A Native Landscape for Interstate 15? a Decision Case in Environmental Science1 Kendra Busse and Phil Allen*

A Native Landscape for Interstate 15? A Decision Case in Environmental Science1 Kendra Busse and Phil Allen*

ABSTRACT are too slow to establish. In 1998, during reconstruction of In- terstate 15 (I-15) through Salt Lake City, UT, the environ- Between 1996 and 2001, the section of Interstate 15 (I-15) mental consultant hired to provide recommendations on land- through Salt Lake City, UT, was redesigned, rebuilt, and ex- panded in preparation for the 2002 Winter Olympics. The aes- scape plant selection had to decide whether to recommend the thetic theme proposed for the freeway roadside was announced use of native plants to achieve the “natural” landscape ap- to be a natural landscape consisting of native plants. Dr. John At- pearance desired for the project. wood, a local scientist and plant expert, was hired to provide rec- Professionals who work in fields related to environmental ommendations for plant selections and seed mixes. In the course science will likely encounter philosophical conflicts between of planning the roadside, a conflict surfaced regarding the de- traditional practices and newer approaches based on ecolog- sirability and feasibility of a “native plant landscape.” Atwood’s ical principles, as well as incomplete knowledge upon which preliminary recommendations had been submitted for review by to base important decisions. This case considers the decision other scientists (plant breeders not associated with the freeway whether to recommend the use of native plants for roadside project) who were highly critical of native plants. The plant use or the traditional exotic species that had been used for breeders argued that the only successful I-15 landscape would decades. consist of exotic species selected for superior performance under Utah’s harsh environmental conditions. An all-native roadside THE CASE landscape had never before been attempted in Utah. Atwood’s recommendations would influence the spending of millions of dol- In April 1995 the Utah Department of Transportation lars, and the high visibility of the project meant that failure (UDOT) announced the 1.6 billion dollar reconstruction of I- would seriously undermine his professional reputation. The de- 15 through Salt Lake City, UT. Plans for the 27-km (17-mile) cision whether to use native plants along I-15 illustrates the kind stretch of freeway included expanding the paved surface to 12 of real-life dilemma that can occur when attempting to resolve lanes and connecting the interstate with several suburban an environmental issue. The case was developed for use in envi- communities through a common design theme. An ambitious ronmental science, horticulture, ecology, range management, timetable for project completion was necessitated by the fact and landscape architecture courses, and can be used as a basis that Salt Lake City would host the Winter Olympics in Feb- for discussions about challenges faced when decisions must be ruary 2002. made in the absence of complete data and where experts disagree. The contract for designing and building the freeway was awarded to Wasatch Constructors, who retained Sverdrup/ DeLeuw (a joint venture between Sverdrup Civil Inc. and ILLIONS OF HECTARES of roadside landscapes have tradi- DeLeuw, Cather & Company) to design the project. The aes- Mtionally been maintained through practices that rely thetic theme chosen for the freeway and the associated right- heavily on mowing and applying herbicides. While these of-way landscape emphasized the beauty of the Salt Lake practices allow Departments of Transportation (DOTs) to Valley and the mountains that surround it. This theme was for- meet functional needs, they also require tremendous invest- mally stated as follows: ments in labor, machinery, and chemicals. The “mow and spray” philosophy of roadside vegetation management is In recognition of the significant value the Wasatch and being increasingly challenged for a number of reasons, in- Oquirrh Mountains provide for the Valley, the I-15 Corri- dor Urban Concept celebrates the quality of life and pres- cluding cost, sustainability, and a desire for improved re- tige these mountains bring to the Salt Lake Valley, thus sup- gional aesthetics. Highly diverse native plant communities rep- porting the UDOT Guidelines Theme—Celebration of the resent an appealing alternative to traditional roadsides (John- Native Landscape of the Salt Lake Valley son and Anderson, 1997; USDOT, 1999), although this change (Wasatch Constructors, unpublished report, 1996) in attitude is not without controversy. In the western USA, crit- ics of native plants for roadside landscape use argue that the Closely associated with aesthetic objectives was the recogni- highway environment is often too harsh and that native plants tion that these aesthetics would be accomplished within the delineation of six planting themes or ecosystems (Exhibits 1 and 2). 1 This journal uses SI units, according to the ASA-CSSA-SSSA style. Due The aesthetic theme for the reconstruction of I-15 called for to the circumstances of this case study, however, English units are used, either alone or along with SI units. a philosophical shift from the traditional roadside management practices of UDOT, in which monocultures of crested wheat- Department of Plant and Animal Sciences, Brigham Young Univ., 271 WIDB, grass (Agropyron cristatum R. & S.) or a mixture of crested Provo, UT 84602. Received 12 July 2002. *Corresponding author wheatgrass and one or two other Eurasian grasses were typi- ([email protected]). cally seeded (Johnson and Anderson, 1997; MacMahon, Published in J. Nat. Resour. Life Sci. Educ. 32:118–125 (2003). 1983). Roadside maintenance practices had focused on the http://www.JNRLSE.org © American Society of Agronomy Abbreviations: DOT, Department of Transportation; I-15, Interstate 15; 677 S. Segoe Rd., Madison, WI 53711 USA UDOT, Utah Department of Transportation.

