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The Mono Basin Ecosystem: Effects of Changing Lake Level (1987)

Chapter: 5. Shoreline and Upland Systems

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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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Suggested Citation:"5. Shoreline and Upland Systems." National Research Council. 1987. The Mono Basin Ecosystem: Effects of Changing Lake Level. Washington, DC: The National Academies Press. doi: 10.17226/1007.
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5 Shoreline and Upland Systems INTRODUCTION The shoreline and upland systems are integral parts of the Mono Basin. If the level of Mono Lake rises or falls, the shoreline will be inundated or exposed, and the shore- line system will be altered. Many of these alterations in the shoreline system are controlled by hydrologic changes in the nearshore groundwater, as discussed in chapter 2. Except for the streams themselves and the riparian flora and fauna, the upland system will not generally be affected by changes in lake level. A description of the upland sys- tem is nevertheless necessary for an overall understanding of the basin. This chapter describes the physical components of the shoreline and upland systems--topography, soils, and natural events affecting the systems--as well as the biotic com- ponents--vegetation and wildlife. The interface between the land and the air, controlling aerosol production from the alkali flats, and the interface between the land and the water, controlling the tufa formations and shoreline ero- sion, are also discussed. PHYSICAL COMPONENTS Topography The Mono Basin lies on the border of two major physio- graphic provinces--the Sierra Nevada and the Great Basin-- 121

122 The Mono Basin Ecosystem and is part of both. The first, and still one of the best, descriptions of the Mono Basin was that of I. C. Russell (1889~. The basin includes a variety of features of great interest to geologists, climatologists, and geographers--vol- canos, fault scares, glacial cirques and moraines, tufa for- mations, sand dunes, perennial streams, and several lakes. The watershed extends to the crest of the Sierra and includes Mt. Lyell, Koip Peak, Mt. Dana, and Mt. Conness. The elevations within the basin range from 13,000 ft to about 6,380 ft. the current level of Mono Lake. The geo- morphology of the area is closely related to the geology Studies of the stratigraphy re- vea~ ~ ~ mayor glacial advances and various layers of glacial moraines, volcanic pumice and ash, and erosional sediments from streams. Among the terrain features are several of special importance for their scientific interest and scenic value, including Bloody Canyon (a classic example of Sier- ran glaciation), the Mt. Dana glacier, the Mono Craters, Paoha Island, and Negit Island. Topographic features in the regions surrounding the Mono Basin include the Inyo Craters, Long Valley, Glass Mountain, the Bodie Hills, Sweetwater Mountain, and the White Mountains (Figure 5.1~. Adjoining drainages are the San Joaquin, Tuolumne, and Merced rivers on the western slope of the Sierra, the Walker River to the north, and the Owens River to the south. Topographic maps and aerial photographs available for the Mono Basin are listed in the bibliography. and the paleoclimatology. ~ ~ ~ . ~ . ~ . Soils Gallegos (1986) has provided a soils map for the Mono Basin National Forest Scenic Area. He recognized 53 map- ping units within the scenic area, with the bulk of the soils belonging to the Entiso] order. A few Mollisols and Aridisols were also encountered. Entisols are defined as soils that lack pedogenic horizons except for a slight dark- ening of the surface layer by organic matter. Mollisols are well-developed soils having a surface layer that is heavily melanized and deep (at least 25 cm deep or one-third of the combined depth of the A- and B-horizons). The

Shoreline and Upland Systems 5,~A=~ / I /' ~Twin L.h.s ~ % —~ MATTERHORN ~ t ``PEAK 1~'ONWAY SUP ONION ~~ ~~ ~ \ ~' ret Point,' MONO LAKE ~ MT, WARREN And Gig ) t ·7 Go__ ~~ 2 33 MONO DO 4E ~ ~~ Probe lily MT. CONNESS`` · - `, L" Vlning a\ TIOCA PASS Y ~ ~ It__. ~ Err. DAN 84; O \ ,` ~ Crant KOIP PK ~ ,, Lay FEZ `, AL he {a BALD &IT CLlA1,5S3 T MT LYELL J 13,15B ~,¢> \ \ : %\ tt11,034 ~~) ~ ~~ ~Ntb Lop J c~vsN COWTRACK MT ` 8875 123 'it ~ 'of ~ "A ~ MEND - Y 3,145 °~ Solon ~~ 'N \~_/ 13,055 *'I \ ~ \ %~ Chummy I WHITE MrN \ 14,_ 14 242 FIGURE 5.1 Topographic and other features of area sur- rounding Mono Lake. surface layer has a soft, crumbly structure when dry and has calcium as the dominant cation on the colloidal exchange particles. Aridisols have at least one pedogenic horizon, but never have water continuously available for plant growth for as much as 90 days when soil tempera- tures are above 5.0°C. As Gallegos (1986) has noted, the soils of the scenic area have developed from two primary parent materials (Figure 5.2~. Soils of areas to the west, southwest, and northwest of Mono Lake are derived principally from the granitic core of the Sierra and from metasedimentary rocks that were uplifted with the Sierra and are now exposed as scattered fragments along the crests and sides of the mountain range. These soils are usually coarse textured and bear variable amounts of rock fragments in the profile.

124 The Mono Basin Ecosystem Lake sediments or ash or allavlum deposits with high water tables and alkaline reaction Ash cinders or volcanic craters Solls neutral or silghtly to strongly acidic 1 Reeldual or transported soil derived form granite and metals sedimentary rocks Sons acidic to circumneutral FIGURE 5.2 Area. MONO LAKE 0 1 2 3 SCALE IN MILES Soils of Mono Basin National Forest Scenic The rest of the soils of the scenic area are derived from either rhyolitic ash or cinder deposits or from heteroge- neous lake sediments. Black Point and Negit Island are both of volcanic origin, but the material is darker (basalt) anc chemically distinct from the rhyolitic Mono Craters. The rhyolitic deposits are young, highly permeable to water, and extremely infertile. The lake sediments are, of

Shoreline and Upland Systems 125 course, of mixed origin. Since the lake has progressively receded in its undrained basin, accumulated salts impreg- nate its younger sediments. Gentle slopes along the north and east shores of the lake result in large exposures of saline lake sediments and high water tables as the lake recedes. As a consequence, soils along those shores differ strongly from soils of the western and southern shores, where the landscape rises more steeply from the water's edge. In the latter areas, acidic soils occur within a few hundred meters of the high- ly alkaline, damp shorelines adjacent to the lake. In con- trast, sediments that are strongly influenced by the lake with respect to both chemistry and water table often ex- tend for a kilometer or more (sometimes up to 4 km) away from the current shoreline along the north and east shores. Soil salinity problems appear to be exacerbated along these shores by water draining from the Bodie Hills via Wilson Creek. That water becomes highly saline and alkaline as it percolates through the lake sediments. · . l hUS at a large number ot sites, water rises to the soil surface by capil- larity and leaves behind its load of soluble salts as it eva- porates. The commonest soils on the mountainous west end of the scenic area are Typic Xerorthents (Table 5. 1~. These are Entisols formed in areas having moist winters and dry summers. The combining term ortho- conveys the idea of genuine or true. -~ ~~- -~ :~ := _: Entisol, an orthent soil is a true or genuine Entisol. The - tiara the Cllt-t-1Y _~.nt ~~.Rl~nOtes an extensive morainal deposits in the mountains there support Typic Cryorthents and Typic Cryoborolls. The cryo- prefix designates soils that have a mean annual temperature at 50 cm of over 0° but less than S.0°C. Rhyolitic outcrops have developed Typic Haploxerolls. Soils ending in -oil are ~ -I ~ -- The moraines and alluvial fans at the mouth of Lundy Canyon support Xeric Torripsamment, Durorthidic Xeric Torripsam- ment, and Typic Xerorthent soils. The ash and cinder plains along both east and west sides of the Mono Craters to the south of the lake have developed Dystric Xerorthent, Typic Xeropsamments, Xeric Torripsamments, and Xeric Torriorthent soils (Table 5. 1~. Dystric soils are dystrophic or infertile due to displacement Mollisols or soils with deep, ctar~-co~orea ep~pec~ons.

126 The Mono Basin Ecosystem TABLE 5.1 The Major Soil Subgroups Encountered on Each of the Three Major Parent Material Types (Figure 5.1 ) Around Mono Lake Granite- Rhyolitic Lake and Alluvial metasedimentary Ash Sediments Typic Xerorthents Typic Cryorthants Typic Cryoborolls Typic Haploxerolls Xeric Torripsamments Durorthidic Xeric Torripsamments Typic Xerorthents Xeric Torripsamments Xeric Torriorthents Typic Xeropsamments Dystric Xerorthents NOTE: Technical names are used for the soil subgroups listed, since they convey information concerning root zone temperature and seasonal water availability, profile development, presence of a water table within the soil profile, and texture of parent material. See Gallegos (1986) for location of the various soils in the landscape. Haplaquents Durorthidic Xeric Torripsamments Durorthidic Xeric Torriorthents Aeric Haplaquents Typic Psammaquents Typic Haplaquents Typic Xerorthents Xeric Torripsamments Xeric Torriorthents Xerollic Camborthids of biologically essential cations by hydrogen. Such soils are strongly acidic in reaction. Xeric Torripsamments are the most widespread soils in the area, but Xeric Torrior- thents and Typic Xeropsamments are also widespread. The commonest soils on the north and east shores of Mono Lake are Haplaquents, Durorthidic Xeric Torripsam- ments, Durorthidic Xeric Torriorthents, Aeric Haplaquents, Typic Psammaquents, and Typic Haplaquents (Table 5. 1~. Aquents are Entisols in which a water table occurs in com- bination with conditions of poor soil aeration. The prefix hapla- carries the meaning of simple or minimal h~ri7.nn Durorthidic soils have a weakly cemented silicon pan within the surface meter. Black Point supports Xeric Torripsamments and Typic Xerorthent soils. The major upland soil on Paoha Island is a Xeric Torriorthent. The principal upland soil on Negit Island is mapped as a Xerollic Camborthid. Orthids are Aridisols that do not have a high clay or a high sodium horizon. Camborthids have an altered (cambic) subsurface horizon that is development. ~ .. .

Shoreline and Upland Systems 127 generally redder or browner than the surface horizon. These soils are circumneutral to strongly alkaline in reac- tion. Levels of soluble salts are often so high in some of these soils that all plant life is excluded. The low fertility of upland soils to the south and west of the lake is striking when parameters for those soils taken in connection with this report are compared with soils from comparable elevations and vegetation types in the Bonneville Basin of western Utah (Table 5.2~. The data demonstrate that for most variables, the soils derived from rhyolitic ash contain significantly smaller amounts of ele- ments essential for biological systems than those formed from granitic and metasedimentary parent materials. Both of those Mono Basin parent materials produce soils that are highly impoverished in phosphorus and exchangeable bases relative to the common soils of uplands in the Bonneville Basin (Table 5.2~. Recent experimental plantings of container-grown stock of salt-tolerant native shrubs (Atriplex canescens and Sar- cobatus vermiculatus) on the sandy beaches of the north shore suggest that the erosive action of windblown sand and adverse soil chemistry combine to make revegetation with shrubs an unlikely means of stabilizing such an area (Romney et al., 1986~. Direct seeding of grasses and shrubs also shows little promise, but hand plantings of saltgrass (DistichZis spicata) rhizomes are often successful on the less harsh portions of the north shore (Romney et al., 1986~. Natural Events Hydrogeomorphic Events Hydrogeomorphic events discussed here include avalan- ches and erosion. The steep eastern escarpment of the Sierra is prone to large, destructive avalanches during and following periods of prolonged snowfall. Particularly af- fected are the canyons, in which snow sliding downward from the higher slopes is funneled into a narrow valley, thus deepening the mass and increasing its momentum. Avalanches are common in winters when dry, windy periods between major storms create an icy or wind-crusted snow

