Plant ComPosition Standing CroP and Environmental ' Pa rame te r s in the Estuary of the ChurchiII River, Manitoba. by MARIA W. ZBIGNIEWICZ À thesis oresented to the University of Manitoba ^- in Partial fulf illment of the requirements for the degree of Master of Science ln The FacultY of Graduate Studies winnipeg, Manitoba (c ) M.w. zbigniewicz, 1985 PLANT COMPOSITION, STANDING CROP AND ENVIRONMENTAL PARAMETERS IN THE ESTUARY OF THE CHURCHILL RIVER, MANITOBA BY MARIA W. ZBIGNIEI,TICZ A thesis st¡bmitted to the Faculty of'Craduate Studies of the University of Manitoba irl partial fulfill¡nent of the reqltirentelrts of the degree of MASTER OF SCIENCE o 1986 Pernrission has beert grarlted to the LIBRARY OF THE UNIVER- SITY OF MANITOBA to lend or sell copies of this thesis. to the NATIONAL LIBRARY OF CANADA to microfilnr this thesis and to lertd or sell copies of the film, and UN\TIVERSITY MICROFILMS to publish an abstract of this thesis. The author reserves other publicatioll rigltts, and rreither tlte thesis ¡ror extettsive extracts lronl it ntay be printed or other- wise reproduced without the autllor's writte¡r perlttissiolt' ÀBSTRACT patterns of plant compositÍon, standing crop and environmen- taI parameters of four transects positioned along the lower 17km of the churchill River estuary are described. Three major plant communities, distributed according to salinity are identified. Two saline transects are dominated by Puc- cinellia phrvqanodes in the lower geolittoral zone, carex subspathacea in the mid and upper geolittoral zones and Ca- lamaqrostis deschampsioides in the epilittoraL zone' The - brackish transect is dominated bY EIeoc har i s uniq uml s 1n the l-ower geolittoral zone and carex aquatilis in the mid geolittoraf zone. The freshwater transect is dominated by Eleoc haris acicu lar i s. This study indicates that salinity (quantified by the ex- changable sodium percentage value and the potassium concen- tration) determines the composition of the plant communites up river, while relative elevation determines the vertical distribution of species wíthin each community' Mean above-ground standing crop values along the four transects ranged from 1OZ to 2149 ¡-z comparing favorably with other sub-arctic sites. Above ground standing crop values were 16 to 489 m- 2 lower in 1984, probably as a re- sult of the many reprecusions of decreased precipitation' 11 Mean below-ground standi ng crop values along the four tran- sects ranged from 798 to 201 59 m- 2. Above-ground:below- ground standing croP ratios ranged from 1:1 to 1¿23. Mean salinities of tidal ¡vater f or the 1983 and 1984 growing seasons decreased up river from 16ppt at Sandspit to 7.0ppt at Esker and were 0.Sppt at Pumphouse which is non- tidal. Mean transect soil salinity values for the 1983 growing season showed a simil-ar trend with 4.oppt at Sand- spit and 0.7PPt at PumPhouse. 11r ÀCKNO!.TLEDGEMENlS This research was made possible by the funding of Manito- ba Hydro and the Northern studies committee of the universi- ty of Manitoba in the form of research grants to Dr. J.M. Shay. During the course of my studies I have been assisted and advised by many individuals. First, I would like to thank my supervisor, Df. J.M. Shay whoSe guidance and support were valuable throuqhout the project. The help of my other com- mittee members; Mr. R. Eilers, Dr. B. Irvine and Dr. K. Mount is much appreciated. I would like to give special ac- knowledgement to Dr. Mount for his invaluable statistical adv ice . I thank everyone at the churchill Northern studies centre for providing both an enjoyable and stimulating atmosphere in which to work. In particular, the logistic help of P. Dueck, G. NeeI, and J. Simpson is gratefully acknowledged. The field work for this study was conducted with the much appreciated assistance of J. Briskie, J. Barr and c.T. shay as well as several volunteers from the C.N.S.C.. G' Keleher kindly conf irmed plant identifications' 1V FinaIIy, I am especially indebted to my husband' L. Gor- don GoldsborougLr, who helped with field work, drafting of figures and proofreading. I am most grateful to him for his encouragement and suPPort. v CONTENTS ABSTRACT.... 11 lV ACKNOWLEDGEMENTS . Cha er Þage ï INTRODUCTION .1 History of ChurchiIl River diversion .1 Objectives..." ,'l II. LITERATURE REVIEW .8 Salt marshes . I Comrnunity Structure 11 ProductivitY 15 Soil 19 Physical and chemical Properties 19 Salinity 21 TidaI and interstitial water exchange 21 tlater table 24 Redox Potential . 25 Plant zonation 26 Inundation...... 28 Salinity .. 29 Inundation and salinitY 31 Other mechanisms . 32 33 ITT. STUDY AREÀ GeomorphologY 33 CI imate 35 Vegetat i on 36 42 IV. METHODS Fieldmethods .... 42 Siteselection .... 42 Main and lateral transect positioning 43 Vegetation.... 44 TransectsamPling ... 44 . Standing crop samPling 44 Environmental Parameters . 46 Tida] inundation.... 46 Water qualitY (tiAat and interstit.ial ) 47 Soils . 49 v1 LaboratorY methods . 50 Soils . ' ' 50 Ðataanalysis .. .. '. 52 Vegetation........ 