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Ecoregion profile: St-Laurent Lowlands

Hugo Larocque, Doug Trant and Giuseppe Filoso, Environment Accounts and Statistics Division

The St-Laurent  Lowlands ecoregion (Map 1) is one of Canada’s 194 ecoregions. It covers a total area of over 40,000 square kilometres, slightly less than the Canadian average.¹ The ecoregion extends from Brockville, Ontario to Québec along the St. Lawrence River, and also includes a portion of the Ottawa River valley.

Map 1 St-Laurent Lowlands ecoregion

In the 2006 Census, the St-Laurent Lowlands had the third highest population density in the country, with 158 persons per square kilometre. The two ecoregions with the highest population density were the Lower Mainland ecoregion of British Columbia² and the Lake Erie Lowland ecoregion.³ Despite its high density, with 21% of the Canada’s inhabitants, the population of the St-Laurent Lowlands ecoregion grew only 31% between 1971 and 2006, while that of Canada as a whole grew 47% (Table 1). The main population centres in this ecoregion are the Ottawa–Gatineau, Montréal, Trois-Rivières and Québec metropolitan areas.

Table 1 St-Laurent Lowlands ecoregion

The St-Laurent Lowlands ecoregion is suitable for agriculture given its predominantly clay soil type and proximity to the St. Lawrence River and other bodies of water. It is also a relatively flat area, with the exception of the Monteregian Hills. The land cover is mainly agriculture, forest and developed land (Chart 1 and Map 2). Farmland and forests make up over 80% of the total land area of the St-Laurent Lowlands ecoregion.

Chart 1 St-Laurent Lowlands ecoregion, by type of land cover, circa 2000

Map 2 Land cover, St-Laurent Lowlands ecoregion, circa 2000

The main crop is corn. In 2006, the area under corn cultivation in this ecoregion accounted for 39% of the total corn cropland in the country. From 1971 to 2006, soy cultivation grew considerably: the area in soy rose from approximately 600 hectares in 1971 to over 240,000 in 2006. The region also produces maple syrup: the 8 million maple tree taps in the region, accounted for 23% of the total taps in Canada in 2006 (Table 1).

The ecoregion contains a large number of dairy farms. Despite a 56% decline in the number of dairy cows between 1971 and 2006, the St-Laurent Lowlands ecoregion still accounted for 33% of the country’s dairy cows in 2006. The number of pigs in this ecoregion jumped 193% from 1971 to 2006. During this period, the proportion of pigs in this ecoregion rose from 13% to 24% of the total number of pigs in the country (Table 1).

Notes

1. The Canadian average is approximately 45,000 square kilometres.
   
2. D. Trant, H. Larocque and G. Filoso, 2009, “Ecoregion profile: Lower Mainland of British Columbia,” EnviroStats, Statistics Canada Catalogue no. 16-002-X200900411031, Vol. 3, no. 4.
   
3. G. Filoso and H. Larocque, 2010, “Ecoregion profile: Lake Erie Lowland,” EnviroStats, Statistics Canada Catalogue no. 16-002-X201000111135, Vol. 4, no. 1.