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Shoreline and Upland Systems 129 surface on which the new snow slides easily. Melt-freeze metamorphism is also important in the formation of icy surfaces. The most widespread and destructive avalanches in re- cent years occurred throughout the Sierra in February 1986. Damage to vegetation was extensive over a wide range of elevation from mountain hemlock and lodgepole pines near Tioga Pass to aspen and pinyon pines near Mono Lake. Widespread avalanches also occurred in 1921, 1952, 1969, and 1982. Meteorologic events determine the frequency and sever- ity of erosion episodes along the lakeshore, on lands ex- posed by the receding lake, and in the steep canyons. As noted below in the section on the land-water interface, strong winds cause lake waves that alter the shoreline and batter nearshore tufa formations. Such winds also blow sand into shifting dunes and transport fine alkali dust, salts, and other particulates to altitudes up to several thousand feet and for distances of tens to hundreds of miles. The extent of wind erosion on surrounding hills and mountain uplands depends in large measure on whether ri- parian vegetation has been previously destroyed by fire or, less commonly, by overgrazing. Other forms of erosion that affect landforms, particularly streambed and ephemeral stream channel erosion, are associated with high-intensity rainfall and associated flash floods. Such episodes occur most frequently from midsummer to early fall. A particu- larly memorable event was experienced on Post Office Creek in early August 1955. Heavy thunderstorm rains caused a flash flood that severely damaged Tioga Lodge and washed about 20 automobiles into Mono Lake; no one was killed or injured (H. Klieforth, personal communica- tion). F. Ire In an environment such as that of the Mono Basin, where summer precipitation is scanty and unpredictable, wildfires in the natural vegetation are common. Both low- altitude photographs and space satellite images (Ustin et al., 1986) show conspicuous fire scars in the shrublands and

130 The Mono Basin Ecosystem forests of the general area. Woody-stem aging techniques and government records reveal that fires have burned re- peatedly throughout at least the past century in the Mono Basin. Historic records demonstrate that the fires result from both natural causes ("dry" lightning) and direct human intervention. Fires are known to have swept over all veg- etative types in the basin, including marshes, brushlands, woodlands, and forests. Because of broken terrain and locally sparse plant cover, few individual fires have burned over large areas. Within the scenic area, there are known scars of over 40 fires that burned in years ranging from before 1875 to 1986, but no fire larger than 100 acres is apparent. Most fires burn fewer than 10 acres before natural factors or direct intervention by fire-control teams limits their spread. Since plants differ in their ability to regrow after fire, fires in woody vegetation in particular alter the composi- tion of the plant cover for decades after the actual pas- sage of the blaze. Forest trees such as the quaking aspen (Populus tremuloid~es) sprout profusely after fire, while other associated trees (e.g., Abies concolor and Pinus jef- freyi) are killed by crown fires. At lower elevations or on drier slopes, the major species of the pinyon-juniper wood- lands are severely affected by crown fires. Pines mono- phyIla, Juniperus osteosperma, Cercocarpus ledifolitcs, and Artemisia tridentata all fail to sprout after fire, and soils are stabilized solely by herbaceous species (which are often sparse in these woodlands) for many years after a fire. In the upland shrublands of the pumice flats south of Mono Lake, neither of the dominant shrubs (Artemisia tri- d~entata and Purshia trid~entata) sprout after fire. As a result, fire scars remain sparsely vegetated for many years on such sites. Grasses and perennial herbs perform poorly on these sites, and adapted annual plants are small and short-lived. Sprouting shrubs and herbs are the rule on sites nearer the lake, where water tables are near the surface and soils are often at least somewhat saline. The grasses Distichlis spicata and Spartina gracilis sprout vigorously after fire, as do associated shrubs such as Chrysothamnus nauseosus,

Shoreline and Upland Systems 131 Salix exigua, Sarcobatus vermiculatus, and Shepherdia ar- gentea. Since the soils on upland sites in the Mono Basin are generally coarse and well drained, fires on those soils rare- ly result in erosion by running water. Infiltration rates are rapid enough to preclude the accumulation of surface rivulets that might result in gully formation. On fine- textured sands, fires may permit enough wind action to produce small mounds before natural recovery of the vegetation cover is adequate to prevent soil movement. Fires on the steeper slopes of the Sierra portion of the scenic area do sometimes result in significant erosion by water. The result may be gentle sheet erosion without the formation of rills or gullies, but topsoil with its content of biologically essential elements does creep slowly downslope. In a few cases, torrential rains or heavy snowpacks have accumulated on fire-denuded slopes and released heavy flows that have produced gullies and moved sediments into stream channels and even into the lake itself. Field obser- vations made while conducting this study suggest that such erosional events in connection with wildfires are not com- mon even along the Sierra front. Of 12 historic wildfire sites examined by a member of the committee, K. T. Harper, only one showed any evidence of significant soil loss from surface runoff. At that site, organic matter in the surface 15 cm of soil was only about 20 percent less than that of adjacent areas that were unaffected by fire. It would thus appear that upland fires produce few ero- sional events that would significantly affect Mono Lake chemistry directly. Another adverse effect of fire on steep, wooded slopes along the Sierra face is enhanced frequency of snow ava- lanches. In some situations, fires appear to have opened avalanche tracks that have not fully healed in a century. Avalanches are not only hazardous to humans, but they also redistribute natural precipitation and alter local runoff of surface water. While fire is not a serious threat to vegetation near the lake, there are other areas within the Mono Basin where fire could damage the ecosystem. These areas include the lower hills covered by mature sage and bitterbrush stands,

132 The Mono Basin Ecosystem the Jeffrey pine forests on the sides of the Mono Craters and other volcanic soils, and the steep slopes west of Mono Lake covered with pinyon pine, juniper, and mountain mahogany. The coniferous forests are vulnerable to partic- ular sequences of events such as long periods of hot, dry weather followed by thunderstorms with much lightning and little rain. Lightning fires followed by gale-force winds can. spread ground fires to tree canopies. Such fires are extremely difficult to control in steep terrain. Recovery from such fires may require many years because of slow vegetation growth rates and rapid snowmelt and runoff. Volcanic Activity and Ashfalls Ashfalls from volcanic activity have influenced the Mono Basin throughout its history. The oldest known ash- fall event occurred about 700,000 years ago. The Aeolian Buttes in the southern portion of the basin are a weath- ered remnant of that ash deposit. The tan-colored buttes are formed from a welded ash known as Bishop Tuff. This welded ashfall forms a bed some 300 ft thick at a depth of between 1300 and 1600 ft below the surface in a deep well on Paoha Island (Gilbert et al., 1968~. The bed appears to be about 500 ft thick in the well at Cain Ranch (Putnam, 1950~. The Bishop Tuff eruption was far more massive than any known in historic time and spread a recognizable ash layer over much of western North America. Approxi- mately 125 mi3 of solids were expelled in the event. For contrast, about 1 mi3 of material was displaced in the 1980 eruption of the Mount St. Helens in Oregon. Other major rhyolitic eruptions occurred at various lo- cations over the Long Valley Caldera (from which the Bishop Tuff had been expelled) about 500,000, 300,000, and 100,000 years ago. Each of those events produced ashfalls in the Mono Basin, some 30 mi to the north (Miller et al., 1982~. The first of many eruptions along the Mono Crater fracture line occurred approximately 40,000 years ago. About 30 separate domes occur along the north-south axis of the Mono Craters, with the domes becoming progres- sively younger from south to north. Rhyolitic plugs, cin- ders, and ash are associated with each eruption. Wood

Shoreline and Upland Systems 133 (1977) suggested that the volume of material ejected per unit time has increased substantially in the last 10,000 years. During the past 2,000 years, eruptions have oc- curred every 200 to 300 years (Sarna-Wojcicki et al., 1983~. The most recent cinder cone along the Mono Craters frac- ture is Panum Crater, which is only about 625 years old. A more recent upwelling of magma appears to have ele- vated Paoha Island above water level less than 220 years ago. Although several ash vents spread ash and ejected pumice blocks at the time Paoha Island emerged from the lake, the island itself is composed primarily of lake sedi- ments (S. Stine, University of California, Berkeley, personal communication, 1986~. The Mono Craters and their associated beige-colored ashes are chemically uniform throughout. Black Point, in contrast, is basaltic in nature, as are the deep, black ash deposits that occur around that outcrop (Lajole, 1968~. From ~ to 20 ft of basaltic ash accumulated about 13,300 years ago around what is known today as Black Point. The volcanic plug at Black Point is about 13,500 years old (Lajoie, 1968~. The foregoing volcanic events have lain down dozens of ash layers that lend a distinctively banded aspect to cross sections of sediments underlying Mono Lake. In the Wilson Creek formation alone, 19 separate ash layers occur. The layers range in thickness from a fraction of a millimeter to over 10 cm (Lajoie, 1968~. That unique sequence of ash layers has proven to be an invaluable tool for geologists attempting to decipher the history of Mono Lake and its prehistoric antecedent, Lake Russell. The deep ash layers that occur locally on the national scenic area have left an indelible stamp on contemporary soils and vegetation. The larger prehistoric ashfalls and pumice block ejection events must also have had important if not profound impacts on chemical, physical, and biolog- ical characteristics of Mono Lake. As suggested elsewhere in this report, ashfalls may have eliminated fish from pre- historic Mono Basin. The possibility exists that other forms of life were also periodically eliminated by volcanic events in the basin, but events such as these must remain speculative until concrete fossil evidence becomes available. Certainly the record of prior volcanic activity strongly

134 The Mono Basin Ecosystem supports the idea that similar events can be expected again in the Mono Basin. Earthquakes Strong earthquakes in Mono County occurred on May 25, 1980, and July 20-21, 1986 (Kahle et al., 1986; Kerr, 1985, 1986~. Long-range planning for the Mono Basin Sce- nic Area and other projects in the area cannot ignore the probability of other major earthquakes within the next few decades. The recent seismic activity and related phenom- ena in Long Valley have been studied by several investi- gators (Kerr, 1985, Williams, 1985; Linker et al., 1986~. Historic Land Use Knowledge of early human activities in Mono Basin and archaeological research in the region are summarized and discussed by Aikens (1983~. Farquhar (1965) provides an informative account of the history of the Sierra Nevada, while Calhoun (1984) reports on many events of historical and environmental interest in the Mono Basin. Intensive use of the Mono Basin by nonnative peoples began in the 1 850s with activity focusing on explorations for gold and later development of mine properties. Mining activities demanded transportation, lumber, and food. The town of Lee Vining was one of several communities to sup- ply such demands of the mining industry in the 1 850s. Lumber mills were built on several of the streams that terminate in Mono Lake. In addition, large flocks of sheep and some cattle were grazed in the area in the late 1 800s. Ultimately almost 50,000 acres of farm and associated irri- gated pastureland were fenced around the margins of the lake. Although the level of mining activity in the region around Lee Vining was reduced substantially by the crash of the stock market in 1881, the agricultural industry sur- vived. By 1905, the Southern Sierra Power Company was in existence and acquiring water rights in the Mono Basin for power generation. By 1920 most of the rights to water

Shoreline and Upland Systems 135 from Rush and Lee Vining creeks were controlled by either the Southern Sierra Power Company or the Cain Irrigation Company (LADWP, 1984~. In 1923, the City of Los Angeles filed claims on surface waters from several streams tributary to Mono Lake, to supplement waters already being exported from Owens Val- ley to the south. Claims were filed for surplus waters from Mill, Lee Vining, Walker, Parker, and Rush creeks. In 1930, the citizens of Los Angeles approved a $30 million bond to fund acquisition of water rights on the east slope of the Sierra and construct the Mono Basin-Long Valley water storage facilities. At this time Los Angeles purchased the water rights held by the Southern Sierra Power Company, the Cain Irrigation Company, and several smaller owners. Later in the 1930s, the federal government withdrew all public lands in the Mono Basin from entry in an apparent attempt to protect the water rights held by the City of Los Angeles. In 1940, California issued permits to Los Angeles to continuously divert up to 200 cubic feet/second (cfs) of water from the Mono Basin and to store 93,540 acre-ft/yr there (LADWP, 1984~. This diversion was to be made through the first aqueduct constructed as part of the Mono Basin project. Construction on that aqueduct had begun in 1934 and was completed in 1941. In 1963, Los Angeles began construction of a second aqueduct capable of trans- porting 210 cfs, with 70 cfs of the water to come from Mono Lake tributaries. The second aqueduct was completed in 1970. In 1984, an average of 138 cfs (about 100,000 acre-ft/yr) were continuously exported from the Mono Basin via the aqueduct system. Since 1974, Los Angeles has held a California state license for diversion of as much as 167,800 acre-ft/yr of water from the Mono Basin (LADWP, 1984~. Los Angeles annually leases about 13,000 acres of un- irrigated rangeland in the Mono Basin to private stockmen. An additional 2,000 acres of irrigated pastureland adjacent to Mono Lake are owned by the city and are leased to private operators each year. The city supplies about 8,700 acre-ft/yr of water for irrigation of leased pastures. Currently the Inyo National Forest manages the federal lands within the Mono Basin National Scenic Area. It

