Ottawa is located on the border between Canadian Shield and Mixwood Plains ecological zones. This location defines its relatively rich biodiversity. Species occurring in the northern Canadian (Ontario) Shield Ecozone and Southern Mixwood Plain Ecozone can be found here, often in the same habitats.

Moose (Alces alces) and White-tailed Deer (Odocoileus virginianus) in Ottawa Valley

Ontario Shield Ecozone is associated with Precambrian Shield, which occupies approximately 60% of Ontario stretching from the Hudson Bay Lowlands to the Thousand Islands area on the south. The shield is represented by the limestone bedrock which forms specific landscapes with rock outcrops and alvars grown by coniferous forests with Black Spruce (Picea mariana), Balsam Fir (Abies balsamea), Jack Pine (Pinus banksiana) and Tamarack (Larix laricina) on the north and mixed and deciduous forests with Sugar Maple (Acer saccharum) and North-American Beech (Fagus grandifolia) on south. All these forest types can be found in Ottawa Valley and in the Ottawa Greenbelt.  The area is abundant with lakes and rivers; many wetlands are shaped in the result of beaver activity. Although there are some extracting industries in this area, such as mining, logging and hydro-energy, it is relatively intact and still keeps the core diversity typical for the boreal forest and taiga biomes.  

Mixwood Plains Ecozone occupies only 10% from the total area of Ontario, but it has the densest human population and the area is heavily developed in the result of human activity. It is located on the limestone to south of the Precambrian Shield and bounded by three large Great lakes – Lake Huron, Lake Erie and Lake Ontario, and the St. Lawrence River. The area, especially in its northern and eastern parts, is mostly flat. Many flat plains are developed for agricultural production, creating conditions for the movement of some southern prairies and grassland species to the north. Two major rivers – Ottawa and St. Lawrence – form their watersheds in this area with diverse wetlands and rich species diversity. Vegetation is very diverse and presented both coniferous and deciduous trees.  Carolinian forests are grown on the south of this zone; tolerant hardwood forests are represented mostly on the north and in the areas around Ottawa. The most typical trees of this Ecozone growing around Ottawa are coniferous such as a White (Pinus strobus) and Red pines (Pinus resinosa), Eastern Hemlock (Tsuga canadensis), Eastern Red Cedar (Juniperus virgniana), Eastern White Cedar (Thuja occidentalis), and deciduous such as a Sugar (Acer saccharum), Red (A. rubrum), Striped (A. pensylvanicum) and Silver (A. saccharinum) maples, Red (Quercus rubra) and White (Q. alba) oaks, American (Ulmus americana) and Slippery (U. rubra) elms, Yellow (Betula alleghaniensis) and Paper birches, Eastern Black Walnut (Juglans nigra), Butternut (J. cinerea), Trembling Aspen (Populus tremuloides), Balsam Poplar (P. balsamifera), Basswood (Tilia americana), Bitternut Hickory (Carya cordiformis) and others. In spite of development and expanding of urbanization, only about 1.5% of this ecozone is protected. In this eco-zone, many areas, unique landscapes and habitats need urgent protection, because they become isolated in human-created “matrix” and fragmented by growing road network. Road corridors create conditions for dispersal of exotic alien species, which replace native species and form the new environment.   

Animal species diversity in Ottawa valley is relatively high, because species belonging to both – Canada Shield and Mixwood Plain ecozones – occur in this area. In spite of human activity, many species well adapted and live in close human neighborhood. Some of them sometimes create tiny problems for local gardeners. Some species are well preserved since the time when this area was not developed. Another species has been dispersed relatively recently. For example, a White-tailed Deer (Odocoileus virginianus) spread to the north, because evident climate change and created favorable conditions for this species in open mixed woods altering with farms, which provide rich harvest of herbs. Other species, such as an American Red Squirrel (Tamiasciurus hudsonicus), opposite, moves to the south and compete with an Eastern Grey Squirrel (Sciurus carolinensis) for habitats in the towns and greenbelts. Bird feeders placed along trails ensure feeding for both squirrel species; therefore, their populations in the cities and around cities are flourishing.  Groundhogs (Marmota monax), Eastern Chipmunk (Tamias striatus) and raccoons (Procyon lotor), Eastern Cottontail (Sylvilagus floridanus) and other mammals in some degree benefited from urban development and established successful urban populations, which survive in suburban areas and in the city parks. However, roads provide limiting barriers for many mammal species and their dispersal to the new areas is often impossible. Bird species in Ottawa Valley are diverse and abundant; but their composition usually change with seasons. Diverse reptile and amphibian species are also well represented. The diversity of invertebrates and especially insects is large in the southern regions; In the northern regions, several species of bloodsucking insects can be very numerous in the summer, creating certain inconveniences for visiting these places.

The Ottawa region is attractive for any naturalist, who interested to know more about wildlife in Canada. Any season here is fascinating. However, perhaps, late spring – the end of May and the beginning of June, as well as autumn – the end of September – the beginning of October – are most attractive to naturalists, since it is in these seasons that one can observe a greater number of species, flowering “festivals” and bright autumn colors.