LATE QUATERNARY PLANT ZONATION AND CLIMATE IN SOUTHEASTERN UTAH

Plant macrofossils from packrat middens in two southeastern Utah caves outline development of modern plant zonation from the late Wisconsin. Allen Canyon Cave (2195 m) and Fishmouth Cave (1585 m) are located along a continuous gradient of outcropping Navajo Sandstone that extends from the Abajo Mountains south to the San Juan River. By holding the site constant, changes in the floral composition for a plot of less than one hectare can be observed, even if sporadically, over tens of millennia. At Allen Canyon Cave, Engelmann spruce-alpine fir forest was replaced by the present vegetation consisting of pinyon-juniper woodland on exposed ridgetops and cliffside stands of Douglas fir, ponderosa pine, and aspen. Xerophytic woodland plants such as pinyon, plains prickly pear, and narrowleaf yucca arrived sometime in the middle Holocene between 7200 and 3400 B.P. At Fishmouth Cave, Utah juniper in Holocene middens replaced blue spruce, limber pine, Douglas fir, and dwarf and Rocky Mountain junipers in late Wisconsin samples. Quantitative climatic estimates are derived for the late Wisconsin by applying vertical gradients for temperature and precipitation to the amount of vegetation depression. The Fishmouth Cave sequence indicates a minimum lowering of 850 m for blue spruce, limber pine, and dwarfmore » juniper. A depression of at least 700 m for Engelmann spruce and alpine fir is suggested for the Allen Canyon locality. Use of conservatively low gradients for stations below 2080 m yields a 3-4 C cooling from present mean annual temperature and 35 to 60% more rainfall than today. Steeper gradients associated with more mountainous terrain suggest a 5 C lowering in temperature and up to 120% increase over modern precipitation. 81 references, 6 figures, 10 tables.« less

[1]  T. Wigley,et al.  Historical climatology , 2020, Nature.

[2]  J. Betancourt,et al.  Biogeographic Implications of a Packrat Midden Sequence from the Sacramento Mountains, South-Central New Mexico , 1984, Quaternary Research.

[3]  J. Betancourt,et al.  Packrat Middens from Canyon de Chelly, Northeastern Arizona: Paleoecological and Archaeological Implications , 1984, Quaternary Research.

[4]  Ronald P. Neilson,et al.  Biogeography of two southwest American oaks in relation to atmospheric dynamics , 1983 .

[5]  K. Cole,et al.  Use of packrat middens to determine rates of cliff retreat in the eastern Grand Canyon, Arizona , 1982 .

[6]  K. Cole.  Late Quaternary Zonation of Vegetation in the Eastern Grand Canyon , 1982, Science.

[7]  J. Kutzbach,et al.  The Sensitivity of the African-Asian Monsoonal Climate to Orbital Parameter Changes for 9000 Years B.P. in a Low-Resolution General Circulation Model. , 1982 .

[8]  R. S. Thompson,et al.  Late Quaternary Environments and Biogeography in the Great Basin , 1982, Quaternary Research.

[9]  J. Betancourt,et al.  Holocene Vegetation in Chaco Canyon, New Mexico , 1981, Science.

[10]  J. Kutzbach,et al.  Monsoon Climate of the Early Holocene: Climate Experiment with the Earth's Orbital Parameters for 9000 Years Ago , 1981, Science.

[11]  J. Mead,et al.  The Late Pleistocene and Holocene Fauna and Flora of Vulture Cave, Grand Canyon, Arizona , 1981 .

[12]  J. Mead.  The Last 30,000 Years of Faunal History within the Grand Canyon, Arizona , 1981, Quaternary Research.

[13]  M. B. Davis,et al.  Holocene Climate of New England , 1980, Quaternary Research.

[14]  S. Mullen.  An Investigation of Small Synoptic-Scale Cyclones in Polar Air Streams , 1979 .

[15]  J. Houghton.  A Model for Orographic Precipitation in the North-Central Great Basin , 1979 .

[16]  P. Wells.  An Equable Glaciopluvial in the West: Pleniglacial Evidence of Increased Precipitation on a Gradient from the Great Basin to the Sonoran and Chihuahuan Deserts , 1979, Quaternary Research.

[17]  W. Spaulding,et al.  Development of Vegetation and Climate in the Southwestern United States , 1979, Science.

[18]  M. Miles.  Predicting temperature trend in the Northern Hemisphere to the year 2000 , 1978, Nature.

[19]  S. L. Welsh.  PROBLEMS IN PLANT ENDEMISM ON THE COLORADO PLATEAU , 1978 .