136 The Mono Basin Ecosystem issues grazing permits to private operators who graze either sheep or cattle on the public lands of the scenic area. Most of the grazing rights are exercised during late spring to early fall. Grazing Cattle have been in the Mono Basin since the 1 850s. Large ranches have been major components of the Mono County economy since the early days of settlement; several are still present in the scenic area. The impacts of grazing by domestic sheep and cattle are probably the most widespread of any related to European people. In the national scenic area the impacts of grazers were concentrated first on the natural wet meadows along the western margins of the lake. As early as 1881, Israel Russell, a pioneer interpreter of the geologic history of Mono Lake, concluded that the wet meadows had been "nearly ruined" by domestic grazers. It is also apparent today that much of the vegetated land between the Pole Line Road and the north shore of the lake has been heavi- ly affected by grazing. Shrub cover has been reduced sig- nificantly near areas where fresh water accumulates at the surface, and perennial herbaceous growth is cropped so closely that both escape and nesting cover for wildlife are severely reduced. Annual plants alien to the region now flourish in this portion of the scenic area. Some (e.g., Davis and Gaines, 1987) have suggested that bunchgrasses and various perennial herbs once filled the interspaces between shrubs throughout the sagebrush zone of the scenic area. This does appear true in the sagebrush zone along the west end of the scenic area, where morainal and alluvial soils are derived from granite and a scattering of metasedimentary parent materials. On the pumice plains to the south of the lake, however, few bunchgrasses or perennial herbs of consequence are apparent in the sage- brush zone unless local conditions result in greater annual precipitation or surface availability of good-quality ground- water. Considering the minimal amounts of calcium and magnesium in the pumice soils and the known inefficiency of grasses in acquiring those ions in competition with

Shoreline and Upland Systems 137 dicotyledonous plants (Woodward et al., 1984), it seems likely that bunchgrasses, at least, have never been impor- tant on these sites. It is also known that perennial fortes (herbaceous dicots) perform poorly on perennially dry and nutrient-impoverished microsites in the sagebrush zone (Harper and Harper, 1973~. Given the low average annual precipitation received by these sites and the nutritionally deficient soils, it is unlikely that perennial fortes ever made a major contribution on the pumice plains. Roads The most-traveled paved roads in the Mono Basin are U.S. 395 just west of Mono Lake, Route 120 over Tioga Pass, which passes near the Mono Craters, and the Pole Line Road to Hawthorne. There are many dirt roads in the basin, most of which are used mainly for exploration and recreation. Among the problems that must be confronted by managers of the scenic area is the dust raised by vehi- cles using these unpaved roads and the increasing invasion of roadless areas by off-road or all-terrain vehicles. Such traffic also disturbs deer and other wildlife. Closing some of the unpaved roads to traffic would probably be in the best interests of both wildlife and soil stability. Certainly such closures would simplify management. Other roads in the area should remain open to the public, but they are vulnerable to drifting sand or snow and would require regular parroting to ensure safety of travelers. Some dirt roads should be paved, and others should be designated for foot travel only. Mining From the early days of the settlement of the Mono Basin by nonnative Americans, mining has been a major economic activity. The ghost town of Bodie, now a Cali- fornia state park, was once a temporary home to several thousand. miners. Similarly, Aurora, Lundy, and. other areas in the region were once active mining complexes. Roads leading to these mountain sites and scars of the mining

138 The Mono Basin Ecosystem excavations are visible from Mono Lake and nearby areas. Mining activity is much less prominent now, the principal operation in the scenic area being the pumice excavation at the Mono Craters. Nevertheless, mining interests remain active. A particular problem is the habit, not easily con- trolled, of some mining companies to explore and prospect terrain by bulldozer. Such actions damage plant, archaeo- logical, and scenic resources. Logging Demands for mine timbers, ranch fencing, lumber for homes, and fuel for warmth created another and equally important enterprise, the timber industry. Hundreds of acres of Jeffrey pines were harvested for lumber, while pinyon pines and junipers were used for fence costs and firewood. Lumber mills were established on most of rho creeks within the Jeffrev nine fit ~ . . . Local place names, such as Mill Creek and Mono Mills, are reminders of that history. Railroads were built to carry the wood to Bridge- port, Bodie, and other towns. As a consequence of this enterprise, most of the present conifer forest consists of second growth or younger trees. The timber industry is still active. In the proposed forest plan for the Inyo National Forest, several large areas are designated for timber harvesting. The cutting of dead and downed trees for firewood an. ~ nrnbl~m for . the scenic area. This practice, often carried out illegally . In remote areas where wood-cutting is prohibited, is a threat to wildlife habitat, relict trees, and scenic resources. Curtailment of the use of local wood for camp fires within the scenic area and in adjoining wilderness areas should be considered. Recreation The fastest growing component of the economy of the eastern Sierra is recreation. The town of Mammoth Lakes has grown rapidly during the past 30 years as a result of

Shoreline and Upland Systems 139 the popularity of skiing in winter and fishing, hiking, and other vacation activities in summer. Mono Basin is north of the traffic that brings skiers and fishing enthusiasts from southern California to Mammoth Mountain and Crow- ley Lake, but it is a secondary destination for many of those visitors as well as travelers from Yosemite via Tioga Pass. Plans for the scenic area should include provisions for diverse recreational interests including fishing, boating, hiking, camping, photography, cross-country skiing, and bird and wildlife watching. Some areas should be preserved where such activities could be enjoyed without the intru- sion of motorized vehicles. BIOTIC COMPONENTS Vegetation In the following sections, shoreline vegetation and ri- parian vegetation are discussed separately. In this report, the term riparian vegetation is used to mean vegetation that occurs along streams. Each discussion includes a des- cription of the vegetation and the major environmental factors that influence it. A brief description of the upland vegetation is provided, although this vegetation is unlikely to be affected by changes in lake level. Shoreline Vegetation Description of Vegetation Types. the land exposed as Mono Lake mosaic of herbaceous and shrub communities (Figure 5.31. The patchiness has resulted from a complex array of very localized environmental conditions. The controlling vari- and available moisture Vegetation established on has receded is a patchy ables are primarily soil salinity (Bolen, 1964~. These variables, in turn, are a consequence of amount of precipitation, water table depth, spring flow, and salt deposition from the lake. The presence of vegeta- tion around springs and areas with shallow water tables is readily seen in a Landsat near-infrared photograph (see back cover).

140  tg'(. r..;` ,\~Isi { .:- ~ to of. .~ ~ The Mono Basin Ecosystem

SAore~e ~~d ~/~d S>~'e~~ 141 FIGURE S.] Vege1atlon map of the hlstorlca1 shorelands of Mono Lake. Prepared from 1982 aerla1 photos (summer sod ~ 1~\

142 The Mono Basin Ecosystem There have been few studies of the shoreline vegetation of Mono Lake. In 1982 a vegetation map (Figure 5.3) was made from infared photographs. In 1976 a team of scien- tists sampled a series of transects selected to represent both typical and unique shoreline phenomena at various locations around the lake using the Braun-Blanquet releve method (Burch et al., 1977~. For example, some transects passed through springs that had been exposed by the re- ceding lake, while others extended across broad expanses of barren, saline exposed lake bed and the vegetated strand and ultimately terminated in an upland shrub community. Except for the rabbi/brush-dominated communities occurring on the raised terraces of the alluvial fans of Lee Vining and Rush creeks, the transects represent most gradients occurring around the lake. Transect samples were taken in 1976 when lake level was at approximately 6378 ft above sea level. After 1976, the lake dropped to approximately 6372 ft. but more re- cently it has risen to 6380 ft (November 1986) as unusually heavy runoff has supplied more water than could be trans- ported or stored in water management reservoirs. Rising water has inundated some areas sampled by Burch et al. (1977~. Vorster (1985), in a discussion of the water balance of a, vegetation (plants with roots to the groundwater table) since 1940 and sampled four transects at representative locations along the shoreline of the lake. He showed that between the years 1940 and 197S, phreatophyte communities along the lake- shore increased from 170 acres to 1360 acres. Short-term increases from 1978 to 1982 were difficult to discern from aerial photographs. Phreatophyte communities included any vegetation that used shallow groundwater such as marsh areas with Scirpus and Juncus as well as dense stands of saltgrass. Data presented by Burch et al. (1977) and Vorster (1985) from shoreline transects along with information from the vegetation map (Figure 5.3) can be used to create repre- sentative cross sections of the topography and vegetation at points along the shoreline. The four cross sections pre- sented in Figure 5.4 are based on locations where ground- . Mono Lake. analyzed chances in nbre.ntonEvte

Shoreline and Upland Systems 143 water depth and electrical conductivity (EC) were measured in 1986 (see chapter 2~. These cross sections do not rep- resent actual vegetation gradients but are representative of existing vegetational gradients that demonstrate the relationship of vegetation types to the lake edge, topogra- phy, and groundwater. At least seven types of associated vegetation occur on Mann Lake shorelines and ad iacent upland areas. These - · · · , ~ . . types, as used in the cross sections, are described below and are based on personal observations and descriptions, with modifications, from Burch et al. (1977~. These vegeta- tional associations correspond well with Vorster's (1985) plant assemblages and assemblages used on the vegetation map (Figure 5.3~. . . ~ . ~ Wet Marsh: Water table at surface from nonlake sources, lush herbaceous growth of Scirpus americanus, Scirpus nevadensis, Hordeum jubatum, Ranunculus cymba- laria, Mimulus guttatus, Epilobium adenocaulon, Muhienber- gia asperifolia, Polypogon spp., and other species. Transition Marsh/Dry: Transition areas between marshy and dry environments, soil moisture variable, transition grades either from dry lake sediments upslope into marsh or marsh upslope into drier conditions. Primarily herba- ceous growth with variable density from sparse to lush. Herbaceous species include representatives from both marsh and dry habitats. Alkaline Herbs: Areas with alkaline crusted soils or mud with generally low moisture availability. Vegetation characterized by herbaceous plants such as CleomeZ/a par- viflora, Bassia hyssopifolia, Puccinellia airoides, Scirpus spp., and Distichlis spicata often occurs. Wet Shrub: Moist areas with a dense herbaceous cover but with more than 5 percent shrub cover. Common her- baceous species < include Scirpus nevadlensis, Scirpus amer~canus, Distichlis spicata, and Juncus effuses, while shrubs include Sarcobatus vermiculatus and Salix exigua but not in association.

144 6440 6430 6420 6410 Ul 6390 6380 6370 6440 6430 6420 z 6410 LU 6390 6380 6370 The Mono Basin Ecosystem NAW BEACH a V -3 at_ - - - (2000) (39s0) 200 0 200 400 600 booty , . , . , . , . . . . 800 1000 1200 1400 1600 1800 HORIZONTAL DISTANCE (if) OLD MARINA - b 2 u, I I ~ _~) 720) ~ '' (510 V ~' (980 100 0 100 200 300 400 500 HORIZONTAL DISTANCE (if) FIGURE 5.4 Profiles of vegetation types relative to shore- line topography, water table, and soil water electrical con- ductivity (EC) near four representative locations at Mono Lake. Lake level (v) is at elevation 6380 ft. Ground sur-

Shoreline and Upland Systems 145 COUNTY PARK / 6450 g C 6440 6430 r 6420 he o J MU 6410 6400 6390 6380 at' ~(372) ~sa) ~G%/ it// ,2) (50) 6370 , I, I, ',,, I . I .,, I . I . I ., 400 200 0 200 400 600 800 1000 1200 1400 1600 1800 HORIZONTAL DISTANCE (lo) TEN MILE ROAD 6450 6440 6430 6420 6410 6400 6390 6380 6370 d 400 0 400 800 Cur / I Width olSoopage Face I 1 1~(23,500) ': I (6,500) ~ 1 (7,000) v ~ 1 (l7~5oo) (291500) (28,300) ( ' ) I ~ I 1 1 1200 1600 2000 2400 2800 3200 3600 HORIZONTAL DISTANCE (if) face is a solid line, water table is a dashed line, and soil water EC (pmhos) at piezometers (vertical lines) is given in parentheses. Groundwater data are from fall 1986. Vegetation types are described in the text.

