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Theme: Human/Ecosystem Interactions

Key finding 8
Protected areas

National key finding
Both the extent and representativeness of the protected areas network have increased in recent years. In many places, the area protected is well above the United Nations 10% target. It is below the target in highly developed areas and the oceans.

An analysis of protected areas in the Mixedwood Plains was conducted for ESTR using data from the Conservation Areas Reporting and Tracking System (CARTS) and the ecozone+boundaries6 established for use in the project.169 The CARTS database, maintained by the Canadian Council on Ecological Areas (CCEA), houses data on protected areas in Canada categorized using standardized categories developed by the International Union for the Conservation of Nature (IUCN). The categories refer to the primary management objective of the protected area.

Prior to 1992 (the signing of the Convention on Biological Diversity), 0.7% of the ecozone+ was protected. By May 2009, protected areas in the Mixedwood Plains Ecozone+covered 1.6%Footnote one i of the landbase and  totalled 1,887 km2 (Figure 18), including:170

  • 843 km2 in 172 protected areas (0.7% of the ecozone+) classified as IUCN categories I-IV, categories that include nature reserves, wilderness areas, and other parks and reserves managed for conservation of ecosystems and natural and cultural features, as well as those managed mainly for habitat and wildlife conservation;
  • 1,044 km2 in 283 protected areas (3.3% of the ecozone+) classified as IUCN categories VI, a category that focuses on sustainable use by established cultural tradition; and
  • 0.16 km2 in 12 protected areas (all established since 2000; <0.01% of the ecozone+) not classified by IUCN category.
Figure 17. Distribution of protected areas in the Mixedwood Plains Ecozone+, May 2009.
Southern Ontario
Long description for Figure 17

This map shows that the majority of protected areas in this ecozone+ are along the St. Lawrence River and on the northern tip of the Bruce Peninsula. A few very small protected areas are scattered through the rest of the ecozone+.

Source: Environment Canada, 2009171 using data from the Conservation Areas Reporting and Tracking System (CARTS), v.2009.05, 2009;172 data provided by federal, provincial, and territorial jurisdictions

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Figure 18. Growth of protected areas in the Mixedwood Plains Ecozone+, 1984–2009. Data provided by federal and provincial jurisdictions, updated to May 2009. Only legally protected areas are included. IUCN (International Union for Conservation of Nature) categories of protected areas are based on primary management objectives (see text for more information).
bar chart
Long description for Figure 18
This stacked bar graph shows the following information: Cumulative area protected (km2)
Year protection establishedIUCN Categories I-IVIUCN Category VI

Source: Environment Canada, 2009171 using data from the Conservation Areas Reporting and Tracking System (CARTS), v.2009.05, 2009172 data provided by federal and provincial jurisdictions

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Based on the CARTS data, the amount of protected area in the Mixedwood Plains is the lowest of any of the terrestrial ecozone+ in Canada and well below the Convention on Biological Diversity’s target to protect 10% of each of the world’s ecological regions.

Because the Mixedwood Plains Ecozone+ is predominately a private land base with few government lands available for protection, growth in traditionally designated protected areas has been very difficult. Other regulatory approaches have and continue to be used to provide  protection for lands significant to biodiversity conservation.173 Protection is achieved through a number of designations and mechanisms with varying degrees of protection (see Evidence from Ontario and Evidence from Quebec sections below).

Evidence from Ontario

In the Ontario portion of the Mixedwood Plains, only those protected areas which are IUCN categories I–III have been categorized and submitted to the CARTS database. This means there are a large number of protected areas in Ontario which have not been classified which would likely be members of the IUCN categories IV–VI. Consequently, the number of protected areas for the Ontario portion of the ecozone+ is currently underestimated. (In constrast, in Quebec, all protected areas have been assigned an IUCN category.)

Historically, the first protected area within the Ontario portion of the Ecozone+ was Queen Victoria Niagara Falls Park established in 1887. The second oldest provincial park in Ontario, and the oldest in the Ontario portion of the ecozone+ is Rondeau Provincial Park which was established in 1894 on the north shore of Lake Erie. Growth of regulated protected areas has been slow and large gaps in representation or biodiversity protection still remain. The rate of protection started to increase in Ontario in the late 1960s and continued into the 1970s. Funding during this time period came from two sources: the Federal Agricultural and Rehabilitation (later Rural) Development Act (ARDA) and the Canada-Ontario Rideau-Trent-Severn (CORTS) committee (Killan 1993). Under ARDA, between 1967 and 1975, the federal government provided financial assistance, on a cost-sharing basis, to assist in underwriting the purchase and start-up costs of new provincial parks in economically depressed and declining rural areasFootnote two ii (Killan 1993). In 1975, the federal and Ontario governments accepted the CORTS committee’s recommendations of acquiring both extended use and day-use parks along the Rideau and Trent Severn waterways. Most of the land acquisition undertaken along the Rideau system was expansion of existing parks and park reserves. The second major increase in the amount of protected areas in Ontario came in response to the Strategic Land Use Planning Program (SLUP) and the associated District Land Use Guidelines (DLUG) which were written between 1980 and 1983 (Killan 1993). The SLUP and DLUG programs were large scale planning efforts to accommodate the competing interests (e.g., forestry, tourism, protected areas, mining) on Ontario’s Crown lands. Once the decisions were made in the SLUP and DLUG programs, approximately 26 new provincial parks or park additions were created in the Ontario portion of the ecozone between 1983 and 1989Footnote three iii.

A summary of key designations and mechanisms with their corresponding policy and level of protection are noted in Table 8 and described in further detail below.

Table 8. Ontario portion of the Mixedwood Plains Ecozone’s diversity of protected areas related to legislation and general IUCN Classification.Footnote four iv
SitesDesignation/MechanismLegislation or Key PolicyProtection/ IUCN Classification
Federal and Provincial SitesNational Parks *Footnote five vCanada National Parks Act (2000)Fully Protected – IUCN II
Federal and Provincial SitesProvincial Parks *Provincial Parks and Conservation Reserves Act (2006)Fully Protected – Nature Reserve – IUCN Ia; Natural Environment, Waterway and Recreation classes – IUCN II; Cultural Heritage IUCN III
Federal and Provincial SitesConservation Reserves*Provincial Parks and Conservation Reserves Act (2006)Fully Protected – IUCN II
Federal and Provincial SitesWilderness Area*Wilderness Areas Act (1959)Fully Protected for WA in MWP Ecozone is less than 260 ha – IUCN III
Federal and Provincial SitesNational Wildlife Areas*Canada Wildlife Act 1994Fully Protected  - IUCN variable Ia; Ib; II; III or IV
Federal and Provincial SitesMigratory Bird Sanctuaries*Migratory Bird Convention Act (1994)Fully Protected only if located within regulated designations such as National Wildlife Areas.  If this is the case their IUCN classification can vary among IUCN categories Ia; II; III or IV.
Federal and Provincial SitesProvincial Wildlife Management AreasFish and Wildlife Conservation Act (1997)Fully Protected if in regulation – IUCN IV or V
Federal and Provincial SitesNational Historic SitesHistoric Sites and Monuments Act (1985) and the Canada National Parks Act (2000)Fully protected – IUCN III
Federal and Provincial SitesNational Capital Commission’s GreenbeltNational Capital ActFully protected within the Greenbelt are Core Natural Areas (IUCN Ia), Natural Area Buffers (IUCN II) and Natural Area Links (IUCN II).
Selected Provincial-Municipal Designations and MechanismsConservation Authority LandsConservation Authorities Act 1990Fully protected for those lands within CA properties that are managed to protect biodiversity – IUCN variable from Ia; II; III or IV.
Selected Provincial-Municipal Designations and MechanismsProvincially Significant WetlandsProvincial Policy StatementFully protected under policy – IUCN Ia; III or IV
Selected Provincial-Municipal Designations and MechanismsAreas of Natural and Scientific Interest (ANSI)Provincial Policy StatementPartially protected under policy for development and site alteration can occur.  If fully protected under Official Plans IUCN 1a or III.  Fully protected if a component of another protected designation e.g. provincial park.
Selected Provincial-Municipal Designations and MechanismsEnvironmentally Sensitive Areas; Community Forests and/or other areas.As defined in a municipal Official Plan or in a MNR plan or Conservation Authority planToo variable to provide level of protection or IUCN category.  Site by site assessments would be required.

