Management of Restored and Revegetated Sites...ment. Managers have little or no control over climatic factors, outbreaks of rabbits, insects, rodents, or dis-ease, which can affect

USDA Forest Service Gen. Tech. Rep. RMRS-GTR-136. 2004 193

Richard Stevens

16Chapter

Management of restored and rehabilitated ranges can be di-vided into (1) post-treatment, which we are most concerned withherein, and (2) management of the subsequent mature commu-nity. Immediate post-treatment management can positively ornegatively affect the ultimate success and longevity of a project,and the actual returns and benefits received. It is essential tofollow good post-treatment management practices to obtain themaximum return on investments made. The post-treatmentmanagement period may last as long as 10 years followingtreatment.

Management of restored and rehabilitated ranges will varydepending on the goals or objectives of the project. The mostcommon overall objective of a project is to enhance soil stability.Some companion objectives could be to provide for maximumestablishment and maintenance of seeded and desirable indig-enous species, increase livestock production, improve wildlifehabitat, and improve the appearance of the landscape.

Management ofRestored andRevegetated Sites

194 USDA Forest Service Gen. Tech. Rep. RMRS-GTR-136. 2004

Chapter 16 Management of Restored and Revegetated Sites

The principal immediate post-treatment manage-ment objective should be to provide for maximumestablishment and development of seeded and desir-able indigenous species. Once this has been accom-plished, other objectives will likely follow.

An important step in any revegetation project is theselection of species to be seeded. Many species used inrangeland improvement projects are adapted to a widearray of range types. Individual plant species do notrespond to various management practices in the sameway and to the same degree on all sites.

Amount and distribution of precipitation in theIntermountain West is perhaps one of the most im-portant factors in determining to what degree a rangeimprovement project succeeds or fails during the es-tablishment period. Above-average precipitation canresult in some outstanding successful projects. Projectsshould be planned on the basis of average yearlyprecipitation. Below-average precipitation during yearsof establishment will change post-treatment manage-ment. Managers have little or no control over climaticfactors, outbreaks of rabbits, insects, rodents, or dis-ease, which can affect the success and complicate thepost-treatment management of a project (fig. 1). Oneor all of these factors has the potential of destroying orreducing the success of a project.

Managers must control the influence that humanactivities and grazing animals have on a project.These factors can positively or negatively affect thesuccess of a project. During the establishment period,livestock grazing and any damaging activities of manmust be controlled. Human activities and grazinganimals can trample seedlings, pull seedlings up,remove foliage, reduce plant vigor and rate of estab-lishment, reduce growth, retard seed production,

Figure 1—Effect of heavy blacktailed jackrabbituse on seedling establishment and forage pro-duction. Mule deer and jackrabbit use on the left,mule deer use only on the right.

decrease or slow down soil stabilization, and spreadand increase the abundance of undesirable plantspecies.

The manager makes the decisions concerning when,where, how much, and what type of grazing and humanactivity is to occur following treatment. Project objec-tives and management plans should be based on sitepotential, expected rate of establishment, plant com-munity makeup, and climatic factors. The presence orabsence of rodents, rabbits, insects, and disease mustbe considered. Plans have to be flexible enough tocompensate for any changes from the expected whenthe decision is made to graze, or not to graze, and howmuch. Development and condition of the project andnot plans should determine post-treatment grazing.

If the project objective is only soil stabilization, estab-lishment and maintenance of seeded species would besimpler than when other objectives are considered. Bypreventing grazing or other disturbing influences, oneshould be able to accomplish the desired objective ofsoil stabilization with less effort and in less time.

As a general rule, treated and seeded sites shouldnot be grazed until at least the end of the secondgrowing season following seeding (tables 1 and 2;Plummer and others 1968; Reynolds and Martin 1968;Vallentine 1980; Vallentine and others 1963; fig. 2).Minimum period of rest following treatment will varywith vegetative type treated; grass, forb, and shrubspecies seeded; climatic conditions immediately pre-ceding, during, and following treatment; soils; seed-bed preparation and seeding techniques employed;presence and severity of competing weedy species;plant disease; and number and kinds of insects, ro-dents, or rabbits on the site (table 2).