146 The Mono Basin Ecosystem Dry Open: Dry areas with no shrubs and generally very sparse herbaceous cover. Soils are usually well drained and sometimes saline. They typically support Salsola pestifera, Psathyrotes annua, Bassia hyssopifolia, and Distichlis spi- cata. Transition Dry/Shrub: Transition area from dry non- shrub areas into dry shrub areas with shrub cover of 1 to 5 percent. Herbaceous species are those found in the dry open vegetation type, while shrub species are those found in the dry scrub type. Dry Scrub: Generally upland vegetation with Shrub cover greater than 5 percent and typically a sparse her- baceous layer. Common shrubs range from Chrysothamnus spp. nearer the lake to Artemisia tridentata, Purshia tri- dentata, and Prunus andersonii in older (>30 years) stands of upland vegetation. A brief discussion of each of the four transects both gives a picture of the different gradients from lake to up- land around the lake and helps make possible predictions about how shoreline vegetation will change with fluctua- tions in lake level. Transect 1 (Figure 5.4a) is located near Navy Beach. Little or no vegetation occurs immediately adjacent to the shoreline. Above this is a marsh area with Carex, Juncus, and Scirpus. This grades into a sparse stand of saltgrass (Distichlis spicata). Saltgrass increases in density away from the lake. This saline grassland eventually grades into scattered rabbitbrush (Chrysothamnus nauseosus) and greasewood (Sarcobatus vermiculatus). Near the original shoreline of the 1 940s, rabbitbrush and big sagebrush (Artemisia trid~entata) grow in mixed stands to within a few thousand feet of the lake, but rabbitbrush is replaced by bitterbrush (Purshia tridentata) in the upland dry scrub association. Transect 2 (Figure 5.4b) is on the southwest edge of the lake near the O1d Marina. Here marshy vegetation grows near the lakeshore. Bulrush (Scirpus nevadensis), Chenopodfium fremontii, Ranunculus cymbalaria, and foxtail barley (Hord~eum jubatum) are major constituents of the

Shoreline and Upland Systems 147 cover. This vegetation type grades into an alkaline herbs type dominated by saltgrass and smother-weed (Bassia · · ~ . ~ ~ _~ _ _ ~ 1_ _ hyssopifolia) on its upper cage. Anove tnls area, wnere one microenvironment is drier, rush and saltgrass are predom- inant. At still higher elevations, the vegetation is very sparse in the area where the shoreline rises rapidly. There the vegetation is a transition into upland dry scrub. %, · . ~ . — Transect 3 (Figure 5.4c) is at the northwestern corner of the lake near County Park on a steep shoreline. Vege- tation near the lake is wet marsh, dominated primarily by scirDus species. Above this. where the groundwater is still ~ rid ~~ 7 . ~ ~ . · ~ . . ~ ~ ~ . near the surface, a wet snrun community, won arroyo w~- low as the dominant and rush, muhly grass and bulrush as herbaceous components, occurs. This vegetation grades into an upland dry scrub community with bitterbrush, Prunus andersonii, and big sagebrush as dominants. Transect 4 (Figure 5.4d) is located on the northeastern shore of the lake near Ten Mile Road and crosses an ex- tensive, barren, salt-encrusted shoreline. Except for a few scattered plants, the first 3000 ft of shoreline is barren. The water table in this area is near the surface but is too saline to support vegetation. Above this level near the old shoreline (>6418 ft elevation) the terrain is irregular and the water table becomes deeper. The vegetation closest to the barren shoreline is primarily saltgrass, but rapidly grades into dry scrub characterized by rabbitbrush and big sagebrush. Depending on microenvironmental conditions, the dominant species in the upland area are big sagebrush, rabbitbrush or saltgrass, or a combination of these. Several general vegetation patterns emerge from analysis of the vegetational cross sections and shoreline studies. For a lake level of approximately 6380 ft. the first ~ to 10 ft above lake level are generally barren. Above this barren area, stands of saltgrass of variable density occur unless the surface is moistened by spring flow or freshwater seep- age. If there is a freshwater source, marshy vegetation develops near the lake. Such cover is usually dominated by rush species. Wet areas well removed from the lake often · - . ~ ~ · ^~ ~ . ~ ~ support arroyo willow and are classl~leo as wet snrun vege- tation. Edges of the marshy areas are transitional to dry open vegetation, where saltgrass and rush are codominants. Twenty to thirty vertical feet above the shoreline, dry

148 The Mono Basin Ecosystem scrub vegetation appears. Generally the dry scrub nearer the lake is characterized by rabbitbrush species. Above this, near or above the 1940s shoreline (about 6418 ft), big sagebrush is initially the characteristic shrub. In older stands and in stands on more fertile sites, Prunus ander- sonii or bitterbrush may invade and become codominants with big sagebrush. Successional studies on a beach between Black Point and Negit Island on black lava sands show similar patterns (Brotherson and Rushforth, 1985~. Above the barren shore- line, three vegetational zones were identified. The zone closest to the lake was an annual plant zone, the next a transition zone being invaded by saltgrass, and the third an area with developed saltgrass vegetation. Brotherson and Rushforth showed that saltgrass established at random points on the beach and then expanded by rhizomes. They suggested that the vegetational differences were due to rates of invasion rather than soil differences in this area. Rather, soil differences may be due to the presence of saltgrass because saltgrass glands secrete salts and inten- sify surface salinity of soils where it grows (Hansen et al., 1976~. The major difference in soil in the three zones was greater concentration of soluble salts in soils of the salt- grass zone. The annual plant zone was dominated by Psathyrotes annua and Mentzelia torreyi, while saltgrass was the primary species in its zone. Environmental Factors Inf luencing Shoreline Vegetation. Environmental factors influencing the growth and distribu- tion of plants are extensive and varied. However, studies in the Great Basin have shown that water availability and soil characteristics may play a more significant role than other factors (Bolen, 1964~. Water Availability: The invasion of exposed shoreline by vegetation is often dependent on the availability of fresh water from springs or shallow groundwater. Where springs occur, marsh vegetation may develop, even near the lake where soils would normally be barren and salt- encrusted. This is demonstrated, for example, at County Park (Figure 5.4c), where springs occur near the lake, and

Shoreline and Upland Systems 149 at Warm Springs, where they are well removed from the shoreline (see Table 2.2 and Figure 5.3~. Extensive areas of shallow groundwater may also foster development of marshy vegetation, although weak flows may result in sparse cover. This type of marsh develop- ment extending across thousands of feet of shoreline oc- curs at Simon's Spring, which follows a geological fault from the upland out into the lake (see Table 2.2 and Figure 5.3~. If fresh water is not available for vegetation establish- ment in areas exposed by the receding lake, either the newly exposed shore remains barren, a common situation near current lake edges, or a vegetation generally charac- terized by saltgrass develops. Saltgrass is usually an indi- cator of saline conditions rather than of low water availa- bility. As noted above, higher salinity at saltgrass sites may be a result of the plant's ability to exude salts and thus may not be reflective of initial soil conditions (Hansen et al., 1976~. Soils: Soil conditions along vegetational transects show a general gradient from high pH soils (often >9) near the lake to lower pH values on older exposed or upland areas (Burch et al., 1977~. Concurrent with this gradient is- a general decrease in soil electrical conductivity (EC), an indicator of soluble salts. These patterns do not always hold true, however. In areas with freshwater springs, soil pH may drop below S. Areas that may catch windblown soil particles, as on Paoha Island or along the northeastern shoreline (Transect 4, Figure 5.40), tend to have higher pH and EC values than more sheltered areas such as the western shorelines of the lake. Burch et al. (1977) reported a general relationship be- tween soil pH and conductivity, and vegetation type. The upland dry scrub vegetation is generally found on soils with the lowest pH and EC observed in the area; dry open, wet marsh, and wet shrub associations have intermediate values; while transition marsh/dry and alkaline herbs asso- ciations tend to occur on soils of higher pH and EC. However, local conditions may strongly influence soil chemistry.

150 The Mono Basin Ecosystem Riparian Vegetation Description o f Vegetation Types. .~ ~ ~ ~ e ~ Rinarian vegetation in the Mono Basin is representative of streamside communities along much of the eastern Sierra Nevada above 1800 m. Taylor (1982) describes nine riparian communities typical of the 1500- to 2800-m elevational zone in the eastern Sierra. Eight of these communities found in the Rush and Lee Vi- ning creek drainages are briefly described below. Betula occid~entalis-Salix [asiolepis: This community of small trees and shrubs constitutes one of the most preva- lent of the mid-elevation habitat types of the region. It is best developed between 1200 and 2200 m and is mainly confined to streams with lower flow rates. Mean canonv height is about ~ m. rare in this vegetation. trichocarpa individuals or clones may be present. This habitat type grades , · . . . · . Conifers and tall deciduous trees are A few Pinus jeffreyi and Populus or clones may be present. into the Pinus jeffreyi-Populus r~cnocarpa type at its upper elevational limits and into the Salix laevigata-Elymus triticoides type at its lower eleva- tional limit. A typical stand of this vegetation may include Salix rigida and S. exigua, Rosa woodsii, Rhamnus califor- nica, and herbaceous species of such genera as Juncus, Carex, Mubltenbergia, Poa, Solidfago, Aster, and Mimulus. Pinus jeffreyi-Populus trichocarpa: This association creates one of the more important riparian habitat types of the eastern Sierra Nevada. This type is found on most of the larger streams in the region. The two dominant spe- cies are usually of about equal importance in the stands. -' 50 m in height and 2 m in diameter. In two dominant species, Populus tremuloidles, l rees can reach addition to the Pinus contorta, Abies concolor, and Juniperus occid~entalis are frequent. This habitat type grades into Pinus contorta-Populus tremutoid~es vegetation above about 2200-m elevation mostly along low-gradient sections of streams in glacial valleys (e.g., Lee Vining Creek) where soils are well drained. Shrubs that may occur in this vegetation type in- clude species of Rosa, Cornus, Sambucus, Prunus, and Amelanchier. Herbaceous genera may include Juncus, ~ . _ -

Shoreline and Upland Systems 151 Agrostis, Carex, EZymus, Poa, Solidago, Epilobium, Aster, and others. Pinus contorta-Populus trichocarpa: This type is the high-elevation equivalent (above 2200 m) of Pinus jeffreyi- Populus trichocarpa vegetation. It lacks some lower- elevation species such as Betula occidentalis. Higher- elevation herbaceous species such as Aquilegia formosa and Lupinus pratensis serve to distinguish this type from the lower-elevation type. This type is typically found along Rush Creek above Grant Lake Reservoir. Populus tremuloides-Carex lanuginosa: This association is common at mid-elevation along the eastern Sierra Pnn~lu.c ~r~muloides-Carex lanucinosa: . streams. Although P. tremuloides is not exclusively a ripa- rian species above 2500 m, it is often the riparian domi- nant. This type, with a canopy of about 15 m, is usually found where there is seepage along the water course. It is one of the most species-rich riparian types along the east- ern Sierra. This type can be seen in the glacial valley along Lee Vining Creek at 2200 m. Carex praegracitis- Juncus baZticus: This habitat type occurs in outwash meadows along low grade streams. It is dominated by graminoids and is species-rich. It, like the preceding type, is common along Lee Vining Creek at 2200 m. Abies concolor-Populus trichocarpa: This association type is infrequent but not unimportant as riparian vegeta- tion. It occurs along steep grade streams above 2200 m. Both dominant species function as facultative riparian spe- cies within this elevation zone. Pinus contorta may also occur within this type. Salix rigida-Salix [asiandra: This type is most common nl~no ~tream.s ahove 2200 m with low flow rates. It is more species-rich than its lower elevation counterpart, Salix exigua- Juncus balticus. Typical stands occur as narrow bands of willows traversing shrub-steppe desert. ~—~——45 v ~^ _~^v ~ ~

152 The Mono Basin Ecosystem Above 2500 m, riparian plant community types dominate more area. However, at these elevations, riparian species become less obligate and more facultative as riparian and upland habitats become ecologically more similar. These riparian communities are on the outer edges of the Mono Basin and thus have little effect on the lake. Photographs taken in 1940 have been used to describe the riparian communities of various streams that fed Mono Lake prior to diversion of water by the City of Los Ange- les. The two streams most extensively surveyed (Taylor, 1982) were Lee Vining and Rush creeks. Both creeks had extensive riparian communities extending from the glaciated valleys above the points of stream diversion down to the alluvial fans at the lake's edge. The riparian vegetation along Lee Vining Creek from the area above highways 120 and 395 to an area about halfway between highway 395 and the lake was dominated by an association of quaking aspen (Populus tremuloides) and black cottonwood (P. trichocarpa). The understory shrubs of this association were Cornus stolonifera and Rosa woodsii. This vegetation type graded into the Jeffrey pine-black cottonwood (Pinus jeffreyi-Populus trichocarpa) (also quaking aspen) habitat type upstream where the creek emerges from the canyon. Quaking aspen occurred in stands from below highway 395 almost to the lake's edge. Two major associations occurred on the alluvial fan. One was the sandbar willow-wire rush (Salix exigua- Juncus balticus) type, which formed thickets. The other was a wire rush-sedge (Juncus balticus-Carex praegracilis) associ- ation, which formed meadows. The latter of these appar- ently occurred on poorly drained soils. Irrigation canals have also developed riparian strand vegetation. These strands include representatives of var- ious riparian communities, ranging from quaking aspen stands to rush meadows. Photographs taken of Rush Creek below Grant Lake Reservoir in 1940 show riparian vegetation to be as well developed as along Lee Vining Creek. The range of ripa- rian vegetation types was also as variable as on Lee Vining Creek, with extensive stands of black cottonwood and quaking aspen along the channel and willow thickets along the streams just above the alluvial fan.