118 • J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 control of vegetation through spraying herbicides (especially Exhibit 1. Six proposed ecosystems for the I-15 freeway landscape. The broadleaf herbicides), grading, and mowing. This approach to overall concept was for a matrix of grasses to be interspersed with small “islands” of woody plants and wildflowers. These planting landscaping did, in general, provide adequate erosion control themes were repeated along the 27-km (17-mile) corridor as illus- and required minimally trained maintenance employees. How- trated in Exhibit 2. ever, repeatedly disturbing the roadsides by mowing and Wasatch Front Landscape—Plants that are indigenous and similar spraying prevented native plant communities from re-estab- to those that could be found along the Wasatch Front. lishing and perpetuated the invasion by numerous species of Mountain Creek Landscape—Reflecting plantings found along the weeds. streams and creeks that flow from the mountains to the Jordan A natural landscape comprised of a large variety of native River† and the Great Salt Lake. species would require a very different management approach. Salt Marsh Landscape—These plantings are similar to those found For example, herbicide applications in a diverse plant com- in wetlands and detention basins and are tolerant to high concen- munity typically focus on spot-spraying target weeds rather trations of salt. They are similar to the plantings found west of the than broadcast coverage. This would require maintenance I-15 corridor between the Great Salt Lake and Antelope Island com- personnel to be able to identify a wide variety of native species munities. as well as weeds, but would use much less herbicide. The ad- Alpine Landscape—These are plantings indigenous to the foothill and ditional cost of increased personnel training needed to main- mountain range areas along the Wasatch Front. tain native plantings was estimated to be more than offset by West Desert Landscape—The plantings will reflect the vegetation one the considerable cost savings associated with significantly would find as they proceed west toward Antelope Island or the Oquirrh Mountains. reduced spraying and mowing (Johnson and Anderson, 1997). Widening the freeway to 12 lanes made the right-of-way Salt Lake Valley Landscape—These plantings reflect the meadows and grasslands similar to those the early settlers may have en- slopes steeper than in the original I-15, so steep that mowing countered as they came into the Salt Lake Valley. would be unsafe in many places. † Note:The Jordan River roughly parallels I-15. Mountain streams dis- charge into the Jordan River, which empties into the south end of the Great Salt Lake. The Landscape Task Force An important constraint in the I-15 reconstruction was that created a “Landscape Task Force,” comprised of representa- the project was designed and constructed simultaneously (i.e., tives from each professional group. A brief background sum- the design was completed in a prioritized series of phases, with mary and priorities for each Landscape Task Force participant construction beginning in early phases of the project before follows. design for other sections was completed). This led to a num- Builder. Wasatch Constructors, a conglomerate of several ber of critical deadlines that required all professional groups construction companies, was created as a joint venture to involved in the reconstruction (e.g., the freeway builder, en- build the I-15 corridor. They held the responsibility and lia- gineers, landscape architects, landscape contractor, and free- bility for the entire project. They were motivated by signifi- way manager) to act under significant time pressure. To fa- cant financial incentives (millions of dollars) to complete the cilitate communication and issue-resolution among the vari- project according to a predetermined timetable. In addition, ous entities involved in the project, Wasatch Constructors to assure that the ambitious timetable did not compromise

Exhibit 2. Landscape concept for a section of the I-15 reconstruction, showing five of the six proposed ecosystems. The landscape was expected to com- plement the freeway design while still meeting important functional requirements such as safety and erosion control.

J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 • 119 Exhibit 3. Soil test results for stockpiled topsoils and borrow pits. wood to provide recommendations regarding plants and seed pH Sand Silt Clay OM† mixes for the six different planting themes that would com-

