Volume 1, Number 7, Page 1 Fall,1997 Summer, 1997 GROWING Points Department of Environmental Horticulture • University of California, Davis Restoration Ecology: Renewing Our Disturbed Landscapes - Part Il Restoring Native Perennial Grasses to Rural Roadsides in the Sacramento Valley By Robert L. Bugg, Assistant to the Director, Sustainable Agriculture Research and Education Program, UC Davis, Cynthia S. Brown, Graduate Research Assistant, Dept. of Agronomy and Range Science, UC Davis, and John H. Anderson, Owner, Hedgerow Farms Landscape disturbance due to road-building is pervasive throughout California. Rights of way that extend beyond road edges create sizable areas that require maintenance to reduce fire hazard and maintain motorist visibility. In rural areas, roadside management schemes emphasize herbicides and tillage to suppress resident vegetation. An alternative approach could involve the establishment and maintenance of native perennial grasses. These grasses may be grown in conjunction with other native flora and may provide habitat for desirable wildlife while potentially reducing the threat of flooding, erosion and siltation, wildfire, and incidence of resident vegetation. Perennial sod-forming and monocultures. In Trial I, different bunch grasses were once common polycultures were established. in much of California, including Each seeded plant complex fea- the Sacramento Valley and the sur- tured a different mix of grasses rounding foothills. However, by seeded to each topographic zone. the mid-1800s, the native grasses It is important to assess the col- were greatly reduced, presumably lective performance of various by a combination of prolonged species in such polycultures be- drought, overgrazing by feral and cause aesthetic, ecological, and domestic cattle, cultivation, and general management consider- competition from invasive annual ations dictate that polycultures of grasses and forbs introduced from various grasses will be used in the Mediterranean area. practical roadside projects. There is growing awareness By contrast, in Trial II indi- of and concern for the conserva- vidual species were seeded across tion of California’s native flora. Figure 1. Polyculture of perennial grasses established for this study in Yolo all the topographic zones de- Highway rights of way represent scribed below. Such monocul- County, Sacramento Valley, California. thousands of miles of potential tures are important to evaluate habitat for native plants, including grasses and ration, there are now opportunities to reestab- because numerous accessions could have roles forbs. Further, many find the complexity of lish portions of the native grasslands. in various topographic zones. Their variable established native plant communities more The purpose of this study was to seed and performance in those zones must be assessed aesthetically pleasing than the stands of star evaluate establishment of non-native and na- individually to avoid potentially confounding thistle or wild oat that commonly line Califor- tive perennial grasses, including several local effects of competition from neighboring seeded nia roadsides. Along with increased public accessions (descendants from seed collected at perennial grasses. In both polycultures and interest in native grasses and ecological resto- a single site), both in polycultures and in monocultures, widely used cultivars of non- In This Issue... 1 Restoration Ecology 4 News From the Ex Files 5 Master Gardener International Conference 6 Notes From the Chair 7 Profiles in EH 8 World Wide Web Site The University of California, in compliance with the Civil Rights Act of 1964, Title IX of the Education Amendments of 1972, sections 503 and 504 of the Rehabilitation Act of 1973, and the Age Discrimination Act of 1975, does not discriminate on the basis of age, religion, color, national origin, sex, mental or physical handicap, or age in any of its programs or activities, or with respect to any of its employment policies, practices, or procedures. Nor does the University of California discriminate on the basis of ancestry, sexual orientation, marital status, citizenship, mental conditions (as defined in section 12926 of the California Government Code), or because individuals are special disabled veterans or Vietnam era veterans (as defined by the Vietnam Era Veterans Readjustment Act of 1974 and Section 12940 of the California Government Code). Inquiries regarding this policy may be directed to the Affirmative Action Director, University of California, Agricultural and Natural Resources, 300 Lakeside Drive, 6th Floor, Oakland, CA 94612-3560, (510) 987-0097). Volume 1, Number 7, Page 2 Fall,1997 Summer, 1997 ummer, 1997 Travelled Unimproved Recovery Back Field Way Shoulder Area Berm Edge