[20]  G. Brakenridge,et al.  Evidence for a Cold, Dry Full-Glacial Climate in the American Southwest , 1978, Quaternary Research.

[21]  P. Thompson,et al.  Oxygen and hydrogen isotopic ratios in plant cellulose. , 1977, Science.

[22]  Val L. Mitchell.  The Regionalization of Climate in the Western United States , 1976 .

[23]  P. Wells.  Macrofossil Analysis of wood rat (Neotoma) Middens as a Key to the Quaternary Vegetational History of Arid America , 1976, Quaternary Research.

[24]  O. A. Schwartz,et al.  Observations on the Home Range of the Desert Woodrat, Neotoma lepida intermedia , 1975 .

[25]  G. D. Debuchananne.  Geohydrologic Considerations in the Management of Radioactive Waste , 1974 .

[26]  J. E. Hales.  Southwestern United States Summer Monsoon Source—Gulf of Mexico or Pacific Ocean? , 1974 .

[27]  H. E. Wright,et al.  Present and Past Vegetation of the Chuska Mountains, Northwestern New Mexico , 1973 .

[28]  R. Stones,et al.  Natural History of the Desert Woodrat, Neotoma lepida , 1968 .

[29]  G. G. Raun.  A Population of Woodrats in Southern Texas , 1966 .

[30]  H. E. Wright.  The Last 10,000 Years: A Fossil Pollen Record of the American Southwest. , 1964, Science.

[31]  M. Davis.  On the theory of pollen analysis , 1963 .

[32]  E. L. Peck,et al.  Terrain Influences on Precipitation in the Intermountain West as Related to Synoptic Situations , 1962 .

[33]  W. P. Cottam,et al.  Some Clues to Great Basin Postpluvial Climates Provided by Oak Distributions , 1959 .

[34]  W. P. Lowry,et al.  Synoptic Climatology of the Arizona Summer Precipitation Singularity , 1955 .

[35]  E. Antevs.  Geologic-Climatic Dating in the West , 1955, American Antiquity.

[36]  L. Ellison.  Subalpine Vegetation of the Wasatch Plateau, Utah , 1954 .

[37]  Inez M. Haring.  A CHECK-LIST OF THE MOSSES OF THE STATE OF ARIZONA. II. , 1947 .

[38]  F. S. Baker.  Mountain climates of the western United States. , 1944 .

[39]  Raymond Price,et al.  CLIMATE OF THE WEST FRONT OF THE WASATCH PLATEAU IN CENTRAL UTAH1 , 1937 .

[40]  P. Damon,et al.  Calibration of radiocarbon dates: tables based on the consensus data of the Workshop on Calibrating the Radiocarbon Time Scale , 1982, Radiocarbon.

[41]  W. Spaulding.  The Late Quaternary vegetation of a southern Nevada mountain range , 1981 .

[42]  R. J. Reed,et al.  Cyclogenesis in Polar Air Streams , 1979 .

[43]  R. S. Thompson,et al.  Arizona Radiocarbon Dates Ix: Carbon Isotope Dating of Packrat Middens , 1978, Radiocarbon.

[44]  Arthur M. Phillips.  Packrats, plants, and the Pleistocene in the lower Grand Canyon , 1977 .

[45]  T. Devender,et al.  Late Pleistocene and Modern Plant Communities of Shinumo Creek and Peach Springs Wash, Lower Grand Canyon, Arizona , 1976 .

[46]  R. Thomas,et al.  Late Pleistocene plants and animals of the Sonoran Desert: a survey of ancient packrat middens in southwestern Arizona , 1973 .

[47]  R. J. Steinhoff,et al.  Geographic variation in Pinus flexilis and Pinus strobiformis and its bearing on their taxonomic status. , 1971 .

[48]  R. A. Bryson,et al.  Tentative Climatic Patterns For Some Late Glacial and Post-Glacial Episodes In Central North America. In Life, Land and Water , 1967 .

[49]  R. Bryson.  Air Masses, Streamlines and the Boreal Forest , 1966 .

[50]  I. J. Witkind.  Geology of the Abajo Mountains area, San Juan County, Utah , 1964 .

[51]  P. Martin.  The Last 10,000 Years: A Fossil Pollen Record of the American Southwest , 1963 .

[52]  G. M. Richmond.  Quaternary stratigraphy of the La Sal Mountains, Utah , 1955 .

[53]  G. Pearson.  Management of Ponderosa Pine in the Southwest. , 1950 .

[54]  H. E. Gregory.  The San Juan country, a geographic and geologic reconnaissance of southeastern Utah , 1938 .