− prise the roadside. Atwood earned a Ph.D. in horticulture and g kg 1‡ Stockpiled topsoils§ taught college courses in landscape design, arboriculture, and 600 North (clay loam) 7.5 350 330 320 52 environmental science. His scientific credentials included 1500 South (sandy clay loam) 7.7 590 200 210 18 7200 South (loam) 7.4 500 300 200 22 several publications dealing with native plants and weeds as White Hills Borrow Pit¶ (loam) 7.5 460 290 250 4 well as considerable experience in soil science. While At- Monroc Borrow Pit¶ (loamy sand) 7.6 870 70 60 4 wood’s main role was to recommend plants and seed mixes, † Organic matter. he was also asked to evaluate soils and determine which, if any, − ‡ Divide g kg 1 by 10 to convert to %. amendments were needed. Atwood was responsible for sub- § Topsoil existing along roadside before reconstruction was scraped off and stored at locations indicated, and respread before seeding and planting. mitting recommendations to the landscape architects, and ¶ Expanding the freeway from 8 to 12 lanes required significant amounts of fill mate- was occasionally asked to attend Landscape Task Force meet- rial. Fill was obtained from borrow pits located near the north (White Hills) and south (Monroc) ends of the project. Approximately 70% of the fill came from Monroc and ings. 30% from White Hills. The reconstruction project appealed to Atwood on several levels. As an avid outdoorsman, he spent many hours hiking, quality of the project, Wasatch Constructors was required to running, and biking in local mountains and deserts where he warranty the freeway for a period of 10 yr. observed native plant ecosystems. Through these observa- Engineers. Sverdrup/DeLeuw was a joint venture of two tions and his research projects, he learned about successful companies who designed the freeway reconstruction. In ad- growth patterns of native plants. His interest in native plant dition to overseeing the civil engineering aspects of the design, communities led him to become involved in the Utah Native they hired the landscape architects. The engineers operated Plant Society. As a passionate volunteer, he spearheaded the under extreme time deadlines, because construction could restoration of foothills near the campus where he taught. not proceed until their plans were completed. The I-15 reconstruction project also professionally ap- Landscape Architects. Landscape architects came from pealed to Atwood. Not only was there a significant financial two firms (Allred, Soffe, Wilkinson & Nichols and Gillies, incentive, but he was excited by the magnitude and public im- Stransky, Brems & Smith Architects) who were retained by pact of the decisions he would influence, and the amount of Sverdrup/DeLeuw to develop the necessary landscape plans money spent based on his recommendations. Atwood also for the project. Responsibility for the labor was divided geo- knew that good results from this consulting job would likely graphically (north and south halves, respectively) between the lead to additional consulting opportunities in the future. two firms. They also faced deadline pressures and required rec- Despite his enthusiasm for the project, both personally ommendations for suitable plants and seed mixes before their and professionally, Atwood was anxious about the demand- designs could be completed. They were responsible to see that ing schedule of the project. Many of his final recommenda- the objectives within the aesthetic theme were met while tions needed to be made within a matter of weeks, during a working within budget constraints. time in the semester when he would be very busy with giving Landscape Contractor. Nakae and Associates was a Cal- exams and grading them. ifornia-based landscape contractor with no previous experience in Utah. They were selected to landscape the I-15 re- Related Issues construction partly because they had just completed a similar Atwood was aware of several factors that needed to be con- project (i.e., “natural” landscape along a comparable stretch sidered in order to recommend the best plants for a particular of freeway) in Orange County, California. Their responsibil- location. These included soils features (texture, nutrient lev- ities included installation of irrigation systems, seeding, and els, water holding capacity, slope, and aspect), application of planting, but did not include selection of plants. Nakae was re- de-icing salts (budgeted by UDOT at 1.14 Mg per lane per quired to complete all landscaping by the project deadline kilometer (2.0 tons per lane per mile) per year, weed compe- (September 2001) and was required to guarantee plant survival tition, water requirements of native plants, plant and seed for 1 yr following landscape installation. Therefore, Nakae was availability, water runoff from pavement, and erosion. He concerned that plants and seed mixes chosen for the project arranged for soil tests to be completed for each of the three had the highest probability for success. types of soil that would be used in the project (Exhibit 3). His Long-Term Freeway Manager. Following construction understanding was that woody plants would be irrigated at and installation of the landscape, UDOT had complete re- least through establishment and that all seeded areas would be sponsibility for maintaining the freeway and roadside right- completely unirrigated. Based on consideration of all these of-way. The UDOT’s primary concerns included safety, factors, Atwood prepared a preliminary set of plant lists and drainage, erosion control, weed control, and public perception seed mixes for each ecosystem/planting theme. These lists in- of roadsides. The UDOT representatives on the Landscape cluded a minimum of 13 native species for each ecosystem and Task Force included the maintenance supervisor as well as the focused on plants that were native to the Salt Lake Valley. vegetation manager. Unknown to Atwood at the time he submitted preliminary Environmental Scientist Consultant. The I-15 landscape recommendations, several competing priorities and strong was to be installed by seeding grasses, shrubs, and wildflow- differences of opinion existed among Landscape Task Force ers and transplanting trees and some shrubs. Because Land- members. Even though the aesthetic theme had been accepted scape Task Force participants had limited knowledge of na- formally, the degree of support for native plants by Landscape tive plant ecosystems, Sverdrup/DeLeuw retained Dr. John At- Task Force members was highly variable. A number of con-