Side Back Slope Slope Open-Cut Ditch Figure 2. Schematic diagram of roadside topographic zones. native perennial grasses can provide valu- Low-statured bunchgrasses, e.g., Festuca could also be used on the back slope and in able benchmark data by which to gauge per- idahoensis (Idaho fescue), Poa secunda ssp. intermittantly-flooded ditch beds. The field formance of the native species. secunda (pine bluegrass), and low-growing edge is subject to inadvertent damage by her- The present research addressed whether forms of Hordeum brachyantherum ssp. bicides and agricultural implements. There- local forms of several native perennial grasses californicum (California barley) are perhaps fore, the rhizomatous Leymus triticoides can be established and managed on disturbed most suitable for the unimproved shoulder (creeping wildrye or beardless wildrye) is sites. In light of the likelihood of within- because they permit maximum visibility by probably appropriate. This species is tall- region genetic distinctness of different popu- motorists, are unlikely to break up pavement statured, recovers rapidly from mechanical lations of native grasses such as Elymus in the adjoining travelled way and, although damage, and is believed by some workers to glaucus (blue wildrye), we believed that local they tolerate close mowing, require no mow- show resistance to glyphosate, a commonly- forms of native perennial grasses should be ing in many cases. used broad-spectrum contact herbicide. used if available. The experimental site was Festuca rubra (creeping red fescue), Experimental Design: set amid farmlands and was susceptible to Bromus carinatus (California brome), and The trials were conducted at Hedgerow run-off, flooding, and the inadvertent effects lower-growing forms of E. glaucus are inter- Farms, approximately 8 km north of the town of herbicide drift and various agricultural pro- mediate in height and are candidates for use in of Winters, Yolo County, California. For both duction practices. In these important respects, the recovery area, through which motor ve- Trials I and II, there were five experimental the study reflects real-world conditions rather hicles occasionally travel. Perennial grasses blocks involved, with Blocks I and II situated than rigorous local control by researchers. like Hordeum brachyantherum ssp. on Brentwood silty clay loam (fine, montmo- Rural roadsides may be viewed as typi- brachyantherum (meadow barley), H. rillonitic, thermic Typic Xerochrepts [Class 1 cally comprising several topographic zones brachyantherum ssp. californicum, B. agricultural soil]) and Blocks III-V on Capay (Figure 2): (1) unimproved shoulder; (2) re- carinatus, Melica californica (California silty clay (fine, montmorillonitic, thermic covery area; (3) side slope; (4) open-cut ditch oniongrass), Nassella (Stipa) pulchra (purple Typic Haploxererts [Class 2 agricultural soil]). (drainage); (5) back slope; (6) back berm; and needlegrass), Nassella (Stipa) cernua (nod- In Trial I, each level of plant complex (7) field edge. These zones present a range of ding needlegrass) and Elymus multisetus included a different mix of perennial grasses environmental conditions and management (squirreltail) are candidates for both the re- seeded into each of several roadside topo- options and requirements, and may necessi- covery area and the side slope. The moderate graphic zones, based on principles discussed tate the use of a variety of plant materials. biomass production of these grasses makes earlier. Trial I involved 3 factors: plant com- Various native perennial grasses have diverse them unlikely to interfere with motor vehicles plex, block, and topographic zone. Plots environmental optima and tolerances and dif- that occasionally use the area. Also, these were arrayed in 5 randomized complete blocks; fering growth habits, and thus may lend them- grasses are drought tolerant and thus adapted each plot extended along 7.63 m of roadside selves to different topographic zones. to these two zones that may receive less water and was 7.63-9.15 m wide, extending to the In general, it is a reasonable goal to use than do either the unimproved shoulder or the edge of an agricultural field. Thus, each plot plant species that lead to reduced total above- open-cut ditch. comprised all the roadside topographic zones ground biomass, yet retain high proportions H. brachyantherum ssp. brachyantherum previously mentioned. As noted earlier, dif- of perennial vegetative groundcover. Other is tolerant of intermittant flooding and has ferent mixes were sown into the various topo- things being equal, this should reduce the moderate stature. Thus, it would tolerate graphic zones. Seeding rates were relatively threat of flooding, wildfire, and soil ero- conditions