Soft Chess

Soft Brome or Lop Grass is commonly grazed.

This species is widely introduced in temperate parts of the world.

Annual or biennial; culms erect or rarely ascending from a decumbent base, up to 100 cm high. Leaf-blades greyish-green, up to 20 cm long, 2-7 mm wide; sheaths softly hairy. Panicle 3-16 cm long, greyish-green or purplish, erect and loose at first, afterwards contracted and nodding, the branches clustered. Spikelets narrowly ovate to oblong, 6-12-flowered, 12-22 mm long excluding the awns, the lemmas overlapping and concealing the internodes; glumes pubescent, the lower narrowly elliptic, 5-8 mm long, 3-7-nerved, the upper elliptic, 6-9 mm long, 5-7-nerved; lemmas narrowly elliptic to narrowly ovate in side view, bluntly angled on the margins, the lower 8-11 mm long, herbaceous with narrow hyaline margins, 7-9-nerved, pubescent, minutely 2-toothed at the tip with a straight awn 5-10 mm long from just below the tip; palea shorter than the lemma, ciliolate on the keels; anthers 0.7-15 mm long.

Annual. Culms erect from a creeping or obliquely ascending base, 30–80 cm tall, minutely hairy immediately below inflorescence, nodes thinly hairy. Leaf sheaths pubescent; leaf blades linear, flat, 3–5 mm wide, soft, both surfaces pubescent; ligule ca. 1 mm. Panicle erect, usually dense, 5–10 cm; branches short; pedicels mostly shorter than spikelets, pubescent, spikelets many. Spikelets oblong, 12–20 × 4–6 mm, usually hairy, florets 6–12(–16), distal florets mostly sterile; rachilla internodes ca. 1 mm, with small bristles; glumes unequal, margins membranous, pubescent, obtuse, lower glume 4–5 mm, 3–5-veined, upper glume 5–8 mm, 5–7-veined; lemmas elliptic, 8–11 × ca. 2 mm in side view, papery, glabrous, prominently 7–9-veined, pubescent, margins membranous, apex obtuse, minutely 2-toothed, awned from 1–2 mm below apex; awn 5–10 mm, stout, straight; palea shorter than lemma, keels ciliate. Anthers 0.2–1 mm. Caryopsis shorter than or as long as palea. Fl. and fr. May–Jul. 2n = 28.

Distribution: Pakistan (Punjab, cultivated in N.W.F.P.); throughout Europe and western Asia; introduced into North and South America, Australia etc.

F1 & Fr. Per.: April-July or August.

Gansu, Hebei, Qinghai, Taiwan, Xinjiang [Pakistan, Russia; SW Asia, Europe; adventive in America and Australia].

Avena mollis (Linnaeus) R. A. Salisbury; Bromus mollis Linnaeus; B. secalinus Linnaeus var. hordeaceus (Linnaeus) Linnaeus; Serrafalcus hordeaceus (Linnaeus) Grenier & Godron; S. mollis (Linnaeus) Parlatore.

Bromus hordeaceus is native to Eurasia, where it is most common in the Mediterranean region. It has naturalized in all other continents except Antarctica. Soft chess is most common in low-elevation valleys and foothills of California where the climate is Mediterranean; in fact, it is more abundant Mediterranean areas of California than in Europe.

While Soft chess is considered palatable and nutritious, it is not a preferred grass by most native ungulates or livestock. In California it is the most common dominant grass, having replaced perennial bunchgrasses in about 1860, chiefly through overgrazing regimes and its prolific seed production. In areas of grazing cessation, there is evidence that native grasses re-establish their abundance.

More info for the terms: fire frequency, forbs, frequency, grassland, prescribed fire

Fall and spring prescribed burning in east-central Oregon had no significant effect on soft chess frequency in postfire year 1 or 2 [81]. See the Research Project Summary of this study for more information on fire effects on soft chess and 60 additional grasses, forbs, and woody plant species. See the PDF of Hansen's [40] thesis, The effect of fire and fire frequency on grassland species composition in California's Tulare Basin, for information on the response of soft chess and other herbs to prescribed fire in an annual grassland community.

soft chess
soft brome

More info for the term: cover

In Utah, cover value of soft chess for small mammals, small nongame birds, and upland game birds was rated fair.  Cover value for waterfowl was rated poor [26].

