Revegetation Guidelines for Western Montana - Global Restoration ...

Native vs. non-native species selection
Land managers are shifting from seeding introduced grasses, such as crested wheatgrass, for widespread
adaptability, easy establishment, forage production, and competitiveness with noxious weeds to reestablishing
native species to maintain or restore the genetic and ecological integrity of native ecosystems. This shift to native
species is based on changing social values as a result of advances in ecological knowledge.
The benefits of using natives include (partially adapted from Harper-Lore 2000):
• Erosion control – many native grasses and forbs have rhizomes or deep and fibrous root systems, helpful in
preventing soil erosion. Blue wildrye can provide quick erosion control. Streambank and thickspike
wheatgrass are both strongly rhizomatous grasses with excellent seedling vigor, also used for erosion control.
‘Bandera’ Rocky Mountain penstemon was developed for its fibrous root system and is often included in
reclamation seed mixes for its ability to control erosion;
• Vegetation management – short-growing native grasses, such as Idaho fescue, sandberg bluegrass, canby
bluegrass, and ‘Nortran’ tufted hairgrass reduce roadside mowing maintenance;
• Ecology and aesthetics – native plants can maintain ecological stability and establish a more natural setting.
In a Glacier National Park study, Tyser et al. (1998) found the use of natives for roadside revegetation was
preferable for ecological and aesthetic reasons;
• Resilient – natives represent a genetic product of an environment and are adapted to the means and extremes
of an area. Natives can maintain excellent performance under a variety of conditions and exhibit less of a
boom or bust response to environmental extremes than some of the introduced species (Brown and Wiesner
1984). For instance, non-native crested wheatgrass can perform well in an average rainfall year, but drought in
combination with other environmental conditions severely limits its performance. Many native grasses, forbs,
and shrubs are resilient to drought (See Tables 2 and 4) and replacement plantings should be rare;
• Improved water quality – fertilizers and other agricultural runoff into surface water is greater with sod or
common turfs than from deep-rooted native grasses, such as slender wheatgrass.
Many non-native grasses are competitive with noxious weeds. However, some native grass species can also be
effective competitors. High seral, native bunchgrasses, such as Idaho fescue and ‘Covar’ sheep fescue, have the
ability to compete with noxious weeds and invasive grasses, such as cheatgrass, on degraded sites. Thickspike
wheatgrass, slender wheatgrass, western wheatgrass, and Canada wildrye are also competitive.
Step 8 – Assist establishment
Seedling establishment is the most critical phase of revegetation (James 1992). However, variation
in soil, site exposure, and climate can hinder this vulnerable phase. Further, failures in
establishment are usually caused by a combination of factors – the most important are insufficient
soil moisture or intense weed competition (Jacobs et al. 1998). Schoenholtz et al. (1992) stated
early revegetation success is more a function of moisture than of soil nutrient availability and Masters
et al. (1996) stated weed interference was the primary constraint to successful establishment of
native plants. Enhancing establishment can increase revegetation success. Avenues of enhancing
establishment include:
a) Using species adapted to local site conditions and using high-quality, certified seed;
b) Reducing or eliminating weed interference through herbicide treatments or early seral cover
crops that work to reduce the availability of soil nitrogen;
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