Shoreline and Upland Systems 153 Photographs taken in 1954 show a great reduction in the riparian communities along both Lee Vining and Rush creeks. Reduction of vegetation along Rush Creek was not as dramatic as along Lee Vining Creek. Flow in Lee Vin- ing Creek above highway 395 was reduced to a small stream, while Rush Creek continued to maintain some ripa- rian vegetation because flows equivalent to about 25 per- cent of pre-1941 volumes were released during the 1941 to 1954 period. Lateral meadows were desiccated and areas of willow thickets along the channel were greatly reduced because of reduced flows. Between the highway and the lake, a fire in the early l950s eliminated most of the woody riparian vegetation along Lee Vining Creek. The quaking aspen strand that had extended almost to the alluvial fan was destroyed. The willow thickets had also largely disappeared and only some rush meadows remained by 1954. Both Lee Vining and Rush creeks showed accelerated loss of riparian woodlands and buildup of extensive stands of dead or fallen timber during the late l950s and in the 1960s and 1970s (Taylor, 1982~. Periodic releases of water into Rush Creek in the 1970s and 1980s either maintained the remnants of the riparian community or, in some cases, stimulated recruitment and regrowth of riparian species. Thus in 1986, various reaches along Rush Creek showed a revived riparian forest or recruitment of riparian tree or shrub species onto the gravels adjacent to and in the stream channel. Populus and Salix species appear to have recovered more completely than others under these circum- stances. Taylor (1982) also studied Mill Creek because it had been diverted for hydroelectric power in 1909. Although there was reduced flow along the creek, a well-developed riparian community of quaking aspen remained. An irri- gation diversion from Mill Creek built before 1900 supported riparian communities of Jeffrey pine-black cottonwood and sandbar-Pacific willow (Salix exigua-S. lasiandra). Below highway 395, there was a declining stand of Jeffrey pine and black cottonwood, while closer to the lake riparian vegetation was mostly gone. Nearer the lake, rising groundwater has maintained a degraded stand of black cottonwood.

154 The Mono Basin Ecosystem Environmental Factors Inf luencing Riparian Vegetation. The major factors influencing riparian vegetation in Mono Basin are water availability, grazing, and fire. These fac- tors are discussed below. Water Availability: Riparian vegetation by definition occurs on the bank of a body of water, either a river or a lake. Thus, availability of water becomes the most influen- tial environmental factor controlling the establishment and survivability of the community. Water availability is, in turn, influenced by a variety of other factors, many of which are associated with valley or stream topography and/or geology. These factors include valley type and sub- strate, varying from the high mountain valleys (either V- or U-shaped with a bedrock or boulder substrate) to mid- elevation valleys (usually U-shaped and filled with till down to the alluvial fans at the foot of the mountains with sub- strates of gravels or finer fill). Stream reaches in the upper valley types tend to be gaining reaches (surface streamflow increases), while reaches crossing the alluvial fans tend to be losing reaches (surface streamflow decreases). Gaining reaches add water through surface or subsurface input, while losing reaches lose water through percolation into the substrate. Other factors influencing water availability are stream gradients ranging from steep at high elevations to shallow on alluvial fans; channel width (the width of the incised channel along which ripa- rian vegetation establishes); floodplain width (the width of the portion of the valley that is influenced by periodic flooding and available groundwater); floodplain cross sec- tion (the width of the plain and steepness and height of the channel and floodplain banks); and streamflow (the amount of surface water carried by a stream per unit time, reported as cfs (cubic feet per second) or volumes per year (e.g., acre-feet per yearly. Subsurface flow is not included in this term but may be as important. The riparian vegetation in the Mono Basin occurs along streams from the high elevations of the Sierra Nevada down to the alluvial fans where streams enter the lake. The high-elevation riparian communities are influenced by local precipitation, streamflow, and groundwater. Because precipitation in the Sierra Nevada is relatively high, many

Shoreline and Upland Systems 155 of the riparian species there function facultatively; that is, they grow both along the streams and in upland commu- ~ , ~ ~ _ _ ~ ~ ~ ~ ~ nltles. ,, little or no alluvial deposit in the channel, and a narrow cross section. Riparian vegetation is limited. At mid-elevations, for example in the valleys of Lee Vining and Rush creeks about 1000 ft above the lake, the glacial valleys are U-shapeci and have sufficient glacial till and alluvium to support extensive riparian stands. The floodplains are relatively wide, and streamflow and ground- water are adequate to maintain any established riparian · em. community. These high-elevat~on streams nave steep gradients, ~ hese areas receive so little rainfall in the summer that most riparian species are obligate. The dis- tance over which groundwater spreads from stream chan- nels and saturates the valley fill will influence the width of the riparian strand. As streams leave the mountain valleys and cross the alluvial fans along the edge of the lake, they lose water to the alluvial deposits. Should lake levels recede, there is enough substrate in such areas to allow streams to dowocut through the fill and create deep channels within which riparian vegetation can establish. Temporary or artificial diversions may cause flooding of alluvial fans beyond nor- mal stream channels and permit the establishment of new riparian thickets or meadows. Most riparian vegetation above Mono Lake but below diversions on the creeks that feed the lake is located on alluvial fans or along shallow-gradient streams that flow through deep channels across the fans. Reaches of streams in these areas are losing reaches. Because the primary source of water for the riparian vegetation in these envi- ronments comes from instream flow, flows large enough to balance losses to both evapotranspiration and percolation are required to maintain the vegetation. Inadequate flows will result in desiccation and loss of less drought-tolerant riparian species in such situations. Most riparian vegetation on the alluvial fans at Mono Lake is currently either depauperate or already dead. Di- version of the streams and resulting low flows across these losing reaches have left insufficient water to maintain a healthy riparian community. In the years since water diversions began in 1941, mortality of riparian species has

156 The Mono Basin Ecosystem been greater than recruitment (Taylor, 1982~. Thus, riparian vegetation has been reduced or eliminated along most streams below the diversion points. Recently, streamflow in Rush Creek has been maintained at a sufficient level, either through controlled releases or releases of surplus water, to encourage new recruitment or regrowth of some of the depauperate riparian stands. On the lower part of the alluvial fan, however, the combina- tion of heavy releases, depauperate riparian vegetation, and lower lake levels has caused deep downcutting. Severe channel erosion has undercut and destroyed many remnants of the riparian community and eroded alluvium where re- cruitment might otherwise have occurred. Locally, along the new channels, some recruitment of riparian species has taken place on floodplain gravels. The alluvial fan of Lee Vining Creek has not been dowocut as much as that of Rush Creek, because there have not been large, long-term releases of surplus runoff. A few riparian plants can be found in the usually dry creek channel, maintained by what must be a limited amount of subsurface flow. Grazing: Although grazing has had profound effects on riparian systems elsewhere in the semiarid West (Davis, 1982; Kauffman and Krueger, 1984), grazing damage in the riparian areas above Mono Lake cannot be easily demon- strated. Grazing does occur in the upland shrub commu- nities of the Mono Basin. Cattle and sheep would be ex- pected to have access to the basin's riparian vegetation, but two factors reduce the severity of grazing in the ripa- rian zones considered here. First, most of the riparian areas are at the west end of the lake along the streams that rise in the Sierra Nevada. Those streams flow through areas where the land use is more closely super- vised than it is in the open rangelands to the east of the lake. Some of the streams also flow through recreational or populated areas, where grazing is controlled. Second, most of the riparian vegetation below the diversion aque- duct has been eliminated or damaged by diversion of much of the flow. Because grazing animals feed on herbaceous understory plants and young woody plants that are depaup- erate, and because there has been little or no recruitment

Shoreline and Upland Systems 157 of woody riparian species, livestock are not attracted to riparian areas below the diversion points. Grazing thus appears to be less significant than water diversions as a factor affecting the vigor of riparian vegetation in the Mono Basin. Fire: Fire normally is not important in riparian systems because of the moisture in the habitat. However, in the early 1 950s a fire along Lee Vining Creek between the diversion and Mono Lake destroyed a large portion of the riparian vegetation, as discussed earlier. Because water flow in the creek was reduced at that time, recruitment of riparian species was limited and full recovery of the ripa- rian community was prevented. Regeneration and Evapotranspiration of Riparian Vegetation. The two primary riparian genera, Populus (cottonwood and aspen) and Salix (willow), have not been well studied with respect to the requirements for regeneration along streams (Strahan, 1984, Bradley and Smith, 1985~. Most studies demonstrate that both genera establish best in gravelly substrates. Populus species usually establish where high streamflows deposit the seeds, in a location that experi- ences above-normal fluctuations in streamflow and is close enough to the stream to obtain supplemental water. Mature Populus does not withstand extensive periods of inundation. Thus, Populus does not commonly occur in stream channels but rather on the edge of the floodplains or terraces. Calculations of evapotranspiration by a water consump- tive method for cottonwood (Populus spp.) in the western United States vary between 62 and 92 in./yr, with an aver- age 72 in./yr (Blaney, 1961~. This early research on water consumption was developed assuming phreatophytes were wasteful and thus the evapotranspiration may be high. However, more recent studies on evapotranspiration, for example Pallardy and Kozlowski (1981) for Populus in the Midwest, emphasize individual leaf transpiration and stoma- tal conductance and are difficult to relate to forest com- munities. If the 72 in./yr is a high estimate of water consumption by Populus, any streamflows established to

158 The Mono Basin Ecosystem satisfy this consumption should be more than sufficient for riparian vegetation maintenance. A general average evapo- transpiration for willow in the western United States is 54 in./yr (Muckel, 1966~. This means that 1 acre of cotton- wood will lose 6.0 acre-ft/yr through evapotranspiration and 1 acre of willow will lose 4.5 acre-ft/yr. Upland Vegetation Five upland communities were described by Klyver (1931) for the eastern side of the Sierra Nevada. He in- cluded alpine communities, subalpine forests, lodgepole pine forests, Jeffrey pine woodlands, and sagebrush. Kuchler (1977) mapped and described the following vegetation com- munities in the Mono Lake area: alpine communities, upper montane and subalpine forests, northern Jeffrey pine forest, juniper-pinyon woodland, and sagebrush steppe. No truly alpine communities are situated within the Mono Basin National Forest Scenic Area. Likewise, sub- alpine forests, which are often dominated by Pinus albicaulis, do not occur in large enough areas within the scenic area to show up on maps. Populus tremuloides is found in more mesic areas of the mountainous portion of the scenic area (Figure 5.5~. Jeffrey pine woodlands do occur within the scenic area, both in the west on the Sierra and along the sides of the Mono Craters. This spe- cies generally occurs in open, discontinuous stands in the area. It can be found associated with Juniperus species, Purshia tridentata, Arctostaphylos patula, Ceanothus velutinus, Artemisia tridentata subsp. vaseyana, or Populus tremuloides, depending on local environmental conditions. At higher elevations, Abies concolor and Pinus contorta become regular members of older stands. The juniper-pinyon woodland is usually characterized by Pinus monophylla and Juniperus osteosperma in the eastern portion of the Mono Basin. Artemisia tridentata and Purshia trid~entata are regular members of this association in the Bodie Hills northeast of Mono Lake and along the foothills of the Sierra Nevada west of the lake. In the latter area Juniperus osteosperma drops out of the assoc~a- tion. At higher elevations of the Sierra, Juniperus