More info for the term: cool-season

Soft chess is a cool-season exotic grass [38,49,50].  It is usually an annual but is sometimes a biennial in the Great Basin and the Northeast [35,95].  The erect to ascending plants are 4.4 to 26 inches (11-65 cm) tall.  Soft chess is generally pubescent, but culms and/or spikelets are occasionally glabrous [50].  Awns are straight and from 0.16 to 0.4 inch (4-10 mm) long [95].

Soft chess is native to Eurasia, where it is most common in the Mediterranean region [61,95].  It has naturalized in all other continents except Antarctica [54,95].  Soft chess is widely distributed but scattered and uncommon in most of North America [35,38,54,59], ranging from coastal southern Alaska south to Baja California and east to Maine, North Carolina, and Texas [22,35,38,50,54,83].  Soft chess is most common in low-elevation valleys and foothills of California and southwestern Oregon where climate is mediterranean.  It is more abundant in mediterranean areas of California than in Mediterranean Europe [61].

More info for the terms: fire management, fire regime, forbs, frequency, grassland, prescribed fire, seed

Fire autecology:  Summer and fall fires have no direct effect on soft chess.  Soft chess has usually senesced and shattered seed when the fire season starts.  The seed is not killed until fire temperatures rise above approximately 200 degrees Fahrenheit (93 deg C).  Since grassland fires are usually fast-burning and relatively "cool," soft chess seed is usually not damaged by fire [71,80].  Fire can affect relative abundance of soft chess in the postfire plant community, however [61,82].  Fire removes mulch, which favors annual forbs over soft chess.  Some soft chess germinates the fall after fire, but best germination occurs in mid-succession, when mulch layer is moderate [7,9]. FIRE REGIMES:  California native grassland - Data are lacking to quantify intensity and frequency of fire in pristine California prairie. It is generally accepted that lightning-caused fire was part of the evolutionary history of California prairie.  The California Division of Forestry reported an average of 312 lightning-ignited fires per year in its fire protection area, which is 43 percent woodland-annual grassland. Frequency of lightning-caused fires was probably at least as great in the presettlement era [45]. Native Americans may have used frequent fire to enhance production of edible perennial bunchgrass seeds [13].  Fire enhances flowering and seedling recruitment for some perennial bunchgrasses native to California prairie including purple needlegrass [62] and bottlebrush squirreltail [99].  Both species show mass flowering after fire and require mineral soil for establishment [36,60]. Annual grassland - Since California annual grassland has existed for less than two hundred years, it has no evolutionary history of fire. Like the perennial grassland that preceded it, however, California annual grassland is a fire-tolerant ecosystem [61].  Studies attempting to promote native perennial bunchgrasses over exotic annuals by using prescribed fire have had mixed results.  These results are summarized in FIRE MANAGEMENT CONSIDERATIONS. 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: cover, density, forbs, frequency, grassland, phenology, prescribed fire, relict, seed, shrub