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Federal and provincial sites

Within Ontario, regulated protected areas include national and provincial parks, conservation reserves, and wilderness areas. National parks (3) are a federal designation under the National Parks Act (2000) and represent 17,820 ha. The key provincial designations are provincial parksFootnote six vi (45,597 ha) and conservation reserves (2,632 ha), both designated under the Provincial Parks and Conservation Reserves Act (2006). Wilderness areas designated under the Wilderness Areas Act (1959) are considered fully protected with only one site (39 ha) of ten occurring outside existing provincial parksFootnote seven vii. This suite of protected areas represents 66,088 ha or 0.7% of the ecozoneFootnote eight viii and fall within the IUCN categories Ia, II, or III.

A number of additional federal and provincial designations (2) and one conservation mechanism are dedicated to species and species population management within the ecozone+.  Federally, National Wildlife Areas (NWAs) make up 5,143 ha with federal Migratory Bird Sanctuaries (MBSs) contributing another 5,026 hectares. Adding provincial Wildlife Management Areas (25,826 ha) (WMAs) results in at grand total of 35,995 ha, or 0.4%, of the ecozone+ for this general class of protected areas. Wildlife Management Areas are mechanisms for conservation of species, habitats and ecosystems. They provide full or partial protection via the Fish and Wildlife Conservation Act (1997) via land use planning direction on Crown land or via landowner agreements on private lands. Some WMAs have been captured within Conservation Authority lands or provincial parks and are subject to specific legislation and planning.  National Wildlife Areas may qualify as IUCN category Ia, Ib, II, III, or IV and provincial WMAs as IUCN categories IV or V. MBSs qualify as an IUCN category only when part of a NWA.

Federal cultural/ historic areas such as National Historic Sites include the Trent-Severn waterway and the Rideau Canal (a UNESCO World Heritage Site).  The majority of these are within the Mixedwood Plains Ecozone+ and contribute additional fully protected lands that make up to 0.01% of the ecozone.  IUCN protected area classification is still not known for these heritage sites; however, depending on achievement of IUCN criteria and evaluation they may qualify as IUCN Category III protected areas.

Finally, National Capital Commission lands (about 10,000 ha) provide further direction for the management of biodiversity by including local and regional ecosystems within a 20,000 ha greenbelt. The National Capital Commission’s greenbelt provides for partial and fully protected natural areas depending on the zone discussed. Three zones within the greenbelt--Core Natural Areas, Natural Area Buffers, and Natural Area Links--would qualify as fully protected. Some additional consideration in recognizing the entire greenbelt as an IUCN Category V may be warranted (Gray et al., 2009).

Provincial-municipal designation and mechanisms

Other provincial and municipal site specific natural heritage area designations and conservation mechanisms include provincially significant Areas of Natural and Scientific Interest (ANSIs), Provincially Significant Wetlands (PSWs), significant woodlands, Conservation Authority (CA) Properties, Environmentally Sensitive Areas (ESAs), and community/municipal forests and open space lands that are managed for conservation. This group of natural heritage areas is very diverse in its level of protection ranging from full to partial protection, which is achieved through several interrelated and often complementary protection mechanisms. For example, MNR identifies (or confirms) whether wetlands are provincially significant (PSW) while protection may be afforded by a conservation authority regulation and a municipality designating the PSW in its Official Plan for protection. Other mechanisms such as zoning by-laws and site alteration by-laws may need to be in place to implement official plan policies and control land use. Ontario provides policy direction on land use planning for natural heritage interests (amongst a range of provincial interests) through the Provincial Policy Statement issued under the Planning Act. ANSIs, PSW, and CA properties include both full and partial protection. If fully protected they would be classified as IUCN 1a or III (ANSIs), 1a, II, or IV (PSW), and 1a, II, III, and IV (CA), but a site by site assessment is lacking and the level of custodial protection management is not uniform throughout the ecozone+. Private land adds an additional complication for these designations for private land features are not protected in perpetuity--so they are at risk of being lost over the medium to long term. Total hectares involved for identified ANSIs, PSWs, and CA properties approaches 900,000 ha, or 10.5%, of the ecozone+. Finally the Provincial Policy Statement provides municipalities an opportunity to recognize natural heritage systems (e.g., core natural heritage areas with linkages) within their planning processes and products.  To date, identifying and protecting National Historic Sites in municipal Official Plans is still a rather new concept and requires a more concerned effort across the ecozone+ than has occurred in the past.

IUCN classification for ESAs, community forests, or partially protected areas is unknown with identification determined on a case-by-case basis.  For example, ESAs encompass such designations as ANSIs but could also involve areas of local interest as well (e.g., bird nesting areas, deer wintering yards, recharge areas). The level of protection is determined by the policies within Official Plans and via restrictions in zoning by-laws that only apply when approvals under the Planning Act are being sought; therefore protection varies greatly across the ecozone+. To identify and maintain a certain IUCN level of protection, periodic site assessments of values and policies would have to occur as well as enhanced commitments to protection by landowners and governments.

Landscape-scale mechanisms

Previously discussed protection designations and mechanisms are enhanced through provincial direction captured in specific geographies that work at a landscape level.  Land use plans such as the Greenbelt Plan (covering 728,450 ha), the Oak Ridges Moraine Plan (190,000 ha), and portions of the southern section of the Niagara Escarpment Plan and the Lake Simcoe Watershed Plan provide landscape level direction for municipalities for the planning and management of their conservation lands.  For the most part, these larger landscape level plans provide policy direction for full to partial protection to a broader range of natural heritage features and areas than what is provided solely by the PPS under previously mentioned designations and mechanisms. Unfortunately, some land use activities fall outside of the Planning Act and the Provincial Policy Statement. Such activities may negatively impacted NH areas and features regardless of the protection provided to these areas via planning mechanisms. Finally, a protection partnership among federal, provincial, regional, and local interests is found within the Rouge Park Alliance Partnership. This geography approaches a landscape scale and includes some 4,072 ha. This area may contain lands that could achieve IUCN categories Ia, II, III, and IV protected area status with the overall area being classified as category V.

Private landowner mechanisms

Private landowner mechanisms and contributions to natural heritage/biodiversity protection involve a significant suite of actions ranging from government programs with private landowners [Conservation Land Tax Incentive Program(CLTIP) and Managed Forest Tax Incentive Program (MFTIP)] to non-government organization lands (NGOs, such as the Nature Conservancy of Canada and Ontario Nature) to national private non-profit organizations (Ducks Unlimited) to Ontario Heritage Land Trust properties (a provincial government non-profit agency).  Also existing within the ecozone are individual land trusts. Land trusts are charitable organizations that assist in achieving land/conservation agreements and/or are involved in stewardship of such agreements.  Level of protection ranges from full to partial protection to sustainable forest management activities under MFTIP.  The diversity of lands held and the diversity of objectives and mechanisms used make IUCN category identification difficult. Where full protection is achieved properties may qualify as IUCN Categories Ia, III, or IV. Private landowner mechanisms may reach 0.1% of the ecozone+.

Evidence from Quebec

In Quebec, significant protected areas were added in the years 1993, 2000, and 2005. Much of the recent increases have been due to the addition of Categories IV (“Habitat/Species Management Areas”) and VI (“Protected Areas with Sustainable Use of Natural Resources”) protected areas. In Quebec, protected areas are classified within 21 designation categories which all correspond to the broadly adopted IUCN protected area categories.174 At present, protected areas are not listed per ecozone+, the provincial registry sums up the information per designation class for the entire territory.