120 • J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 flicts surfaced in the form of memos and verbal communica- Exhibit 4. Letter solicited by the Utah Department of Transportation tion. Atwood became increasingly aware of these issues as the (UDOT) Vegetation Manager, a member of the Landscape Task Force. The letter is authored by a plant breeder who was not a mem- deadline approached for his final set of recommendations. ber of the Landscape Task Force. (Names of individuals have been Several important concerns arose, all of which had potential changed.) implications for which plants he should recommend. These are highlighted below. February 6, 1998 1. “This is not the way we manage roadsides in Utah.” Thomas Child, Vegetation Manager It became increasingly clear that UDOT employees at several Utah Department of Transportation levels were reluctant to change their landscape management 4501 South 2700 West approach. In casual conversation, Atwood overheard mainte- Salt Lake City, Utah 84119 nance supervisors boasting that “it does not matter what they plant—we can kill it.” This was a concern because mainte- Dear Tom: nance practices could ultimately eliminate most plants on At- Jonathan Carter, Ian McDonald and I have reviewed the seed mixes for wood’s preliminary list. the I-15 Corridor. We are convinced that proposed dryland mix would be a failure. The area that is being seeded has been drastically modified from 2. “Canyon plants are prettier than valley plants.” The the original native environment, and for the most part, will not support landscape architects were supportive of native plants, but fa- the species that are native to the undisturbed surrounding areas. vored native canyon vegetation instead of the more rugged and We suggest that you use a core mix in the dryland areas consisting of 20% drought tolerant shrubs, grasses, and flowers that were in- Western wheatgrass, 30% Vavilov Siberian crested wheatgrass, 30% digenous to the Salt Lake Valley. However, the average annual Tegmar intermediate wheatgrass, 10% bottlebrush squirrel tail, and 10% other species. The other species probably should not include Indian rice- precipitation in the Salt Lake Valley was only 38 cm (15 grass. inches), whereas precipitation averaged 46 to 61 cm (18–24 We are not experts on the wild flowers, be we concur with the choice of inches) in the lower canyons and foothills. While trees and Indian paintbrush, globemallow, and blue flax. Many of the others are shrubs were going to be planted in areas with an irrigation sys- probably OK. tem, UDOT had no long-term irrigation management plan for The saline sites (not marshes), you should consider beardless wildrye and I-15. Atwood was familiar with a previous UDOT project NewHy. The proposed mix for the marshes look OK to us; however, poor where the irrigation system had been abandoned as soon as re- germination and lack of seedling vigor will be a problem. pairs were needed. Few species had survived. Therefore, it was The meadow mix #4 looks a mess. Is this a real dry meadow? How about impossible for Atwood to know whether plants from the lower smooth or meadow brome, tall fescue, NewHy, Tegmar intermediate canyons and foothills would be supplied with the supple- wheatgrass, thickspike wheatgrass, western wheatgrass, and basin wildrye? This mix would be changed depending on the available mois- mental irrigation water they would need in the long run. Fur- ture. If water is limited (25–38 cm [10–15 inches] precipitation), crested ther complicating his evaluation process was the recognition wheatgrass, Tegmar, Thickspike wheatgrass (Sodar), and western wheat- that the freeway corridor would be a heat sink and that most grass would be a good mix. water runoff from the freeway would be directed to drain We really do not have enough expertise to make intelligent comments on pipes and retention basins rather than to the roadside. other mixes; however, we would use greasewood only as a last resort. 3. Nobody had clearly defined native. Members of the Give us a call if you have any questions. Landscape Task Force were vague in their definition of just Sincerely, what a “native plant” was. Many members were more concerned that drought-tolerant plants with a “natural” look be D. K. Hatch used and did not necessarily care that such plants be indige- Research Geneticist nous to the Salt Lake Valley. Atwood was aware that many of the worst invasive plant species in Utah were exotic landscape plants that had escaped from “natural” gardens. Although Atwood was not entirely opposed to non-native 4. Some outside experts argued that native plants would plant species in natural landscapes (he had used several exotic not work. Exotic plant species and traditional roadside land- species in landscaping projects), he was becoming increas- scape practices had been used for decades. A completely na- ingly concerned that the non-native grasses advocated by the tive landscape had never been attempted by UDOT. While na- plant breeders were becoming increasingly invasive in many tive plants had been included in some plantings and seedings, wild habitats. For example, in the canyon restoration Atwood they often met with little success. In particular, many desir- spearheaded, intermediate wheatgrass (Agropyron inter- able native species failed to establish from seeds during dry medium, recommended by the author of Exhibit 4) was the years. Also, forbs (wildflowers) and woody plants were most difficult to control “weed.” quickly eliminated by mowing and broadcast application of 5. Each member of the Landscape Task Force had dif- broadleaf herbicides, practices that UDOT felt needed to con- ferent priorities. For example, the landscape architects and tinue to control weeds. The UDOT vegetation manager was the landscape contractor were concerned about successful especially concerned that native plants might not work along aesthetics, partly because a beautiful I-15 landscape would the freeway, and he submitted Atwood’s preliminary lists for help them compete for future projects. For engineers and review by scientists whose primary expertise involved range- builders, erosion control in the right of way was the primary land improvement through breeding of exotic grass varieties vegetation issue of concern. They feared that slopes could “un- that could withstand the harsh conditions of Utah and sur- ravel” during the vegetation establishment phase, which would rounding states. These plant breeders were highly critical of necessitate costly repairs and increase liability. Consequently, Atwood’s preliminary recommendations (Exhibits 4 and 5). aesthetics was not a significant concern.

J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 • 121 Exhibit 5. Letter solicited by the Utah Department of Transportation (UDOT) Vegetation Manager, a member of the Landscape Task Force. The letter is authored by a plant breeder who was not a member of the Landscape Task Force. (Names of individuals have been changed.)

