understory consisted predomin- Effects on Associated Species of Burning, antly of bluebunch wheatgrass (Agrcpyron spicutum) , thick- Rotobeating, Spraying, and Railing Sagebrush spike wheatgrass (A. dusystuch- yum), Idaho fescue (Festucu ida- hoensis), plains reedgrass WALTER F. MUEGGLER AND JAMES P. BLAISDELL (Culumugrostis montunensis), subalpine needlegrass (Stipu Range Conservationists, Intermountain Forest and Range columbiuna), blue grasses (Poa Experiment Station, Forest Service, U. S. Department of spp.) , Agriculture, Ogden, Utah. threadleaf sedge (Curex filifoliu), fleabane (Erigeron corymbosus) , lupines (Lupinus Control of big sagebrush effect of various selective spp.), and minor amounts of (Artemisia tridentata) on heav- methods of sagebrush control. other grasses and forbs. Besides ily infested areas has long been Blaisdell (1953) reported in de- the dominant big sagebrush, the recognized as an effective range tail the effect of sagebrush burn- shrubby vegetation included improvement practice. By kill- ing on residual vegetation on spmeless gray horsebrush (Te- ing this one undesirable species the Upper Snake River Plains of trad ymiu cunescens) , down y the grazing capacity of range- Idaho. Bohmont (1954), Hyder rabbitbrush (Chrysothumnus lands can often be increased and Sneva (1956)) and Blaisdell puberulus) , and antelope bitter- manyf old. and Mueggler (1956) are among brush (Purshiu tridentutu) . A During the past 20 years sev- those who have studied the more detailed listing of species eral methods have been devel- effect of the sagebrush-killing and relative amounts can be oped to reduce sagebrush num- 2,4-D sprays on associated vege- found in Table 2. bers and bring about such range tation. Burning, spraying, roto- Methods improvement (Pechanec et al., beating, and railing as well as 1954). Generally these methods other methods were described by A 54-acre area was divided can be divided into two main Pechanec et al. (1954)) but only roughly into quarters, and a dif- categories: those that destroy all general information was pre- ferent treatment was imposed existing vegetation, and selective sented on the relative effects of upon each. An untreated check methods that destroy sagebrush these methods on associated veg- was reserved adjacent to the without complete destruction of etation. Evidently little infor- treated areas. Field-scale treat- the herbaceous understory. mation is available on direct ments were used and cost data When there are few plants of comparisions of various meth- were kept. desirable species, consideration ods of sagebrush removal under One-quarter was sprayed in in the selection of a control carefully controlled conditions. early June 1952 using a ground method generally need” be given A comparison of four methods spray unit with a 16-foot boom only to effectiveness of sage- of sagebrush control that main- mounted on a truck. The 2,4-D brush removal, relative cost, and tained the native herbaceous ethyl ester (Weedone 48) was development of a satisfactory understory-burning, rotob,eat- applied in a water carrier at the seedbed. Establishment of for- ing, railing, and spraying with rate of 2 pounds of acid and ap- age species will be dependent 2, 4-D-was started in 1952 on proximately 20 gallons of water upon artificial seeding. On the the Upper Snake River Plains per acre. Unfortunately it was other hand, if a good stand of in southeastern Idaho. The study necessary to spray the area when desirable species is present, it is area is in a fairly homogeneous, winds were fairly high. Spray upon these that increased pro- dense stand of big sagebrush be- drift, combined with unexpected duction should depend; selection tween 2 and 3 feet in height, on rockiness of the area, resulted in of the eradication method should the spring-fall range of the U. S. poor spray coverage with the not only consider degree of sage- Sheep Experiment Station near ground vehicle. For this reason brush kill and cost but also the Dubois, Idaho. The topography the sagebrush kill on the experi- effect of treatment upon these has only slight relief with little mental area was much lower associated plants. It is with this surface drainage; the sandy- than would ordinarily be ex- question of the effect of treat- loam soil is underlain by basal- pected. Similar treatments on ment on associiated fbrage tic lava. Precipiation averages nearby areas have caused almost species that this paper is con- about 13 inches annually. complete eradication of big sage- cerned. A good understory of native brush. Considerable information has perennial species was present One of the areas was roto- already been obtained on the throughout. This herbaceous beaten in early August 1952. A 61 62 ’ WALTER F. MUEGGLER AND JAMES P. BLAISDELL standard Case rotobeater with windward. The fire was set si- was of necessity made prior to chain flails was run over the multaneously along both wind- the early June spraying and con- area only once to shred the ward edges and a hot, clean burn sequently before plant maturity. brush. The machine was ad- was obtained. At this time it was difficult to justed so that the flails just The entire study area was de- segregate individual grass spe- cleared the ground surface. ferred from grazing the year of cies rapidly; therefore all grasses Ample power was supplied by a treatment and the year follow- were handled as one unit in the wheeled tractor. ing. Moderate grazing by sheep 1952 inventory. The 1953 and Railing was also done in early was permitted thereafter. 