The human footprint in the Quebec portion of the Mixedwood Plains Ecozone+ is evaluated at 62%, where agriculture alone occupies more than 50% of the territory.175 In such a setting, it does not come as a surprise that the protected area network shows the lowest connectivity index out of 13 natural provinces. Habitat loss and fragmentation is one of the most important ecological issues in southern Quebec. Private land tenure hinders the implementation of an extended network for the conservation of key habitats. In spite of those considerations, the proportion of protected areas has increased by more than 1,400 km2 from 2002 to 2009.175 More than 90% of protected areas are different wildlife habitats smaller than 10 km2 that belong to IUCN category VI. The Quebec national parks (5) and Gatineau Park (National Capital Commission) contribute 77.8 and 361.3 km2 respectively, while MBSs (12) and ecological reserves (15) maintain protection over 76.6 and 24.5 km2, respectively. In order to improve the representativeness of different habitats, the ecozone+would benefit from a better provision of mixedwood stands such as yellow birch–balsam fir–maple sugar, yellow birch–maple sugar, maple sugar–linden tree and black pruce stands.175 An assessment of the present protected area network to secure species at risk habitats and improve plant and animal population recovery is also needed.

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Key finding 9

National key finding
Stewardship activity in Canada is increasing, both in number and types of initiatives and in participation rates. The overall effectiveness of these activities in conserving and improving biodiversity and ecosystem health has not been fully assessed.

The two most comprehensive national conservation programs, the Ecological Gifts Program (EGP) and the Natural Areas Conservation Program (NACP), have brought about significant environmental benefits in the ecozone+. Between 1995 and 2010, the EGP has allowed land trusts, conservation groups, municipalities, as well as provincial and federal departments to secure 13,057 ha on 339 properties in Ontario and 2,381 ha on 43 properties in Quebec, either as full title or as conservation easements. As of June 2011, the Nature Conservancy of Canada and partner groups, such as Ducks Unlimited Canada, had secured 7,199 ha through 87 conservation projects (5,441 ha in Ontario and 1,758 ha in Quebec) under the $225 million NACP.

Habitats protected under these programs have to meet stringent ecological significance criteria.176,177 The majority of the secured lands are wetlands or forested lands.  Properties acquired through NACP and EGP protect 72 species listed under the federal Species at Risk Act, including shumard oak (Quercus shumardii; Special Concern), climbing prairie rose (Rosa setigera; Special Concern), blue ash (Fraxinus quadrangulata; Special Concern), American ginseng (Panax quinquefolius; Endangered), grey fox (Urocyon cinereoargenteus; Threatened), yellow-breasted chat (Icteria virens; Endangered), loggerhead shrike (Lanius ludovicianus; Endangered), peregrine falcon (Falco peregrinus; Special Concern), short-eared owl (Asio flammeus; Special Concern), least bittern (Ixobrychus exilis; Threatened), northern dusky salamander (Desmognathus fuscus; Endangered), eastern foxsnake (Pantherophis gloydi; Endangered), blue racer (Coluber constrictor foxii; Endangered), milksnake (Lampropeltis triangulum; Special Concern), Lake Erie watersnake (Nerodia sipedon insularum; Endangered), spiny softshell (Apalone spinifera; Threatened), and endemic species such as copper redhorse (Moxostoma hubbsi; Endangered) in the Richelieu River and Victorin’s gentian (Gentianopsis virgata; Threatened) as well as Victorin’s spotted water-hemlock (Cicuta maculata; Special Concern) inhabiting the St. Lawrence tidal marshes.

Evidence from Ontario

With a high proportion of the Mixedwood Plains Ecozone+ in private ownership, voluntary stewardship activities are a crucial component of biodiversity conservation. Stewardship can include protection through easements and land securement, incentive programs, and restoration activities such as planting trees. Education and awareness activities such as nature interpretation centres and programs for youth can be seen as contributing to stewardship. Stewardship activities in the Mixedwood Plains involve a wide range of organizations and participants from the non-government sector, the agricultural sector, industry, First Nations, government, and private individuals.

Overall, stewardship in the Ontario portion of the Mixedwood Plains is best summarized by two long-term trends: increasing levels of public engagement; and the increasing scale of stewardship activities.

Stewardship activity has grown considerably in recent years as demonstrated by recent trends in participation levels in many stewardship programs. The provincially administered Managed Forest Tax Incentive Program and Conservation Land Tax Incentive Program provide property tax relief to participating properties. The Managed Forest Tax Incentive Program grew from just under 9,000 participating properties in 1998 to over 11,000 properties in 2008, covering more than 758,000 ha.178 Likewise, the number of properties participating in Conservation Land Tax Incentive Program roughly doubled over the same timeframe, with current participation at 16,000 properties covering 216,000 ha (Figure 19).

Figure 19. Growth of the Conservation Land Tax Incentive Program, 1991–2008.
line chart
Long description for Figure 19
This line graph shows the following information:
YearTotal parcels of landTotal area (ha)

Source: adapted from Ontario Ministry of Natural Resources, 2008181

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Agricultural stewardship comprises a significant portion of the stewardship activity in the ecozone+ with 65% of all Ontario farms participating in the Environmental Farm Program with 12% of farms implementing Best Management Practices such as nutrient or riparian management between 2005 and 2008.179 Similarly, over the last 5 years, the number of projects completed by the Ontario Stewardship Program has increased by over 15%, with more than 650 projects completed in 2009.70 New programs also aim to expand the stewardship sector. One example is the 50 Million Trees Program which fosters partnerships to support the planting of 50 million trees by 2020 to combat climate change.180

Alongside this growth in stewardship participation, there has also been a shift towards landscape-scale stewardship initiatives which attempt to focus stewardship activities to priority areas and projects based on an overall conservation strategy. Examples include the Oak Ridges Moraine Conservation Plan182 and the Lake Simcoe Protection Plan,183 both of which are supported by stewardship activities targeted to priority areas. Similarly, the Canada Ontario Agreement Respecting the Great Lakes Basin Ecosystem184 supports stewardship projects that are linked to priority watersheds and outcomes such as restoring coastal habitats, improving water quality, and maintaining and enhancing fish populations. Other examples include the development of the Conservation Blueprint for the Great Lakes by the Nature Conservancy of Canada185 and the community-led development of natural heritage systems facilitated by the Ontario Ministry of Natural Resources.

The last decade has also seen a growth in organizational coordination with the goals of fostering collaboration, developing guiding frameworks for stewardship activity, realizing efficiencies in implementation, and generating a higher profile for the sector as a whole.186  This coordination takes place at the local level, facilitated by organizations such as Ontario Stewardship, individual Conservation Authorities or network organizations like the Carolinian Canada Coalition. At the provincial scale, the Stewardship Network of Ontario and the Biodiversity Education and Awareness Network support the implementation of stewardship engagement activities outlined in Ontario’s Biodiversity Strategy.187

While there has been significant growth in stewardship actions, the coordination of stewardship activities, and the number of people involved in stewardship, there is little sustained measurement of the cumulative outcome of the breadth of stewardship activities.186 The adequacy of stewardship actions should be measured against the health and functionality of the ecosystem. The downward trends in the supply of many habitat types and declines in species richness outlined in this report suggest that the scale of current stewardship efforts is insufficient to offset both the area’s historic biodiversity losses and current stressors on the ecosystem.146,186,188 Notwithstanding publications such as How Much Habitat is Enough?,189 more effort is required to define what constitutes an adequate level of conservation and stewardship and tools to measure and compare the efficiency of the protection measures put in place. The development of meaningful targets and the monitoring of progress against those targets at the ecozone+, ecodistrict, and watershed levels would assist in measuring the overall effectiveness of stewardship actions over time and help ensure future ecosystem functionality and the provision of ecosystem services.