March 19, 1998 successful seeding and the establishment of young plants under semiarid conditions. Thomas Child It has been our collective experience in the seeding of over grazed and dis- Roadside Vegetation Manager turbed lands in those dryland areas that establishment of a planting that will Utah Department of Transportation effectively stabilize the soil should be a primary concern. Nevertheless, suc- 4501 South 2700 West cess does not come with every planting even if one uses the most vigorous, Salt Lake City, UT 84119 drought tolerant, and best adapted species. Year-to-year variations in the weather have profound effects on seedling establishment. Furthermore, the Dear Tom: probability of success goes down, often to zero, if anything less than the Thank you for the opportunity to review the I-15 roadside revegetation seed- best adapted species are planted. ing recommendation of John Atwood. His seed mix recommendations are One concern is that decisions relative to species recommendations for of considerable concern to me and to the team of research scientists here roadsides are easily driven by desires to create a floral display that may be at USDA-Agricultural Research Service, Forage and Range Research Lab- unrealistic for the site under consideration. In this instance, these are harsh oratory (FRRL). Let me explain the reason for our concerns and give a lit- dry sites that also receive considerable salt applications each year due to tle history of our research Unit and clarify the reason for any attached mod- snow/ice control. Another important factor is DOT’s requirements to con- ification to those recommendations. trol noxious weeds. Because many of those areas suffer from repeated in- The Forage and Range Research Laboratory is made up of 8 PhD research festations of undesirable and noxious weeds, most areas are sprayed at least scientists and about the same number of support personnel. Revegetation every few years. Flowers and shrubs are highly susceptible to and are work was initiated by the USDA here on the Utah State University Cam- killed by such sprays. Why are the current I-15 right-of-ways in the Salt pus in 1927 shortly after congressional attention was directed to the over- Lake Valley dominated by grasses? Certainly a major reason is that the grazed and degraded rangelands in the western U.S. The initial charge of plants are adapted to the area and are resistant to chemical spraying. our Unit was to identify plant species and develop seeding techniques to It may be educational to closely observe the roadsides along Highway 89/91 effect revegetation of semiarid rangelands in the intermountain west. Dur- between Logan and Wellsville. That road was widened and reworked sev- ing the first 50 years, a wealth of information and knowledge about the seed- eral years ago. Grade cuts were made near the Little Bear River. Large ing of native and introduced species was assembled. For the past 15–20 amounts of money and effort were spent in an attempt to establish many years, our research efforts have been focused on the development of new flowers and other native species. Although the moisture conditions are much and improved plant materials for use on arid and semiarid lands because better in Cache Valley than along I-15 and excellent rich topsoil was used, few available species were found to be adapted to the altered and degraded none of those “flowers” are now present. If flowers will not survive along rangeland conditions present on many areas. We have released 15 new cul- roads in Cache Valley, there is little chance they will even establish in Salt tivars/varieties/germplasm during that time. The process of releasing new Lake county. plant material requires that they be grown with and compared side-by-side with many other known plant materials on the possible sites to which they We have years of data that compares many of the species in question on side- may be adapted. Again those years of research have provided opportuni- by-side test plots. Our recommendations are based on the results of those ties to evaluate many plant materials. That is our mandate form the Fed- studies. eral Government. Finally, let me restate that we are not advocates of either native or intro- We have no reason to prefer either native or introduced. Our present con- duced plant materials. We base our plant recommendations not on origin cern is that the knowledge developed by the FRRL be considered in the or race, but on plant performance under the conditions in question. I close highly visible and important task of revegetating I-15 right-of-ways, and by asking, “Should we spend tax money in futile attempts by planting that the taxpayers’ money be spent with some accountability. Those areas species that will never establish?” I would argue that our primary goal have much in common with many degraded rangelands we have spent years should be stabilization of the soils along I-15 at the most reasonable cost. of research effort on. It is a fact that we will never have floral gardens along I-15 until we mod- ify the soil and then apply the amount of water to them that occurs in those Several considerations must be made—some of which may easily be over- areas that do have beautiful flowers. looked in an attempt to “return to the natural” or native condition. Clearly, the ecosystem that existed on the areas along I-15 in the Salt Lake Valley We congratulate you on the excellent job you are doing and wish you well has been destroyed; top soils were removed, and a few inches of new (dif- in your many endeavors. ferent soil) is being put in its place. However, all plant materials, organic matter, soil structure and horizons, associated microflora, and most nutri- Sincerely, ents were destroyed or are not being replaced. Furthermore, the Salt Lake Valley is a semiarid desert that receives insufficient rainfall to support R. Nelson Young many of the proposed species. A critical and germane issue is effecting a Research Leader

6. Plant biases affected others’ opinions. Several Land- ommendations engineers informed Atwood that because they scape Task Force members had favorite plants they wanted in- could not verify where a particular soil would be used on the cluded; similarly, everybody seemed to have some plants they project, they wanted a single seed mix and/or plant palette for hated. These preferences and prejudices disregarded which each ecosystem (i.e., one that would work for every soil type plants were best from an ecological perspective, whether na- and slope situation within an ecosystem). This concerned At- tive or non-native. As an example, an early proposal called for wood because soil texture and organic matter were highly vari- pine trees to be planted along the corridor from the Salt Lake able (Exhibit 3). Few plants that tolerated 870 g kg−1 (87%) airport to the ski resorts for the Olympics; however, this would sand and 4 g kg−1 (0.4%) organic matter (Monroc soil) would be impractical since the airport abuts the Great Salt Lake and thrive in the clay loam that had only 350 g kg−1 (35%) sand surrounding soils are regularly inundated with excessive salt. and 52 g kg−1 (5.2%) organic matter (600 North Topsoil). 7. Engineers wanted seed mixes to be universally suc- 8. The landscape contractor wanted to seed all species cessful. It was originally envisioned that Atwood’s recom- at a location at the same time, and at the same depth. mendations would be tailored to a given soil, slope, and pro- Species on Atwood’s preliminary lists varied with respect to posed ecosystem. However, near the deadline for final rec- optimum seeding depth. For example, with many native

