FORAGE KOCHIA COMPETITION WITH CHEATGRASS IN CENTRAL UTAH E. Durant McArthur A. Clyde Blauer Richard Stevens ABSTRACT Forage kochia (Kochia prostrata [L.] Schrad.) plantings on cheatgrass (Bromus tectorum £.)-dominated highway rights-of-way and near an abandoned farm also domi­ nated by cheatgrass showed forage kochia to be competi­ tive with cheatgrass. The forage kochia plantings were made between 1970 and 1979 at about a dozen mostly semiarid study sites in three central Utah counties (Carbon, Sanpete, Sevier) and evaluated between 1986 and 1988. Recruitment of new forage kochia plants at most study sites demonstrates that the species is becoming integrated into the existing plant communities. Some plants have established in nearby, more natural com­ munities. A wildfire at one site provided evidence that forage kochia is adapted to recovery after.burning, an important characteristic for any species that is to coexist with large, dominant cheatgrass populations. INTRODUCTION Forage kochia (Kochia prostrata [L.] Schrad.) is a long-lived, woody-based shrub or subshrub, ranging in height from less than 30 to over 100 em (12 to 40 inches) (fig. 1). It is native to arid and semiarid regions of central Eurasia, extending to the Mediterranean Basin and northeastern China (fig. 2), where it grows on alkaline, stony, and sandy steppes and plains at elevations ranging from 0 to 2,400 m (0 to 8,000 ft) (Balyan 1972). The spe­ cies includes considerable taxonomic diversity. Balyan (1972) recognized a green subspecies (ssp. virescens) and a grey one (ssp. grisea) with additional varieties in the latter subspecies. Although each taxon encompasses con­ siderable adaptive variation, each is best adapted to a particular soil type and climatic regime (Balyan 1972; Shishkin 1936). The species forms a polyploid complex Figure 1-Line drawing (about one-fifth actual size) based on x = 9 (Herbel and others 1981; McArthur and ·of 'Immigrant' forage kochia (Kochia prostrata ssp. Sanderson 1989; Pope and McArthur 1977). virescens). Forage kochia is well adapted to the climate and soils Paper presented at the Symposium on Cheatgrass Invasion, Shrub Die­ of the Intermoutain area, especially in the pinyon-juniper, Off, and Other Aspects of Shrub Biology and Management, Las Vegas, NV, sagebrush, and salt desert shrub communities (Keller April 5-7, 1989. E. Durant McArthur is Project Leader and Chief Research Geneticist, and Bleak 1974; McArthur and others 1974; Stevens Intermountain Research Station, Forest Service, U.S. Department of Agri­ and others 1985). It is a valued plant for animal forage culture, Shrub Sciences Laboratory, Provo, UT 84606. A. Clyde Blauer is and for rehabilitation of disturbed soils both in Eurasia Professor, Division ofNatural Sciences, Snow College, Ephraim, UT 84627 and seasonal Botanist, Intermountain Research Station. Richard Stevens (Alimov and Amirkhanov 1980; Balyan 1972; Nechaeva is Project Leader and Wildlife Biologist, Wildlife Habitat Restoration 1985; Nechaeva and others 1977; Nemati 1977) and west­ Project, Utah Division of Wildlife Resources, Ephraim, UT 84627. em North America (Aldan and Pase 1981; Davis 1979; 56 This file was created by scanning the printed publication. Errors identified by the software have been corrected; however, some errors may remain. :ao 20 Figure 2-Natural distribution of Kochia prostrata. Adapted from Shishkin (1936). The solid line outlines the area of distribution. The Roman numerals refer to floristic provinces: Ill, Central European; V', West­ ern Mediterranean; v·, Eastern Mediterranean; VI, Balkan Peninsula and Asia Minor; VII, Lesser Armenia . and Kurdistan; VIII, Iran; IX, India and Himalayas; X, Sinkiang; XI, Mongolia; XII, China and Japan; XV, Tibet. Davis and Welch 1984, 1985; McArthur and Stevens 1983; For taxonomic treatment of big sagebrush (Artemisia tri­ McArthur and others 1974; Otsyina 1983; Stevens and dentata) and rubber rabbi thrush (Chrysothamnus nau­ others 1985). seosus) subspecies see McArthur (1983) and McArthur Like forage kochia, cheatgrass (Bromus tectorum L.) and Meyer (1987), respectively. Origin of plant species is a native to Eurasia that is also well adapted to the (native or introduced) was taken from Welsh and others Intermountain area (Mack 1981). Unlike forage kochia, (1988) and Albee and others (1988). The ecological meas­ however, cheatgrass is an unwanted invader because ures density and cover class (Cox 1967; Daubenmire 1969) it has displaced productive native vegetation by its com­ were used to measure performance of forage kochia and petitive establishment and fire climax characteristics associated plants. Our density values are given as (Leopold 1949; Pickford 1932; Piemeisel1951; Young plantslm2 (10.8 ft2). Our cover class values were modified and others 1979). slightly from those suggested by Daubenmire to cover This