Plant Ecol (2017) 218:81–94 DOI 10.1007/s11258-016-0648-z #905 Challenges and limitations to native species restoration in the Great Basin, USA Tony Svejcar . Chad Boyd . Kirk Davies . Erik Hamerlynck . Lauren Svejcar Received: 28 April 2016 / Accepted: 9 August 2016 / Published online: 5 January 2017 Ó Springer Science+Business Media Dordrecht (outside the USA) 2016 Abstract The Great Basin of the western USA is an bunchgrasses, principally utilizing heavily mecha- arid region characterized by high spatial and temporal nized agronomic approaches, have been met with variability. The region experienced high levels of limited success. A multitude of environmental factors ecological disturbance during the early period of Euro- contribute to the lack of restoration success in this American settlement, especially from about region, but seedling mortality from freezing and 1870–1935. The principal plant communities of the drought has been identified as a primary demographic Great Basin are sagebrush steppes, dominated by limitation to successful bunchgrass establishment. various Artemisia shrubs and perennial bunchgrasses Novel approaches to overcoming limitations to bunch- that represent the largest rangeland ecosystem in North grass establishment will be required for restoration America. In low to mid-elevation sagebrush commu- success. Increased national concern and a near listing nities, exotic annual grasses have displaced native of the greater sage-grouse, a steppe-obligate species, to plant species and are associated with a dramatic Endangered Species status, has spurred greater regio- increase in size and frequency of wildfires. Degrada- nal support and collaboration across a diversity of tion in this region is driven by processes that cause the stakeholder groups such as state and federal land and loss of mature bunchgrasses, which, when intact, limit wildlife management agencies, county planners, and exotic annual grass invasion. Historically, large eco- ranchers. nomic investments to restore degraded Great Basin rangeland through establishment of native Keywords Great Basin Á Restoration Á Sage steppe Á Catastrophic fire Á Cheatgrass Á Medusahead Á Bunch grasses Communicated by Dr. Olga Kildisheva, Dr. Lauren Svejcar and Dr. Erik Hamerlynck. T. Svejcar (&) Á L. Svejcar Introduction to the Great Basin, USA Eastern Oregon Agricultural Research Center, Oregon State University, 67826-A Hwy 205, Burns, OR 97720, USA The goal of this paper is to describe the general setting, e-mail: [email protected] past restoration practices, and the potential future for restoration in the Great Basin of the USA. It is C. Boyd Á K. Davies Á E. Hamerlynck important to understand both the geophysical setting Eastern Oregon Agricultural Research Center, USDA- Agricultural Research Service, 67826-A Hwy 205, Burns, of the region and past history. The region has been OR 97720, USA defined by both hydrologic and floristic parameters. 123 82 Plant Ecol (2017) 218:81–94 Two common definitions include (1) the area of the drainage, and prior geologic activity created an western US that is internally drained, with no outlets to extremely variable environment. Volcanic activity the ocean (hydrologic definition) and (2) a floristically deposited ash layers in portions of the Great Basin and defined region dominated by shrub/steppe and wood- plate tectonic activity resulted in crustal thinning, land plant communities (Pellant et al. 2004). The generating a series of north/south oriented mountain hydrologic Great Basin covers in excess of ranges, creating large topographic variation (Fiero 293,000 km2 and includes much of Nevada and Utah, 1986). An example of this variability can be seen in a major portions of Oregon and California, and small soil map of the Northern Great Basin Experimental areas of Idaho (United States Geological Survey Range (NGBER) in southeastern Oregon (Fig. 1, 2013). The floristically defined Great Basin includes Lentz and Simonson 1986). Although the area is only more area, with shrub/steppe communities dominated about 6500 ha, there are 54 soil map units within the by species of Artemisia and Atriplex, and woodlands experimental range. This high variability makes it dominated or codominated by species of Juniperus. difficult to generalize restoration plans, and research Using either definition, the Great Basin is bounded on must be viewed based on site characteristics associ- the west by the Sierra Nevada and Cascade ranges and ated with a specific research effort. on the east by the Rocky Mountains. We will refer to The period of Euro-American settlement of the the region as the Great Basin, but will focus our region largely began with the gold mining boom in restoration discussion on the western sagebrush steppe California in the late 1840s and early 1850s (Table 1). or sagebrush semidesert. The sagebrush steppe biome This was a period of unprecedented westward migra- stretches to the Great Plains of the central US, but the tion and