California:  annual grassland - Use of prescribed fire to increase the balance of natives relative to non-natives such as soft chess has had mixed results.  In all cases, "remnant" California prairie contains exotic annuals, and attempts to eliminate the exotics have been unsuccessful [61].  However, fire sometimes tips the balance toward natives.  Perennial bunchgrasses are well adapted to frequent fire [20,94].  Some authors have reported that fire favors native bunchgrasses over exotic annuals [1,70].  However, Garcia and Lathrop [33] reported no increase in purple needlegrass after burning, and Lathrop and Martin [66] found that native deer grass (Muhlenbergia rigens) decreased under some burning regimes.  In view of the differences in phenology and life histories between perennial bunchgrasses and annual grasses such as soft chess, it would be instructive to know how burning in different seasons affects the ratio of native to non-natives.  Since annual grasses produce seed about a month earlier than perennial grasses, precise timing of burning may alter the balance of reproductive success between annual and perennial grasses [61]. When used with prescribed grazing, fire may favor purple needlegrass and reduce soft chess and other annual grasses.  Langstrotti [65] found that on the Jepson Prairie (a relict perennial grassland reserve in Solano County, California), short-term, intensive grazing by domestic sheep in early spring (late March or early April) combined with late summer (early September) prescribed fire favored tillering and seedling establishment of purple needlegrass over exotic annual grasses including soft chess.  Purple needlegrass had been declining on the reserve for a number of years.  Frequency of soft chess was significantly reduced (p=0.05) by early spring grazing and late summer fire.  The treatments reduced soft chess cover to less than 2 percent.  Early spring grazing reduced average seed mass, and the number of soft chess seeds was reduced by 76 percent (p=0.25).  Late summer fire reduced soft chess cover by 50 percent (p less than 0.001).  Summer grazing and late summer fire also reduced soft chess, but not as much.  Data from the spring grazing/late summer fire treatments follow.                             grazed-     ungrazed-                                  burnt      unburned                             _______    __________ soft chess frequency (%)      39.7         3.0 soft chess seeds/sq dm       198       1,343 soft chess seed mass (mg)      0.57        0.97 Effects of postfire seeding of ryegrass on soft chess:  Seeding Italian ryegrass (Lolium multiflorum) to reduce postfire erosion had little effect on postfire growth of soft chess and other exotic bromes in southern California chaparral.  Coverage of annual bromes was similar on unseeded plots and on plots seeded with Italian ryegrass [15]. Oregon: big sagebrush - Prescribed fire had little effect on soft chess in a basin big sagebrush/bluebunch wheatgrass community in John Day Fossil Beds National Monument, Oregon.  Weather patterns occurring after fire greatly influenced plant community composition, however.  One study area was prescribed burned on September 25, 1987; an adjacent study area was prescribed burned on May 24, 1988.  Prescription burning was followed by 3 years of drought, which appeared to greatly reduce soft chess cover.  By the third postfire year, soft chess was absent from all treatments including the unburned control.  Density of other annual grass species was also greatly reduced on all treatments including the unburned control.  Density of annual forbs increased on all plots, and density of native perennial grasses did not change.  Density of woody shrub species was greatly reduced on burned plots but did not change on control plots.  Average density of soft chess (plants/sq m) on unburned control, fall-burned, and spring-burned plots is given below.  Numbers in parenthesis are the standard errors of the mean; different letters denote a significant difference between years (p less than 0.1) [82].                  1987      1988      1989                 _________   _______   ______ control       160a (87)    0b (0)   0b (0)  fall burn      82a (28)   10b (8)   0b (0) spring burn    --         37a (16)  0b (0)

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More info for the term: therophyte

Therophyte

More info for the terms: caliche, shrubs

Soft chess occurs mostly in waste places in Alaska, the Pacific Northwest, the Great Plains, the Southwest, and the East [35,38,54,59]. Soils and aspect:  Soft chess grows on a variety of soil types including serpentine and caliche [19,72,80].  Best growth occurs on clay loam and sandy soils [80].  In inland California, soft chess is most common on deep, clayey soils [2] receiving 26 to 40 inches (650-1,000 mm) of annual precipitation [12].  On the coast, it is most common on sandy soils [47].  In Somewhere, California, McNaughton [72] found that soft chess occurred on all aspects but was most common on southwest slopes. Climate:  Dry mediterranean climates are most favorable to soft chess. Soft chess is probably more common in California than in its native Mediterranean because the drier California climate favors establishment of annual grasses over perennial herbs and shrubs.  The relatively moister climate of the Mediterranean favors perennials [61]. Outside mediterranean regions of California and southwestern Oregon, soft chess is most common in the cold climates of the Pacific Northwest [50] and in northern portions of the Great Basin [95].  It is uncommon in warm desert regions [49,59].  Soft chess is probably not well adapted to the climate of the Southeast:  It does not occur further south than North Carolina, where it is very rare [76]. Elevation:  Soft chess occurs at the following elevations: California   below 6,300 feet (2,100 m) [49] Colorado     5,000 to 9,200 feet (1,500-2,800 m) [42] Utah         4,220 to 8,350 feet (1,280-2,530 m) [95]

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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):

   233  Oregon white oak
   246  California black oak
   248  Knobcone pine
   249  Canyon live oak
   250  Blue oak-foothills pine
   255  California coast live oak