1955 inventories were made later August. The rail used was con- Each area, including the un- in the growing season, and structed of three 11-foot sections treated check, was sampled by grasses were segregated by indi- of heavy railroad rail loosely 20 permanent, 48-square-foot vidual species with the exception bolted together at the ends to circular plots spaced in a regular of two pairs, Agropyron dasysta- make a semiflexible 33-foot pattern. The weight estimate chyum-Calamagrostis montanen- length of rail. The center section method (Pechanec and Pickford, sis and Carex filifolia - Festuca was of double weight. Drags 1937) was used to obtain herbage idahoensis. Because of similarity were attached to the rear to keep production by species prior to of vegetative appearances, the rails upright. A deisel motor treatment (1952)) 1 year after grouping in these two pairs was patrol pulled this rail over the treatment (1953)) and 3 years necessary for rapid field identi- area twice, once each way. after treatment (1955). Esti- fication. The fourth area was burned in mates were also made of the per- Results And Discussion late August. Prior to burning, a centage of herbage available to standard fire line was con- sheep, that is, the percentage Eff ecfs of Treatments structed, consisting of a double that was not obstructed by All four treatments caused grader line and a lOO-foot back- brush. sizable reductions in sagebrush fired strip on the leeward sides In order to obtain pretreat- and increases in herbaceous spe- and a single grader line on the ment data, the 1952 inventory cies (Fig. 1). Burning and roto- cl GRASS .I’ . .,.:j::. F 0 R B S 900 q others SHRUBS sagebrush ‘52 ‘53 /55 ‘52 ‘53 ‘55 ‘52 ‘53 ‘55 ‘52 ‘53 ‘55 ‘52 ‘53 ‘55 UNTREATED BURNED ROTOBEATEN SPRAYED RAILED FIGURE1. Grass, forb, and shrub herbage production prior to treatment (1952) , and 1 year (1953) and 3 years afterward (1955) , as compared to production on untreated range. EFFECTS OF SAGEBRUSH TREATMENTS ON ASSOCIATED SPECIES 63 beating reduced sagebrush con- caused better than a one-third damage from 2,4-D is common siderably more than spraying increase, and railing resulted in (Bohmont, 1954; Hurd, 1955; and railing. Burning brought approximately a one-fifth in- Blaisdell and Mueggler, 1956). about a much greater increase in crease of grass. Apparently Very pronounced reductions forbs than any of the other treat- burning was the only treatment of shrubs occurred with all ments, and rotobeating and that actually injured the grasses. treatments. This reduction re- spraying a greater increase in Although other treatments flects the effect of treatment grasses. Railing caused inter- caused no injury, only on the upon sagebrush which composed mediate increases in both grasses sprayed area were grasses able almost 95 percent of before- and forbs. Despite general in- to take immediate advantage of treatment shrub production. creases in grasses, forbs, and the release from sagebrush com- Greatest reductions in sagebrush shrubs other than sagebrush on petition. During the first grow- were apparent the first year all treated areas, total vegetal ing season after treatment after treatment; thereafter pro- production 3 years after treat- grasses were noticeably more duction increased slightly. After ment was still considerably less vigorous on the sprayed range 3 years sagebrush production on than on the untreated area. The than on adjacent areas, and herb- the burned area was still only 11 inability of a predominantly her- age production was greatly in- percent and on the rotobeaten baceous cover to produce as creased. Substantial gains in area only 14 percent of what it much foliage dry matter as a grass production the first year would have been with no treat- shrub-herb complex has been after spraying with 2,4-D is ap- ment; production on the sprayed previously observed by Blaisdell parently the rule (Bohmont, and railed areas was 50 and 43 (1953). 1954; Hurd, 1955; Hyder and percent, respectively. Produc- It should be noted that there Sneva, 1956). However, the rea- tion of the shrub group exclud- were differences in herbage pro- son for such increase on the ing sagebrush was increased by duction on the various areas sprayed area and not on the roto- all treatments with the excep- prior to treatment as well as beaten or railed area is not clear.