created the conditions which led to extensive shift in precipitation (more summer and less spring settlement. By mid-1869, a railroad was completed and winter) in the eastern portion of the biome makes across the northern Great Basin, allowing transport of it ecologically distinct from the western sagebrush people and materials into and out of the region to steppe. either the east or west. Because of the arid nature of the To provide a sense of restoration challenges, we region, programs to transfer land from the federal will break past history of the Great Basin into two government to private ownership (Homestead Acts) segments: (1) recent geologic history (from the end of did not function as intended (Svejcar 2015). These the Pleistocene about 11,700 years before present) and programs (initiated in the early 1860s) were developed (2) the period of active Euro-American settlement for the eastern US and not modified adequately for the from about 1850 to present. The geologic history of Great Basin. Thus, much of the land remained in the Great Basin is important for understanding the public ownership, and there was no planning for how physical setting and variability of this region. Toward the lands would be managed. The livestock boom of the end of the Pleistocene, the climate was much the late 1880s and lack of oversight on land-use cooler and wetter than present day, and there were resulted in huge numbers of livestock and serious land extensive marshes and lakes in the region. For degradation (Young and Sparks 1985). A significant example, present day Great Salt Lake has a surface drought and harsh winters during this period magnified area of 4400 km2 and maximum depth of about the overgrazing issue. It was not until the mid-1930s 7–10 m depending on the year. The Great Salt Lake is that laws were passed to bring order and management a remnant of the Pleistocene-era Lake Bonneville, to the publicly owned lands of the Great Basin. The which at its peak was almost 52,000 km2 in size and damage inflicted on this arid region resulted in more than 300 m deep. There were other large significant restoration efforts, which will be described Pleistocene lakes, such as Lake Lahontan to the west, in a subsequent section. which at its peak was equal to 8 % of surface area of Two other events that would impact the need for the state of Nevada (Nevada Division of Water restoration were (1) the introduction of cheatgrass Resources 2000). As climate dried, these lakes (Bromus tectorum L.) and other exotic annuals in the receded, and there was sorting of soil particle sizes later 1800s and (2) the severe drought of the 1930s. along the shorelines. In fact, peak shoreline levels are Cheatgrass is an invasive annual grass that is now still visible in portions of the Great Basin. The almost ubiquitous on low and mid-elevation Great combination of dramatic climate shifts, internal Basin rangelands (e.g., Kitchen 2014). This species 123 Plant Ecol (2017) 218:81–94 83 Fig. 1 Soil map of the 6500 ha Northern Great Basin Experimental Range (NGBER) competes with native seedlings and dramatically from 4 to 13 °C. He depicts annual precipitation as increases the number of wildfires in many areas ranging from 13 to 49 cm, and often falling as winter (Whisenant 1990). The drought of the 1930s caused snow, with almost no summer precipitation except in widespread abandonment of homesteads (lands the mountains. recently transferred from public to private ownership) Spatial variation in climate is only one part of the and put additional stress on native plant communities. challenge faced by vegetation managers and restora- tion practitioners in the Great Basin. A second major challenge is high annual weather variability (e.g., Climate—present and future Fig. 2). Figure 2 represents crop year precipitation at the NGBER over a 70-year period. About one of every The climate of the Great Basin is influenced by its 4 years falls within ±10 % of the long-term average landforms. The Sierra Nevada and Cascade Mountain and values regularly range from 15 to 45 cm. West ranges to the west exert a strong rain shadow effect on (1999) estimated the coefficient of variation in total much of the region. The large elevational and topo- annual precipitation to be about 30 % for sagebrush graphic variation from the north/south mountain steppe ecosystems. The combination of high spatial ranges (Fiero 1986) also influences climate. The and temporal variability creates significant challenges basins generally average less than 25 cm, whereas for reseeding and other restoration efforts in the the higher elevation sites can average over 50 cm in region. Projections suggest climate variability will annual precipitation. Bailey (1995) describes the increase in the future (Mote et al. 2013). Some of the climate of the Intermountain Semidesert and Desert projected changes may strongly interact with both size Province (central and southern Great Basin) as being and frequency of wildfires.