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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):

More info for the term: shrub

   FRES28  Western hardwoods
   FRES29  Sagebrush
   FRES30  Desert shrub
   FRES34  Chaparral-mountain shrub
   FRES38  Plains grasslands
   FRES42  Annual grasslands

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

More info for the term: forest

   K009  Pine-cypress forest
   K026  Oregon oakwoods
   K030  California oakwoods
   K033  Chaparral
   K034  Montane chaparral
   K035  Coastal sagebrush
   K038  Great Basin sagebrush
   K040  Saltbush-greasewood
   K048  California steppe

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This species is known to occur in association with the following Rangeland Cover Types (as classified by the Society for Range Management, SRM):

More info for the terms: grassland, shrub, shrubland, woodland

   201  Blue oak woodland
   202  Coast live oak woodland
   203  Riparian woodland
   204  North coastal shrub
   205  Coastal sage shrub
   206  Chamise chaparral
   207  Scrub oak mixed chaparral
   208  Ceanothus mixed chaparral
   209  Montane shrubland
   214  Coastal prairie
   215  Valley grassland
   414  Salt desert shrub

Soft chess is nutritious and palatable forage.  Sampson and others [81] rated it the best forage of all California's annual bromes.  The awns are short and soft, and livestock graze soft chess even after seeds mature.  Because soft chess matures later than most annual grasses and the seeds do not readily shatter, cattle graze it well into summer, gaining extra nutrition from the seeds [80,81]. Use of soft chess by native ungulates may be sparse in some areas.  In Point Reyes National Park, California, tule elk and mule deer avoided soft chess and ripgut brome.  Although grasses were the primary component in the fall diets of tule elk, the elk used the annual bromes very little.  Grasses were less important in the diets of mule deer, but annual bromes were the least preferred of the grass species that the mule deer grazed [37].

More info for the terms: cover, forbs, grassland, habitat type, hardwood, mesic, seed, tree

Soft chess is typically dominant in annual grassland communities of
California and southwestern Oregon [9,61,63].  It is an important
component of some sagebrush (Artemisia spp.) steppe and Palouse prairie
communities of eastern Washington and Oregon and southern Idaho,
especially where cheatgrass (Bromus tectorum) is a community dominant
[24,82].  Soft chess is not usually important in other plant communities
in which it occurs [38,54,76,83].

California annual grassland - The native prairie that occurred on
coastal and inland valleys of California and southwestern Oregon has
been almost entirely replaced by annual grassland, agricultural land, or
urban areas [9,19,41,45].  Conversion from native prairie to annual
grassland occurred in less than two hundred years [45,61].  Soft chess
is thought to have naturalized in native California prairie in about
1860 [45].  Species composition of native grasslands was poorly
documented and will always be open to debate [96].  Most experts agree
that coastal prairie and mesic inland valleys were dominated by
perennial bunchgrasses [10,11,20,45,61].  Drier inland valleys may have
been dominated by native annual grasses [8].  Hoover [52] argued that
most native California prairie was dominated by annual forbs.

Species composition in California annual grassland is complex and
varied:  Even slight differences in climate, topography, and soil type
can alter species composition [45,61].  However, soft chess dominates
California annual grassland communities more often than any other plant
species [45,46,47].  In Pinnacles National Monument, for example, soft
chess has 26 percent cover and 100 percent frequency:  It is the most
commonly occurring seed plant in the Monument [41].  Even where it is
not dominant, soft chess is usually an important component of annual
grassland vegetation [45,61].

Publications describing plant communities in which soft chess is a
dominant part of the vegetation are listed below.

Plant communities of Santa Rosa Island, Channel Islands National Park [19]  
Vegetation and floristics of Pinnacles National Monument [41]
Valley grassland [45]
Coastal prairie and northern coastal scrub [47]
Plant associations within the Interior Valleys of the Umpqua River
  Basin, Oregon [85]

Plant species commonly associated with soft chess in California and
southwestern Oregon are listed below.

