MANITOULIN-LAKE SIMCOE (#134) The Manitoulin-Lake Simcoe ecoregion stretches from the islands of northern Lake Huron, through southcentral Ontario, to the eastern end of Lake Ontario. The climate and biodiversity of this ecoregion is highly influenced by the Great Lakes. The Niagara Escarpment and several areas with hilly landscapes are the dominant landform features, along with the Great Lakes coast. This ecoregion provides habitat for over 75 species at risk, and includes several species of global conservation concern that are restricted in their range to the coasts of the Great Lakes. This ecoregion includes several large cities and areas that are intensively farmed. Almost 40% of this ecoregion remains in natural cover and only 1.9% is within conserved/protected areas. LOCATION The ecoregion extends eastward across southcentral Ontario, from Man- itoulin Island to the Frontenac Arch at the east end of Lake Ontario. The northern edge is marked by the edge of the Canadian Shield. In the U.S., this ecoregion is part of the eastern Great Lakes and extends into northern New York. CLIMATE/GEOLOGY The climate in this ecoregion is characterized by warm summers and mild winters. The mean annual temperature is approximately 6⁰C. The mean annual summer temperature is 16.5⁰C and the mean winter temperature is -4.5⁰C. The mean annual precipitation ranges from 750 to 1,000 millime- tres. Precipitation is generally evenly distributed throughout the year. The ecoregion is characterized by flat to rolling topography. The most prominent landform features include the Niagara Escarpment and several areas with hills that resulted from glacial deposits (such as the Oak Ridges Moraine). The ecoregion also has areas of dry sandy soils, limestone bed- rock plains and dozens of Great Lakes islands, including Manitoulin Island, the largest freshwater island in the world. VEGETATION The Manitoulin-Lake Simcoe ecoregion was once dominated by vast mixed forests interspersed with wetlands, oak savannahs and limestone barrens. The dominant forests are characterized by sugar maple (Acer saccharum), American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), northern red oak (Quercus rubra) and American basswood (Tilia americana). Pioneer species that establish in disturbed sites include eastern white pine (Pinus strobus), paper birch (Betula papyrifera) and trembling aspen (Populus tremuloides). Wetter sites are characterized by silver maple (Acer sacchari- num), balsam fir (Abies balsamea), black ash (Fraxinus nigra) and northern (eastern) white cedar (Thuja occidentalis). Drier sites contain (northern) red oak, eastern white pine and red pine (Pinus resinosa). Open limestone and dolostone barrens — called alvars — can be characterized by mosses, grass- es or low shrubs. This ecoregion also includes sand barrens, inland marshes and fens, and coastal marshes. Historically, most of the forests were old-growth, and disturbances were lim- ited to gaps from large trees falling, tornadoes, ice storms and by large flocks of passenger pigeons (Ectopistes migratorius; now extinct). Fire and flooding also played a role in many vegetation communities, including alvars. Indige- nous Peoples managed some vegetation types by creating forest openings for agriculture and maintaining open canopies in oak savannahs through fire. 1 Ranking categories for biodiversity threat and conserved/protected area are relative to other ecoregions in the southern Canada study area (5=highest, 4=higher, 3=high, 2=low, 1=lower, 0=lowest). The lowest score for conserved/protected area is 1. For biodiversity and threat, the highest category based on measures and criteria approach is used. * Including the waters of the Great Lakes. Photo by NCC Kyle Marquardt MANITOULIN-LAKE SIMCOE (#134) FRESH WATER AND COASTS The ecoregion is within the Great Lakes drainage (Atlantic Ocean basin) and includes the sections of the Lake Ontario and Lake Huron drainage. Major rivers include the Saugeen, Maitland, Trent and Moria rivers, and the headwaters of the Grand River (Figure 1). In addition to the Great Lakes, this ecoregion includes hundreds of inland lakes. These cover approximately 5% of the land portion of the ecoregion. The largest of these include Lake Simcoe, Lake Scugog, Rice Lake and Gull Lake. Wetlands, primarily treed swamps, occur across the ecoregion. Large coastal wetlands occur in some of the sheltered bays of Georgian Bay, river mouths and around Prince Edward County. Wetlands cover approximately 5.6% of the ecoregion. This ecoregion includes over 4,300 kilometres of Great Lakes coast. Common coastal habitats in the ecoregion include low rocky shores, cliffs, cobble beaches, bluffs and sand beaches. AT-RISK VEGETATION COMMUNITIES Mike Dembeck Rare vegetation