Shoreline and UpZand Systems MONO LAKE Shorellnes Drained Largety Lak. Barren Deposits with Few weth Annuals ARTR & Distichtis PUTR CHNA (Old Burns) .~. ~ ~ ~ ~ ~ A~ ~ Marshes with Db~hUe, Scln~us ~ ~ O ~ Alluvial Shrublands Rlparlan CADO ~ l~ke with Zon. JUBA Sediment PUTR PODUIU, wth ARTR trichocarw ARTR PRAN Salix SAVE GRASS ·nd Distichtis Po~ulus trennuloldo' 159 _ - PONDS PUTR monophvil. osteosDerma Shrublands CHVI with (Denser Varlous Cover Associstes than ARTR-PUTR etc ) ~ @~ Juniperus PIJE For - t Vdm VaHe of Assoclates (Plnus leHr~l) Mono Basin National For- . . . · . . . ~ ~ W" Artemlele cereocarPus Me~ novx ledltollus wm wltn Chnmothemnus Varloue vlxidl~lome Assoclates FIGURE 5.5 Vegetation map of est Scenic Area. ARTR = Artemisia tridentata, PU IK = Purshia tridentata, CHNA = Chrysothamnus nauseosus, SAVE = Sarcobatus vermiculatus, PRAN = Prunus andersonii, GRASS = mixed grasses, CADO = Carex douglasii, JUBA = Juncus balticus, CHVI = Chrysothamnus viscidiflorus, PIJE = Pinus jeffreyi.

160 The Mono Basin Ecosystem occidentals often becomes common, occurring in associa- tions with Pinus jeffreyi and other species. The sagebrush steppe surrounds most of Mono Lake. It is dominated by Artemisia tridentata and Chrysothamnus species in the early successional stages of the type. Ulti- mately Purshia tridentata becomes codominant with sage- brush on the rhyolitic pumice soils that cover the valley floor south and southeast of the lake (Nord, 1965~. Pinus jeffreyi may form forested stringers into this association. At lower elevations, Artemisia tridentata is represented by subspecies tridentata. At higher elevations, as on the shoulders of the Mono Craters and the foothills of the Sierra Nevada, A. tridentata subsp. vaseyana prevails. The Mono Basin race of Purshia tridentata is unusually robust (up to 2 m tall) and upright in form (Nord, 1965~. The sagebrush steppe is far more floristically impover- ished on pumice soils than on glacial rubble and alluvial outwash soils derived from the granitic and metasedimen- tary rocks of the Sierra. On the western margins of Mono Basin, sagebrush steppe vegetation is enriched by a variety of shrubs and subshrubs including Eriogon?cm species, Leprodactylon pungens, Prunus andlersonii, Tetrad~ymia spe- cies, and Xanthocephalum. Associated herbaceous species also contribute much more cover on the western fringes of the basin. Common perennial herbs include Arabis species, Astragalus species, Crepis species, Oryzopsis hymenoides, Phlox [ongifolia, Sitanion hystrix, and Stipa species. Data taken in connection with this study demonstrate that the granitic soils are more fertile than the pumice soils (Table 5.2~. Vorster (1985) shows that areas adjacent to the western end of the lake also receive more precipitation than do the pumice flats south of the lake. The combined effects of greater fertility and more precipitation exert a strong influence on composition and productivity of the sagebrush steppe. Shrubs capable of tolerating both salinity and high water tables become prominent on lake sediments close to the shores of Mono Lake. Sarcobatus vermiculatus and Chrysothamnus nauseosus are the principle species in such a situation. They dominate extensive areas along the north shore of the lake (Figure 5.5) and are not uncommon along shorelines all around the lake. Saltgrass usually is repre-

Shoreline and Upland Systems 161 sensed in such communities and forms thick swards where water tables are near the surface. Artemisia tridentata subsp. tridentata is a common component of these sites where water tables rarely rise higher than 1.0 m below the surface. At sites where surface flows of water occur seasonally but later disappear completely, Carex douglasii and Juncus balticus become prominent. Abandoned irrigated fields near L ~ ~ support this association of plants as do many floodplains adjacent to the streams that flow into the lake (Figure 5.5~. the lake often Wildlife The Mono Basin supports a diverse community of terres- trial and aquatic vertebrates, many of which do not rely on the resources of Mono Lake itself. Most of these species are typical of the Sierra Nevada and Great Basin regions and are widespread. For most species, the populations in the Mono Basin represent only small segments of their re- A few species, however, deserve special attention because the Mono Basin popula- tions are an important portion of their regional popu- lations, because they are endangered, or because they are the object of recreational hunting or fishing. , ~ spect~ve regional populations. Fish In the geologic past, Mono Lake and its tributaries were connected to the large water system of the Great Basin and shared its fish fauna. As the lake level declined, the basin became isolated from the rest of the system. When European explorers reached the Mono Basin in the nineteenth century, no fish were found there (Moyle, 1976; Vestal, 1954~. This is surprising in view of the geologic and faunal history of the area. The most plausible expla- nation for the absence of fish is that they were destroyed by volcanic activity; fish bones are present in the streams in the basin beneath volcanic deposits (Moyle, 1976~. ,,

162 The Mono Basin Ecosystem Fish have been introduced into the basin since the late nineteenth century, and today the following species are present (Moyle, 1976, and personal communication, Univer- sity of California, Davis): golden trout (Salmo aguabonita), rainbow trout (S. gaird~neri), cutthroat trout (S. clarki), brown trout (S. trutta), brook trout (Salvelinus fontinalis), Owens sucker (Catostomus fumeiventris), tui chub (Gila bicolor), mosquitofish (Gambusia affinis), threespine stickle- back (Gasterosteus aculeatus), and Sacramento perch (Archoplites interruptus). Of these species, only the cut- throat trout, tui chub, and Owens sucker are native to nearby drainages on the east side of the Sierra; the rest are either west-side species or species native to the east- ern United States or Europe. Most of the species are found primarily in lakes in the basin. The principal stream species, in order of abundance, are: brown trout, rainbow trout, brook trout, and threespine stickleback. At lower elevations, the most important streams for trout fishing are Rush and Lee Vining creeks; in both streams wild brown trout are the most important contrib- utor to the fishery. In Lee Vining Creek, a small, repro- ducing brown trout population was maintained for 1 to 2 km below the diversion by leakage from the dam and sea- sonal input from Log Cabin Creek. Summer flows are typ- ically 1 to 2 cfs, but the deep pools in the channel (cre- ated at times of higher flows) provide habitat for the adult trout. Prior to the augmentation of flows in 1986, the creek dried up in summer upstream of where it crosses highway 395, causing occasional kills of trout that had colonized the dewatered areas during the winter (P. Moyle, personal communication, 1987~. Rush Creek was completely dry below the diversion until the last several years, when exceptionally heavy snowpacks put more water in the basin than could be diverted. The renewed flows down Rush Creek permitted a large, fast- growing population of brown trout to establish itself (EA Engineering, Science, and Technology, Inc., 1985), and sub- sequently court-ordered flows of 19 cfs have maintained the fish populations and fishery. It is difficult to specify minimal flows required to main- tain viable populations of trout in lower Lee Vining and lower Rush creeks. It is necessary to have sufficient

Shoreline and Upland Systems 163 continuous flows to provide the habitats needed for repro- duction, adult feeding, juvenile feeding, instream production of aquatic insects, and habitat for juveniles to escape predation. Up to some point, a greater streamflow will support a greater fish population. In addition, different species have different requirements. The Instream Flow Incremental Methodology (IFIM) model (Bovee, 1982), which relates streamflow to habitat preference of a species, and hence is both site-specific and species-specific, is widely regarded as a reliable method for estimating flow require- ments for fish species in streams like Rush and Lee Vinine ~. ~ ~ , e creeks. The IFIM model has not yet been applied to those streams (it has been applied to Lee Vining Creek above the diversion), but LADWP and the California Department of Fish and Game plan to remedy this lack in 1987 or 1988. Birds Of the over 290 species of birds recorded as visiting or using the Mono Basin (Gaines, 1986), only four that use the shoreline or upland habitats are discussed in detail in this report. Of these, three species--the bald eagle (Haliaetus leucocephalus), the peregrine falcon (Falco peregrinus), and the snowy plover (Charadrius alexana~rinus)--deserve special attention because they are included on state and federal endangered species lists. The fourth, the sage grouse (Centrocerctcs urophasianus), special management of its in the basin. is hunted and may require traditional mating-display areas Bald eagles only pass through the Mono Basin while migrating, and the small numbers and brief durations of their visits probably mean that little specific management action is required on their behalf. Similarly, peregrine falcons visit the basin irregularly and in small numbers, but this might soon change. Peregrine falcons have been rein- troduced into areas near the Mono Basin (Cede and Dague, 1987~. Therefore, if they become established as breeders, local pairs may use the basin as a hunting area. Sage grouse, which are hunted, use traditional communal display areas (leks) during their annual courtship and mating activities. While at these leks, whose location in

164 The Mono Basin Ecosystem the basin can be identified, they are sensitive to distur- bance, especially of the kind that might occur in the sce- nic area. The snowy plover population that nests at Mono Lake was first censused thoroughly in 1 97S, when 348 breeding adults were detected (Page and Stenzel, 1981~. This popu- lation accounted for 11 percent of the nesting snowy plov- ers known in California. No recent censuses of the entire population are available, but intensive work with small seg- ments of the population (e.g., Page et al., 1983) has not suggested any dramatic changes in the size of the popula- tion. The snowy plovers nest primarily on the exposed playa and pumice dunes of the lake's eastern shore. They feed on invertebrates captured at the lakeshore or around springs and seeps. Nests can be located up to 1 km from these feeding sites, and the precocial hatchlings must be led to these areas by their parents in order to feed. Pred- ation of plover chicks by California gulls seems to be the primary mortality factor affecting the population's dynam- ics. Despite these losses, Page et al. (1983) have found the adult survival and reproductive performance of Mono Lake's snowy plovers to be adequate for intrinsic popula- tion maintenance. The snowy plover population has probably benefited to some extent from recent drops in the lake level because additional areas of playa have been made available for nesting. Because we do not know if the current population is being limited by the available playa area, it is impossible to predict whether or not the population might grow in response to an expansion of the playa by further lake level drops. In any event, there is probably some point beyond which the commuting distance from nest to shoreline feed- ing areas becomes prohibitively great, so a continued ex- pansion of the width of the playa would not indefinitely expand plover habitat. On the other hand, one can predict with greater certainty that a flooding of the playa area by rising lake levels would be detrimental to the population. A complete inundation of the playa would restrict nesting plovers to the limited area of high pumice dunes. The carrying capacity of these dunes in conjunction with a flooded playa is unknown.

Shoreline and Upland Systems 165 Access to food, rather than space for nesting territo- ries, may limit the snowy plover population. If this limita- tion pertained, drops in the lake level would result in a concomitant reduction in the length of the shoreline, thus restricting feeding opportunities. A collapse of Mono Lakers invertebrate populations would affect the plover population--as it would other birds that feed on inverte- brates--but because plovers also feed around spring-fed seeps, they would probably not totally abandon the Mono Basin as a nesting site. Because none of the other shoreline or upland bird pop- ulations in the Mono Basin constitute such a large portion of their respective regional or continental populations, the committee only summarizes information of their habitat, their seasonal occurrence in the Mono Basin, their status while in the basin, their approximate population size in the basin, and how they are likely to respond to possible dis- turbances in the basin. Appendix A presents this informa- tion for the bird species known to occur in the Mono Basin (Hart and Gaines, 1983~; the committee obtained details on each species from a variety of sources, including Grinnell and Miller (1944), Small (1974), Marcot (1979), Hart and Gaines (1983), Gaines (19X6), Verner and Boss (1980~. Mammals Over 70 species of mammals have been reported from the Mono Lake-Tioga Pass region (see Appendix B) (Harris, 1982~. Many of these are restricted to the regions of higher elevation and are unlikely to be affected by deci- sions concerning the management of the scenic area. Others reside in the scenic area, but for reasons of habitat preference or lifestyle are relatively immune to changes in water levels, grazing, or fires. A few species, in particular those that depend on riparian habitats or marshy areas, are sensitive to lake levels and streamflow, while those species that compete with cattle for forage will be affected by grazing pressure and by fires (e.g., white-tailed hare, pygmy rabbit, pronghorn, and bighorn sheep).

