Montana Field Guide

This ecological system, composed of highly variable montane conifer forests, is found throughout Montana. It is associated with a submesic climate regime with annual precipitation ranging from 250 to 1,000 millimeters (10-39 inches), with most precipitation occurring during winter, and April through June. Winter snowpacks typically melt off in early spring at lower elevations. Elevations range from valley bottoms to 1,676 meters (5,500 feet) in northwestern Montana and up to 2,286 meters (7,500 feet) on warm aspects in southern Montana. In northwestern and west-central Montana, this ecosystem forms a forest belt on warm, dry to slightly moist sites. It generally occurs on gravelly soils with good aeration and drainage and a neutral to slightly acidic pH. In the western part of the state, it is seen mostly on well drained mountain slopes and valleys from lower treeline to up to 1,676 meters (5,500 feet). Immediately east of the Continental Divide, in north-central Montana, it occurs at montane elevations. Douglas-fir (Pseudotsuga menziesii) is the dominant conifer both as a seral and climax species. West of the Continental Divide, occurrences can be dominated by any combination of Douglas-fir and long-lived, seral western larch (Larix occidentalis), grand fir (Abies grandis), ponderosa pine (Pinus ponderosa) and lodgepole pine (Pinus contorta). Aspen (Populus tremuloides) and western white pine (Pinus monticola) have a minor status, with western white pine only in extreme western Montana. East of the Continental Divide, larch is absent and lodgepole pine is the co-dominant. Engelmann spruce (Picea engelmannii), white spruce, (Picea glauca)or their hybrid, become increasingly common towards the eastern edge of the Douglas-fir forest belt.

montane elevations, mixed coniferous forests, Abies grandis, ustic soils

Douglas-fir is the dominant conifer; west of the Continental Divide, occurrences are dominated by a mix of Douglas-fir and long-lived, seral western and other species, including lodgepole pine and western white pine. East of the Continental Divide, larch is absent and lodgepole pine is the co-dominant. Engelmann spruce or white spruce, or their hybrid, becomes increasingly common towards the eastern edge of the Douglas-fir forest belt. Grand fir may occur in this forest type, but is typically confined to relatively warm and moister sites in northwestern and west-central Montana.

Undergrowth is dominated by graminoids, such as bluebunch wheatgrass (Pseudoroegneria spicata), Columbia brome(Bromus vulgaris),blue wildrye (Elymus glaucus), pinegrass (Calamagrostis rubescens), Geyer’s sedge (Carex geyeri), and Ross’ sedge (Carex rossii). Common forbs that occur in the understory include American pathfinder (Adenocaulon bicolor), heartleaf arnica (Arnica cordifolia), queen’s cup beadlily (Clintonia uniflora), twinflower (Linnaea borealis), and beargrass (Xerophyllum tenax). The shrub understory contains a variety of shrubs, such as Rocky mountain maple (Acer glabrum), kinnikinnick (Arctostaphylos uva-ursi), common juniper (Juniperus communis), oceanspray (Holodiscus discolor), mallow ninebark(Physocarpus malvaceus), common snowberry (Symphoricarpos albus), birch leaf spiraea (Spiraea betulifolia), dwarf bilberry (Vaccinium caespitosum) or mountain huckleberry (Vaccinium membranaceum)on colder, more mesic sites. In the western part of the state, the Douglas-fir/mountain huckleberry association is the most common type found in the Lolo, Bitteroot and Flathead Mountain ranges on relatively cold sites up to 2,073 meters (6,800 feet) (Pfister et al, 1977).

Restoration strategies will depend largely on the severity of the fire. Early successional stages may be dominated by fireweed (Chamerion angustifolium) and other forbs, graminoids and understory shrubs. Dominant species such as Douglas-fir, lodgepole pine and western larch regenerate well following fire. However, prolonged drought conditions and high soil temperatures on bare mineral soils can impede natural regeneration.

Intense fires occurring during summer months cause considerable damage to native perennial grasses, forbs and shrubs, and may completely destroy existing seed banks, especially on steep facing slopes and ridegtops. Steep slopes may require reseeding with native grasses to prevent soil erosion. In some cases, severely burned sites will require replanting with conifer seedlings. Generally, larger container volume of nursery stock results in higher outplanting success than bareroot nursery stock, especially where spring and early summer precipitation patterns are unpredictable, or whre exposed mineral soil temperatures are high during the first year of establishment. Generally, 6-8 cubic inch container stock types are used on milder sites with good site preparation, and 10, 15 or 20 cubic inch container stock is used on the hotter, drier aspects or sites. Conifer stocking rates must be developed on a site-by-site basis and to meet management objectives.