BOTANICAL AND ECOLOGICAL CHARACTERISTICS
SPECIES: Deschampsia cespitosa | Tufted Hairgrass 



GENERAL BOTANICAL CHARACTERISTICS : 
Tufted hairgrass is a densely cespitose [37,94] cool-season [90] native
perennial bunchgrass [26,70].  Culms are hollow [37], slender [29,89],
erect [63], and 8 to 48 inches (20-120 cm) in height [35,37,43,48].
Abundant leaves form basal tufts [74,84]; blades are 0.8 to 13 inches
(2-33 cm) [34] long and 0.04 to 0.16 inch (1-4 mm) wide [74,90].  The
inflorescence is generally a loose, open panicle [39,49], though
occasionally narrow and contracted [35,48,63]; it is 4 to 12 inches
(10-30 cm) long [37,39,67].  Branches are whorled [35,84], hairlike
[63,94], and spikelet-bearing near their tips [29,84].  Spikelets are
two- to occasionally three-flowered [37,48].  Lemmas are awned toward
the base [49,67,90].  The fruit is a caryopsis [37].

Tufted hairgrass root distribution was measured on the Beartooth Plateau
above Red Lodge, Montana.  In the 4 inch (10 cm) cores taken,
approximately 45 percent of root mass was in the upper 0.8 inch (2 cm)
of soil, with lower proportions in each succeeding 0.8 inch (2 cm) [99].



RAUNKIAER LIFE FORM : 
   Hemicryptophyte


REGENERATION PROCESSES : 
Tufted hairgrass reproduces by seed [43,70,90].

Tufted hairgrass is self-incompatible.  Seeds of tufted hairgrass can be
dormant and persist in the seedbank [34].  Germination is enhanced by
light and by cold storage.  Tufted hairgrass seeds were collected in
September 1983 on the Beartooth Plateau, Montana; filled seeds had 81
percent viability.  Tufted hairgrass seeds were given 90 days of dry
cold storage or wet cold storage in light or dark conditions.  Day
temperatures were 64 degrees Fahrenheit (18 deg C) for 14 hours and
night temperatures were 39 degrees Fahrenheit (4 deg C) for 10 hours.
Over 30 days from beginning of treatment, tufted hairgrass seeds showed
the following accumulated germination response [17]:

                             Percent Germination         
 
                            Light            Dark

     Dry Cold Storage        95               64
     Wet Cold Storage        63               46

Tufted hairgrass germination response was significantly (p<.001) better
in light than in dark conditions, and also in dry cold than in wet cold
storage conditions.  Light increased total percent seed germination more
than did cold storage [17].

Tufted hairgrass seeds collected in 1983 on the Beartooth Plateau showed
a decrease in viability from 80 percent at the time of collection to 35
percent 3 years later [18].  Viability of filled tufted hairgrass seeds
produced in different years on the Beartooth Plateau was significantly
(p<.001) variable.  About 40 percent of seeds collected in 1986 were
filled; almost 100 percent were filled in 1983.  Viability of filled
tufted hairgrass seeds varied from about 1 percent in 1984 to about 80
percent in 1983.  This variation is attributed to the severe and
unpredictable nature of the alpine environment [14].

In the Richardson Mountains on the Yukon Territory-Northwest Territories
border, tufted hairgrass plants produced no seed the year of planting
but did so during their second year [93].


SITE CHARACTERISTICS : 
Tufted hairgrass is common in grassland communities within its
circumglobal range.  In the Northern Hemisphere it occurs from sea level
to over 14,100 feet (4,300 m) elevation [10].  It is found in very moist
to saturated habitats at the margins of bogs and marshes and in sloughs,
moist areas along shores, drainage ditches, and moist draws, and in
moderately dry to very dry locations on slopes [34,43].  It is
frequently found on disturbed sites, especially at higher elevations and
moist habitats [10].

In Colorado tufted hairgrass grows best in moist habitats, wet meadows,
and bogs.  It often occurs in nearly pure stands in moist, favorable
sites.  It generally requires 20 inches (500 mm) of precipitation a year
[23].  On drier, less favorable sites it grows in open stands in
association with other plants [46].  In northwestern Montana tufted
hairgrass is a facultative wetland species [5].

Tufted hairgrass grows on a variety of soil types and textures.  It is
found on sandy loam [45,79,98], sandy clayey loam [6], silty loam [47],
loam [6,47,64,66], loamy clay [6,66], and clay [6].  Tufted hairgrass
growth is rated fair on sandy loam and good on loam and clayey loam
[26,43].  It is found on gravel in Alaska [95], Michigan [98], and Utah
[64].  It occurs on granitic material in Idaho [32] and Wyoming [53].
It is found on peat in British Columbia [96] and on calcareous seeps in
Illinois [88].  It grows on pumice in Oregon [97] and on volcanic soils
in Wyoming [53].

Tufted hairgrass is adapted to cool, acid locations [68] but it also
grows on somewhat alkaline soils [43,77].  It has been found on soils
varying from pH 3.3 on mine tailings in Ontario [43] to pH 8.4 in
central Idaho [77].  However, it generally grows best in soils with pH
5.2 to 5.5 [54].  Tufted hairgrass will tolerate some saline water
[48,71]; along the north-central Oregon coast, tufted hairgrass occurs
in high saltmarsh that is very occasionally flooded by salt water
during the summer growing season [31].  Some tufted hairgrass
populations are adapted to growing on spoils with elevated levels of
heavy metals [43].