166 The Mono Basin Ecosystem In general, there is very little information on the popu- lation sizes of any of the resident mammals. A few are known to be abundant or rare, but quantitative data are lacking for all but a very few species. Three species are endemic to the eastern Sierra region: the Inyo shrew, the Panamint kangaroo rat, and the Panamint chipmunk. Pygmy rabbits are endemic to the Great Basin. All occur in the Mono Basin. Three species of shrews found in the Mono Basin are thought to be rare: the Mt. Lyell shrew, the Inyo shrew, and the Merriam's shrew. The first two are probably dependent upon riparian habitats and wetlands. The Merriam's shrew is unusual for a shrew in that it pre- fers arid habitats, such as the dunes northeast of Mono Lake. The white-tailed hare and the pygmy rabbit are also species that make use of the scenic area and are believed to be rare. Both may be adversely affected by grazing and hunting. Riparian areas may be important for the white- tailed hare. Another species of concern, the mountain bea- ver, is dependent on access to fresh water and uses ripa- rian areas with dense brush along the west side of Mono Lake (J. Harris, Mills College, personal communication). Harris (personal communication) details several areas of importance to mammal populations. These areas include riparian and wetland habitats; Black Point, an area with an unusually high diversity of small mammals; and Mono Dunes, with the local race of dark kangaroo mouse (Microdipodops megacephalus poliontus), the rare Merriam's shrew, and the Ord's and Panamint kangaroo rats. The dunes are fragile ecological islands, and excessive grazing on these areas may well damage these habitats. The ripa- rian zones provide important habitats for many species and corridors for exchange and movement of mammalian popula- tions between the Sierra and Mono Lake. LAND-AIR INTERFACE Environmental Factors Controlling Wind Storms The interaction between the atmosphere and the land surface has been discussed from different viewpoints in preceding sections of this report. Thus in this section,

Shoreline and Upland Systems those discussions will not be repeated. additional aspects are discussed briefly below 167 Instead, a few Mountain waves as shown in Figure 5.6 (Holmboe and Klieforth, 1957) ' -I ~ ~ --~-- Pacific frontal storms. The surface winds are locally strong and are capable of carrying dust, smoke, and other fine particulates as high as 16,000 ft into the atmosphere. They are also capable of transporting sand, salts, other coarse sediments, and loose vegetation such as tumbleweeds and concentrating them in areas where surface winds de- crease in speed or converge in direction. arc c,nmmr~n in advance of anoroacnln~ l he common diurnal wind pattern in the summer begins with an easterly, upslope breeze in the morning in response to solar heating and convection along the eastern escarp- ment of the Sierra. During the afternoon, the wind shifts to westerly in response to solar heating of the mountain ranges east of Mono Lake, and probably also to a larger scale diurnal pattern involving the Sierra and the western Great Basin. This diurnal pattern prevails when the synop- tic flow aloft {from 10~000 to 20,000 ft above sea level) is Surface winds associated with this pattern are light to moderate and are not responsible for dust storms or transport of larger particulates. During episodes of convective cloud development and thunderstorm activity, the diurnal pattern is magnified, leading to the commonly observed sequence shown in Fig- ure 5.7 (from Powell and Klieforth, in press). In this pat- tern there are strong local downbursts, which frequently cause blowing sand and dust locally and may damage vege- tation and structures. In a recent report, Cahill and Gill (1987) presented the results of a computer model of air quality in the vicinity of Mono Lake in which they predicted the frequency and intensity of particulate levels near Mono Lake for various lake levels and wind velocities. Their model does not appear to consider variations in air mass thermal stability and wind shear, nor does it recognize mesoscale phenomena and diurnal wind patterns. Nevertheless their results are useful for some considerations of air quality. Another recent report by Saint-Amand et al. (1986) sum- marized the results of over 10 years of field studies of dust storms from Owens and Mono valleys. They pointed ~ , weak and from the Pacific

168 25 20 g 15 a 10 The Mono Basin Ecosystem 35 . MILES 33- 400 700 850 FIGURE 5.6 Vertical cross section of Sierra lee wave showing air flow pattern and cloud forms (Holmboe and Klieforth, 1957~. Out that the worst dust storms in Owens Valley were associated with northerly winds aligned with the axis of the valley (parallel to the Sierra), and that such storms transport significant quantities of dust for over 100 mi. In both Owens and Mono basins, strong southerly winds also cause major dust storms. Saint-Amand et al. describe dif- ferences between dust episodes in the two basins and dis- cuss possible treatments to alleviate dust problems. Consequences of Wind Storms Most of the content of the windborne material is inor- ganic particulates of geologic origin--sand, salts, and other compounds. These materials when airborne affect visibility and air quality. Larger particulates transported along or

Shoreline and UplandF Systems EARLY MORNING ( 4~r Lightning ~ (~9~.'r A EARLY TO MID-AFTERNOON (W or E) 169 _ ·: MID-MORNING _ (Over Mountalns) LATE MORNING _. ~. ~ --; ~~ - h - ~~—~~ ~g <~ ~ `~ Dark ~ Acre—. .~- Ace.. ~~ ~ (~- LATE AFTERNOON OR EARLY EVENING (E) EVENING (E) FIGURE 5.7 Typical diurnal sequence of cloud development and precipitation during summer monsoon season (Powell and Kileforth, in press). near the surface of the ground affect vegetation, tufa for- mations, wildlife, and human activities. The reports by Cahill and Gill (1987) and Saint-Amand et al. (1986) discuss the composition of airborne particulates and their relation to human respiratory problems. The stabilization of sand dunes, playas, exposed lands, and other erosion-prone ter- rain has been addressed recently by various groups with consideration of experimental plantings, placement of drift fences, and other treatment. Much more research is needed on all of these problems. It should be noted that the dust problems of Owens Basin are greater and different in kind from those of the Mono Basin. The town of Lee Vining and nearby popula- tion centers are rarely physically affected by airborne dust or blowing sand from the playas surrounding Mono Lake. However, in the future there could be a decrease in air quality caused by smoke and automobile exhausts from heavily populated areas at Mammoth and the June Lake area. Such an increase in aerosols coupled with low-level

170 The Mono Basin Ecosystem temperature inversions could also lead to decreased visibil- ity and a possible increase in the frequency and duration of fog over Mono Lake. LAND-WATER INTERFACE Tufa Dynamics The tufa towers, formed when carbonate materials pre- cipitate as described in chapter 3, are a significant scenic attraction of the Mono Basin. As la ke level has declined in the past, groves of lithoid tufa towers have become ex- posed at the locations and elevations shown in Figure 5.~. These towers range in height from a few feet to tens of feet. The fragile sand tufa, whose locations are shown in Figure 5.9, are castlelike features that form when the car- bonate material acts as a cementing agent for sand par- ticles. These formations are not greater than approximate- ly 6 ft in height. The sand tufa are highly erodible. Wave action associ- ated with changes in lake level could be expected to topple these formations. On the other hand, the lithoid tufa tow- ers are hard and less erodible, although wave action against the base of the towers has been observed to cause towers to topple. Observations at the South Tufa Area by personnel of the Mono Lake Tufa State Reserve suggest that towers that are already unstable may topple with a slow recession of the lake. If the lake level shifts abrupt- ly, otherwise secure towers may be jeopardized. Approxi- mately 24 percent of the changes in tufa formations in the South Tufa Area, one of the most frequently visited tufa areas, appear to have been caused by the wave action from rising lake levels (memo from Dave and Janet Carte, Mono Lake Tufa State Reserve, to Russ Guiney, January 31, 1986~. Shoreline Erosion As lake levels fluctuate, the shoreline topography will be modified by erosion from wind, surface water runoff, and lakeshore processes. This erosion is significant to the basin ecosystem to the extent that abrasion from wind

Shoreline and Upland Systems I · LITHOID TUFA TOWERS N Bridgeport Creek Tufa ` ' ~'''''.'''.'''''''.'.''.''''.''.2'.''''''.''.'' -'it ~ It Island .... :: 6415-6370 ft : ::::::: ::::: County Park, De ham eau Creek: < r Paoha Isla ~~ — A^A_d `1 g * Ring ~ | 171 Warm ,:: . Springs ,......... 643C ft .....~.......... 64 :::: ~v_-wv~ .. . ::::: ~— 1 Boundary of Scenic Area 0 1 2 3 , SCALE IN MILES FIGURE 5.S Locations and elevations of bases of lithoid tufa towers. Elevations are estimated by observations and have not been surveyed. Does not include locations of beach rock or tufa-coated boulders. (Courtesy of N. Upham, U.S. Forest Service.) inhibits vegetation growth and rapid erosion of surficial soils destroys habitats. No published reports describe these processes in the Mono Basin. Nevertheless, some general observations can be made about the extent of erosion that will occur if lake levels decline.

172 H RANGE OF SAND TUFA FORMATIONS | N ~ . ~ TIFF..-. 1!!~ The Mono Basin Ecosystem .~ .............................................. at, ................................. .................................... ............................... ............................................... .......................................... ~.,,,, ~ ~ ,: ' '''' ''' ''''''' ''' ' """""" "' '1 A.;.;; .;;;; ; ;.;.;.; ;.; ;.; ~ ..................... .......................................... ................................... ~: ~ n ................ ~ ' 2.""'""""""'""""""""] . ~ ~ . ~ ~ '''' '' '" '""I'":: 2 2 2 2 2 2-2.~ ,2.~ ,2 ~ 2-- )~ _ ;~ it ~ r.:a° . < ~~Ne itIsland .................... t . N ...................................................... ) ... j^ .\ ........................ _. 2.;.; ;.; ; ~ ........................................ _ N............................................... .............................................................. `................................................ ...................... \........................................... \.................................... ~........................................ ]................................. \.................................... ~ ......................... t...~........................ ]..~....................................... /~...................................... '.~.' ........ '..~.............................. , ,..., ..................... .. ........ /~' ............. '\ d~' .................. i. em..  ,,.,,. - ,,.~ i mono B... ,,, ,,,, ,, ,, .. ,, ,.,, ...., ....... ,, . ,, ,,, .,, ,, ................... ~ .................. : :. :,:,:, .: ~ 1 Lee Vinin · I 2 ' 2 : g I ....................................... , ! 1 ............................................... ' 1 ................................. , ., ., ,. ~ . '.~ _ ~.;..~ ~...~. I.. ............ t::~:: : ~ :~~ A, ~ Paoha Island ~ ...,,, ..,, ., ~ t::::::::::::::L .,...,. ;~ .,.,., ., .,, .t ..-.2,.,...,~ 1 ', , ..... ,, - , ~ , . on ::: .~.:.6 9.. :.:::::- ::::: I........................................................................... L222""''"'"''2'222'""'222'''"'"""''""""''"'''"''i"""''-''': ' i'"' - - : ::: 64 _6432 ::: .:.:: :.: . 2 22 2.. 222 .. -...~642,,8.,.,;.: :,:,. :. ,:...... ~ 1.,., . ... : ' ' ... - ' ' 2 ''-'' ~,........................................................................................... ~ ~ 2 2 2 .................. ~::::::::::::::::.::,::::,:::::::::::,:,:,:::::::::::.::,:,:::::::::::::::::::: i.2'2 2 '"'""""""""'''''' 122""""""2""""222""22 '''''''''''.'.'.'..'....'.'.'.'.............. i'2'2 '.' '""''''' . [.............................................................................................. ~ '22.2 2.' ""'"'"''''''''' t................................................................................................... 12 2 ' ' ' ................................. ` """''""''""":"""'''''''' I,:.: :.:.:, ,:2..,,:........................ JO ,:,.,:,:,: ,: :' ' 2 ~22";"""""2"'22222"2""! l _ Boundary of Scenic Area O · 2 3 J SCALE IN MILES FIGURE 5.9 Locations and elevations of bases of sand tufa. Elevations are estimated by observations and have not been surveyed. (Courtesy of N. Upham, U.S. Forest Service.) If lake levels drop, several types of shoreline erosion will occur. Declining lake levels will increase the gradient of streams entering the lake, increasing channel erosion in the vicinity of where the streams enter the lake. As the streams adjust to new base levels, the channels will incise,

