Montana Field Guide

These lush grassland systems are found in upper montane to subalpine, high-elevation,zones, and are shaped by short summers, cold winters, and young soils derived from recent glacial and alluvial material. In subalpine settings, dry grasslands may occur as small meadows or large open parks surrounded by higher elevational forests, but typicall will have no tree cover within them. In general, soil textures are much finer, and soils are often deeper than in the neighboring forests. Most precipitation occurs as heavy snowpack in the mountains with spring and early summer rains. This system is composed of bunch grass species, with a diversity of cool season forbs. It is similar to the Rocky Mountain Lower Montane, Foothill and Valley Grassland ecological system, but is found at higher elevations and has additional floristic components with more subalpine taxa. In Montana, this system generally occurs as two plant communities: a rough fescue-Idaho fescue (Festuca campestris-Festuca idahoensis) association occurring on moister sites, such as the north and east-facing slopes and benches in the mountains; and the Idaho Fescue-bluebunch wheatgrass (Festuca idahoensis-Pseudoroegneria spicata) association occurring on drier sites, such as ridges, hilltops, and south and west facing slopes and benches. At elevations greater than 2286 meters (7,500 feet), Idaho fescue becomes dominant, sometimes associated with slender wheatgrass (Elymus trachycaulus), or in certain areas, tufted hairgrass (Deschampsia cespitosa). Noxious species invasion, fire suppression, heavy grazing, and oil and gas development are major threats to this system.

This ecological system grades into the Northern Rocky Mountain Lower Montane, Foothill and Valley Grassland ecological system at its lower elevational limit, and into Rocky Mountain Alpine Fellfield and Alpine Turf systems at its upper limit. In northwestern and west-central Montana it forms within upper elevation Douglas-fir (Pseudotsuga menziesii), lodgepole pine (Pinus contorta), spruce-fir (Picea engelmannii-Abies lasiocarpa) and whitebark pine (Pinus albicaulis) forests. Immediately east of the Continental Divide, it occurs on high ridges (5200 feet or higher) bordering the northwestern Great Plains and on steep mountain slopes and benches above 5200 feet along the Rocky Mountain Front to west-central Montana. Elevations represented by the northernmost extent of this system are approximately 2075-2200 meters (6,800-7, 200 feet). In southern Montana, this system is regularly found at elevations up to 2930 meters (9600 feet) with extremes at 3050 meters (10,000 feet). Sites range from small meadows to large open grasslands surrounded by high elevation forest types. Young soils are derived from recent glacial and alluvial material, but tend to be deeper than soils in adjacent forest communities or in alpine plant communities.

Rough fescue (Festuca campestris) and Idaho fescue (Festuca idahoensis) are the dominants of this system. In Montana, this system generally occurs as two plant community associations: 1) Rough Fescue-Idaho Fescue, found on moister sites such as the north- and east-facing slopes and benches in the mountains; and 2) Idaho Fescue-Bluebunch Wheatgrass, found on drier sites such as ridges, hilltops, and south and west facing slopes and benches. At elevations greater than 2,280 m (7500 feet), Idaho fescue becomes solely dominant or is associated with slender wheatgrass (Elymus trachycaulus); in some areas, it may associated with tufted hairgrass (Deschampsia cespitosa) (Cooper et al. 1999).

On relatively pristine, moist sites, rough fescue (Festuca campestris) canopy cover can approach 70% and form a nearly continuous cover. Rough fescue is most common in northwestern Montana, although it occurs as far south and east as the Anaconda-Pinlar Ranges. Other grasses are typically interspersed with the rough fescue, especially Idaho fescue (Festuca idahoensis) and other mesic site graminoids such as western needlegrass (Achnatherum occidentale), Richardson’s needlegrass (Achnatherum richardsonii), basin wildrye (Leymus cinereus), Raynolds’ sedge (Carex reynoldsii), Hood’s sedge (Carex hoodii), and Liddon sedge (C. petasata). The rhizomatous ecotype of bluebunch wheatgrass (Pseudogeneria spicata) also occurs sporadically on mesic sites, whereas the purely tussock form is consistently represented only at the xeric extremes. Other graminoids include oatgrass (Danthonia species), prairie junegrass (Koeleria macrantha), Sandberg’s bluegrass (Poa secunda), slender wheatgrass (Elymus trachycaulus), andneedle and thread (Hesperostipa comata). At higher subalpine elevations, alpine timothy (Phleum alpinum), tufted hairgrass (Deschampsia cespitosa), spike trisetum (Trisetum spicatum), obtuse sedge (Carex obtusata), and single spike sedge (Carex scirpoidea) become common.