122 • J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 species best establishment occurs with surface seeding, while case specifically involves landscaping of a freeway roadside, others emerge best from a depth of 3 cm. Atwood was con- the issue of whether to require native plants frequently arises cerned that this restriction would make it difficult to create sus- in a number of other contexts. Some examples of situations tainable native plant communities that would thrive for sev- that require decisions on whether to choose native plants in- eral decades. clude: landscaping of campgrounds in national forests, revegetation of public lands following a major disturbance such as The Decision wildfire or strip mining, legislation in communities or re- gions where exotic ornamental plants have become invasive Atwood was faced with a dilemma. He had originally been species, water shortages leading to the need for drought-tol- hired to provide recommendations about which native plants erant landscape plants, revegetation of weed-infested range- would work best for the I-15 landscape. He valued the ecol- lands, and efforts to reduce maintenance costs in public parks. ogy, sustainability, and beauty that a complex, high-biodiver- Preliminary versions of the case were class-tested in a sity landscape could accomplish, but he recognized that fail- sophomore-level environmental issues course composed of ure of an all-native landscape would be highly visible. Atwood students from various majors in 1999, a junior-level urban had achieved good success in the ecological restoration proj- forestry course for horticulture majors in 2002, and a senior- ect near his campus, but he was in charge of that project. While level landscape design course with students from various ma- Atwood had observed successful native roadside plantings in jors in 2002. While the case elicited a variety of responses from Minnesota, Iowa, and Arizona (drip-irrigated in Arizona), he the different courses, two points are worth noting here. First, was well-aware that an all-native planting in the dry Salt Lake the majority of students were already familiar with the term Valley had never before been attempted and therefore had native plant, but few of the students had considered that de- never before been successful. He was uncertain that the UDOT ciding whether to use native plants could be an important would manage the landscape effectively in the long run, even issue before exposure to this case. Second, for students with if the design and installation were successful. He did not a previous background in environmental education that in- know if existing UDOT personnel would alter their manage- cluded an understanding of the importance of sustainable ment techniques to ensure survival of native plants, espe- landscapes, the awareness that native plants may not always cially broadleaf species. Atwood’s recommendations would be the best practical choice for a natural landscape some- directly influence the spending of several million dollars. times came as a shock. Also, while he knew a great deal about native plants, many of The following suggestions are offered for teaching this the species had not been tested previously in the specific en- case. vironment created by a freeway corridor. By the time At- wood learned of the issues and concerns of Landscape Task • In addition to assigning the case for reading before class dis- Force members, he had only 3 wk to resolve them and make cussion, there is other valuable information that will gen- his final recommendations. At this point his consulting fees erate a wider variety of perspecitves than are presented in would not change whether he recommended native or exotic this case. These sources include recent journal readings or species. What should he recommend? Internet searches in the areas of invasive plant species (e.g., Mullin et al., 2000), the regionally important need for water TEACHING NOTE conservation in urban landscapes (numerous websites are Case Objectives available, often associated with Cooperative Extension in drought stricken areas), and further arguments advocating After completing this case, students should have a better: the use of native plants (e.g., Native Plant Society websites). • The instructor may begin the in-class discussion by divid- 1. Understanding of the advantages and limitations of ing the class into small groups (3–5 students) with each using native plant for natural landscapes. group assigned to one of the discussion questions in the next 2. Appreciation for the difficulties involved in decision- section. Each student first rapidly answers the question in- making for an environmental issue where different pri- dividually in as much detail as he/she can in 2 to 4 min, then orities conflict and experts disagree. a group answer is generated (also under time pressure). A 3. Awareness of the challenges involved in making im- group leader may be assigned to assure that each group portant environmental decisions in the absence of com- member participates in developing the answer to the ques- plete data. tion (with the threat that a non-participant may be assigned to be spokesperson for the group). Depending on student en- Use of the Case rollment, multiple groups may be assigned the same ques- “A Native Landscape For I-15?” presents an authentic sit- tion. uation that illustrates conflicts that frequently arise associated • Following or during a group answer, the instructor may in- with the issue of native vs. non-native plants. (Note: The terject comments based on material from the author’s in- names of all individuals in this case have been changed; com- terpretation that follows discussion questions in order to pany names and all other information is factual). Often the stimulate alternative thinking or liven the discussion. Ad- question of whether/when to use native plants becomes a con- ditionally, students from other groups may be allowed to troversial and emotional topic. The case as presented was de- challenge an opinion. The instructor may wish to reserve veloped for use in an advanced landscape design course, but some questions for consideration by the entire class. may also be adapted for use in environmental science, ecol- • Alternatively, groups of students may be assigned to repre- ogy, horticulture, or range management courses. While the sent a particular perspective on the Landscape Task Force