Shoreline and Upland Systems 173 creating steep banks along the channel, increasing sediment load into the lake, and lowering the adjacent water table. The result of the increased sediment load is progression of delta sediments into the lake and perhaps increased tur- biditY from suspended fine-grained sediments. Stream channel downcutting caused by the past lowering ot fame levels is apparent along Rush, Lee Vining, and Mill creeks. In addition, diversion of water from Mill Creek has caused dowocutting in Wilson Creek. Even if lake levels remain constant in the future, erosion of bank sediments in these areas, with increased sediment input to the lake, will con- tinue as currently oversteepened banks continue to erode. If lake levels decline in the future, the induced erosion will further incise stream channels, increasing sediment transport to the lake. If lake levels rise, the stream will adjust to a new base level, causing aggradation of channel deposits and decreased sediment load to the lake. Lowering lake levels would expose large areas- of lake bed to erosion by wind, abrasion, surface water, and lake wave action. The effects of wind abrasion are discussed earlier. In addition to downcutting in stream channels by surface water flow, exposed lake beds are subject to rill and sheet erosion by overland flow. This process removes fine sediments from exposed surfaces and increases the transport of sediments to the lake. Prediction of future erosion rates and sediment loads is difficult, however, because the rate of erosion in a particular area depends on a number of factors such as the credibility of the exposed sediments, the amount of lake level change, and the slope of the exposed lake bottom. The shoreline process of greatest concern probably is the potential destruction of the islets in the vicinity of Paoha Island (S. Stine, University of California, Berkeley, personal communication, 1987~. Geomorphic ant! erosional features on the islets indicate that they are highly credible bv lake wave action. ., _ As with other shoreline erosional processes, however, the extent and rate of erosion that might occur as lake levels change will depend on the amount of lake level change and the number of fluctuations to which the shoreline is subjected.

174 The Mono Basin Ecosystem REFERENCES Aikens, C. M. 1983. The Far West. Pp. 149-201 in An- cient North Americans, J. D. Jennings, ed. San Francisco, Calif.: W. H. Freeman. Blaney, H. F. 1961. Consumptive use and water waste by phreatophytes. ASCE J. Irrig. Drain. Div. 87(IR3~:37-46. Bolen, E. G. 1964. Plant ecology of spring-fed salt marshes in western Utah. Ecol. Monogr. 34:143-166. Bovee, K. D. 1982. A guide to stream habitat analysis using the Instream Flow Incremental Methodology. In- stream Flow Information Paper 12. Washington, D.C.: U.S. Fish and Wildlife Service. Bradley, C. E., and D. G. Smith. 1985. Plains cottonwood recruitment and survival on a prairie meandering river floodplain, Milk River, southern Alberta and northern Montana. Can. J. Bot. 64:1433-1442. Brotherson, J. D., and S. R. Rushforth. 1985. Invasion and stabilization of recent beaches by salt grass (Distichlis spicata) at Mono Lake, Mono County, California. Great Basin Nat. 45:542-545. Burch, J. B., J. Robbins, and T. Wainwright. 1977. Botany. Pp. 114-142 in An Ecological Study of Mono Lake, Cali- fornia, D. W. Winkler, ed. Institute of Ecology Publica- tion 12. Davis, Calif.: University of California, Institute of Ecology. Cade, T. J., and P. R. Dague. 1987. Peregrine Fund News- letter No. 14. Ithaca, N.Y.: Cornell Laboratory of Ornithology. Cahill, T. A., and T. E. Gill. 1987. Air Quality at Mono Lake. Report to Community and Organization Research Institute, University of California, Santa Barbara. Calhoun, M. 1984. Pioneers of Mono Basin. Lee Vining, Calif.: Artemisia Press. 172 pp. Davis, J. W. 1982. Livestock vs. riparian habitat management--there are solutions. Pp. 175- 184 in Proceedings of the Wildlife-Livestock Relationships Sym- posium, April 20-22, 1981, Coeur d'Alene, Idaho, J. M. Peek and P. D. Dalke, eds. Moscow, Idaho: University of Idaho Forest, Wildlife and Range Experiment Station. Davis, L., and D. Gaines. 1987. Grazing away the scenic area: report looks at pastoral problems. Mono Lake Newsletter 9~3~: 13- 14.

Shoreline and Upland Systems 175 Dummer, K., and R. Colwell. 1985. Vegetation map of the Historical Shorelands of Mono Lake, California. Scale 1 :24,000. Prepared from 1982 aerial photos. Prepared by the State of California for State of California vs. U.S. Civil No. S-80-696. U.S.D.C.E.D. Calif. EA Engineering, Science, and Technology, Inc. 1985. Trout Population Size and Habitat Characteristics of Rush Creek Between Grant Lake Dam and Mono Lake. Prepared for the Los Angeles Department of Water and Power. 6 pp. Farquhar, F. P. 1965. History of the Sierra Nevada. Berkeley, Calif.: University of California Press. 262 pp. Gaines, D. 1986. Birds of Yosemite and the East Slope. Lee Vining, Calif.: Artemisia Press. Ciallegos, J. 1986. Mono Basin National Forest Scenic Area soils analysis. Unpublished report to the Inyo National Forest, Bishop, Calif. Gilbert, C. M., M. N. Christensen, Y. Al-Rawi, and K. R. Lajoie. 1968. Structural and volcanic history of Mono Basin, California-Nevada. Pp. 275-329 in Studies in Volcanology: A Memoir in Honor of Howel Williams. Geol. Soc. Am. Mem. 116. Washington, D.C.: U.S. Geological Survey. Grinnell, J., and A. H. Miller. 1944. The Distribution of the Birds of California. Pacific Coast Avifauna No. 22. Hansen, D. J., P. Dayanandan, P. B. Kaufman, and J. D. Brotherson. 1976. Ecological adaptations of salt marsh grass Distichlis spicata (Gramineae), and environmental factors affecting its growth and distribution. Am. J. Bot. 63:635-650. Harner, R. F., and K. T. Harper. 1973. Mineral composi- tion of grassland species of the Eastern Great Basin in relation to stand productivity. Can. J. Bot. 51 :2037- 2046. Harris, J. H. 1982. Mammals of the Mono Lake-Toga Pass Region. Lee Vining, Calif.: Kutsavi Books. 55 pp. Hart, T., and D. Gaines. 1983. Field Checklist of the Birds of the Mono Basin. Lee Vining, Calif.: Mono Lake Committee. Holmboe, J., and H. Klieforth. 1957. The effect of the Sierra Nevada on a Pacific storm. Pp. 99- 117 in Investigations of Mountain Lee Waves and the Air Flow over the Sierra Nevada. Final Report to the U.S. Air

176 The Mono Basin Ecosystem Force on Contract AF 19~604~-728. Los Angeles, Calif.: University of California, Meteorology Department. Kahle, J. E., W. A. Bryant, and E. W. Hart. 1986. Fault rupture associated with the July 21, 1986 Chalfant Val- ley earthquake, Mono and Inyo counties, California. Calif. Geol. 39(11):243-245. Kauffman, J. B., and W. C. Krueger. 1984. Livestock im- pacts on riparian ecosystems and streamside management implications: a review. J. Range Manage. 37~5~:430-438. Kerr, R. A. 1985. Inyo Domes drilling hits pay dirt. Science 227:504-505. Kerr, R. A. 1986. Do California quakes portend a large one? Science 233:1039- 1040. Klyver, F. D. 1931. Major plant communities in a transect of the Sierra Nevada Mountains of California. Ecology 12:1 - 17. Kuchler, A. W. 1977. The map of the natural vegetation of California. Pp. 909-938 (plus map) in Terrestrial Vegetation of California, M. G. Barbour and J. Major, eds. New York: Wiley. Lajoie, K. R. 1968. Late Quaternary Stratigraphy and Geologic History of Mono Basin, Eastern California. Ph.D. dissertation, University of California, Berkeley. 379 pp. Linker, M. F., J. O. Langbein, and A. McGarr. 1986. Decrease in deformation rate observed by two-color laser ranging in Long Valley Caldera. Science 232:213- 216. Los Angeles Department of Water and Power. 1984. Back- ground Report on Geology and Hydrology of Mono Basin. Report of the Aqueduct Division, Hydrology Section. Los Angeles, Calif. Ludwig, J. A. 1969. Environmental Interpretation of Foot- hill Grassland Communities of Northern Utah. Ph.D. dissertation, University of Utah, Salt Lake City. 100 PP. Marcot, B. G., ed. 1979. California Wildlife/Habitat Rela- tionships Program. Eureka, Calif.: U.S. Forest Service, Six Rivers National Forest. 899 pp. Miller, C. D., D. R. Mullineaux, D. R. Crandell, and R. A. Bailey. 1982. Potential Hazards from Future Volcanic Eruptions in the Long Valley-Mono Lake Area, East-

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178 The Mono Basin Ecosystem States and the role of Silicic volcanic ash layers in correlation of latest-Pleistocene and Holocene deposits. Pp. 52-57 in Late-Quaternary Environments of the United States, Vol. 2: The Holocene, H. E. Wright, Jr., ed. Minneapolis, Minn.: University of Minnesota Press. Small, A. 1974. The Birds of California. New York: Win- chester Press. 310 pp. Strahan, J. 1984 Regeneration of riparian forests of the Central Valley. Pp. 58-67 in California Riparian Sys- tems: Ecology, Conservation, and Productive Manage- ment, R. E. Warner and K. M. Hendrix, eds. Berkeley, Calif.: University of California Press. Taylor, D. W. 1982. Riparian Vegetation of the Eastern Sierra: Ecological Effects of Stream Diversions. tribution No. 6. Lee Vining, Calif.: Research Group. Con- Mono Basin Ustin, S. L., J. B. Adams, C. D. Elvidge, M. ReJmanek, B. N. Rock, M. O. Smith, R. W. Thomas, and R. A. Wood- ward. 1986. Thematic mapper studies of semiarid shrub communities. Bioscience 36:446-452. Verner, J., and A. S. Boss. 1980. California Wildlife and Their Habitats: Western Sierra Nevada. U.S.D.A. Forest Service General Technical Report PSW-37. Berkeley, Calif.: U.S. Forest Service, Pacific Southwest Forest and Range Experiment Station. 439 pp. Vestal, E. H. 1954 Cr~.1 r~t,~rn~ from Reich Creek Test ~ ^ ~~ ~~ ~ Calif. Fish Stream, Mono County, California, 1947- 1951. Game 40:89-104. Vorster, P. 1985. A Water Balance Forecast Model for Mono Lake, California. Master's thesis, California State University, Hayward. Earth Resources Monograph No. 10. San Francisco, Calif.: U.S. Forest Service, Region 5. Williams, S. N. 1985. Soil radon and elemental mercury distribution and relation to magmatic resurgence at Long Valley Caldera. Science 229~55 l -551 Wood. S. H. 1977. Distribution, correlation, and radiocar- bon dating of late Holocene tephra, Mono and Inyo cra- ters, eastern California. Geol. Soc. Am. Bull. 88:89-95. Woodward, R. A., K. T. Harper, and A. R. Tiedemann. 1984. An ecological consideration of the significance of cation-exchange capacity of roots of some Utah range plants. Plant Soil 79:169-180.

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Mono Basin is a closed hydrologic basin spanning the border between California and Nevada. Los Angeles has been diverting streams since 1941 that normally would flow into Mono Lake. It has been predicted that continued diversion will have major ecological consequences for the natural resources of the Mono Basin National Forest Scenic Area. This book studies the ecological risk assessment that considers the effects of water diversions on an inland saline lake. It examines the hydrology of the Mono Basin, investigates the lake's physical and chemical systems, studies the biological relationships, and predicts the effects of changes in lake levels on the ecosystem.

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