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Ecosystem conversion

Ecosystem conversion was initially identified as a nationally recurring key finding and information was subsequently compiled and assessed for the Mixedwood Plains Ecozone+. In the final version of the national report,3 information related to ecosystem conversion was incorporated into other key findings. This information is maintained as a separate key finding for the Mixedwood Plains Ecozone+.

The Mixedwood Plains Ecozone+ has undergone some of the most extensive changes in land cover of any ecozone+in Canada. In 2011, 68% of the ecozone+ was agricultural land (second only to the Prairie Ecozone+ which has 87% agricultural land cover).8 Most of the land in the Quebec portion of the ecozone+ was cleared between 1800 and 1880 at a time associated with the first population peak in the area14 while the amount of cleared land in Ontario was at its maximum around 1920.18 (The changes in major natural biomes or ecosystems are discussed in Key Findings 1 thorough 7). In this section, the driving forces behind these changes, the expansion of urban areas, shoreline conversion, agricultural intensification, and loss of agricultural land, are discussed.

Expansion of urban areas

According to the 2006 Census of Canada, 53% of Canada’s population was located in the Mixedwood Plains Ecozone+. The Windsor–Québec Axis, which runs through the core of the ecozone+, is considered the urban heartland of Canada.190,191 Between 1971 and 2006, the population of the Mixedwood Plains grew by 51%, which was higher than the population growth in the rest of Canada (42%).192,193 This increase in population is not equally distributed throughout the ecozone+.  Census Canada data for the Ontario portion of the ecozone+ on population patterns and trends between 1951 and 2006 showed that by 2006, the area of sparsely populated (< 10 persons/km2) and rural land (10 to 25 persons/km2) had declined to 58% of the 1951 level, while the land area with urban population densities (60 to 400 persons/km2) had almost tripled. Growth was largest in the semi-urban category (25 to 60 persons/km2) (Figure 20). These trends are characteristic of urban deconcentration, a process in which population decline in the centre of cities is matched by population growth and expansion in suburban areas.191

Figure 20. Trends in land area by population density class in the Ontario portion of the Mixedwood Plains Ecozone+, 1951–2006.
line chart
Long description for Figure 20

This line graph shows that, for this region between 1951 and 2006, land area decreased in both the rural (from 39,000 km2 to 27,000 km2) and sparsely-populated (from 24,000 km2 to 9,000 km2) population density classes. The largest increase in land area was in the semi-urban density class (from 11,000 km2 to 25,000 km2), with smaller increases in the urban (from 5,000 km2 to 14,000 km2) and dense urban (from 1,000 km2 to 5,000 km2) classes. All these numbers are approximate.

Source: Census of Canada, 2010194 Category definitions:191 dense urban (>400 persons/km2), urban (60–400 persons/km2), Semi-urban (25–60 persons/km2), rural (10–25 persons/km2), sparsely populated (< 10 persons/km2)

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Analysis of land cover data confirms the census data. Comparing Landsat data from 1974 and 1990 with data from 2005, Ahern et al.8 found urban land cover increased by 667.1 km2 (62.6%) in the Golden Horseshoe area of Ontario.8 This increase came from loss of agricultural land and, to a lesser extent, losses of forest cover (for discussion of impacts of habitat loss on interior forest birds (see Species of special economic, cultural, or ecological interest). The greatest expansion was centred on Toronto. There was relatively little growth in the Hamilton and Niagara regions between 1974 and 1990 but it appears to have accelerated between 1990 and 2005. The overall rate of urbanization in the Toronto–Hamilton–Niagara region was 20.3 km2/yr between 1974 and 1990, increasing to 22.8 km2/yr between 1990 and 2005.8 When land conversion was examined in the Toronto area alone, similar findings were observed with the most significant land use conversion from 1993 to 2007 being to urban uses, followed by conversion to golf courses and pits and quarries.195

Analyses of landscape change in Quebec have consistently found urban cover increased from the 1950s to 2001.22,25,38,196 In Quebec, urban growth has focused around Montréal and Québec with an increase in urban area of 227 km2  or 20% (from 1,153 to 1,380 km2 ) between 1993 and 2001.  Most of this expansion occurred on high quality fertile soils25 at the expense of annual and perennial crop land and forested land.21,25

Urban expansion generally causes native species to have reduced survival and reproduction near homes197 and native species richness often drops with increased urban density.198 When urban trees from ten cities in southern Ontario were examined, it was found that urban trees had significantly lower mycorrhizal fungal colonization (mycorrhiza help the trees gain nutrients from the soil) than trees from rural environments, though it was not clear what was responsible for the difference.199 Some species adapted to urban habitats are experiencing declines. Loss of forest cover  has been seen to cause both decreases in the populations of interior forest nesting birds (See Species of special economic, cultural, or ecological interest) and losses of large predators from many areas of the ecozone (See Food webs).

Shoreline conversion

Loss of natural shoreline has been an ongoing process since the arrival of European settlers as development in the ecozone+ was initially focused along shorelines.15 However, further shoreline conversion has also occurred more recently. When land use change was examined for the American portion of the Great Lakes, it was found that between 1992 and 2001, 2.5% of the Great Lakes watershed had experienced shoreline change. Changes due to new construction included a 33.5% increase in low-intensity development and a 7.5% increase in road area.  Agricultural and forest land each experienced a 2.3% decrease in area and development was mostly concentrated near coastal areas.200 Most of the wetland loss was within 1 km of the shoreline.200

Similar data were not available for the Canadian portion of the Great Lakes, however, in a detailed study of 660.8 km of shoreline along southern Georgian Bay, the extent of shoreline alteration was mapped and assessed (Figure 21).201 The highest levels of shoreline alteration occurred in the Town of Midland (51.7%), City of Owen Sound (39.1%), and Town of Collingwood (34.8%). Very little alteration has occurred in the Municipality of Northern Bruce Peninsula (1.2 %) which has a high percentage of shoreline in protected areas (including National and Provincial Parks, Nature Conservancy of Canada and provincial Nature Reserves) as well as rocky, steep terrain that restricts shoreline development.  The high levels of alteration found in the towns of Midland and Collingwood (Figure 22) were associated with shorter weekend commuting distance from urban centres in the Greater Toronto Area, deeper soils, and flatter terrain.201

Figure 21. Shoreline alteration in southern Georgian Bay.
Map of Georgian Bay
Long description for Figure 21

This map shows the location of conservation lands and the type and location of shoreline alteration along southwestern Georgian Bay from. The largest areas of conservation lands are in the Bruce Peninsula, in the central part of Grey County, and in the Georgian Bluffs and Blue Mountains areas. The most extensive type of shoreline alteration is groynes, which are found almost continuously along the shoreline from Port McNicoll to the east end of Wasaga Beach, from the west end of Wasaga Beach to Meaford and along the shoreline of Owen Sound Bay and the Georgian Bluffs. Groynes also occur sporadically along the coast of the Southern Bruce Peninsula. Concentrations of hardened shoreline are found around Midland, along Wasaga Beach and at Collingwood, Owen Sound and Wiarton. Dredges and docks occur sporadically along the coast and marinas are located at Penetanguishene on the southeastern tip of Georgian Bay and at Tobermory on the northern tip of the Bruce Peninsula.