When grazing is allowed, it should be lighter thanwould normally be allowed with a fully mature com-munity, even if forage production figures suggestthat heavier use might be permitted. Grazing shouldonly occur when it is least damaging to the newlyestablished species. Spring and early summer use canbe very damaging on newly seeded ranges (fig. 3).Special considerations should be given to seeded andindigenous shrubs, because shrubs establish and de-velop much slower than grasses and forbs. There areslow growing and fast growing shrubs (table 3; fig. 4).The level of grazing should be controlled to allowseeded and released shrubs to establish, and growenough that they will not be harmed by grazing. Asgrasses and forbs mature, cattle and sheep use will beless detrimental. During the establishment period,the intensity of grazing has to be adjusted on a seasonto season basis, and allowance made for phenologicalstage of development, as well as for climatic and bioticinfluences.

The drier the treated site, the slower that plantedspecies will establish and develop. Species seeded on ajuniper-pinyon site that receives 11 inches (27.9 cm) ofannual precipitation will establish and develop slower



Table 1—Recommended minimum years of nongrazing following revegetation of different vegetative types, andaccording to special treatments and site conditions.

Recommended growingSpecial treatment or seasons with no livestock

Vegetative type site conditions grazing following seeding

Subalpine 3Aspen-conifer 2Aspen, Gambel oak, maple Broadcast seed prior to leaf fall 3Ponderosa pine 2Mountain brush 2Juniper-pinyon Above 14 inches (36 cm) annual precipitation 2Juniper-pinyon Below 14 inches (36 cm) annual precipitation 3Mountain big sagebrush 2Basin big sagebrush Above 14 inches (36 cm) annual precipitation 2Basin big sagebrush Below 14 inches (36 cm) annual precipitation 3Wyoming big sagebrush Above 12 inches (30 cm) annual precipitation 3Wyoming big sagebrush Below 12 inches (30 cm) annual precipitation 4Black sagebrush 3Shadscale 3 to 4Black greasewood 2Inland saltgrass 1Blackbrush 3

than the same species on an adjacent juniper-pinyonsite that receives 14 inches (35.6 cm) annual precipita-tion. The drier sites will require at least an additionalyear or more of nonuse (table 2). If a sagebrush areathat receives an average of 15 inches (38.1 cm) annualprecipitation is treated and seeded and then receivesonly 10 to 11 inches (25.4 to 27.9 cm), the first one ortwo seasons following seeding, grazing may have to

Table 2—Additional growing seasons of nonuse (beyond rec-ommended growing seasons indicated in table 1)required due to special conditions.

Site conditions Years

Burned and broadcast seeded +1Slower growing shrubs seeded +2 to +4

or released (table 3)Seedings in cheatgrass, red brome, +l to +3

medusahead, or halogetoncommunities

Poor seedbed conditions +1Erosive soils +l to +3Soils with exposed and +2

disturbed subsoilPrecipitation 2 or more inches +1 to +3

(5 cm) less than averageduring first growing season

Precipitation 2 or more inches +1(5 cm) less than average duringsecond and third growing season

Outbreak of insects or disease +1 to +3Excessive number of rodents and rabbits +1 to +3

be delayed by as much as 2 years beyond what wasplanned to obtain adequate establishment and growth.

Seeded species need to be given the opportunity toput down substantial root systems, to accumulatecarbohydrate reserves, and, in the case of some grassesand forbs, to produce a seed crop. To ensure a healthyvigorous plant community it is essential that grassesand forbs be given the opportunity to produce seed thefirst few years following seeding and every few yearsthereafter. Improper grazing and sub-optimal climaticconditions are the two major factors that negativelyaffect seed production.

Figure 2—A highly productive 4-year-old reha-bilitation project in a juniper-pinyon-Gambel oaktype. The site was grazed lightly at the end of thesecond growing season following seeding. Lightgrazing occurred the third year following seeding.



