**2.2 Review of upper level generalizations of Canada**

The Ecological Framework from Canada Ecological Stratification Working Group in 1996 defined four upper levels of ecosystems as a nested hierarchy. Definitions and the number of map units for the four levels of generalization are outlined in **Table 1** in Ref. [39] and **Figure 1B** and updated by Statistics Canada in 2018.

In brief, Bailey's 100 Polar Domain only included an area with short summer and low temperature throughout the year, which had been divided into three major Divisions, Icecap Division, Tundra Division, and Subarctic Division, furthermore had been recognized and delimited into 13 Provinces (124,125,126, M121, M125, M126, M127,131,135,139, M131, M135, M139). Bailey also extended Humid Temperate Domain (200) to Canadian Territorial and classified Warn Continental Division (210), Hot Continental Division (220), Marine Division (240), Prairie Division (250), and Dry Domain (300) overlaying with Canada subcontinent. However, the Provinces' descriptions had very little content about Canadian Territory (242, 244,245,251, 331, 332, etc.).

Bailey's 100 Polar Domain overlays the area of Canadian eight Ecozones of Arctic Cordillera (covers Ecoregion 1–7), Northern Arctic (Ecoregion 8–31), Southern Arctic (Ecoregion 32–49), Taiga Plains (Ecoregion 50–67), Taiga Shield (Ecoregion 68–86), Boreal Shield (Ecoregion 87–116), Atlantic Maritime (Ecoregion 117–131), Taiga Cordillera (Ecoregion 165–171) in **Figure 1B**. Furthermore, Bailey's 200 Humid Temperate Domain covers the area of Canadian six Ecozones of Mixedwood Plains (covers Ecoregion132–135), Boreal Plains (Ecoregion 136–155), Prairies (Ecoregion 156–164), Boreal Cordillera (Ecoregion 172–183), Pacific Maritime (Ecoregion 184–197), Montane Cordillera (Ecoregion 198–214). In addition, the Prairies in Canada is extended from 200 Humid Temperate Domain to 300 Dry Domain.

Early pioneering works in North America evolved from forest and climate classifications and were often climate-driven, referred to in [1, 2, 13, 31, 32]. The use of more holistic classifications was recent from 1980′ to 1990′. The holistic approaches were recognized and considered the importance of a broad range of physical and biotic characteristics for identifying ecosystem regionalization and classification. They recognized that ecosystems of any size or level were not always dominated by one particular factor. In describing the ecoregion framework of Canada in [13], Wiken indicated, "The Ecological land classification is a process of delineating and classifying ecologically distinctive areas of the Earth's surface, which can be viewed as a discrete system that has resulted from the mesh and interplay of the geologic,


*E.g.* **11.1.165.0858** *represented ecozone, ecoprovince, ecoregion and ecodistrict coordinately.*

#### **Table 1.**

*Upper level ecosystem classification of Canada.*

*Implement and Analysis on Current Ecosystem Classification in Western Utah of the United… DOI: http://dx.doi.org/10.5772/intechopen.100557*

landform, soil, vegetative, climatic, wildlife, water, and human factors.". Therefore, land classification can be applied incrementally on a scale-related basis from sitespecific to broad ecosystems.

Because of underlying dynamics of the ecosystems, the multiple patterns of correlation among the biotic, abiotic, and human factors produced the complex; these approaches were apt to produce a converging depiction of regions and significant ecosystem boundary overlapping between Canada and the United States in Refs. [1, 34, 35, 38, 39]. Thus, Canada's continental upper level ecoregion framework defined the ecological Mozaic on a sub-continental scale, representing an area of the Earth's ecological units characterized by interactive and adjusting abiotic and biotic factors. It is not possible to equate Canada and US classification systems directly in [31].