Source: Buck et al., 2010201

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Figure 22. Photos showing level of shoreline alteration in the Collingwood area of Ontario in 1954 (left) and 2008 (right).
Photos of Collingwood

Source: Buck et al., 2010201

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Loss of natural shoreline has been associated with changes in fish species composition.202,203,204 In a study of 62 coastal wetlands throughout the Great Lakes, the wetlands in Lake Erie and Lake Michigan with agricultural watersheds, turbid water, and little submerged vegetation were dominated by generalist, tolerant fish.204 The largely natural watershed of Lake Superior by comparison, had clear water, abundant submerged vegetation, and a diversity of fish species.204 Disturbed conditions were also associated with more non-native species.204 In Minnesota (just outside the ecozone+), both black crappies (Poxmoxis ngromaculatus) and largemouth bass (Micropterus salmoides) were more likely to nest near undeveloped shorelines than near developed ones.203 When fish communities were studied along the southeastern shoreline of Lake Ontario, it was found that fish abundance increased significantly with increases in submerged vegetation cover as did the frequency of smaller-bodied fish species. Large-bodied fish species such as common carp (Cyrinus carpio) were associated with areas with less submerged vegetation.205

Loss of agricultural land and agricultural intensification

Canada’s most productive agricultural soils are found within the Mixedwood Plains Ecozone+. While the ecozone+ contains only 9% of Canada’s agricultural land, it yields 38% of its agricultural production.206,207  Based on census data from 1971 to 2006 for the Ontario portion of the ecozone+ (Figure 23), the total amount of agricultural land, the number of cattle, and the amount of improved pasture decreased, while cropland increased.208

Figure 23. Trends in selected agricultural characteristics in the Ontario portion of the Mixedwood Plains Ecozone+, 1971–2006.
line chart
Long description for Figure 23
This line graph shows the following information:
YearAgricultural land area (km2)Cropland area (km2)Fertilized land area (km2)Improved pasture area (km2)Number of cattle

Source: Statistics Canada, 2008208

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When the crops under production are examined for the ecozone+ there has been a major increase in soybean production (Figure 24) that reflects the introduction of varieties suitable for more northern climates.209,210

Figure 24. Trends in hectares planted by crop in the Ontario portion of the Mixedwood Plains Ecozone+, 1976–2006.
line chart
Long description for Figure 24
This line graph shows the following information: Hectares planted (numbers approximate)
Corn (grain)650,000900,000750,000780,000785,000800,000650,000
Corn (silage)360,000290,000200,000150,000140,000150,000160,000

Source: Statistics Canada, 2008208

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Based on land cover information derived from satellite imagery, between 1985 and 2005, the amount of agricultural land in the ecozone+ decreased by 0.13%.8 Losses are a result of growth in urbanization, the expansion of scattered non-farm rural residences, abandonment of marginal farmland, and re-growth of forest. Within the remaining farmland, agricultural intensification has reduced pasturelands and increased cropland. When landscape change was studied in the Quebec portion of the ecozone+, a large-scale transition from dairy-oriented farming activity to more intensive agricultural was observed.25 Cover of annual crops increased by 7% from 1993 to 2001 with an associated decrease of 6% in cover of perennial crops.25 The large increase in pig production is considered a potential explanation for this shift in land use. Corn is used as feed for these animals and 98% of all of the corn production in Quebec occurs in the Mixedwood Plains Ecozone+.25 In addition, new corn hybrids have been developed which are suited to this region. The transition from perennial crops to annual crops was also seen over the long term (1950 to 1997) in southern Quebec.21,22 A detailed study done in the Haut-Saint-Laurent area of the ecozone+  showed that agricultural practices intensified from 1958 to 1993, with the number of fields decreasing from 1964 to 1998 and an associated increase in average field size from 2.51 to 3.04 ha.

Agricultural intensification has been linked to an overall decrease in the suitability of agricultural land as wildlife habitat (see Agricultural landscapes as habitat ), declines in birds of grasslands and open/agricultural lands (see Species of special economic, cultural, or ecological interest), and declines in bumblebees (see Species of special economic, cultural, or ecological interest).211

Loss of natural vegetation, fragmentation, and species loss have also been linked to the transmission of wildlife-borne diseases. The transmission of West Nile Virus and Lyme Disease have both been linked to losses of natural habitat and species diversity (See Conclusion: Human Well-being and Biodiversity : Constraint of infectious disease).

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Key finding 10
Invasive non-native species

National key finding
Invasive non-native species are a significant stressor on ecosystem functions, processes, and structure in terrestrial, freshwater, and marine environments. This impact is increasing as numbers of invasive non-native species continue to rise and their distributions continue to expand.

The United Nations Convention on Biological Diversity recognises non-native invasive species as one of the greatest threats to global biodiversity.212 Invasive species can take many forms-- aquatic or terrestrial plants (e.g., European frog-bit Hydrocharis morsus-rane and garlic mustard Alliaria petiolata), aquatic invertebrates (e.g., zebra mussel Dreissena polymorpha), fish species (e.g., round goby Neogobius melanostomus and rudd Scardinius erythrophthalmus) earthworms (Lumbricus terrestris), or forest pests (e.g., emerald ash borer Agrilus planipennis and Sirex woodwasps Sirex noctilio). Comprehensive data on the distribution, spread, and invasion rates of many species groups (taxons) are not available.213 Information is available for terrestrial plant species. In 2008, the Mixedwood Plains Ecozone+ had 139 non-native invasive plant species, the greatest number found in any ecozone+ in Canada (other ecozones+ with very high levels are the Atlantic Maritime Ecozone+ with 130 species, the Pacific Maritime Ecozone+ with 124 species, and the Boreal Shield Ecozone+ with 123 species).214

The Mixedwood Plains has a long settlement history which has facilitated the introduction and spread of non-native species. Aboriginal peoples living in the ecozone+ likely transported animals and plants into the Great Lakes area, beginning a trend that accelerated with European settlement.215 Invasion occurred through many mechanisms including unintentional releases, ship-related introductions, deliberate releases, entry via canals and water diversions, and movement along railroads and highways. As human activity and global trade has increased in the Great Lakes watershed, the rate of introduction of exotic species has also increased. Of the 185 known non-native species in the Great Lakes, 100 species (54%) entered the lakes in the period between 1959 and 2006.216

Invasive species can have many impacts. They may compete with native species for food and habitat,217,218,219,220 be novel predators,221 be less nutritious prey,222 and provide poorer quality habitat for wildlife.223,224 A preliminary analysis of the 1998 Committee on the Status of Endangered Wildlife in Canada (COSEWIC) list of assessed species indicated that 25% of all endangered species, 31% of all threatened species, and 16% of all vulnerable species (now called species of special concern) in Canada were in some way at risk due to the impacts of invasive species.225 Later, Venter et al.226 indicated that introduced or alien species were threatening 22% of the species assessed by COSEWIC (as extinct, extirpated, endangered, threatened, or special concern).

Garlic mustard has been able to out-compete many of the native woody and herbaceous species found in the ecozone+ and the estimate of its spread rate in adjacent areas in the United States is 64,000 km2 per year.227 No single mechanism explains the success of this species but a combination of plant traits, all slightly different from those of native plants, seems to confer garlic mustard with tremendous success in the new habitats it invades.227,228

The forests of the ecozone+ evolved without earthworms, so the introduction and establishment of these species alters natural functions. There are 15 species of lumbricid earthworms living in the ecozone+ considered to be invasive which arrived accidentally due to European settlement.229,230 These worms are able to consume leaf litter much more quickly than naturally occurring decomposers thus altering nutrient cycling (carbon and nitrogen) and soil food web interactions.231,232 Earthworms may also increase N2O (nitrous oxide) emissions and could therefore contribute to production of greenhouse gases.233

Modelling of extinction rates of North American freshwater species has predicted a future extinction rate of 4% per decade due to a variety of threat factors including invasive species.234 A species that exemplifies the kind of change an invasive species can have on aquatic ecosystems is the zebra mussel (Dreissena polymorpha). The zebra mussel forms huge colonies and filters large quantities of plankton from the water column. The colonization of a waterbody is followed by declines or complete losses of native mussel species.99,235,236 Zebra mussels are preyed upon by round goby in their native and introduced range and the spread of zebra mussels has facilitated the spread of the goby.221 Zebra mussels have been shown to bio-accumulate polycyclic aromatic hydrocarbons (PAHs), flouranthene, pyrene, chrysese, benzo-anthracene, PCB aroclor, arsenic, chromium, and barium.237 Accumulation of these contaminates, as well as type E botulism in zebra mussel tissue, is thought to represent a potentially realistic hazard to organisms (fish and birds) that feed on them.237 Between the time zebra mussels were first discovered in Lake St. Clair in 1989 and the year 2004, the estimated cost of their damage to drinking water treatment and electric power generation facilities within their North American range was $267 million dollars with the annual costs around $30,000/yr/facility.238

Figure 25 shows the distribution of zebra mussels across the Ontario portion of the ecozone+ in 2009.

