Needlegrass Rush

More info for the terms: cover, formation, marsh

A black-rush-dominated coastal marsh in Mississippi was burned in late
February during low tide when the marsh surface was exposed. The
immediate effect was the removal of 71 percent of the vegetative cover.
Most culms were only partially burned. Incomplete combustion of black
rush was apparently due to the formation of a steam layer along the
marsh floor and/or the high moisture content of the culms near the
sediment [9].

More info for the terms: fire exclusion, prescribed fire

The Research Project Summary Vegetative response to fire exclusion and
prescribed fire rotation on 2 Maryland salt marshes provides information on
prescribed fire and postfire response of plant community species, including
black rush, that was not available when this species review was written.

black rush
black needlerush
needlerush
needle rush
needle grass

More info for the terms: cover, marsh

Black rush presumably provides good hiding cover for the birds and small
mammals that inhabit and visit coastal marshes.

The long-billed marsh wren, clapper rail, and seaside sparrow nest
primarily in black rush [19,25]. Rice rats, which prey on bird eggs,
also nest in black rush, usually in the vicinity of nesting long-billed
marsh wrens and seaside sparrows [19]. The black duck and occasionally
other waterfowl also nest in black rush [17].

More info for the terms: density, herb, marsh

Black rush is a tufted, coarse and rigid, rhizomatous, perennial
grasslike herb. It tolerates a wide range of environments, which
greatly affects its density and growth habit. Where soil water salinity
is low, black rush is often very robust, with leaves reaching over 7
feet (2.1 m) in height, while in hypersaline areas the plants are
dwarfed, often less than 1 foot (0.3 m) tall [5]. Both tall and short
stature plants occur in most salt marshes, with the tallest plants
occurring near open water (low soil salinity) and the shortest near land
(high soil salinity because of longer and more frequent periods of
exposure) [25]. Conversely, plant density increases farther inland. In
northwest Florida, stem density and height varied with elevation as
follows [25]:

low marsh upper marsh high marsh
(deep water) (shallow water)

density (shoots/m2) 1660 2097 4719
live shoot density 885 993 1692
dead shoot density 776 1164 3029

mean height (inches/cm) 40/102 35/88 31/78

Rhizomes average about 0.35 inch (9 mm) in diameter, and are primarily
located within 4 inches (10 cm) of the soil surface [5,28].

Black rush is primarily restricted to coastal marshes and estuaries of
the South Atlantic and Gulf Coast states. Its distribution is
continuous from New Jersey to southern Florida, and westward to
southeastern Texas. Scattered outlying populations also occur in
Connecticut, New York, Mexico, and the Caribbean Islands [4].

More info for the term: fire regime

Black rush survives fire by sending up new growth from surviving
underground rhizomes after aboveground plant portions have been
consumed.

FIRE REGIMES :
Find fire regime information for the plant communities in which this
species may occur by entering the species name in the FEIS home page under
"Find FIRE REGIMES".

More info for the terms: fresh, fuel, headfire, marsh, peat, prescribed burn

Prescribed burning on a 4- to 5-year rotation can be used to maintain
the vigor of black rush marshes. Burning more frequently would be
difficult because of insufficient fuel. It takes more than 3 years for
total biomass to reach preburn levels [13].

In southern Florida salt marshes, adequate wind is needed when
conducting a prescribed burn in order to push the fire over open water.
If standing water is not present, soil moisture should exceed 65 percent
on areas underlain by peat, to prevent its ignition. Salt marshes
bordered by mangrove (Rizophora mangle, Avicennia germinans) are easy to
burn because the mangrove acts as a fire break. Where fresh and
saltwater marsh merge, fire can be confined to the salt marsh by
knocking a swath through the fuel at the vegetative boundary and setting
a headfire from that line [27].

