A Taxonomic and Ecologic Study of the Riverbottom Forest on St. Mary River, Lee Creek and Belly River in Southwest Alberta, Canada
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Brigham Young University BYU ScholarsArchive Theses and Dissertations 1974-08-01 A taxonomic and ecologic study of the riverbottom forest on St. Mary River, Lee Creek and Belly River in southwest Alberta, Canada Robert Keith Shaw Brigham Young University - Provo Follow this and additional works at: https://scholarsarchive.byu.edu/etd BYU ScholarsArchive Citation Shaw, Robert Keith, "A taxonomic and ecologic study of the riverbottom forest on St. Mary River, Lee Creek and Belly River in southwest Alberta, Canada" (1974). Theses and Dissertations. 7976. https://scholarsarchive.byu.edu/etd/7976 This Dissertation is brought to you for free and open access by BYU ScholarsArchive. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. f fO L2- ol 'tJ A TAXONOMICAND ECOLOGIC STUDY OF THE RIVERBOTTOMFOREST ON ST. MARYRIVER, LEE CREEKAND BELLY RIVER IN SOUTHWESTALBERTA, CANADA A Dissertation Presented to the Department of Botany and Range Science Brigham Young University In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy by I Robert Keith Shaw August 1974 ACKNOWLEDGEMENTS The author wishes to extend his thanks to all those who have helped make this work possible. Gratitude is expressed to Dr. S. L. Welsh, Dr. J. R. Murdock and Dr. C. Lynn Hayward of Brigham Young University for their counsel and guidance during the course of this study. The use of the Herbarium of Brigham Young University and the assistance rendered by its curator, Dr. S. L. Welsh, in identifying plant specimens are gratefully acknowledged. The author also wishes to express his appreciation to his wife Shirley and his brother Mike for being a very willing field crew during the study. iii TABLEOF CONTENTS Page ACKNOWLEDGEMENTS.. •• iii LIST OF TABLES•• . V LIST OF FIGURES . vii INTRODUCTION. 1 GEOLOGYAND GEOGRAPHY . 8 CLIMATE . 15 LITERATUREREVIEW . .. 20 METHODSAND MATERIALS . 25 RESULTS General Features of River Valleys and Riverbottom Forest •• . 32 The Climax Forest 45 Taxonomic Treatment . 88 KEYSAND DISTRIBUTIONS 90 DISCUSSION• • 191 SUMMARYAND CONCLUSIONS • 209 LITERATURECITED. • 213 iv LIST OF TABLES Table Page 1. Mean monthly streamflow in cubic meters per second of St. Mary Riyer, Lee Creek and Belly River in southwest Alberta, Canada •••••••••••• . 4 2. Mean monthly precipitation in centimeters and inches for Cardston, Alberta; elevation 1151 meters •• 5 3. Mean daily temperature in degrees Centigrade and degrees Fahrenheit at Cardston, Alberta ••• 16 4. Results of the mechanical analysis of soils sampled at 9 sites occupied in part by a pioneer river- bottom forest community and in part by a sandbar willow community • • • • • • • • • • • • • • • 35 5. Percentage of the valley cross-section occupied by mature riverbottom forest at the 10 study sites in southwest Alberta • • • • • ••••• 40 6. Mature tree stratum data from 10 riverbottom forest stands in southwest Alberta. • • • • • ••• 47 7. Tree reproduction data from 10 stands of mature riverbottom forest in southwest Alberta ••• 49 8. Clumped shrub data from 10 mature riverbottom forest stands in southwest Alberta •••••••••••••• 52 9. Thicket shrub data from 10 mature stands of river- bottom forest in southwest Alberta . 54 10. Herbaceous vegetation data from 10 mature stands of riverbottom forest in southwest Alberta ••••• 57 11. Summary of herbaceous species stand dominants based on a minimum importance value of 7.5 or more in at least one stand • • • • • • • • • • • • • • • 64 12. Unoccupied space (rock, litter, bare soil) in 10 stands of mature riverbottom forest measured at the herb stratum level •••••••••• . 66 V Table Page 13. Community similarity and dissimilarity totals for the 10 stands in the riverbottom forest community of southwest Alberta· ••••••••••••• 68 14. Penetrometer readings from ten mature stands of riverbottom forest in southwest Alberta. • ••••• 71 15. Summary of soils analyses (Bouyoucos, 1936) for 10 mature stands of riverbottom forest, adjacent gravel bars and fescue prairie grasslands in southwest Alberta. • • • • • • • • • • • • • •• , 72 16. Average diameter and age, and largest diameter and age, of mature trees in 10 stands of riverbottom forest in southwest Alberta ••••••••••••••• 74 vi LIST OF FIGURES Figure Page 1. Streams of southwest Alberta, Canada . 2 2. Subsurface geological strata in southwest Alberta 10 3. Study sites on St. Mary River, Lee Creek and Belly River in southwest Alberta • . • • • • • • • • • 26 4. St. Mary River 3 kilometers downstream from the St. Mary Dam • • • • • • • • • • • • • • • • • • 33 5. Site 4 - Woolford Park, a typical riverbottom forest stand on the second terrace of St. Mary River. 