J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 • 123 in responding to the discussion questions. This approach (Note: Questions 1–5 can be answered before reading the helps assure that a variety of opinions will be represented. Authors’ Analysis. Question 6, which the instructor may choose not to raise in order to help students retain ownership Discussion Questions of the decision (See Bouda et al., 1996), can best be addressed after reading the Authors’ Analysis.) In discussing the case, factors that affect decision-making regarding the use of native plants on the I-15 landscape should be identified and evaluated. Some possible questions to ac- Authors’ Analysis of the Decision complish this include the following. Recognizing that even the best plants and seed mixes could 1. Why did the decision whether to recommend native not guarantee complete plant establishment, Atwood was de- plants create a dilemma for John Atwood? termined to provide recommendations that would maximize 2. What is the appropriate landscape for I-15? Is Atwood the probability for project success. Representative recom- obligated to use native plants in the landscape? mendations are included in Exhibit 6; his complete recom- 3. What constitutes an appropriate “native” plant along the mendations are available from the authors. right-of-way? Atwood had to consider each of the concerns described ear- 4. Would the exotic species recommended by the author lier. A brief description of how he dealt with each issue along of the first letter (Exhibit 4) work better than native with his rationale follows. plants? How could you be certain? (Note: The plant 1. “This is not the way we manage roadsides in Utah.” breeders who wrote letters in Exhibits 4 and 5 did not Atwood was convinced that UDOT personnel required edu- have soil test results and were unaware of the Aesthetic cation and persuasion. Due to his involvement in the I-15 Theme for the I-15 reconstruction.) project, Atwood was invited to be the keynote speaker at the 5. Do you think a bureaucracy like UDOT could maintain 2000 UDOT annual vegetation management conference. He a natural landscape like the one Atwood envisioned? presented a seminar on ecological principles of roadside man- 6. What did Atwood recommend? To what extent did At- agement. In addition, he focused considerable efforts (memos wood’s recommendations satisfy the priorities of each and phone calls) on younger UDOT employees who were Landscape Task Force participant? more open-minded about change.

Exhibit 6. Recommendation for Wasatch Front Landscape, as an example of Atwood’s final recommendations. Complete recommendations are available from the authors. Wasatch front seed mix #2 drill seeding† Shrubs Special seeding considerations Seeding rates [kg ha−1 (pounds acre−1), PLS] Black sagebrush (Artemisia nova A. Nels.) 0.45 (0.40) Wyoming big sagebrush (Artemisia tridentata Nutt.) 0.22 (0.20) Green ephedra (Ephedra viridis Cov.) 5.60 (5.00) Subtotal for shrubs 6.27 (5.60)

Grasses Rhizome or bunch Seeding rates [kg ha−1 (pounds acre−1), PLS] Slender wheatgrass ‘Revenue’ (Agropyron trachycaulum Malte var. trachycaulum) bunch, rhizome 1.68 (1.50) Indian ricegrass [Orysopsis hymenoides (Roem. & Schult.) Ricker] bunch 1.12 (1.00) Crested wheatgrass ‘Vavilov’ [Agropryon cristatum (L.) Gaertn.] bunch 1.12 (1.00) Needle-and-thread grass (Stipa comata Trin. & Rupr.) bunch 1.12 (1.00) Streambank wheatgrass ‘Sodar’ (Agropyron riparium Scribn. & Sm.) rhizome 1.12 (1.00) Intermediate wheatgrass ‘Tegmar’ [Agropyron intermedium (Host) Beauv. var. intermedium]) rhizome 0.56 (0.50) Western wheatgrass (Agropyron smithii Rydb.) rhizome 0.56 (0.50) Snake River wheatgrass ‘Secar’ [Pseudoroegneria spicata (Pursh) Love] bunch 2.24 (2.00) Sand dropseed [Sporobolus cryptandrus (Torr.) A. Gray] bunch 0.28 (0.25) Subtotal for grasses 9.80 (8.75) Total—Pure live seed, PLS 16.00 (14.35)

† Notes for Seed Mix #2 Drill Seeding: 1. Recommended seeding procedure following seedbed preparation (subject to modification as needed): A. Drill-seed all grasses and shrubs except sand dropseed, black sagebrush, and big sagebrush (1.6 cm [5/8 inch] deep). Drill shrubs in separate drop boxes, separately from grasses where possible. B. Drill sand dropseed, black sagebrush, and big sagebrush at 0.3 cm (1/8 inch). C. Nakae is having a rangeland drill built specifically for this project. Further refinements of seeding procedures will be likely, depending on the drill’s capacity. 2. In irrigated areas, the following can also be seeded at 2.5 cm (1 inch): Cow mex (Stansbury cliffrose) at 1.7 kg ha−1 (1.5 pounds acre−1), Rhu tri (oakbrush sumac) at 5.6 kg ha−1 (5 pounds acre−1), and Cer led (curl-leaf mountain mahogany) at 3.9 kg ha−1 (3.5 pounds acre−1). In unirrigated areas, these will fail to establish on Monroc borrow nearly every year.

Explanation: All native trees and shrubs listed in the Wasatch Front Landscape can be seeded, with different probabilities for success. In Utah, many of these plants naturally establish from seed only during wet years or “wet cycles” of years. Due to limited seed availability and/or low expectation for success even with the highest quality seed and best seeding procedures, certain plants that will be established as transplants (with irrigation) are not included in the above list. Most drought-tolerant trees and shrubs are slow to establish, and seeded woody plants may compete poorly with grasses. Even transplanted shrubs will compete poorly with grasses where grasses are irrigated. Use of the Wasatch Front Seed Mix should probably be avoided where irrigation to transplanted shrubs occurs, or the grasses should be omitted from the mix in these areas.

