Recent Vegetation Changes Along the Colorado River Between Glen Canyon Dam and Lake Mead, Arizona Recent Vegetation Changes Along the Colorado River Between Glen Canyon Dam and Lake Mead, Arizona By RAYMOND M. TURNER and MARTIN M. KARPISCAK GEOLOGICAL SURVEY PROFESSIONAL PAPER 1132 UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1980 UNITED STATES DEPARTMENT OF THE INTERIOR CECIL D. ANDRUS, Secretary GEOLOGICAL SURVEY H. William Menard, Director Library of Congress Cataloging in Publication Data Turner, Raymond M. Recent vegetation changes along the Colorado River between Glen Canyon Dam and Lake Mead, Arizona. (Geological Survey professional paper ; 1132) Bibliography: p. 22-24. 1. Botany-Arizona-Ecology. 2. Botany-Colorado Valley-Ecology. 3. Vegetation dynamics-Arizona. 4. Vegetation dynamics-Colorado Valley. I. Karpiscak, Martin M., joint author. II. Title. III. Series: United States. Geological Survey. Professional Paper ; 1132. QK147.T87 581.5 79-25928 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 Stock Number 024-001-03269-4 CONTENTS Page Page List of common plant names and scientific equivalents ________ IV Distribution of major plant species—Continued Abstract _______________________________________ 1 Rabbitbrush ______________________________16 Introduction ____________________________________ 1 Desert broom._______________-________16 Acknowledgments ____________________________________ 3 Waterweed ______________—____________ ————— _17 Changes in Colorado River streamflow regime ________ 3 Seep willow __________——— ——— ——— ______ —— —— _17 Floods _________________________________ 3 Emory seep willow __________________ ____17 Daily stage.__________________________ 6 Apache plume _________________________________17 Annual discharge_________________________ 7 Netleaf hackberry __________________________ ———17 Monthly discharge __________ _______________________? Redbud ________________________________________—17 Changes in channel and alluvial deposits in the Colorado Cattail________________________________17 River below Glen Canyon Dam ______________________ 8 Reed——___________________________ _________________ -18 A history of photography on the Colorado River __________ 10 Spiny aster________________________ ————— ___18 Vegetation _______________________________________12 Sandbar willow _______________ —— ——— __ — _ ————— _18 Distribution of major plant species ___________________13 Goodding willow _______________________-18 Bermuda grass ________________________________14 Desert isocoma ____________________— —— ———18 Russian olive __________________________________14 Photographic documentation of changes ____———__ ——— ———18 Saltcedar____________________________________ 14 Summary of changes ______________________19 Elm __________________________________15 Zone of postdam fluvial sediments ____________—19 Camelthorn _________________________________15 Zone of predam fluvial sediments _______________—_19 Catclaw _________________________________15 Zone of predam flood terraces, eolian deposits, and Western honey mesquite ____________________15 stabilized talus slopes __________________21 Fremont cottonwood ____________________________16 General conclusion ____________________—-21 Arrowweed____________________ _____________16 References cited __________________- — ————— -22 Longleafbrickellia __________________________________ 16 ILLUSTRATIONS Page PLATE 1. Map showing Colorado River from Glen Canyon Dam to Lake Mead. _____________________ — — —— ___In pocket 2. Maps showing distribution of selected plant species along the Colorado River. [Includes figs. 7-15.] ___ ————In pocket 3. Maps showing distribution of selected plant species along the Colorado River. [Includes figs. 16-25.] _ —— — __In pocket FIGURE 1. Graph showing yearly range between minimum daily and maximum discharge and yearly range between minimum and maximum stage of Colorado River at Lees Ferry and near Grand Canyon _______-_ ——— — 4 2. Graph showing daily variation in river stage during two selected years, Colorado River at Lees Ferry ___ ——— ——— 6 3. Graph showing total annual streamflow (by calendar year) of Colorado River as recorded at Lees Ferry and near Grand Canyon ______________________________________- ——— ———— 7 4. Graph showing mean monthly discharge as a percentage of total annual discharge, Colorado River, Lees Ferry _ ___ 8 5. Graph showing regression analyses of annual (water year) discharge versus sediment yield _______ — — ———— _ 9 6. Graph showing accumulated volume of degradation below Glen Canyon Dam for various periods between 1956 and 1975 _____________________________________________________-______ 10 7-25. Maps showing distribution of selected plant species along the Colorado