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More info for the terms: geophyte, helophyte

Geophyte
Helophyte

More info for the terms: natural, organic soils, peat, swamp

Black rush inhabits coastal tidal marshes and may extend as far as 10 to
15 miles inland along river estuaries [6]. It typically occurs in
nearly pure stands, forming a distinct vegetation zone that may be
several hundred yards to several miles wide [25]. This zone usually
encompasses a narrow elevational range. In Mississippi, the black rush
zone covered an elevational range of only 0.7 feet (0.2 m), from 1.7 to
2.4 feet (0.54-0.75 m) above mean low water [6,25].

Salinity: Black rush tolerates a wide range of salinities. It has a
greater tolerance to salt than most plants inhabiting brackish or saline
marshes. High-salinity soils tend to favor black rush by removing less
salt-tolerant competitors. Under laboratory conditions, it grows best
in freshwater, but its natural inland distribution is limited by low
salinity. Along Mississippi coastal rivers, black rush is replaced
inland by sawgrass or tree-covered swamp as salinity decreases. Growth
in freshwater habitats may be restricted by soil organisms which feed on
black rush rhizomes [6].

Soil: Black rush grows on a wide variety of soil types, ranging from
almost pure sand to fine silt and clay mixtures. It grows in highly
organic soils, including peat. In black rush stands in Mississippi,
soil pH ranged from 4.5 to 7.0 [6].

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This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

101 Baldcypress
102 Baldcypress - tupelo
106 Mangrove

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This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES16 Oak - gum - cypress
FRES41 Wet grasslands

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This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

K072 Sea oats prairie
K073 Northern cordgrass prairie
K078 Southern cordgrass prairie
K080 Marl - everglades
K090 Live oak - sea oats
K092 Everglades
K105 Mangrove
K113 Southern floodplain forest

More info for the term: marsh

The effects of fire on black rush mortality vary with water depth and
soil moisture. On flooded sites, and on sites with exposed but
saturated soils, fire may consume aboveground plant portions but leave
underground regenerative structures unharmed. When a marsh floor is
completely dry, however, fire can burn deep into the soil, consuming the
rhizomes and killing entire stands [24].

More info for the terms: cover, density, marsh

Habitat: Food and cover are abundant in black-rush-dominated coastal
marshes because plant density and net primary productivity are high.
However, few animal species have adapted to the rigorous conditions
created by the alternating terrestrial and aquatic environment. Those
that have adapted are abundant; thus animal production is high, but
diversity is low [19]. Mammal residents include the nutria, muskrat,
rice rat, and marsh rabbit. Other mammals, such as the raccoon, cotton
rat, mink, and cotton mouse, are common visitors but prefer more
terrestrial, less frequently flooded marsh [19,25]. Black-
rush-dominated marsh is the primary nesting and feeding habitat of the
clapper rail and seaside sparrow. Additionally, more than 60 species of
birds use habitats within this marsh type at least seasonally [25].

Food: Black rush's value as wildlife food is limited. Its small seeds
are eaten only rarely by ducks [17]. Although generally not a preferred
muskrat or nutria food, black rush leaves and rhizomes can be an
important food source for these animals in local areas [6,18].

Black rush is generally avoided by cattle [2].

More info for the term: marsh

Black rush is one of the dominant marsh species of the southern Atlantic
and Gulf coasts. In northwest Florida, it has been estimated that 60
percent of the salt marshes are covered with monospecific stands of this
species [19]. In many situations, monospecific stands of smooth
cordgrass (Spartina alterniflora) form a seaward zone that borders black
rush. The boundary between these communities is usually distinct and
abrupt [4,19].

Black-rush-dominated communities have been separated into three
generalized categories based upon elevation and soil salinity influences
[25]. The number of species associated with black rush tends to
increase as water salinity decreases [4]. The three categories of black
rush marsh are presented below:

(1) Saline marsh, which experiences little dilution of tidal waters.
Associates include smooth cordgrass, saltmeadow cordgrass (S. patens),
giant cordgrass (S. cynosuroides), saltgrass (Distichlis spicata),
glasswort (Salicornia spp.), Olney threesquare (Scirpus americanus), and
saltmarsh bulrush (Scirpus robustus).