In the western United States tufted hairgrass reaches its greatest
development at high elevations, where it becomes a nearly ubiquitous
floral component of most plant communities above treeline [10].  Tufted
hairgrass dominates moist areas of the alpine tundra of the Rocky
Mountains, where it occurs along soil moisture gradients from the middle
of lee slopes with early melting snowdrifts to the bottoms of lee slopes
with very wet meadows [34].

Tufted hairgrass is reported at the following elevations:

                       Feet             Meters

     Arizona       8,800- 9,500       2,680-2,900   [30,56]
     California         <12,800            <3,900   [45,48,67,74]
     Colorado      5,000-14,000       1,500-4,300   [26,46,47]
     Montana       2,500-10,000         800-3,000   [19,26,73,76]              
     Utah          4,500-12,500       1,400-3,800   [26,100]      
     Wyoming       4,000-12,000       1,200-3,700   [26,39]


SUCCESSIONAL STATUS : 
Tufted hairgrass can occur as a colonizer [10] and as a component or
dominant of successional [16] and climax vegetation [81].  It is rarely
found in dense shade [94].

Tufted hairgrass can be an aggressive colonizer on disturbed sites,
particularly in alpine and subalpine regions [10].  In south-central
Montana tufted hairgrass is a colonizer on the Beartooth Plateau, where
there are nearly 200 known alpine vascular plant species.  Tufted
hairgrass is one of fewer than 5 percent of these species that can be
found on virtually all disturbances of more than a few years of age
[7,15].

Tufted hairgrass occurs naturally on both early and late successional
alpine sites [16].  In Alaska on the north slope of the Alaska Range,
tufted hairgrass occurs on gravel terraces in the meadow stage, but does
not occur in the earlier pioneer stage or in later shrub and tree stages
[95].  In the Medicine Bow Mountains of Wyoming, tufted hairgrass occurs
in successional tundra meadow in ribbon forest and in successional
snow-glade vegetation [4].  In the Great Basin of Nevada, tufted
hairgrass is an early seral species that can continue to occupy sites
indefinitely given relatively stable site conditions [66].  In the
alpine zone of the Uinta Mountains, Utah, tufted hairgrass is middle and
late successional in hydrarch succession where alpine glacial lakes have
been or are in the process of being filled with sediment and plant
remains.  Tufted hairgrass is an associate but is not dominant in the
drier climax sedge-grass communities [64].

Tufted hairgrass occurs in climax vegetation.  In northwestern Colorado
it is a dominant in climax communities of wet to mesic subalpine and
alpine zones [47].  In the Medicine Bow Mountains of Wyoming, tufted
hairgrass is a component of climax snow-glade vegetation [4]. In
glaciated plains, foothills, and mountains of western Montana, tufted
hairgrass is a dominant in the climax vegetation of subirrigated and
wetland range sites.  It is also a dominant in alpine grassland climax
vegetation on deep to moderately deep, well drained to poorly drained
soils; these grasslands occur on sloping to steep windswept mountain
tops above timberline [81].

Tufted hairgrass is not generally a part of the understory of wooded
areas [10] or of forests [4].  In Yellowstone National Park tufted
hairgrass occurs in mesic subalpine meadows.  Lodgepole pine (Pinus
contorta var. latifolia) has been progressively invading the borders of
these meadows (for at least 125 years) in the absence of fire.  Tufted
hairgrass generally decreased along transects at the edge of meadows as
the size and age of lodgepole pine increased [52].


SEASONAL DEVELOPMENT : 
In alpine regions tufted hairgrass maintains green leaves throughout the
winter and begins growth very soon after snow release, when temperatures
at soil level are still near 32 degrees Fahrenheit (0 deg C) [64].  In
Utah tufted hairgrass starts growth early in the spring and remains
green throughout the summer [94].

In Colorado tufted hairgrass phenological conditions at elevations
between 9,843 and 12,468 feet (3,000-3,800 m) were observed.  Older
tufted hairgrass leaves began developing autumn coloration about
September 15, 1968; 1 month later it was in winter condition.  Tufted
hairgrass had immature green leaves in winter; the new leaves developed
prior to the initiation of dormancy and remained at one-eighth to
one-fourth the length of mature leaves throughout the winter.  Through
the winter green leaf surfaces were protected by a covering of dead but
undeteriorated leaves from the previous summer.  In the spring no
observable leaf elongation occurred until about 10 days after snow
release [1].

In alpine regions tufted hairgrass reaches maximum flowering
approximately 3 weeks after the initiation of growth [64].  Tufted
hairgrass flowering times are:

          Arizona           June-September  [56]
          California        May-August      [74]
          Colorado          July-September  [26]
          Illinois          June-July       [69]
          Montana           June-September  [26]
          North Carolina    June-July       [78,102]
          Virginia          June-July       [102]
          West Virginia     June-July       [89]
          Wyoming           July-September  [26]
          Great Plains      June-August     [37,63]           
          Northeastern US   May-August      [29]
          Southeastern 
            Canada          May-August      [29]

In alpine regions tufted hairgrass seed matures 7 to 8 weeks after
initiation of leaf growth in the spring [64].

Related categories for Species: Deschampsia cespitosa | Tufted Hairgrass