California: annual grassland - Broad-leaved filaree (Erodium botrys)
commonly codominates with soft chess throughout California annual
grassland.  Red brome (B. rubens) and cutleaf filaree (E. cicutarium)
are also common associates, usually replacing soft chess and
broad-leaved filaree as dominants in portions of the Central Valley
where annual precipitation is less than 12 inches (305 mm) [9].  Other
common annuals include ripgut brome (B. rigidus), slender oat (Avena
barbata), wild oat (A. fatua), rattail fescue (Vulpia myuros), bur
clover (Medicago hispida), and yellow starthistle (Centaurea
solstitialis).  Native perennial associates include purple needlegrass
(Stipa pulchra), Sandberg bluegrass (Poa secunda), melic grass (Melica
californica), California oatgrass (Danthonia californica), bottlebrush
squirreltail (Elymus elymoides), Spanish clover (Lotus americanus), and
ground lupine (Lupinus bicolor) [16,47].

California hardwoods:  Soft chess is dominant to common in the
understory of oak (Quercus spp.) and other upland hardwood types.
Upland tree associates of soft chess not previously listed in SAF COVER
TYPES include valley oak (Q. lobata), tanoak (Lithocarpus densiflorus),
California black walnut (Juglans californica), and California buckeye
(Aesculus californica) [61,87,88].  Soft chess also occurs in Fremont
cottonwood/willow (Populus fremontii/Salix spp.) and other riparian
types [97].

Oregon:  annual grassland - Soft chess/hedgehog dogtail (Cynosurus
schinatus) communities occur on grassy balds of the Umpqua River Basin.
Associated grasses include California oatgrass, pine bluegrass (P.
scabrella), Sandberg bluegrass, and bottlebrush squirreltail [85].

Oregon white oak - Associates of soft chess in Oregon white oak (Q.
garryana) communities of southwestern Oregon include California brome
(B. carinatus), sheep fescue (Festuca ovina), birchleaf
mountain-mahogany (Cercocarpus betuloides), California black oak (Q.
kelloggii), poison-oak (Toxicodendron diversilobum), blue wildrye (E.
glaucus), rough bluegrass (P. trivalis), and burr chervil (Anthriscus
caucalis) [78].

Basin big sagebrush (Artemisia tridentata ssp. tridentata) - At the
Sheep Rock Unit of John Day Fossil Beds National Monument, soft chess
associates in basin big sagebrush communities include Idaho fescue (F.
idahoensis), bluebunch wheatgrass (Pseudoroegneria spicata), cheatgrass,
western yarrow (Achillea millefolium), smallflower woodlandstar
(Lithaphragma parviflora), and western juniper (Juniperus occidentalis)
[82].

A medusahead (Taeniatherum caput-medusae)-rattail fescue-soft brome
community has been described in a bluebunch wheatgrass-Sandberg
bluegrass habitat type near Pendleton, Oregon [18].

More info for the term: graminoid

Graminoid

More info for the terms: cover, fire management, formation, prescribed fire, seed, shrub

Annual grasslands - Soft chess and other exotic annuals probably
replaced native California prairie because native perennial grasses were
severely overgrazed over several periods of extended drought [45,61,74].
Annual grasses are far more prolific seed producers than are perennials.
Once established, soft chess and other annual grasses probably
interfered greatly with perennial grass regrowth, seed production, and
seedling establishment [61].  In a greenhouse experiment, soft chess has
also been shown to interfere with seedling establishment of coyote bush
(Baccharis pilularis), a native chaparral shrub [23].  Soft chess and
other exotic annuals can probably not be eliminated from the California
flora [45,58,61].  Although some fire and grazing treatments have
reduced soft chess and other annuals, results have been mixed.

Control:  grazing - Soft chess may be partially controlled by spring
grazing.  Defoliation within a week after flowering has been found to be
effective in reducing seed formation in annual bromes [30].  Laude [67]
found that removing terminal buds of soft chess prevented leaf
elongation and seed production.  Treatments of spring grazing and fall
fire have been successful in reducing soft chess (see FIRE MANAGEMENT
CONSIDERATIONS).

