nimet breadcrumb-navigoinnissa
Blue-winged teal, green-winged teal, northern shovelers, and pintails frequently select green needlegrass for nest sites because of its height [33,130]. It also provides additional concealment of nest sites for Brewer's and Vesper sparrow [7]. Grosz [52] observed green needlegrass at sharp-tailed grouse brood sites.
The value of green needlegrass as cover for domestic animals and wildlife is rated as follows [30]:
MT ND UT WY Elk poor poor Mule deer good poor poor Pronghorn fair good fair White-tailed deer poor fair Small mammals fair fair good Small nongame birds fair good fair good Upland game birds fair good fair good Waterfowl fair poor poorGreen needlegrass is a tufted, perennial, native, long-lived, cool-season bunchgrass [1,8,14,18,20,24,28,29,35,42,47,65,74,94,99,101,126,128]. At maturity, the plants are 12 to 48 inches (30-122 cm) tall [4,49,51,61,72,86,97,107,109,127,128,139,141]. It has "good" drought tolerance [33,43,109,127], is moderately tolerant of flooding [57] and short-term submergence [139], and is capable of vigorous seedling growth [78]. Green needlegrass has a weak tolerance to shade from scattered shrubs and woodland openings and is very winter hardy [139].
The numerous, mostly basal leaves, are flat to involute and taper to threadlike tips [139]. Average length of leaves ranges from 4 to 12 inches (10.2-30.5 cm) [127]. Inflorescences are narrow, loose spikelets and 4 to 8 inches (10-20 cm) [61,97] long. Awns are bent twice and are 0.75 to 1.5 inches (1.9-3.8 cm) long [51,61,72,97,141]. Old sheath bases are often persistent [141].
Green needlegrass has a deep, up to 4 to 5 feet (122-152 cm) [140], fibrous root system [4,22,88,127,139], similar to needle-and-thread grass. The main roots are 0.04 inch (1 mm) in diameter; lateral spread is 14 inches (35.6 cm) in the first 6 inches (15.2 cm) of soil, and 18 inches (45.7 cm) in the first 12 inches (30.5 cm). The system is well branched and rootlets are abundant to depths of 2.5 feet (76.2 cm) [140].
Effect of fire on green needlegrass depends on season of burn and site characteristics [144]. Depending on the phenological state of the plant, green needlegrass increases or decreases following fire [79,144]. Aboveground vegetation of green needlegrass is usually consumed by fire, but individual culms may survive [35]. Regeneration is through seed and tillering [143]. The effects of fire, increases in growth or decreases in vigor, can be immediate and last up to 3 years following the fire [32,39,80,102,104,141].
FIRE REGIMES:
Fire return intervals for plant communities and ecosystems in which green needlegrass occurs are summarized below. Find further 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".
Green needlegrass is found on foothills, open hillsides and parks, in mountain meadows, canyons, and open woodlands [51,57,61]. It is a pioneer on abandoned croplands and coarse textured disturbed sites [139]. Green needlegrass is generally found in semi-arid, continental climates in a wide range of elevations [7,32,47]. Elevational ranges for green needlegrass are as follows:
Green needlegrass is found in a wide range of temperatures. Mean annual temperatures where green needlegrass is present are 3.4 to 117 degrees Fahrenheit (-15.9 to 47 oC). Green needlegrass occurs in areas with an average precipitation of 10-26 inches (254-660 mm) and the majority of the precipitation occurs between April and September [5,9,11,20,124,134,148]. Mean annual precipitation ranges for green needlegrass are as follows:
ND 14 to 17.1 inches (356-438 mm) [11,17,31,32,40,50,55,98,109] SD 14.7 to 38.6 inches (374-980 mm) [9,35,46,74,87,90,100,112,116,144] AB 10.7 to 12.8 inches (272-326 mm) [20,103] MT 6.74 to 23.14 inches (171-587.8 mm) [12,34,37,66,92,93,102,106,122,131] SK 12.9 to 13.28 inches (327-337 mm) [67,83] WY 10 to 14 inches (254-356 mm) [56]Soils: Green needlegrass is found on a variety of soil types [4,9,31,35,47,48,50,82,83,87,102,109,110,123,144,151]. It is tolerant of heavy clay soils, is less common on loams and sandy soils [90,127], and is weakly to moderately tolerant of soil salinity [139].
Green needlegrass is considered "good" forage based on palatability, nutritive content, and dependability as a forage supply [97,111,128]. The awns do not trouble livestock [97,128]. Green needlegrass is used for hay and pasture production [18,133] and can produce good quality hay on favorable sites [128].
The seeds of green needlegrass are eaten by small mammals and songbirds, such as Vesper sparrow [7,127,139]. It is eaten by elk [92,122], Kaibab mule deer [68], and cattle [92].