(2) Brackish marsh, where tidal waters are routinely diluted before
flooding the marsh. Associates include smooth cordgrass, giant
cordgrass, saltmeadow cordgrass, sealavender (Limonium caroliniana),
Olney threesquare, and common arrowhead (Sagittaria latifolia).

(3) Intermediate marsh, which is transitional between brackish and
freshwater marsh. Associates include common reed (Phragmites
australis), sawgrass (Cladium jamaicense), softstem bulrush (Scirpus
validus), and Virginia iris (Iris virginica).

More info for the term: graminoid

Graminoid

Black rush was effectively controlled with aerial applications of
various herbicides in Florida. Plants were most susceptible to spraying
just before and during flowering. Multiple cuttings also provided
effective black rush control [20].

Black rush is an increaser in coastal marshes grazed by cattle [2,24].

AL CT DE FL GA LA MD MS NJ NY
NC SC TX VA MEXICO

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More info for the term: marsh

In contrast with associated marsh plants which have a single annual
flush of growth, black rush produces new shoots and leaves throughout
the year [7]. Flowering in several states is as follows [3,21]:

southern Florida - March
southeastern Louisiana - March and April
Mississippi - late January to May, peak in March
North Carolina - January to June

More info for the term: marsh

In coastal Mississippi black-rush-dominated marshes, net primary
productivity over a 3-year period was greater on burned than on unburned
marsh. However, black rush recovered more slowly than did species of
cordgrass. Three years after burning, total black rush biomass was
lower than before burning [13].

Myers [20] reported that winter burning increased Olney threesquare when
it occurred as a competing subdominant with black rush. In nearly pure
stands of black rush, however, burning did not change the species
composition of the marsh.

More info for the terms: herb, rhizome

Rhizomatous herb, rhizome in soil

More info for the terms: marsh, perfect, rhizome, seed

Black rush reproduces both sexually and asexually. Existing stands are
maintained through vigorous rhizome growth, while new stands are
established via seed dispersal and seedling establishment. Black rush
reproduction biology presented below is summarized from Eleuterius
[3,6].

Seed production and dispersal: Two flowering types occur in black rush.
Plants produce either perfect flowers only, or pistillate flowers only.
Pistillate-flowered plants produce more and higher viability seeds than
perfect-flowered plants. Seeds from a single inflorescence are shed
simultaneously.

Germination and seedling establishment: Black rush seeds are highly
viable. In Mississippi, germination averaged about 75 percent and 60
percent for seeds from pistillate and perfect flowers, respectively.
Seeds remain viable for more than 1 year and may germinate any time
germination requirements for moisture and light are met. The seeds are
light dependent; thus few seedlings occur on muddy sediments where seeds
are easily covered. Sandy, wet, vegetation-free substrates provide the
best germination sites because seeds are not easily covered, and if they
are covered, sufficient light for germination is able to penetrate the
thin sand covering. In fact black rush seedlings are almost always
restricted to barren, sandy areas. They are almost never found in
established black rush stands or other marsh types. Germination
decreases with increasing salinity, and is inhibited by salinities above
15 parts per thousand. In Mississippi, germination which leads to
successful plant establishment occurs from November to April. Spring
and summer germinants are less likely to survive because surface
sediments dry during the summer and fall resulting in seedling death.

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More info for the term: climax

Obligate Climax Species

Black rush is considered a climax species [4].

The currently accepted scientific name of black rush is Juncus
roemerianus Scheele. [11,22]. There are no recognized varieties,
subspecies, or forms.

Black rush may be useful for shoreline stabilization and for vegetating
dredged spoils, but direct planting is rarely justified because of
erratic transplanting success. For shoreline stabilization, it is
easier to establish other species and allow black rush to naturally
invade where it is best adapted [14]. However, Stout [25] points out
that black rush is very slow to naturally colonize spoil islands in
Mississippi, often taking 10 years. It is estimated that it would take
16 to 35 years for black rush to colonize spoils and form a closed stand
[25].