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, ei- ther 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.