surface, it
sprouts vigorously and prolifically, it increases soil fertility through nitro-
gen fixation, and it forms a leaf litter that protects the soil. Its main use
has been in the rehabilitation of former surface mine sites and for erosion
control, but it is also used to rehabilitate contaminated soils, depleted soils,
gravel pits, and logged areas and to stabilize railroad embankments and
highway edges.

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