Figure 25. Distribution of zebra mussels throughout the Ontario portion of the Mixedwood Plains Ecozone+, 2009. The distribution of this species is very extensive, which could facilitate the invasion of other aquatic invasive species, including the round goby.
map of southern Ontario
Long description for Figure 25

This map shows the distribution of zebra mussel sightings throughout the region, using the following three categories: Zebra Mussel sighting; Zebra Mussel Veliger sighting; and Zebra Mussel not detected.
The heaviest concentrations of zebra mussel sightings were along the northern shore of Lake Ontario, around Lake Simcoe and the Kawartha Lakes, along the shore of Georgian Bay and on both sides of the Bruce Peninsula. Lower numbers of sightings occurred on Manitoulin Island, and along the shores of Lake Huron and Lake Erie. Zebra Mussel Veliger sightings occurred most frequently northeast of Lake Ontario, along the St. Lawrence River, with a few sighting also recorded on the east shore of Georgian Bay, on Manitoulin Island and the northeast shore of Lake Erie. Zebra Mussels were not detected in a few scattered locations throughout central and eastern part of the region and on Manitoulin Island.

Source: Ontario Federation of Anglers and Hunters, 2009239

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Despite the overwhelming negative impact of invasive species on the ecozone+, there have been some good news stories. Studies of mussel populations in the Hudson River in adjacent New York State have shown populations of all four common native bivalves to have stabilized or even recovered--although the zebra mussel population has not declined. How this has happened is not well understood, but it may provide some hope; even after an infestation, native bivalves can persist at population densities about an order of magnitude below their   pre-invasion densities.240

Purple loosestrife (Lythrum salicaria) was choking wetlands across Ontario by the early 1990s. After extensive study, two species of Galerucella beetle were released as a biological control starting in 1992. While the beetles will never completely eradicate purple loosestrife from Ontario,241,242,243 it is now considered controlled and densities of the plant and its ability to produce large quantities of seeds have been greatly reduced. Purple loosestrife has become a part of more naturally-functioning ecosystems.224,239,244,245

Since the Asian long-horned beetle (Anoplophora glabripennis) was first found in the Toronto/Vaughn area in 2003,246 eradication measures were taken and surveillance continues. Though not considered eradicated, there have been no new discoveries or detections of  Asian long-horned beetle in Ontario since December 2007. If five years pass with no Asian long-horned beetles being detected, it will be considered eradicated.247

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Key finding 11

National key finding
Concentrations of legacy contaminants in terrestrial, freshwater, and marine systems have generally declined over the past 10 to 40 years. Concentrations of many emerging contaminants are increasing in wildlife; mercury is increasing in some wildlife in some areas.

Persistent, bioaccumulative, and toxic substances  are long-lasting chemicals that can accumulate in wildlife and humans to levels that can be harmful to ecosystem and human health.248 Government regulations in the 1970s and 1980s banning use and restricting emissions of compounds such as polychlorinated biphenyls (PCBs), pesticides such as dichloro-diphenyl-trichloroethane (DDT), and heavy metals such as lead and mercury, have dramatically reduced the amounts of persistent, bioaccumulative, and toxic substances in the environment (e.g., Hites 2006248). Burdens remain, however, due to past use (from known and unknown contaminated sites), continued use (such as PCBs and mercury), and from by-products of other processes (e.g., Nizzetto et al. 2010249). However, newer in-use chemicals, such as polybrominated diphenylethers (PBDEs), which are flame retardants used in consumer and building products, can leach into air and wastewater and now exhibit increasing con­centrations in the environment (e.g., Zhu and Hites 2004250). Some PBTs are subject to long-range transport from other areas to Ontario, and appear to be contaminating remote lakes and streams (e.g.,  Ma et al.2005251).

Evidence from Ontario

Ontario Ministry of the Environment monitors levels of persistent, bioaccumulative, and toxic substances in various environmental media such as air, water, sediment, and fish. This information is used, for example, to identify site-specific pollution problems, measure effectiveness of pollution reduction policies and management actions, and advise the public on the consumption of fish from a particular location.252

Concentrations of mercury (eg., Figure 26) and PCBs in sport fish from the inland lakes have generally declined in response to various regulatory actions.252 However, depending on the location, size, and species of fish, current levels may result in some restrictions on fish consumption.252 For most of the inland locations in Ontario, mercury remains a major substance of concern, and is the cause of more than 85% of fish consumption restrictions.252

Figure 26. Concentration mercury in 50 cm walleye from Lake Simcoe, Lake Scugog, Rice Lake, Balsam Lake, and Grand River, 1975–2006.
dot chart
Long description for Figure 26
This scatter plot graph shows the following information: Mercury (µg/g) (numbers approximate) A dashed line shows the 1st Advice level (sensitive population) at .26 µg/g.
YearLake SimcoeLake ScugogRice LakeBalsam LakeGrand River

Source: Data from Sport Fish Contaminant Monitoring Program of Ontario Ministry of the Environment253

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Recently, Ontario Ministry of the Environment began to monitor levels of contaminants of emerging concern, such as PBDEs, polychlorinated naphthalenes, and perfluorinated compounds, in water and fish from selected inland locations. Currently, only limited data exist for these compounds. Although consumption guidelines for these compounds are still in development, it is thought that recent actions, such as ban on some compounds (e.g., Environment Canada 2006254), will eliminate the need for fish consumption restrictions due to their relatively low current levels. 

Efforts to reduce impacts of sources of historical persistent, bioaccumulative, and toxic substances continue in the region as water, sediment, and young-of-the-year fish monitoring identifies localized areas with elevated concentrations. Remediation of several sites (e.g., Pottersburg Creek and Lake Clear) has resulted from these efforts.255

Although improvements in concentrations of some toxic substances such as PCBs and mercury in fish have occurred over the past 10 to 20 years,252 stressors on biodiversity due to contaminants remain, as demonstrated by continued fish consumption restrictions due to concentrations of some past-use toxic substances.

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Key finding 12
Nutrient loading and algal blooms

National key finding
Inputs of nutrients to both freshwater and marine systems, particularly in urban and agriculture-dominated landscapes, have led to algal blooms that may be a nuisance and/or may be harmful. Nutrient inputs have been increasing in some places and decreasing in others.

In lakes and streams, phosphorus is an essential nutrient for the growth of aquatic plants and algae, which provide food for aquatic animals. Sources of phosphorus to water include natural weathering of rocks, erosion of soils, decomposition of plants, and human activities such as the application of fertilizers, discharge of treated waste water, and leaching from septic systems.  Excessive phosphorus inputs can result in eutrophication where there is too much plant and algae growth.

Evidence from Ontario

Water quality monitoring of phosphorus and other parameters is undertaken within several Ontario Ministry of the Environment programs. Streams and rivers are sampled through the Provincial Water Quality Monitoring Network by ministry and partner staff.  In general, phosphorus levels have declined since the 1980s in Ontario rivers within the Mixedwood Plains.256,257 However, as indicated in Figure 27, many Ontario Mixedwood Plains rivers and streams continue to exceed the interim Provincial Water Quality Objective of 30 µg/L of phospho­rus, including 49% of 332 monitoring stations in the ecozone+. Elevated phosphorus levels in surface water generally occur where the soils are relatively nutrient rich and the land has been developed for a variety of agri­cultural and urban uses.

