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University of Alberta Charcoal-based Paleofire History of Christina Lake in the Boreal Forest of Alberta by Lana Dee Laird A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degfee of Master of Science Department of Earth and Atmospheric Sciences Edmonton, Alberta Spring 2000 National Library Bibliothèque nationaie 1+1 ,,,da du Canada Acquisitions and Acquisitions et Bibliographie Services services bibliographiques 395 Wellington Street 395. rue Wellington Ottawa ON K1A ON4 Ottawa ON KIA ON4 Canada Canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Canada to Bibliothèque nationale du Canada de reproduce, loan, distribute or sell reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. la forme de microfiche/f?lm, de reproduction sur papier ou sur format électronique. The author retains ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantid extracts fiom it Ni la thèse ni des extraits substantiels may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author' s ou autrement reproduits sans son permission. autorisation. Abstract Annually-larninated sediment (spanning -940 years) from Christina Lake, Alberta was analysed for charcoal, pollen, sediment influx, loss on ignition and vivianite concentrations. The sedirnentology suggests a cooler/wetter "Little Ice Agen interval preceded and followed by warmeddrier conditions. Vivianite concentrations were not found to be a useful palaeoenvironmental indicator. The charcoal profile showed large fire return intervals of -68 years (1083 - 1490 AD), -29 years (1490 -1723 AD), -1 30 years (1723 - 1853 AD), and -1 6 years (1 853-1 949 AD). Vegetation changed Iittle, with the exception of a Pinus pollen decline 1797-1853 AD (possibiy related to cold/wet climate andfor reduced fire activity) and small Populus and Cotylus pollen increases prior to -1 250 AD (possibly related to the warm/dry "Medieval Warm Period"). This is the first long, high-resolution charcoal record from the boreal forest of north-central Alberta, and confirms that even far from any major ecotone, fire activity and vegetation were affected by climatic fluctuations over the last millennium. "If we knew what we were doing, it wouldn't be called research, would it?" Albert Einstein Acknowledgements This thesis could not have been completed without the kind support of the following individuals and organizations. For assistance with field work I thank Amy Reisler, Karen Perronnet, Dr- Ross Wein, Connie Boldt, Michael Liston, Farrah Gilchrist, and personnel from Arnoco Petroleum (who also provided snowmobiles). For laboratory analyses I thank M.J.M. Duke for 137Csanalysis, Diane Caird for XRD analysis, Frank Radford for ICP-AES analysis, Farrah Gilchrist for preparing material for DendroScan, and Environment Canada, Environmentai Protection Sewice who allowed me to use their Total Carbon Analyser machine and Cathy Biehn who patiently trained me on it. For research support I thank the Sustainable Forest Management Network of Centres of Excellence, Alberta-Pacific Forest Industries who paid for the plane on one of the field trips, the J. Gordin Kaplin Graduate Student Award who provided a travel bursary, and the Canadian Forest Sewice, Northern Forestry Centre who provided office and laboratory facilities. NSERC, the Canadian Forest Service, the Walter H. Johns Graduate Fellowship, the Harington Paleoenvironmental Scholarship, and the Sustainable Forest Management Network of Centres of Excellence provided personal funding. Thierry Varem-Sanders wrote the image analysis program for vivianite analysis, taught me how to use DendroScan, built field equipment, kept my computer running, and was helpful in a hundred other ways. For al1 of the above, I am truly grateful. I especially thank Dr. lan Campbell for his cheerful encouragement and assistance on every aspect of this project. Most of all, I am grateful to my family for their love, patience, and unfailing support from start to finish. Table of Contents CHAPTER 1 Introduction ....................................................... 1 1.1 Rationale and Hypothesis ............................................. 1 1.2 Organization of Thesis ................................................ 3 1.3 Literature Review .................................................... 4 1.3.1 Stratigraphie Charcoal Theory and Methods ....................... 4 1.3.2 High-resolution Paleofire Studies in the Canadian Boreal Forest ...... 7 1.3.2.1 Long-term Fire Histories .............................. 7 1.3.2.2 Shorter-term Fire Histories ............................ 