No grazing - Attempts to reduce soft chess cover by cessation of
grazing have sometimes succeeded.  In the short term, cover of soft chess
and other annuals declined after cattle were removed from Golden Gate
National Recreation Area, California, in 1984.  The next 3 years were
droughty, but native perennial cover increased relative to cover of
annuals despite low rainfall [88].  Cessation of grazing also reduced
soft chess in an upper riparian zone in eastern Oregon.  On plots with
10 years of late summer cattle grazing, soft chess cover increased
greatly:  Cover on grazed plots was 1.7 percent the first year of the
study and 47.5 percent in the tenth year.  On exclosures, cover of soft
chess declined over the 10-year study period [39].  However, Heady [45]
found that in Mendocino County, California, soft chess and other annuals
continued to dominate the Hopland Field Station despite protection from
grazing for at least 40 years.

Fire - Studies using prescribed fire to control soft chess are discussed
in the FIRE EFFECTS section.

More info for the term: fresh

Nutritional content of fresh, immature soft chess was as follows [73]:

Protein (N x 6.25, %)           Potassium (%)     4.00
  cattle          14.2          Ash (%)          12.2
  domestic goats  14.5          Crude fiber (%)  24.2
  horses          13.8          Calcium (%)       0.59
  rabbits         13.5          Phosphorus (%)    0.39
  domestic sheep  14.9

     AK  AZ  CA  CO  CT  ID  IL  KS  ME  MA
     MI  MT  NE  NV  NM  ND  NC  OR  RI  SD
     TX  UT  WA  WI  AB  BC  MB  NB  NF  ON
     PE  PQ  SK  MEXICO

More info for the term: seed

Soft chess is planted for hay.  The seed is commercially available [22,25].

In Montana and Utah, palatability of soft chess has been rated fair for
wild and domestic ungulates, small mammals, small nongame birds, and
upland game birds.  Palatability was rated poor for waterfowl in Utah
[26].

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More info for the term: seed

Soft chess germinates and begins growth in fall [28,46].  Vegetative growth slows or stops early in winter and resumes early the next growing season [28].  Flowering occurs in early spring. Seeds mature later in the season than do seeds of most annual grass species.  In California, soft chess seed matures in early summer.  Seeds do not readily shatter upon maturity and are shed about a month after ripening [46,80]. Phenological development of soft chess on the central coast of California was as follows [46]:                            1971            1972                         __________      ___________ vegetative growth       early Feb.      early Feb. boot stage              mid-March       early April flowering begins        mid-April       mid-April peak flowering          late April      mid-April flowering ends          late May        mid-May seeds ripen             early June      late May plant dies              late June       late May seeds disperse             ----         early Aug. Soft chess flowers from May to July in the Pacific Northwest and the northern Great Basin [22,51].

More info for the terms: cover, density, forbs, frequency, grassland, herbaceous, prescribed fire, wildfire, woodland