Where the primary objective is establishment success for desired species, it is more economical to establish a few transplants than apply a sufficient amount of seed to “make it work.” In some cases, sufficient seed quantities simply do not exist commercially.

124 • J. Nat. Resour. Life Sci. Educ., Vol. 32, 2003 By expanding the lanes of traffic within the same right-of- 7. Engineers wanted seed mixes to be universally suc- way, roadside slopes for the new freeway were almost all cessful. The number of species in each seed mix was in- considerably steeper than for the old freeway. The conse- creased. quence was that mowing was impractical in many areas. At- 8. The landscape contractor wanted to seed all species wood recommended that where mowing was necessary, it at a location at the same time, and at the same depth. At- should be done only in the autumn after native species had pro- wood introduced the landscape contractor to practitioners duced seeds, and never where woody plants and wildflowers who specialized in seeding equipment for revegetating sloped were located. sites. Special equipment was created that allowed for broad- 2. “Canyon plants are prettier than hardy valley cast and drill seeding (at multiple depths) simultaneously. plants.” Atwood supplied a strongly worded memo (available Note that steeply sloped sites had to be broadcast seeded, from authors) regarding the need for ongoing irrigation if which requiring a higher seeding rate and resulted in poorer canyon plants were to be used. establishment. 3. Nobody had clearly defined native. During a Land- Initial Results scape Task Force meeting Atwood explained how many introduced species had become invasive, a problem with enor- Areas that were drill-seeded had acceptable plant coverage mous costs to private and public entities including UDOT. on more than 90% of the roadside areas (Nakae and Associ- 4. Some outside experts argued that native plants would ates, personal communication, May 2002). Where plant cov- not work. Atwood concluded that a native roadside land- erage was not acceptable, probable explanations include the following. scape was more consistent with his philosophical and professional background, even though he recognized that the I-15 1. Several snowstorms of less than 7.6 cm (3 inches) dur- project would probably not be entirely successful. He sub- ing the winter of 2001–2002 resulted in heavy applica- mitted his preliminary recommendations for review and re- tion of de-icing salts with minimal moisture for dilution. finement by five ecologists with revegetation experience and A few areas devoid of vegetation were so salty they ap- either a master’s or doctoral degree. He contacted the author peared white on the surface by April 2002. Soil test re- − of Exhibit 5 to verify that the two letters (Exhibits 4 and 5) had, sults yielded sodium levels as high as 550 mg kg 1 in fact, been written with no knowledge of the I-15 aesthetics (parts per million) and sodium adsorption ratios as high theme, soil test results, or irrigation systems. as 39.2, which indicated an extreme sodium hazard. However, to avoid criticism that could arise if the native 2. Areas that were broadcast-seeded remained more com- plants failed to establish, Atwood made the “political” deci- pacted than areas that were drill-seeded (engineering specifications for the freeway required that fill material sion to include in his seeding recommendations very small be compacted to 95%). amounts of traditionally advocated nonnative species (Ex- hibit 6). That way, if the plantings totally failed he could de- Most plants Atwood recommended grew successfully fend the native plant recommendations by pointing out that the along the I-15 roadside; only two species proved unsuccess- nonnatives had not established either. ful in the short run. Interestingly, several new positions were 5. Each member of the Landscape Task Force had dif- tentatively approved within UDOT to hire employees with ex- ferent priorities. Aside from engineering solutions to the pertise in native plant communities. These positions were all problem of erosion control (e.g., specifications called for ero- re-allocated within UDOT to meet other needs. Thus, the jury sion control blankets on slopes greater than 3:1), Atwood re- is still out on whether the largely native I-15 landscape will mained convinced that high plant diversity in the seed mixes prove to be successful. would prove to be the best strategy. His final recommendations REFERENCES (Exhibit 6) included three to four times the number of species typically included in roadside seed mixes, thereby increasing Bouda, F., J. Walker, and S. Simmons. 1996. Those “rascally” rabbits: A bi- the probability that at least some species would establish ological control decision case. J. Nat. Resour. Life Sci. Educ. 25:137–143. Johnson, C.W., and L. Anderson. 1997. Utah’s Rural Roadsides for Wildlife given the wide range of conditions encountered. In all seed Program: A technical manual. Utah Div. of Wildlife Resources and the mixes, some highly salt-tolerant plants were included due to Utah Dep. of Transportation, Salt Lake City, UT. the unknown salt loading from de-icing. MacMahon, J.A. 1983. Nothing succeeds like succession: Ecology and the human lot. Utah State Univ. Press, Logan, UT. 6. Plant biases affected others’ opinions. Atwood pro- Mullin, B.H., L.W.J. Anderson, J.M. DiTomaso, R.E. Eplee, and K.D. vided memos and verbal arguments in Landscape Task Force Getsinger. 2000. Invasive plant species. Issue Pap. 13 [Online]. Available meetings, explaining why each inappropriate plant proposed at http://www.cast-science.org/cast-science.lh/ (verified 26 Aug. 2003). CAST, Ames, IA. was unsuitable for the project. Landscape architects ultimately U.S. Department of Transportation. 1999. Roadside use of native plants. followed Atwood’s recommendations on tree and shrub Federal Highway Administration Publ. FHWA-EP-99-014. U.S. Dep. of species about 90%, and on seed mixes 100%. Transportation, Washington, DC.

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