Figure 27. Median phosphorous concentrations in streams in the Ontario portion of the Mixedwood Plains Ecozone+, 2003-2007.
map of southern Ontario
Long description for Figure 27

This map shows the levels of phosphorus concentrations in the Ontario part of the ecozone+. Concentration levels fall into 4 categories: < 30 µg/L; 30-60 µg/L; 60-120 µg/L; and >120 µg/L.  Most concentrations of >120 µg/L occur in the far western part of the ecozone+, between Windsor and London, with additional occurrences on the Niagara peninsula, at Toronto, south of Lake Simcoe, and north of Prince Edward County. Concentrations of 60-120 µg/L are predominately in the southwestern part of the ecozone+ including the area around Kitchener-Waterloo and Hamilton. This concentration level is also found west of Toronto, south of Lake Simcoe, near Oshawa, in Prince Edward County, near Kingston, along the St. Lawrence River and east of Ottawa. Concentrations of up to 60 µg/L are found predominately in the central and eastern parts of the region, with lower concentrations generally found to the north and east.

Source: data from the Provincial Water Quality Monitoring Network as cited in Kaltenecker and Todd, 2009 Reference258

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An algal bloom is considered to be an excessive growth of algae in a lake or river.259 Favourable conditions for algal blooms include elevated nutrient concentrations (particularly phosphorus), warm temperatures, and shallow, slow moving water, although acidification and the invasion of lakes by dreissenid mussels (zebra mussel Dreissena polymorpha and quagga mussel D. rostriformis bugensis) have also been implicated.260,261,262,263 These growths of algae are a concern because some forms (cyanobacteria, also known as blue-green algae) can produce toxins that can impact human and animal health and can affect freshwater ecosystem processes.264

The Ontario Ministry of the Environment has compiled algal identification reports since 1994. These data indicate that the extent to which algal blooms, particularly cyanobacteria, are being reported in Ontario lakes and reservoirs has increased significantly between 1994 and 2009 (Figure 28). Although algal blooms can be natural phenomena in Ontario lakes, this trend has been attributed to increases in nutrient inputs to lakes, reservoirs, and rivers in some more developed areas, which promotes the growth of algae. Factors associated with climate warming, including warmer waters, reduced water column mixing, and lengthening of the ice-free season, may exacerbate bloom conditions.265,266

Figure 28. Total number of algal blooms in which dominance by cyanobacteria (blue-green algae) was confirmed in Ontario, 1994–2009. Includes areas outside of the Mixedwood Plains Ecozone+.
bar chart
Long description for Figure 28
This bar graph shows the following information:
YearNumber of Reports

Source: Winter et al., 2011267

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Key finding 13
Acid deposition

National key finding
Thresholds related to ecological impact of acid deposition, including acid rain, are exceeded in some areas, acidifying emissions are increasing in some areas, and biological recovery has not kept pace with emission reductions in other areas.

Acid rain has three main components: weak carbonic acid, created when water reacts with atmospheric carbon dioxide; sulphuric acid, created when water reacts with sulphur from the burning of sulphur-containing coal and oil and the smelting of sulphide ores; and nitric acid, formed when water reacts with nitrogen oxides, mainly from the combustion of fossil fuels.

Due to the underlying geology of the Mixedwood Plains, most lakes are well buffered against acidity268 and the focus of research, therefore, has been on terrestrial systems. Direct impact from acid rain has been documented in high-elevation forests in northeastern North America as well as close to point sources such as the smelters in Sudbury, Ontario. At low elevations and in areas more distant from point sources, such as the Mixedwood Plains Ecozone+, the indirect effects of acidic deposition through soil acidification are of concern.269 To maintain the electrical neutrality of drainage waters, base cations--principally Ca2+--are lost. The resulting acidification brings inorganic aluminum hydroxide (Al3+) and hydrogen ion (H+) into solution. The Al3+ impairs nutrient absorption, especially phosphorous uptake by the roots of almost all plants.270 The buffering capacity of soils and the tolerance of plant species to soil acidification vary greatly.271

There are areas in the ecozone+ containing ultramafic rock, which is poor in calcium and potassium but rich in magnesium.272 Recent acid-rain assessments268,273 have indicated that some areas of the ecozone+ receive acid deposition in excess of their critical loadFootnote nine ix.

Although generally this ecozone+ is not highly affected by soil acidification, there are isolated regions which, due to their geologic history, have acid-sensitive soils.274,275,276 The Frontenac Arch is one of two physiographic areas within the ecozone+ with high levels of intact forest cover (see Intact landscapes and waterscapes ); the area also has soils with low buffering capacity, which increases its susceptibility to forest health deterioration due to acidification.

Over the last 40 years, soil acidification due to long-range transport of atmospheric pollution has brought about a reduction in growth (10 p. 100) and recruitment (30 p. 100), and doubled the mortality rate in sugar maple stands (Acer saccharum) while promoting recruitment of American beech (Fagus grandifolia) in the northern part of the ecozone+.277 Application of lime in order to improve soil fertility and nutrition resulted in reduced dieback (factor of 4), doubled the growth rate, increased recruitment by 30 to 58% and reduced beech recruitment by 25%.277

Soil acidity trend data are not available for the ecozone+, however a study by Miller and Watmough276 examined the soil acidification and foliar nutrient status of Ontario’s deciduous forests in 1986 and 2005. They found that mineral soil pH and exchangeable base cations were lower in 2005 but total sulphur, nitrogen, and cation exchange capacity had not changed from 1986. Foliar calcium levels were related to soil calcium levels and were lower in 2005.

Little is known about the impact of soil acidification on soil fauna, but changes in soil fauna have been reported in association with changes in soil pH. Increases in soil acidity have been found to be associated with changes in the soil collembolan (springtail) communities. As soil acidity increases, so does the abundance of collembolans associated with the duff and soil surface. As the acidity decreases, collembolans that stay in the upper mineral soil increase in dominance.278 As soil acidity decreases so does the diversity of symbiotic arbuscular mycorrhizal fungi. The quantity of colonization by mycorrhiza generally increases with pH.279

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Key finding 14
Climate change

National key finding
Rising temperatures across Canada, along with changes in other climatic variables over the past 50 years, have had both direct and indirect impacts on biodiversity in terrestrial, freshwater, and marine systems.

Current trends

Climate change is considered by many to be one of the greatest threats to global ecosystems and biodiversity.280,281 Predictions about our future climate are based on changes that are already being seen.

The Mixedwood Plains is well represented geographically with climate stations and Table 9 summarizes the significant trends in various climate variables for the ecozone+ from 1950 to 2007. This is one of the regions of Canada with the lowest increases in mean annual temperature over this time period.282 Generally, the closer to a pole an area is, the greater the warming experienced.283 Nevertheless,  the climate data showed significant trends for a few variables. There was an overall increase of 1.2°C in summer temperature, a 20% increase in fall precipitation, an overall increase in the number of days with precipitation in the spring, summer and fall, a 4.7% decrease in the ratio of snow to total precipitation, an increase in the number of growing degree days at some stations, and a decrease in snow depth at some monitoring stations (Table 9). Trends vary by season and station.