River from Glen Canyon Dam to Lake Mead: 7. Bermuda grass and elm ________________________ ———— ———————— ——— ——— _- —— -Plate 2 8. Russian olive and desert broom __________________________~——— — — — ———— - ——Plate 2 9. Saltcedar _________________________________________________________________——————-—Plate 2 10. Camelthorn and Apache plume ________________________ ——— ———————————————Plate 2 11. Catclaw._________________________________________________————————Plate 2 12. Western honey mesquite _____ _____________________ _———————————————————Plate 2 13. Fremont cottonwood __________________________________________———————Plate 2 14. Arrowweed ____________________________________________—————————————Plate 2 15. Longleaf brickellia ________________ ________________________________ ______________________—_„__ Plate 2 16. Rabbitbrush and waterweed _____________________—_ ——— ______ ——————— ____—Plate 3 III IV CONTENTS FIGURE 17. Seep willow _______________________________________________________Plate 3 18. Emory seep willow ______________________________________ _______________Plate 3 19. Netleaf hackberry ___________________________________________________________Plate 3 20. Redbud and desert isocoma _____________________________________________ ——— __————Plate 3 21. Cattail ______________________________________________________________Plate 3 22. Reed ___________________ ________________________________________Plate 3 23. Spiny aster _________________________________________________________Plate 3 24. Sandbar willow _____________._________________________ _______________Plate 3 25. Goodding willow ______________________________________________________Plate 3 26-73. Matched photographs showing changes in vegetation ___________________________— — — __ — — ____26-125 TABLES Page TABLE 1. Mean, standard deviation, and coefficient of variation of yearly maximum stage for the Colorado River at Lees Ferry and near Grand Canyon _________________________________________^________——— 5 2. Mean, standard deviation, and coefficient of variation of yearly minimum stage for the Colorado River at Lees Ferry and near Grand Canyon.________________________________ —— __ —— __ —— _ — _______ 5 3. Camera station descriptions, including dates, location, altitude, and photograph credits ——_____ —— ______ —— —— _ 20 LIST OF COMMON PLANT NAMES USED AND SCIENTIFIC EQUIVALENTS agave Agave spp. longleaf brickellia Brickellia longifolia Wats. Apache plume Fallugia paradoxa (D.Don) Endl. mistletoe Phoradendron californicum Nutt. arrowweed Pluchea sericea (Nutt.) Coville monkey flower Mimulus cardinalis Dougl. barrel cactus Ferocactus acanthodes (Lemaire) Britt. Mormon tea Ephedra trifurca Torr. & Rose netleaf hackberry Celtis reticulata Torr. beavertail cactus Opuntia basilaris Engelm. & Bigel. ocotillo Fouquieria splendens Engelm. bebbia Bebbia juncea (Benth.) Greene peppergrass Lepidium montanum Nutt. Bermuda grass Cynodon dactylon (L.) Pers. poison ivy Rhus radicans L. brittle bush Encelia farinosa Gray rabbitbrush Chysothamnus spp. camelthorn Alhagi camelorum Fisch. range ratany Krameria parvifolia Benth. carrizo (see reed) Phragmites communis Trin. red brome Bromus rubens L. catclaw Acacia greggii Gray redbud Cercis occidentalis Torr. cattail Typha spp. red willow Salix laevigata Bebb. coldenia Coldenia spp. reed (see carrizo) Phragmites communis Trin. creosote bush Larrea tridentata (DC.) Coville Russian olive Elaeagnus angustifolia L. desert broom Baccharis sarothroides Gray Russian thistle Salsola kali L. var. tenuifolia Tausch desert isocoma Haplopappus acradenius (Greene) Blake saltcedar Tamarix chinensis Lour. desert plume Stanleya pinnata (Pursh) Britton sandbar willow Salix exigua Nutt. desert trumpet Eriogonum inflation Torr. & Frem. sand verbena Abronia elliptica A. Nels. dicoria Dicoria spp. scouring rush Equisetum hiemale L. dogbane Apocynum spp. seepweed Suaeda torreyana Wats. dropseed Sporobolus spp. seep willow Baccharis glutinosa Pers. dyssodia Dyssodia spp. shrub liveoak Quercus turbinella Greene elm Ulmus minor Mill. slender poreleaf Porophyllum gracile Benth. Emory seep willow Baccharis emoryi Gray smooth horsetail Equisetum laevigatum A. Braun evening primrose Oenothera pallida Lindl. spiny aster Aster spinosus Benth. four-wing saltbush Atriplex canescens (Pursh) Nutt. watercress Rorippa nasturtium-aquaticum (L.) Fremont cottonwood Populus fremontii Wats. Schinz & Thell globemallow Sphaeralcea spp. waterweed Baccharis sergiloides Gray Goodding willow Salix gooddingii Ball western honey mesquite Prosopis glandulosa var. torreyana (Ben- great bulrush Scirpus validus Vahl. son) Johnston hackberry Celtis reticulata Torr. white bursage Ambrosia dumosa (A. Gray) Payne horsetail Equisetum spp. willow Salix