• GENERAL BOTANICAL CHARACTERISTICS
• RAUNKIAER LIFE FORM
• REGENERATION PROCESSES
• SITE CHARACTERISTICS
• SUCCESSIONAL STATUS
• SEASONAL DEVELOPMENT

GENERAL BOTANICAL CHARACTERISTICS:

Timber oatgrass is a native, strongly caespitose, perennial bunchgrass [23,67]. The erect culms are densely tufted and generally reach 4 to 20 inches (10-50 cm) in height [62]. Leaves are mainly basal, flat or involute [69]. The old sheaths and blades are often persistent and wither at the base of the plant [23]. The inflorescence is a narrow panicle, often 1-sided, with short mostly erect branches generally bearing 4 to 9 spikelets [10,23]. One- to 2-flowered spikelets occasionally occur in the axils of the lower leaves [69]. With age, the culms often separate at the nodes where these seed-bearing spikelets are borne. Timber oatgrass has a shallow and fibrous root system [58].

RAUNKIAER LIFE FORM:

Chamaephyte

REGENERATION PROCESSES:

Timber oatgrass reproduces by seed and tillering [57]. This grass also produces self-fertilized spikelets in the axils of the lower leaves [69]. These cleistogamous spikelets enable the plant to reproduce even if development of the flower stalks is retarded [50]. In the Intermountain region, timber oatgrass is apparently largely apomictic (setting seed without fertilization), as the anthers are mostly abortive [10].

SITE CHARACTERISTICS:

Timber oatgrass grows in a wide range of habitats including rock outcrops, sphagnum bogs, dry meadows, grassy balds, and on alluvial flats of river floodplains [3,29,30,53]. It occurs on dry to moist sites from the prairies and grasslands to rocky alpine ridges [22]. In parts of the northern Rocky Mountains timber oatgrass is locally common in subalpine meadows in the fir-spruce zone [40,47]. In British Columbia, it grows in alpine tundra zones [1] and in the Sierra Nevada of California, it occurs in mountain meadows [56]. In fescue grasslands, timber oatgrass occurs in small patches or as a "fairly constant scattering" across the stand [24].

At high elevations timber oatgrass is most abundant in subalpine and alpine parks and meadows but also occurs in openings in upper elevation coniferous types, including fir-spruce and lodgepole pine communities [58,65,69]. It is common in ponderosa pine forests of the Black Hills of South Dakota [59].

Across its wide range, timber oatgrass grows from sea level to more than 12,000 feet (3660 m) in elevation [30]. Generalized elevational ranges of timber oatgrass are as follows [12,61,58,69]:

7,500 to 12,800 feet (2286-3901 m) in CO
3,200 to  8,900 feet ( 975-2713 m) in MT
4,950 to  6,780 feet (1509-2067 m) in SD
8,000 to 12,000 feet (2440-3660 m) in UT
5,000 to 11,000 feet (1981-3353 m) in WY

SUCCESSIONAL STATUS:

Timber oatgrass is an indicator of climax in a number of subalpine and alpine grasslands, fescue grasslands, and forest communities. According to Beetle [3] timber oatgrass is "indicative of long-standing stability in the vegetation." In Nevada, it is often associated with "stable" riparian communities [38].

Depending on the type and severity of disturbance, timber oatgrass is also a constituent in some early seral communities. In lodgepole pine forests of Wyoming, timber oatgrass is most common in immature stands as compared with mature stands [3]. Similarly in ponderosa pine stands of South Dakota, it is more abundant and more productive in clearcut and heavily thinned sapling and pole stands (measured 8 to 15 years after treatment) than in unthinned stands [64].

SEASONAL DEVELOPMENT:

Timber oatgrasss begins growth early in the spring [57]. Flowering occurs from June to August, depending on the location [50]. The seed crop is disseminated during August and September [58].

At lower elevations in California, flowerstalks may appear in April, with the seed cast by June [50]. At higher elevations, these dates are correspondingly later. In Colorado, Montana, and Wyoming, flowering begins in July and ends in August [12].

In western Montana, seasonal development varies according to aspect as follows [44]:

          Southwest                   Northeast                
          range      mean  duration   range      mean  duration
                     date  (days)                date  (days)  
growth
starts    4/28-5/24  5/12  10.2       4/28-5/29  5/16  11.9

1st 
bloom     6/10-7/14  6/25   7.8       6/8-7/8    6/27  10.0

blooming 
over      6/29-7/20  7/9    6.2       7/1-7/21   7/13   6.2

dissemination 
starts    7/22-8/10  7/30   6.3       7/26-8/21 8/3    6.1

plant 
dried     8/18-10/15 9/25  17.4       9/10-11/2  10/6  13.6

Related categories for SPECIES: Danthonia intermedia | Timber Oatgrass