The degree of seedling vigor and rate of establish-ment and growth will influence the timing and inten-sity of subsequent grazing. Species with exceptionalseedling vigor and a fast rate of root and abovegroundgrowth can be grazed sooner than those with lessseedling vigor or a slower establishment and growthrate (table 3; fig. 5). A good indication of well estab-lished, vigorous plants is excellent seed production.When a mixture of species is seeded, management hasto be tailored to accommodate the characteristics andrequirements of all the species. Post-treatment man-agement should be directed toward the slower devel-oping species (table 3). Many forbs develop slower

Figure 3—Results of poor post-treatmentmanagement. The area was grazed tooearly and too heavy the second and thirdyear following seeding. The seeded specieswere weakened and killed by grazing, allow-ing cheatgrass to once again dominate.

Figure 4—Fast growing white rubber rabbit-brush, fourwing saltbush, and big sagebrushare fully established in this 6-year-old rangeimprovement project in a juniper-pinyon type.Antelope bitterbrush growth is considerablyslower. The area was spring grazed by cattleduring the 2 preceding years.

Table 3—Years normally required for certain plant species to establish, mature, and flower.

Fast Intermediate Slow Very slow2 years 2 to 3 years 3 to 4 years 4 to 6 years

Bluegrass, Kentucky Alfalfa Crownvetch BalsamrootBrome, mountain Aster spp. Lupine spp. Bitterbrush, antelopeBurnet, small Brome, Regar Milkvetch, cicer Ceanothus, MartinKochia, forage Brome, smooth Rabbitbrush, low Ceanothus, snowbushOrchardgrass Canarygrass, reed Rabbitbrush, rubber Chokecherry, blackRye, mountain Dropseed, sand Ricegrass, Indian CliffroseSquirreltail, bottlebrush Eriogonum, Wyeth Sacaton, alkali Currant, goldenSweetclover, yellow Fescue, hard sheep Sagebrush, big Elderberry, blueTimothy Flax, Lewis Sagebrush, black Ephedra, greenWheatgrass, crested Globemallow Saltbush, fourwing Mountain mahogany, curlleafWheatgrass, desert Goldeneye, showy Shadscale Mountain mahogany, trueWheatgrass, intermediate Penstemon, Palmer Sweetvetch, Utah Serviceberry, SaskatoonWheatgrass, pubescent Sainfoin Wildrye, Great BasinWheatgrass, slender Sweetanise Wildrye, Russian

Wheatgrass, bluebunch WinterfatWheatgrass, SiberianWheatgrass, tall

than most grasses. Most shrubs develop slower thangrasses or forbs. When shrubs are included in the seedmix, more than 2 years, and possibly 5 to 6 years, ofnonuse following seeding may be required. A fewshrubs such as fourwing saltbush, winterfat, rabbit-brush, forage kochia, and big sagebrush, possess afaster rate of growth and maturation. These specieswill often produce a seed crop and be within 80 percentof their maximum forage production potential within3 years following establishment (fig. 4).

Many range improvement projects are conducted ondepleted sites having some degree of erosion problem.Because of soil loss, site potential may not be as great



Figure 5—Shrubs establish and developmuch slower than grasses and forbs. Grazingmust be closely controlled until all seededspecies become completely established andindigenous species recover.

Figure 6—This disturbed riparian site wasbroadcast seeded. Shrubs were transplantedalong the water’s edge. Grazing should beexcluded until the disturbance is completelystabilized and the shrubs are fully establishedand reproducing vegetatively.

as it once was. The rate of species establishmentand growth is influenced by the soil’s productivitypotential.

Seedling establishment and growth often vary withsite preparation techniques. In soils that have beenlightly tilled (plowed or disked), seedlings can developfaster, and may be more numerous the first and secondyear than on less tilled sites. However, seedlings intilled soils may be more susceptible to transplantingand pulling damage, due to the loose nature of the soil.Young plants growing in sandy soils are more suscep-tible to grazing and transplanting damage than areseedlings on areas with heavier soils.

Depleted aspen and Gambel oak areas can be seededprior to leaf fall, with no other treatment being re-quired. Seedling growth and plant maturity is inhib-ited under these conditions. Grazing is not recom-mended on these areas for at least three or fourgrowing seasons following seeding.