Published classifications listing green
needlegrass as an indicator species or a dominant component of community types
or plant associations are listed below:
Conditions and trends on ponderosa pine ranges in Colorado [23]
The prairie, meadow, and marsh vegetation of Nelson County, North Dakota [31]
The many faces of South Dakota rangelands: description and classification [46]
Wind Cave National Park grassland ecology [48]
Ecologic observations on Pinus ponderosa laws. (Pinaceae) at its eastern most extension in South Dakota
[64]
The climate, soils, and soil-plant relationships of an area in southwestern Saskatchewan
[67]
Alberta's prairie vegetation: past and present use [103]
Production ecology of grassland plant communities in western North Dakota [109]
Vegetation, soil, and cattle responses to grazing on Northern Great Plains range
[110]
Climax vegetation of Montana: Based on soils and climate [114]
Woodlands in northwestern Nebraska [132]
The numerous,
mostly basal leaves, are flat to involute and taper to
threadlike tips [139]. Average length of leaves ranges from 4 to
12 inches (10.2-30.5 cm) [127]. Inflorescences are narrow, loose
spikelets and 4 to 8 inches (10-20 cm) [61,97] long. Awns are bent twice and are 0.75 to 1.5
inches (1.9-3.8 cm) long
[51,61,72,97,141]. Old
sheath bases are often persistent [141].
Green needlegrass has a deep, up to 4 to 5 feet (122-152 cm) [140],
fibrous root system [4,22,88,127,139], similar
to needle-and-thread grass. The main roots are 0.04 inch (1
mm) in diameter; lateral spread is 14 inches (35.6 cm) in the first 6 inches
(15.2 cm) of soil, and 18 inches (45.7 cm) in the first 12 inches (30.5
cm). The system is well branched and rootlets are abundant to depths of
2.5 feet (76.2 cm) [140].
RAUNKIAER LIFE FORM [108]:
Hemicryptophyte
REGENERATION PROCESSES:
Green needlegrass reproduces from seed and through tillering [94,97].
New seeds of green needlegrass have a higher occurrence of
dormancy and a lower germination rate than mature seeds.
Stratification in moist sand was found to be the best treatment
to break dormancy. Fall plantings are successful because overwintering in
soil can break the dormancy [113].
SITE CHARACTERISTICS:
Green needlegrass is found on foothills, open hillsides and parks, in
mountain meadows, canyons, and open woodlands [51,57,61]. It is a pioneer on abandoned croplands
and coarse textured disturbed sites [139]. Green needlegrass is
generally found in semi-arid, continental climates in a wide range of elevations
[7,32,47]. Elevational ranges for green needlegrass are as follows:
White and Wight [145] observed
these dates of development in Montana during 1975 and 1976:
Measured August 8-11, 1980
Measured August 8-11, 1981
Green needlegrass is one of the first in its association to start spring growth in the western Northern Great Plains [57]. It generally starts growth in March, grows vegetatively in May and June, heads out in June, and matures in July [4,22,96,127,139].
Goetz [49] observed these dates of development in North Dakota during 1955-1962:
initiation of fruiting stalk May 26 head emergence June 12 anthesis June 16 seeds mature July 2 seeds starting to shed July 12White and Wight [145] observed these dates of development in Montana during 1975 and 1976:
1975 1976 late boot June 7 May 21 first inflorescence June 10 May 24 anthesis June 23 June 7 start of dissemination July 14 June 21The currently accepted scientific name of green needlegrass is Nassella
viridula (Trin.) Barkworth (Poaceae) [75].
Green needlegrass occasionally hybridizes with Indian
ricegrass (Achnatherum hymenoides) to produce Achnella caduca
(Beal) Barkworth, a sterile plant [51,70].
Nassella viridula is a species of grass known by the common name green needlegrass. It is native to North America, where it is widespread in western Canada and the western and central United States. It is introduced in parts of eastern North America.[2]
This grass forms tufts of stems up to about 1.2 meters tall. It grows from a fibrous root network which may penetrate over 1.5 meters deep in the soil. The leaves are mostly basal. Each is up to 30 centimeters long and tapers to a threadlike tip. The spikelets have awns reaching nearly 4 centimeters long, each bent twice.[3] The plant reproduces via seed and by tillering. The seeds may be dormant for a period of time and may require stratification to germinate.[2]
This grass is found in many types of habitat, including disturbed areas where it acts as a pioneer species. It is also considered a climax species in some regions, such as North Dakota. It is a dominant species and an indicator species in a variety of habitat types. It tolerates a wide range of temperatures and it is drought-tolerant.[2]
A number of animals utilize the plant for food and cover. Many waterfowl and other birds nest in it.
Nassella viridula is a species of grass known by the common name green needlegrass. It is native to North America, where it is widespread in western Canada and the western and central United States. It is introduced in parts of eastern North America.
This grass forms tufts of stems up to about 1.2 meters tall. It grows from a fibrous root network which may penetrate over 1.5 meters deep in the soil. The leaves are mostly basal. Each is up to 30 centimeters long and tapers to a threadlike tip. The spikelets have awns reaching nearly 4 centimeters long, each bent twice. The plant reproduces via seed and by tillering. The seeds may be dormant for a period of time and may require stratification to germinate.
This grass is found in many types of habitat, including disturbed areas where it acts as a pioneer species. It is also considered a climax species in some regions, such as North Dakota. It is a dominant species and an indicator species in a variety of habitat types. It tolerates a wide range of temperatures and it is drought-tolerant.
A number of animals utilize the plant for food and cover. Many waterfowl and other birds nest in it.
Stipa viridula là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Trin. miêu tả khoa học đầu tiên năm 1836.[1]
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Stipa viridula là một loài thực vật có hoa trong họ Hòa thảo. Loài này được Trin. miêu tả khoa học đầu tiên năm 1836.