set of studies was undertaken to document the classes 1, <1 percent; 2, 1-5 percent; 3, >5-25 percent; competitive interactions between forage kochia and 4, >25-50 percent; 5, >50-75 percent; 6, >75-95 percent; cheatgrass and other annual weeds in central Utah 7, >95-100 percent. areas where these annuals are naturalized and forage kochia had been seeded. Study One: Roadside Plantings MATERIALS, METHODS, AND STUDY In the first study, experimental plantings in disturbed highway rights-of-way in Sanpete and Sevier Counties SITES were established (table 1). The study reported here in­ Three studies were undertaken. Taxonomic nomencla­ cludes data collected during the summers of 1986-1988 ture follows Welsh and others (1987), except names for from forage kochia seedings between 1972 and 1979. Study grasses followed the traditional treatment of Hitchcock sites were surface seeded with 'Immigrant' forage kochia; (Hitchcock and Chase 1971; Plummer and others 1978). seeds were raked lightly into the seedbed. 'Immigrant' is 57 Table 1-Locations and descriptions of study sites for the roadside planting study Location Transect Quadrat Site and elevation Description number number Ephraim Canyon, Mouth of Canyon, Roadside, burned, 2 10 Sanpete Co. along Ephraim- and unburned Orangeville Road. 1,780 m (5,840 ft) Nine Mile Reservoir, Along U.S. High- Cut, natural 2 15 Sanpete Co. way 89. 1,645 m (5,400 ft) North of Sterling, Along U.S. High- Cut, natural, 3 25 Sanpete Co. way 89. 1,675 m pasture (5,500 ft) Redmond Cut, Along U.S. High- Cut, crest 3 20 Sevier Co. way 89. 1,570 m (5,150 ft) Redmond Junction, Along U.S. High- Roadside 10 Sanpete Co. way 89. 1,575 m (5,160 ft) Salina Canyon, Along 1-70, Mouth Cut, natural 2 15 Sevier Co. of Canyon. 1,615 m (5,300 ft) Salina Canyon, Along 1-70, Mile- Cut 2 10 Sevier Co. post 57.8, north side. 1, 730 m (5,670 ft) Salina Canyon, Along 1-70, Mile- Cut, natural 3 35 Sevier Co. post58,north (Kochia prostrata side. 1, 725 m and Ceratoides (5,660 ft) lanata plantings) Salina Canyon, Along 1-70, Mile- Cut, natural 2 20 Sevier Co. post 58.5, south (Kochia prostrata side. 1, 735 m and Ceratoides (5,690 ft) Janata plantings) Salina Canyon, Along 1-70, Mile- Cut 4 25 Sevier Co. post 60, north side. 1, 750 m (5,740 ft) Salina Canyon, Along 1-70, Mile- Cut 2 10 Sevier Co. post 7 4, south side. 2,200 m (7,220 ft) Salina Canyon, Along 1-70, Mile- Cut 10 Sevier Co. post 76, south side. 2,230 m (7,320 ft) 58 a selection from P.I.line 314929 of K prostrata ssp. vires­ Study Two: Wildfire cens (Stevens and others 1985). The total study, including the performance of many more plant species, will be re­ This study was a small one drawn from the larger ported elsewhere (Blauer and others 1989). Study One. It differed from other aspects of the first Density and cover class data were collected from 205m2 study in that a wildfire had burned through part of this 2 (3.28-ft ) quadrats on 27 linear transects from 12 study forage kochia seeding. This site was seeded in 1979. sites (table 1). Transects were up to 50 m (168ft) long The wildfire occurred in 1983 or 1984. with quadrats located at regular intervals on alternate Transects were placed in the adjacent burned and sides of the transect at 3- to 8-m (9.8- to 26.2-ft) intervals. unburned areas. The quadrats on the burned site were The intervals were regularly spaced in each transect with spaced at 5-m (16.4-ft) intervals; the quadrats on the the interval value being determined by the length of the unburned site were at 6-m (19.7-ft) intervals (table 1). transect, which in tum was determined by the boundaries This study site was near the mouth of Ephraim Canyon. of homogenous sampled sites. The transects ran through The soil type is Sanpete stony fine sandy loam with a the highway rights-of-way (mostly roadcuts) out into rela­ slope of about 5 percent, an aspect of 315°, and mean tively undisturbed rangelands and pastures in random annual precipitation of29.7 em (11.7 inches) (Price and compass directions not intersecting the highways. Evans 1937; Swenson and others 1981). These were mostly semiarid sites (average annual precipi tion range from less than 25 to more than 60 em Study Three: Cheatgrass Invasion of (10 to 25 inches), of varied slope (range= 0 to 61 percent), over an elevational range of 1,575 to 2,165 m (5,170 to an Abandoned Farm 7,100 ft). The general soil types vary from aridisols The spread of forage kochia into an abandoned farm at through entisols to mollisols (Johnson 1989; Stevens the Gordon Creek Wildlife Management Area was exam­ and others 1983). ined in this study (fig. 3). A small ( <0.25-ha; 0.45-acre) Scofield Spring Glenn Consumer Road Gordon Creek Wildlife Management Area Boundary of Abandoned Farm t Yh Area Seeded to Forage Kochia, 1970 N t---1 30m figure 3-Map of abandoned dry farm area at Gordon Creek, Carbon County, UT.