Fire may reduce soft chess in the short term [48].  Species composition in the postfire plant community is difficult to predict, however. Year-to-year plant composition in annual grassland is highly dependent upon local weather patterns, and even slight differences in annual precipitation can alter species assemblages [61].  Fall weather patterns, especially interactions of precipitation and temperature after rainfall, appear to be overriding factors in soft chess establishment [45,46,57]. Fire affects plant species composition in annual grasslands largely by removing mulch, which affects germination and seedling establishment rates of soft chess relative to associated herbaceous species. Bartolome [7,9] found that soft chess reached highest densities when mulch biomass was at intermediate levels.  Little quaking grass (Briza minor) was favored when mulch biomass was low, as it would be in the immediate postfire environment.  Fescues (Vulpia and Festuca spp.) were favored when mulch biomass was high.  Heady [45] reported that without heavy grazing the mulch layer usually recovers by postfire year 3, and soft chess and other annual bromes regain dominance. Decreases with fire:  Hansen [40] found that fall prescribed fire in Tulare County, California, significantly increased dominance of annual forbs relative to soft chess.  Greatest reduction soft chess and other annual grasses (and greatest increase of annual forbs) was achieved by 3 years of successive fall burning.  Response of native grasses was similar to that of soft chess:  Native grasses were reduced by fall burning, with greatest reduction achieved after 3 years of consecutive fall burning.  Percent cover of soft chess the spring after fall burning follows.         unburned     single     twice-     thrice-                      control      burn      burned     burned         ________     ______     ______     _______       1982       10          less than 1         --         -- 1983        8           5          2         -- 1984       23          44         16          2 1985       12          23         15         10 A July 1947 prescription fire reduced soft chess on ungrazed annual grassland near Berkeley, California.  Precipitation in the fall and winter of 1947-1948 was slightly below average for the area (20.4 inches with the average being 22.6 inches).  Average height and yield of soft chess on two burned and two unburned sites in May of 1948 was as follows [48]:                   burned     unburned                   ______     ________ height (cm)   exclosure I      29.9        29.9   exclosure II     35.0        39.1 yield (g)    exclosure I       0.8         3.1   exclosure II      4.6        13.9   Mixed effects: Chaparral and oak woodland - Density of soft chess increased greatly from prefire levels 5 years after prescribed fall burning in a nonsprouting manzanita-Lemmon ceanothus (Arctostaphylos spp.-Ceanothus lemmonii) community in Mendocino County.  However, density of soft chess had changed little 5 years after prescribed fall fires in nearby nonsprouting manzanita (Arctostaphylos spp.)-Lemmon ceanothus and interior live oak-blue oak (Quercus wislizenii-Q. douglasii) woodland communities.  Average density (plants/milacre) of soft chess was [80]:                                         Postfire year                                   ______________________________ Community             Prefire   1     2      3      4      5 _____________________________________________________________ nonsprouting manzanita-ceanothus     0.0    2.8   7.3   11.2   24.6   30.3 sprouting manzanita-ceanothus     0.3    4.1   6.5    3.8    5.1    2.8 live oak-blue oak       1.5    6.6   6.7    5.8    3.0    1.3 No effect:  Neither spring nor fall prescribed fire had significant effect on soft chess in annual grassland of Sequoia National Park, California.  Precipitation averaged about 200 percent of normal during postfire years 1 to 4.  Soft chess formed an important component of the vegetation (between 10 and 27%) on plots measured before fire and on spring-burned, fall-burned, and unburned plots measured 4 years after fire [75]. Sagebrush steppe - In central Idaho, fire had little effect on soft chess coverage in either the long term or the short term.  A long-term study was conducted above the Snake River Canyon, after a July wildfire occurred 1961 in a rubber rabbitbrush (Chrysothamnus nauseosus)-cheatgrass community.  At postfire year 12, soft chess had declined on both burned and adjacent unburned plots.  (Weather data were not given.)  Soft chess coverage was as follows [24]:                        Unburned                 Burned                  ____________________     ___________________ Postfire year      2      4      12         2      4     12                  ____   ____    _____     _____  _____  _____                  4.80   1.45    trace     trace  trace  trace A short-term study was conducted nearby when an August 1972 wildfire occurred in a rubber rabbitbrush-cheatgrass stand within the Snake River Canyon.  The following spring, soft chess frequency was 21 percent on unburned plots and 18 percent on burned plots [24].

More info for the term: ground residual colonizer

   Ground residual colonizer (on-site, initial community)

More info for the terms: seed, stratification

As an annual, soft chess regenerates entirely from seed.  Soft chess is mostly self-pollinating [55].  Seed set insufficient to maintain soft chess populations has not been observed in the field [17,43].  Ewing and Menke [27,28] found that drought reduced average mass and number of seed, but some plants produced seed even under severe drought conditions.  Viable seeds germinate in their first autumn.  Little seed is carried over from year to year in the seedbank [27,28,98], although dry-stored soft chess seed may remain viable for decades [53]. Germination is best on a seedbed of moderate mulch, but some seed germinates without mulch [7,9].  In the laboratory, soft chess required stratification to germinate [31,32], but not light [31].  Temperature range for germination is wide, with best germination occurring between 50 and 86 degrees Fahrenheit (10-30 deg C) [4,31].  Seeds become dormant with freezing temperatures or temperatures over 100 degrees Fahrenheit (38 deg C) [31,55].  Most germinating seeds survive the sporadic cycles of wetting and drying that are common in fall in mediterranean climates. Flood [31] found that in the greenhouse, germination rates of soft chess seed were actually better when seeds were exposed to several cycles of wetting and drying. Seedling establishment is limited by freezing temperature and exposure to drying.  At the Hopland Field Station, California, soft chess coverage was best when germination was followed by warm autumn nights. Ripgut brome became dominant in years when temperatures fell below freezing in October and November [46].  Survival of soft chess seedlings is enhanced by moisture-retaining clay substrates or mulches [46,47,57]. Kay [57] reported that seedling establishment of soft chess on decomposed granite was 17 times greater when straw mulch was applied. Soft chess seedlings grow rapidly.  Rate of greenhouse-grown soft chess seedlings was as follows [23]:   Age       root length     shoot length (weeks)        (cm)             (cm) _______     ___________     ____________    1            7.2              4.3    5           18.0              6.0    9           50.0              8.0 