33 6. A pioneer riverbottom forest stand before 3 days of over-site flooding •••••••••••••• 37 7. The same gravel bar after 3 days of over-site flooding . 37 8. Site 1 - Cook's Ranch on St. Mary River. 38 9. Site 5 - Town Dam on Lee Creek 38 10. Valley profiles for three stands of mature river- bottom forest in southwest Alberta •••••• . 39 11. A climax riverbottom forest stand on St. Mary River. 42 12. Kearl Ranch picnic grounds on Lee Creek. 42 13. The Woodgrove Park area on St. Mary River ••••• 43 14. Similarity and dissimilarity coefficients between ten stands in the riverbottom forest community of southwest Alberta • • • • • • • • • • • 67 15. Populus angustifolia X balsamifera, dbh 129 cm and approximate age 200 years ••••••• 77 16. Populus angustifolia X balsamifera at Woodgrove Park, St. Mary River ••••••••••• 78 vii Figure Page 17. Composite of mean monthly precipitation, temperature and streamflow correlated with important river- bottom forest events ••••••••••••••• 79 18. Tree leaf-out at Site 4 - Woolford Park in May, 1972 82 19. Faintly visible in the grass are several large stones set in the form of a circle, the "tepee ring~' of the plains Indians ••••••••••••••• 82 20. Beaver utilization.of the riverbottom forest ct Site 5 - Town Dam on Lee Creek •••• . 86 21. Successional schema for the riverbottom forests of southwest Alberta, Canada. • • • • • • • • • ••• 199 viii INTRODUCTION The riverbottom forest community of southwest Alberta, Canada is usually less than 0.8 km in width and occurs on only certain lengths of each stream. It has been utilized for pasture and to a minor extent for firewood and timber, leaving much of the woodland free from excessive disturbance. Many sites along the streams give good indication of the natural composition and appearance of the riverbottom forest. At other places successional trends on gravel bars and stream banks are evident. Detailed taxonomic and ecologic studies are lacking for this community. This study treats several aspects of the riverbottom forest community including the vascular flora, community stratification and composition, successional patterns, seasonal aspect, climate, geography, geology and soils. The St. Mary River, Lee Creek and Belly River originate in alpine tundra (elevation 2,000 - 3,200 meters) on the Lewis Range of the Rocky Mountains in Glacier National Park, Montana (Figure 1). From alpine tundra these streams flow northeast into the Province of Alberta, Canada through montane forest and aspen parkland into the treeless stretches of fescue prairie (elevation 900 - 1,400 meters) where, along the stream courses, the poplar-dominated riverbottom forest community becomes a unique ecological entity. St. Mary River drains about 3,440 square kilometers, Lee Creek about 290 square kilometers, and Belly River about 1,235 square kilo- meters of northwest Montana and southwest Alberta. 2 Porcupine Hills 1580 m 17 km • Standoff Belly River Waterton Mary Reservoir 1113 m • Mountain St. Mary View Lee Creek River 1312 m Milk River Ridge 1433 m _A.l!?.e'tl_a '-C~adJL _ Montana, U.S.A. Lewis Range 3200 m Figure 1. Streams of southwest Alberta, Canada. 3 St. Mary River originates at St. Mary, Montana where the river flows from Upper St. Mary Lake to Lower St. Mary Lake having accumulated water from glaciers, snowbanks, lakes and streams draining some of the most scenic parts of Glacier National Park. From Lower St. Mary Lake it flows northward picking up more water from the Many Glacier and Kennedy Valleys. It crosses the International Boundary at Alberta Township 1, Range 25 where ic also leaves the aspen parkland and begins a northward traverse of the fescue prairie grassland and ultimately the mixed prairie grassland before it discharges into the Oldman River near Lethbridge, Alberta at Township 8, Range 22. Lee Creek originates on the north and east slopes of Old Chief Mountain in Glacier National Park and adjacent Blackfeet Indian Reser- vation, Montana. It flows from alpine meadows in three branches which join where the creek crosses the International Boundary into Alberta at Range 27. Lee Creek flows northeast, emerges from aspen parkland into fescue prairie grassland near the hamlet of Beazer, continues to the town of Cardston and discharges into St. Mary River 3.2 km below the town at Township 3, Range 25. Belly River (a translation from the earlier French name "Gros Ventre") begins in a series of lakes in northern Glacier National Park, flows through spectacular s~enery to the International Boundary at Alberta Range 28. Several kilometers directly west of the hamlet of Mountain View it emerges from aspen parkland and enters fescue prairie grassland. It flows northeast to Standoff, Alberta where it merges with