Sites with aggressive annuals (cheatgrass, red brome,medusahead, and halogeton) on them prior to treat-ment, need to be given special management consid-eration (fig. 3). Care must be taken with grazing.Seeded and indigenous species generally develop slowerin the presence of aggressive annuals than on siteswithout annuals. Livestock grazing in these situa-tions may have to be delayed longer than would nor-mally be needed to allow for proper seedling establish-ment and community development.

Once a seeded community has become established,grazing must be closely regulated. Most annuals arenever totally eliminated from a site. Annuals in acommunity are waiting for the opportunity to increase,and will do so when the seeded community is weakenedthrough misuse. Annuals can once again become thedominate species with improper management (fig. 3).

It is not fully understood how most seeded (nativeand introduced) and indigenous species will respondto each other and to grazing. Because of the manyphysical and biological factors associated with animprovement project, the manager must expect theunexpected, and be flexible enough to adapt manage-ment plans accordingly. To do otherwise may harmsome species in the community, encourage others, anddiminish the potential values and habitats associatedwith the project.

Some projects may include transplanting. Trans-plants establish at various rates. Site characteristics,range condition, age and condition of transplants, soilcondition and type, soil moisture, and occurrence ofpost-planting precipitation can all affect rate of trans-plant establishment. Transplants need to be firmlyrooted and producing good top growth before anygrazing occurs.

Seeded and transplanted species in riparian situa-tions may require a considerable amount of time tobecome established and to stabilize the site. Becauseriparian areas are generally heavily used by livestockand humans, all grazing and human activities shouldbe removed at the time of treatment. Use cannotresume until all seeded and planted species, as well asindigenous species, are completely established or haverecovered, and the disturbed areas has stabilized(fig. 6). When grazing is resumed, animal densities,distribution, and duration of use on the area must beclosely monitored. Proper distribution of livestockbecomes very critical. Human activities must be con-trolled and monitored, and proper action taken whennecessary.



Figure 7—A mourning dove nest in an ungrazedjuniper-pinyon chaining-seeding rehabilitationproject.

Excessive use by big game can result in harm toimprovement projects. The chances of this happeningare small. If this occurs, a reduction in numbers, theexclusion of game animals, and period of nonuse pro-grams can be initiated. This could include the erectionof temporary electric fences, implementation of spe-cial hunting seasons, or herding of livestock and game.If needed, big game reduction programs should becarried out prior to the project. Animal numbers anddegree of use fluctuate seasonally and yearly, depend-ing on weather, conditions of adjacent ranges that biggame use, animals’ health, reproduction rate, preda-tors, disturbances, and type and timing of hunts andhunter success.

Most project areas require access roads. Unneededor undesirable roads should be closed and seeded uponcompletion of each project. When improperly con-structed, roads can become erosion channels. Newroads can increase human activities on a site, result-ing in (a) disturbance of livestock and wildlife activi-ties, (b) reduction in livestock and wildlife use, (c) de-struction of seeded and planted species, especially onriparian sites, (d) additional human use of waterdevelopment, (e) increased on- and off-road vehicletravel, (f) increased fire potential, (g) additional soilerosion, and (h) increased use by horses. New accessroads can likewise concentrate livestock use, resultingin depleted areas.

Destructive and harmful human activities thatshould be controlled on a new rehabilitation projectinclude camping and associated activities, off-road

and on-road vehicle travel, horseback riding, fires,gate closure problems (cattle guards can alleviate thisproblem), wood gathering, livestock trailing and hu-man activity during critical wildlife periods such asbreeding, nesting (fig. 7), fawning, calving, periods ofdeep and crusted snow, low forage availability, andother stressful periods.

Permanent or temporary fences can be used to helpcontrol grazing and human activities. Solar-poweredelectric fences are ideal for temporary protection ofrehabilitation sites. Monitoring and repair of fencingis essential to the success of any project.

Documents

Management of Restored and Revegetated Sites...ment. Managers have little or no control over climatic factors, outbreaks of rabbits, insects, rodents, or dis-ease, which can affect