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

    1  Northern Pacific Border
    2  Cascade Mountains
    3  Southern Pacific Border
    4  Sierra Mountains
    5  Columbia Plateau
    6  Upper Basin and Range
    7  Lower Basin and Range
    8  Northern Rocky Mountains
   11  Southern Rocky Mountains
   12  Colorado Plateau
   13  Rocky Mountain Piedmont
   14  Great Plains
   15  Black Hills Uplift
   16  Upper Missouri Basin and Broken Lands

More info on this topic.

More info for the terms: cover, forbs, grassland, habitat type, shrubs, succession

Soft chess occurs on newly disturbed sites, in mid-succession, and on sites left undisturbed for decades [24,45,61]. California annual grassland - In the absence of disturbance, soft chess and other annual grasses tend to increase at the expense of forbs and perennial grasses [40,45].  Heady [45] found soft chess was an important component of California annual grassland that had not been burned or grazed by livestock for at least 40 years.  Mulch, which accumulates in the absence of heavy grazing and/or fire, tends to favor germination of soft chess and other annual bromes over forbs and perennial grasses [45].  Heady and others [46] reported that soft chess decreased on heavily grazed sites, probably because grazing removed mulch.  Over 3 years, soft chess coverage increased greatly (from 0.9% to 37.3%) on a newly disturbed site on the Hopland Field Station.  However, soft chess coverage remained below 2 percent on plots where mulch was mechanically removed in each of the 3 years [45]. Chaparral - Soft chess and other annual grasses may be successional to chaparral shrubs on some sites.  Repeated burning, often intentional for the purpose of "type-conversion" of chaparral to grassland, has eliminated woody species on some sites.  In the absence of heavy grazing and/or fire, woody plants have recolonized some of these burned sites [21,61,69].  Equilibrium dynamics of annual grassland and chaparral are not well understood, however, and probably differ by site.  On level terrain with heavy clay soil, soft chess and other annual grasses are apparently stable and do not succeed to woody shrubs [61].  Woody species may displace annuals on nutrient-poor, rocky slopes [79]. Palouse prairie - In old-field succession on a bluebunch wheatgrass-Sandberg bluegrass habitat type in eastern Washington, soft chess was an important component of the vegetation on new fields, young fields (1-12 years since cultivation), and old fields (39-52 years since cultivation).  Soft chess cover (percent) was as follows [24]:                             Time since cultivation                                    ___________________________________________________________          New field     1 year     12 years     39 years     52 years          _________     ______     ________     ________     ________            1.25         0.10        1.55         1.30         0.12 

Bromus mollis L. [22,38,50,59,83]
B. molliformis Godron [92]
B. arvensis L. [83]
B. racemosus L. [83,92]
= B. hordeaceus L. [35,49,56,93,95]
B. h. ssp. molliformis (Godron) Maire [49]
= B. h. ssp. molliformis (Lloyd) Maire & Weiller [56]

Most North American systematists recognize Bromus hordeaceus L. as the
scientific name of soft chess [35,49,56,93,95]. European systematists
generally describe this entity as B. mollis L. [51,64]. Subspecies of
soft chess occurring in North America are [56]:

B. h. ssp. hordeaceus L.
B. h. ssp. molliformis (Lloyd) Maire & Weiller
B. h. ssp. pseudothominii P. Sm.
B. h. ssp. thominei (Hardham ex Nyman) Victorin & Weiler

Soft chess hybridizes with erect chess (B. erectus) [3] and intergrades
occasionally with Japanese brome (B. japonicus) [95].