communities have not been well-documented from this ecoregion. Photo by Lorne Associations that are of potential global conservation concern include: • white spruce - northern white cedar - common juniper/dwarf lake iris - bristleleaf sedge shrubland • creeping juniper - shrubby cinquefoil/little bluestem - Richardson’s sedge dwarf-shrubland • bur oak/poverty oatgrass - (prairie-smoke) limestone open woodland • bluejoint - little green sedge - smooth sawgrass - Ontario lobelia fen • northern white cedar - jack pine/shrubby cinquefoil/limestone calamint wooded grassland WILDLIFE Characteristic wildlife includes white-tailed deer (Odocoileus virginianus), snowshoe hare (Lepus americanus), coyote (Canis latrans), eastern gray and red squirrel (Sciurus carolinensis, Tamiasciurus hudsonicus) and eastern chipmunk (Tamias striatus). Bird species include wood thrush (Hylocichla mustelina), eastern screech owl (Megascops asio), mourning dove (Zenaida macroura), great blue heron (Ardea herodias), pileated woodpecker (Dryocopus pileatus) and mallard (Anas platyrhynchos). Several species of large mammals are now extirpated from this ecoregion, including cougar (Puma concolor) and gray wolf (Canis lupus). Other species, such as fisher (Pekania pennant), North American river otter (Lontra canadensis) and American beaver (Castor canadensis), were once extirpated, but have now returned to much of the ecoregion. AT-RISK PLANTS AND ANIMALS There There are over 75 national species at risk in the Manitoulin-Lake Simcoe ecoregion. Areas with higher numbers of national species at risk include Bruce Peninsula, along the Grand River, Penetanguishene Peninsula and the area in and around Prince Ed- ward County in eastern Ontario. In addition, there are 40 species of global conservation concern, with the highest number associat- ed with alvars and coastal areas of the Bruce Peninsula and Manitoulin Island (Figure 2). Species at risk include: • Jefferson salamander (Ambystoma jeffersonianum) • eastern pondmussel (Ligumia nasuta) • Hine’s emerald (Somatochlora hineana)* • northern map turtle (Graptemys geographica) • piping plover (Charadrius melodus)* • massasauga - Great Lakes/St. Lawrence population (Sistrurus catenatus pop. 1)* • eastern loggerhead shrike (Lanius ludovicianus) • Hill’s thistle (Cirsium hillii)* • redside dace (Clinostomus elongatus)* • small white lady’s-slipper (Cypripedium candidum) • upper Great Lakes kiyi (Coregonus kiyi kiyi) • lakeside daisy (Tetraneuris herbacea)* • pale-bellied frost lichen (Physconia subpallida) *nationally and globally at risk (NatureServe) Photo by NCC MANITOULIN-LAKE SIMCOE (#134) LAND USE Agriculture and urban areas are the predominant land uses, occupying approximately 52% and 9% of the ecoregion respectively (not including the waters of the Great Lakes) (Figure 3). Major crops include corn, soybeans and forage crops. This ecoregion experienced a moderate rate of land conversion (2000-2010) (Table 1). The largest driver is expanding urban areas. In some areas of the region, forests are being converted to urban areas and agriculture, and in others marginal farmlands have been reverting back into forest. Major urban centres include Kingston, Belleville, Peterborough, Oshawa, Kitchener-Waterloo, Barrie and Owen Sound. The total population is 2,828,114 (2016), with a growth of just over 26% in the last 20 years. CONSERVATION CONCERNS The Manitoulin-Lake Simcoe ecoregion is very diverse in its biodiversity, land use and threats. There is significant pressure from urban expansion in the south, and in some of the northern areas there is growing demand for recreational properties and second homes. The Manitoulin-Lake Simcoe ecoregion has experienced high historic rates of conversion of natural habitats to agriculture and urban areas. These have generally stabilized for the ecoregion as a whole, although there are still significant land use change pressures in some areas. High-ranking threats identified from the Nature Conservancy of Canada’s (NCC’s) Natural Area Conservation Plans (NACPs) in this ecoregion include invasive species and habitat conversion. Savannah and alvar systems are threatened by the encroachment of woody vegetation, and some species (particularly reptiles) are threatened by roads. The forests have been significantly impacted by introduced forest pests and pathogens, including Dutch elm disease and emerald ash borer (Agrilus planipennis). Populations of grassland birds and aerial insectivores that breed in this ecoregion have been rapidly declining. CURRENT CONSERVATION STATUS The Manitoulin-Lake Simcoe ecoregion includes some of the most developed and most wild landscapes in Ontario, south of the Cana- dian Shield. Almost 40% of this ecoregion remains in natural cover, but this