These grasslands also supports a rich forb flora, including..subalpine taxa, that are absent from Rocky Mountain Montane grasslands. Species found in this system at upper montane elevations include arrowleaf balsamroot (Balsamorhiza sagittata), yarrow (Achillea millefolium), silky lupine (Lupinus sericeus), sticky geranium (Geranium viscossisimum), nine-leaf biscuitroot (Lomatium triternatum), prairie cinquefoil (Potentilla gracilis), sulphur penstemon (Penstemon confertus), little larkspur (Delphinium bicolor), wild strawberry (Fragaria virginiana), Indian paintbrush (Castilleja species), boreal bedstraw (Galium boreale), prairie smoke (Geum triflorum), prairie arnica (Arnica sororia), boreal sagewort (Artemisia frigida), western sagewort (Artemisia ludoviciana), prairie alumroot (Huechera parviflora), prairie crocus (Pulsatilla patens), rosy pussytoes (Antennaria microphylla), silver lupine (Lupinus argenteus), early biscuitroot (Lomatium macrocarpum), woolly groundsel (Packera cana), alyssum leaf phlox(Phlox alyssifolia),Hood’s phlox (Phlox hoodii), buckwheat (Eriogonum species), fireweed(Chamerion angustifolium), and cut-leaf daisy (Erigeron compositus). Subalpine taxa include diverse leaf cinquefoil (Potentilla diversifolia), alpine goldenrod (Solidago multiradiata), boreal crazyweed (Oxytropis borealis), yellow sweetvetch (Hedysarum sulphurescens), smelowskia (Smelowskia calycina), subalpine buckwheat (Eriogonum ovalifolium), yellow buckwheat (Eriogonum flavum), yellow draba (Draba aurea), Rydberg’s penstemon (Penstemon rydbergii), twinflower sandwort (Minuartia obtusiloba), and rock jasmine (Androsace chamaejasme). Species endemic to the northern Rocky Mountain subalpine and northwestern Great Plains are common in the drier, rocky sites, including Rocky Mountain douglasia (Douglasia montana), shining penstemon (Penstemon nitidus), Alberta penstemon (Penstemon albertinus), Parry’s townsendia (Townsendia parryi) and alpine buckwheat (Eriogonum androsaceum).

Shrub species may be scattered among these grasslands, especially shrubby cinquefoil (Dasiphora fruticosa), Woods’ rose (Rosa woodsii), snowberry (Symphoricarpos species), bearberry (Arctostaphylos uva-ursi), Canada buffaloberry (Shepherdia canadensis), and common juniper (Juniperus communis). Serviceberry (Amelanchier alnifolia), and common chokecherry (Prunus virginiana) often occur as patches on north-facing slopes where snow persists longer into the growing season.

Fire return intervals in grassland- Douglas-fir ecotones in southwestern Montana are estimated at 35 to 40 years, although they may be shorter in the grasslands proper (Arno and Gruell, 1983). With fire suppression, shrubs may increase, and trees may encroach on grasslands. Conversely, when fires eliminate shrublands, especially stands of Mountain big sagebrush (Artemisia tridentata ssp. vaseyana) common in southwestern Montana, these grassland systems may develop.

Rough fescue is highly palatable throughout the grazing season, and so tends to attract livestock use. Summer overgrazing for a two to three year period can result in rough fescue loss (Willms and Rhode 1998). Even at moderate stocking rates, livestock grazing decreases cover of rough fescue, especially during summer months. Oatgrass tends to replace rough fescue under moderate or heavy grazing pressure (Willms and Rhode, 1998).

In Montana, noxious exotic species threaten this grassland system through invasion and potential complete replacement of native species. On drier sites,, sulfur cinquefoil (Potentilla recta), leafy spurge (Euphorbia esula), knapweed species (Centaurea spp.), Saint John’s wort (Hypericum perforatum), and whitetop (Cardaria draba) are problematic. Mesic sites within this system are threatened by meadow hawkweed complex (Hieracium pratense, H. floribundum, H. piloselliodes), orange hawkweed (Hieracium aurantiacum), ox-eye daisy (Leucanthemum vulgare), tall buttercup (Ranunculus acris), and Canada thistle (Cirsium arvense). Introduced grasses like Kentucky bluegrass (Poa pratensis), common timothy (Phleum pratense), and smooth brome (Bromus inermis) occur on almost all sites within this system, and can pose significant threats.

Restoration strategies will depend largely on disturbance severity.Modified grazing practices and periodic prescribed fires can help this system to recover without additional restoration. On reclamation sites where soil preparation is required, soil disking techniques that discourage uniform soils and seed beds are preferable. Feathering and smoothing topsoil may benefit invasive species such as Kentucky bluegrass (Poa pratensis) and smooth brome (Bromus inermis), while uneven soil conditions may inhibit their growth, allowing rough fescue (Festuca campestris) and its associated grasses to establish more readily (Desserud, 2006).