9 1.4 References ........................................................ 12 CHAPTER 2 High-resolution Palaeofire Signals from Christina Lake. Alberta: a Cornparison of the Charcoal Signais Extracted by Two Different Methods ...................... 18 2.1 Introduction ................................................... 18 2.2 Study Site ....................................................... 20 2.3 Methodology ...................................................... 21 2.3.1 Core Retrieval and Sampling ................................. 21 2.3.2 Core Dating ............................................... 21 2.3.3 Determination of Near Shore Fire Activity ........................ 21 2.3.4 Charcoal Extraction via Sieving ............................... 22 2.3.5 Nitric Acid Digestion Trials .................................... 22 2.3.5.1 Organics .......................................... 22 2.3.5.2 Charcoal, Clay, Sand, and Sedirnents .................. 23 2.3.6 Total Carbon Analyser Tests .................................. 23 2.3.7 Nitric AcidKotaI Carbon Analysis of Christina Lake Sediment ........ 24 2.4 Results and Discussion .............................................. 24 2.4.1 Experimental Results ........................................ 24 2.4.2 Christina Lake Results ....................................... 25 2.5 Conclusions ....................................................... 27 2.6 References ........................................................ 36 CHAPTER 3 -940-year Fire History from Christina Lake. Alberta ...................... 38 3.1 Introduction ....................................................... 38 3.2 StudySite ....................................................... 40 3.3 Methodology ...................................................... 40 3.3.1 Core Retrieval and Sampling ................................. 40 3.3.2 Core Dating ............................................... 41 3.3.3 Basic Geochemical Analyses ................................. 41 3.3.3.1 Sediment Influx .................................... 41 3.3.3.2 Organics, Carbonates, and Ash ....................... 42 3.3.4 Determination of Near Shore Fire Activity ........................ 42 3.3.5 Charcoal Extraction ......................................... 42 3.3.6 Determination of "Significant" Fire Periods ....................... 43 3.3.7 Pollen Analyses ............................................ 44 3.4 Results ........................................................... 44 3.4.1 Basic Geochemical Analyses ................................. 44 3.4.2 Paleofire Signal and Fire Return Intervals ....................... 46 3.4.3 Pollen .................................................... 44 3.5 Discussion ........................................................ 48 3.5 Summary and Conclusions ........................................... 51 3.6 References ........................................................ 59 CHAPTER 4 Vivianite in the Laminated Sediments of Christina Lake. Alberta. Canada and its Potential as a Paleoenvironmental lndicator ................................. 65 4.1 Introduction ....................................................... 65 4.2 StudySite ......................................................... 65 4.3 Methodology ...................................................... 66 4.3.1 Core Retrievaf and Sampling ................................. 66 4.3.2 Geochronology ............................................ 67 4.3.3 Vivianite Quantification via Image Analysis ...................... 67 4.3.4 Geochemical Analyses ...................................... 67 4.4 Basic Geochemistry of Vivianite Precipitation ............................. 68 4.5 Vivianite as a Paleoenvironmental Indicator .............................. 70 4.5.1 Groundwater Source ........................................ 70 4.5.2 Groundwater Level ......................................... 71 4.5.3 Lake Productivity . Stratification, and Sedimentation ............... 71 4.6 Christina Lake Vivianite - Results and Discussion ......................... 73 4.7 Conclusion ........................................................ 75 4.8 References ........................................................ 81 CHAPTER 5 Summary. Discussion. Conclusion. and Suggestions for Further Research .... 84 5.1 Sumrnary ......................................................... 84 5.1.1 Pollen .................................................... 85 5.1.2 Charcoal .................................................. 86 5.1.3 Sedirnentology ............................................ 87 5.2 Discussion - Potential Impact of Future Climate