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The Ottawa River ((フランス語:Rivière des Outaouais), Algonquin: ''Kitchissippi''), is a river in the Canadian provinces of Ontario and Quebec. For most of its length, it defines the border between these two provinces. ==Geography== The river rises from its source in Lake Capimitchigama, in the Laurentian Mountains of central Quebec, and flows west to Lake Timiskaming. From there its route has been used to define the interprovincial border with Ontario. From Lake Timiskaming, the river flows southeast to Ottawa and Gatineau, where it tumbles over the Chaudière Falls and further takes in the Rideau and Gatineau rivers. The Ottawa River drains into the Lake of Two Mountains and the St. Lawrence River at Montreal. The river is long; it drains an area of , 65 percent in Quebec and the rest in Ontario, with a mean discharge of .〔(【引用サイトリンク】title=Facts about Canada: Rivers )〕 The average annual mean waterflow measured at Carillon dam, near the Lake of Two Mountains, is , with average annual extremes of . Record historic levels since 1964 are a low of in 2005 and a high of in 1976.〔(【引用サイトリンク】title=Historical Water Levels Summary, Ottawa River at Carillon )〕 The river flows through large areas of deciduous and coniferous forest formed over thousands of years as trees recolonized the Ottawa Valley after the ice age.〔Anderson, T.W. 1989. Vegetation changes over 12000 years. Geos (3) 39-47.〕 Generally, the coniferous forests occur on old sand plains left by retreating glaciers, or in wetter areas with clay substrate. The deciduous forests, dominated by maple, beech, oak and ash occur in more mesic areas with better soil.〔Braun, E.L. 1950. Deciduous Forests of Eastern North America. The Blakiston Co., Philadelphia, PA.〕〔Keddy, P.A. 2008. Earth, Water, Fire. An Ecological Profile of Lanark County. General Store Publishing House, Renfrew, Ontario. (revised from first edition 1999).〕 These primeval forests were occasionally affected by natural fire, mostly started by lightning, which led to increased reproduction by pine and oak, as well as fire barrens and their associated species.〔Catling, P. and V. Brownell. 1999. Pages 392-405 in the book Anderson, R.C., J.S. Fralish and J.M. Baskin. 1999. Savannas, Barrens, and Rock Outcrop Plant Communities of North America. Cambridge University Press, Cambridge, UK.〕 The vast areas of pine were exploited by early loggers.〔Hughson, J.W. and C.C. J. Bond. 1965. Hurling Down the Pine. The Historical Society of the Gatineau, Old Chelsea, Quebec. First edition 1964, Revised second edition 1965.〕 Later generations of logging removed hemlock for use in tanning leather, leaving a permanent deficit of hemlock in most forests.〔Keddy, C.J. 1993. Forest History of Eastern Ontario. Prepared for the Eastern Ontario Model Forest Group, Kemptville〕 Associated with the logging and early settlement were vast wild fires which not only removed the forests, but led to soil erosion.〔Howe, C.D. 1915. The effect of repeated forest fires upon the reproduction of commercial species in Peterborough County, Ontario. Pages 116-211 in Forest Protection in Canada, 1913 1914, Commission of Conservation of Canada, William Briggs, Toronto.〕 Consequently, nearly all the forests show varying degrees of human disturbance. Tracts of older forest are uncommon, and hence they are considered of considerable importance for conservation.〔Henry, M. and P. Quinby. 2009. Ontario Old Growth Forests. Fitzhenry and Whiteside, Markham, Ontario〕 The Ottawa River has large areas of wetlands. Some of the more biologically important wetland areas include (going downstream from Pembroke), the Westmeath sand dune/wetland complex, Mississippi Snye, Breckenridge Nature Reserve, Shirleys Bay, Ottawa Beach/Andrew Haydon Park, Petrie Island, the Duck Islands〔Darbyshire, S.J. 1981. Upper Duck and Lower Duck Islands. Trail and Landscape 15:133-139.〕 and Greens Creek.〔Brunton, D.F. 1992. Life Science Areas of Natural and Scientific Interest in Site District 6-12. A Review and Assessment of Significant Natural Areas. Report prepared for Ontario Ministry of Natural Resources, Kemptville, Ontario.〕〔(Ecosystem Diversity ). ottawariverkeeper.ca. Retrieved on 2013-07-12.〕 The Westmeath sand dune/wetland complex is significant for its relatively pristine sand dunes, few of which remain along the Ottawa River, and the many associated rare plants. (Shirleys Bay ) has a biologically diverse shoreline alvar, as well as one of the largest silver maple swamps along the river. Like all wetlands, these depend upon the seasonal fluctuations in the water level.〔Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK〕 High water levels help create and maintain silver maple swamps,〔Toner, M, and P. Keddy. 1997. River hydrology and riparian wetlands: a predictive model for ecological assembly. Ecological Applications 7: 236-246〕 while low water periods allow many rare wetland plants to grow on the emerged sand and clay flats.〔Brunton, D.F. and B.M. Di Labio. Diversity and ecological characteristics of emergent beach flora along the Ottawa River in the Ottawa-Hull region, Quebec and Ontario. Naturaliste canadien 116: 179-191.〕 There are five principal wetland vegetation types. One is swamp, mostly silver maple. There are four herbaceous vegetation types, named for the dominant plant species in them: ''Scirpus'', ''Eleocharis'', ''Sparganium'' and ''Typha''.〔Day, R., P.A. Keddy, J. McNeill and T. Carleton. 1988. Fertility and disturbance gradients: a summary model for riverine marsh vegetation. Ecology 69:1044-1054〕 Which type occurs in a particular location depends upon factors such as substrate type, water depth, ice-scour and fertility. Inland, and mostly south of the river, older river channels, which date back to the end of the ice age, and no longer have flowing water, have sometimes filled with a different wetland type, peat bog. Examples include Mer Bleue and (Alfred Bog ).〔 Major tributaries include: * Bonnechere River * Coulonge River * Dumoine River * Gatineau River * Kipawa River * du Lièvre River * Madawaska River * Mattawa River * Mississippi River * Montreal River * Rivière du Nord * Noire River * Petawawa River * Rideau River * Rouge River * South Nation River communities along the Ottawa River include (in down-stream order): 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ottawa River」の詳細全文を読む スポンサード リンク
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