52 Transect data 52 53 Standingcrop ... o Environmental Parameters . aa 54 Water qualitY (tiAat and interstitial) 54 Vegetation and environmental parameter interactions . 54 Envi ronmental Parameter ordi nat i on 54 Vegetation ordination 55 57 v RESULTS Vegetation..o...' 57 GeneraldescriPtion.." 57 Sandspit . 57 Akud1ik....' 60 Esker . 62 PumPhouse . " 64 Standingcrop.. .. " 66 Environmental Parameters . .' 75 TopograPhY...." 75 Tidal inundation 77 Water qualitY . 81 Tidalwater ... .. " " 81 Interstitial water 83 Soil . ' 85 PhYsica1 Parameters 85 ChemistrY.....""' 89 RedoxPotential . r " 91 Vegetation and environmental parameter interactions ' 95 Principal components analysis of soil data...." 95 Detrended correspondence analysis of vegetation data ' ' 103 Site õrdination (total vegetation matrix) aaaaoa 103 SaIine ordinatiån Sandspit and 107 Akud1 i k ) aaa' Brackish ordination (esxer) . 109 Freshwater ordination (eumphouse) 109 Species ordination . o . 111 119 VI. DISCUSSTON . aa 119 Vegetation 127 Envi ronmental ParameÈers aaa Vegetation and environmental parameter interactions... 134 v11 139 VII. SUMMÀRY 143 REFERENCES Appendi x Daqe A. sPEcrES LIST . o o . r . 160 B. SUMMARY OF SOIL CHEMISTRY FOR EÀCH SAMPLING sTÀTroN...... 164 v11l LIST OF TÀBLES TabIe DAqe 1. Churchill River flows at Red Head Rapids ,6 2. Summary of arctic salt marsh studies ' ' ' ' ' ' . 11 3. Summary of tide levels for churchill, Manitoba. .34 4. Summary of average climatic monthly means ' ' .37 5. Species richness and shannon-weiner diversity indices o . ' ' ' ' ' o 58 6. Species percent cover matrix (Sandspit) ' ' 59 7, Species percent cover matrix (Akudlik) o ' ' o 61 8. Species percent cover matrix (gsker) ' ' ' 63 9. Species percent cover matrix (Pumphouse) ' o 65 10. Total above-ground standing crop (g m-z) 66 11. Total below-ground standing crop (g m-2) 74 12. Àbove-groundlbelow-ground standing crop ratio ' 75 13. TidaI water Salinities for the four transects (PPt).."'o 82 14. Tidal water conductivities for the four transects (ds m-1) . ' ' ' ' 83 84 1 5. Tidal water pH for the four transects ' ' 16. Interstitial water chemistry for the four tranSects . .''''''''' 85 17. Soil parameter means, Standard errors and ranges 88 1g. correlatíon matrix of environmental parameters 90 19, Principal components analysis of soil data ' ' ' 95 1X 20, Principal components analysis of Sandspit and Akudliksoildata..."'. 98 101 21 . Principal components ana Iys i s of Esker soil data components analys i s of Pumphouse soil 22. Principal 103 data oaaaaa x LTST OF FIGURES Daqe F i qure 1, Map showing Churchill River system ' ' o ' .2 tr 2. Location map of the four study transects ' ' ' 3. Generalized physiography . o ' ' ' o . 13 4. Main and lateral transect and sampling station laYout' . o . ' ' ' ' ' 45 5. Passive tidal water sampler. " ' 48 6, Above-ground standing crop . " 67 7. Percent above-ground standing crop (Sandspit) 69 8. Percent above-ground standing crop (Akudlik) ' 71 9. Percent above-ground standing crop (nster) ' 72 10. Percent above-ground standing crop (eumphouse) 73 11. Three dimensional topographic profiles of the fourtransects....".. 76 12. Number of times an elevation was inundated ' ' 78 13. Variation in maximum daily tide heights ' ' 79 14. Inundation profiles of t'idal sites' ' ' ' 80 15. Soil texture of total soil data matrix' ' ' ' 87 16. l'lean soil redox potential . .''''''' 92 17. Mean soí1 redox Potentials at Sandspit... o 94 18. Principal comPonents analYsis of soil data. 97 19. Principal comPonents analYsis of Sandspit and 100 Akudlik soil data. aaaaaaaa 20. comPonents analYsis of Esker soil Principal 102 data. o ' x1 21. Principal components analysis of Pumphouse soil . data. 104 22. DeLrended corresPondence analys i s of samples 105 23. Detrended cor resPondence analys i s of and Akudlik samples :':u:n:' 108 24. Detrended correspondence analysis of samP1es..o..o... :":": . 110 25. Detrended correspondence analysis of Pumphouse samPles . o . r . ' ' ' ' ' ' 112 26. Det rended cor respondence analys i s of aII species 113 27. DeÈrended correspondence analys i s of Sandspit & Akudl i k species . 115 28. Detrended cor respondence analysis of Esker spec ies 116 29. Detrended correspondence analysis of Pumphouse sPecies . o ' ' ' ' 118 30. Sample identification fold out page 141 31 . Species ident,ification fold out page 142 x11 Chapter I INTRODUCTION 1.1 HISTORY OF CHURCHILL RIVER DI TON The Ne1son and Churchill Rivers drain a basin of approxi- mately 1 t378,000km2. The basin lies between the Mackenzie west basin to the nort,h, the Rocky Mountain divide to the ' the Mississippi basin to the south, and the Great Lakes ba- sin and Hudson Bay to the east (McDougaII 1971). The south- ern part of the basin (1,079,000km2) empties into the Hudson Bay via Lake Winnipeg and the Nelson River, while the north- ern segment (299,000km2) empties into the Hudson Bay through the Churchi II River system (t{cDougall 1971) . In 1974t a proposal was made to construct a dam on the churchill River at Missi Fa1ls 288km upstream from the river mouth (figure 1 ).