Table 9. Overview of climate trends for the Mixedwood Plains, 1950–2007.
Climate variableSignificant trends
Temperature(18 stations)
  • Overall of 1.2°C in summer relative to base period (1961-1990) mean
  • No trend in spring, fall, or winter
  • Trends consistent across ecozone+
Precipitation(29 stations)
  • Overall of 20% in total amount of precipitation in fall
  • No trend found in other seasons for total amount of precipitation although significant change was noted in some stations in some seasons
  • Overall in the number of days with precipitation in spring, summer, and fall
  • Overall of 4.7% in ratio of snow to total precipitation
  • No trend in maximum annual snow depth or duration overall (16 stations)
    • 2 stations in the northeastern part of the ecozone+in Quebec show of over 20 cm in maximum snow depth
  • No trend in number of days with >2cm on ground
    • of  >10 days with >2cm of snow on the ground in 4 stations in southern Ontario from August to January and in 1 station in the St. Lawrence Lowlands February to July
Drought Severity Index
  • No trend from 6 stations
  • No extreme or very wet or severe drought years
  • Stations not evenly distributed across  ecozone+
Growing Season
  • No trend in start, end, or length of the growing season overall
    • in number of growing degrees days at some stations

All trends reported are significant at p<0.05 Source: additional data and analysis provided by the authors of Zhang et al., 2011282

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Changes in timing of bird migration have already been recorded.284,285,286 A study at the Long Point Bird Observatory found that for every 1°C  increase in spring temperature, median capture dates of migratory birds averaged across species was one day earlier.284 In a study of 78 songbird species from 1961 to 2006 in Pennsylvania (which is in the same Ecoregion of North America287), spring migration became significantly earlier over the 46 year period and autumn migration showed no overall change.285 When tree swallows were studied throughout North America, it was found that they are breeding earlier most likely due to a long-term increase in spring temperature.286

Changes are also being seen in mammal populations as the northern range limits of many species in the ecozone+are limited by winter conditions.288 The average daily minimum temperatures in January and February have warmed by more than 2°C in the last 100 years which may be allowing the northward expansion of species such as the southern flying squirrel (Glaucomys volans), Virginia opossum (Didelphis virginiana), and little brown bat (Myotis lucifugus).289,290,291 The increased abundance of fisher (Martes pennanti) may be associated with reduced snow depth.292

Predicted change

Aquatic systems are particularly vulnerable to climate change due to the impacts of increased temperature and evaporation combined with potential decreases in precipitation.293 Since fish are not able to regulate their body temperatures they are very dependent on water temperature to maintain important biochemical, physiological, and life history processes.  Water temperature is a critical determinate of fish population growth, survival, and reproduction.294 If climatic warming occurs as projected, surface waters will be warmer for longer periods in spring, summer, and fall which will reduce the duration of winter conditions.295 At the same time, stratification periods will increase, with negative effects on deep water oxygen levels in late summer leading to increased risk of summer kill events for many aquatic species.295 The Mixedwood Plains has the highest diversity of freshwater fishes in Canada.117,161 When fish communities were studied in 43 watersheds throughout the Ontario portion of the ecozone+296 it was found that currently cold-water fish species were present  in 100% of watersheds and 38 of the 43 watersheds had cool-water fishes at more than 66% of the samples sites (Note: many watersheds in the ecozone+ have limited cold-water habitat even though all of the watersheds contain cold-water species). Analysis of the impact of projected warming on these watersheds and the 132 fish species within them (non-native species removed from analysis) showed reduced distribution of cold-water species and an increase in warm-water species.296 Even the least severe climate change scenario reduced cold-water fish species to only 67% of sites by 2025 (decrease of 33% of locations).296 Using the least severe scenario, an index of the likelihood of each watershed in southern Ontario retaining cold-water species after climate change was created. Most of the watersheds projected to retain cold-water species were in the northern portion of the ecozone (Bruce Peninsula, along the shore of Lake Huron, or bordering the edge of the Canadian Shield) while southwestern watersheds were likely to lose them.296 Modeling of the impact of climate change on brook trout (a cold-water species) in Canada showed a 49% decrease in distribution by 2050 with significant changes projected for the Mixedwood Plains,297 with the trout populations of smaller lakes considered to be at greater risk.298  There are many indirect or cascading effects associated with increased temperatures. The timing, size and duration of the spring freshet and the frequency and duration of droughts in southern Canada are predicted to change.299 Some warm-water species such as smallmouth bass (Micropterus dolomieu) are highly effective predators whose distribution is currently limited by temperature related effects.293 When the impact of increases in their distribution due to climate change were modeled,293 it was predicted that they would cause the extirpation of four common cyprinid species, the northern redbelly dace (Phoxinus eos), the finescale dace (Phoxinus neogaeus), the flathead minnow (Pimephales promelas) and the pearl dace (Margariscus margarita) in Ontario.

Many different responses are anticipated in terrestrial systems. Significant increases in plant diseases, such as Fomes root rot (Heterobasidion annosum), have been predicted, as well as declines of oak, ash, and maple forest.300  In agriculture, increases in common smut (Ustilago maydis) and cyst nematode (Heterodera glycines) have been predicted for corn, increases in bean yellow mosaic virus, potato leafroll viru,s and cucumber mosaic virus have also been predicted.300  Hemlock wooly adelgid (Adelges tsugae), an insect pest of hemlock trees, is predicted to significantly increase in its range as it is currently temperature limited, while the impact of Armillaria root rot, already wide spread, is predicted to increase due to increased stress caused by climate change.301 Human diseases may also increase.  For example, West Nile Virus and Lyme disease are expected to increase in Canada with the first expansions occurring within the Mixedwood Plains.  With Lyme disease, modeling predicts a high probability of establishment in the southern areas of Ontario and Quebec302 with the limit of spread in Ontario being a line within 130 km of North Bay.  With West Nile Virus, the earlier onset of spring would prolong the time period in which spread to humans is likely to occur, while increased precipitation may increase mosquito breeding sites (mosquito’s which bite both birds and humans are the vectors for West Nile Virus).303

When climate projections were done for the ecoregions of Ontario, it was found that novel climate conditions (previously non existing combinations of temperature and precipitation) may be created and that many of the currently existing climate conditions will disappear from the province.304 Most forest plant species living in highly fragmented landscapes show low or no ability to colonize new habitat patches; most move only a few metres per year.305,306 In a study to examine tree species distributions under different climate scenarios in the Credit Valley, it was estimated that tree species would have to shift at the rate of 3,000 to 5,000 m/yr in order to keep pace with changing climate, yet most tree species are thought to be able to migrate only on the order of 50 to 300 m/yr.307  In another study looking at how tree species in Ontario would change under different climate scenarios (modeling to the year 2100), which in addition to climate took topography, soils, landuse, and fragmentation into account, it was found that the southern half of the province showed the highest degree of species turn-over and forest type change and was especially vulnerable to the effects of climate change.308  Throughout the ecozone+, due to potential changes in species distribution, forest types which we know today would be reduced and shifted, and many new species combinations and assemblages are likely to occur.308 In the same study, when limits were put on the rate of shift that species could achieve (to 1000 m/yr), the changes in forest cover were even more dramatic.  Under all climate scenarios, tree species richness was lower than currently found throughout the province of Ontario, and large areas in the north as well as the south of the province would have forest types not currently found in the province.308  The high level of fragmentation found in this ecozone+ (see Forests, Grasslands, Wetlands, Lakes and rivers, Coastal, and Ice across biomes, as well as Ecosystem ) will add an extra layer of complexity to species ability to move north and adapt to climate change. The ability of populations to redistribute in a shifting climate may be slowed or prevented in fragmented landscapes.309,310,311,312 Many modeling exercises make the assumption that species movement is possible due to the presence of natural vegetation. In southern Ontario where there often are large areas of urban and agricultural land, the potential for some species to change their distributions will be limited even further.

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Key finding 15
Ecosystem services

National key finding
Canada is well endowed with a natural environment that provides ecosystem services upon which our quality of life depends. In some areas where stressors have impaired ecosystem function, the cost of maintaining ecosystem services is high and deterioration in quantity, quality, and access to ecosystem services is evident.

Evidence from Ontario

Ecosystem services are the direct and indirect benefits that humans derive from healthy, functioning ecosystems. The loss or degradation of natural areas threatens to undermine future economic and social well-being by diminishing the natural foundations on which society is built. The Millennium Ecosystem Assessment has grouped ecosystem services into four comprehensive categories:

  • provisioning services that provide essential raw materials such as food, water and fibre;
  • regulating services that maintain essential life support services such as climate regulation and flood prevention;
  • supporting services such as soil formation, nutrient cycling and pollination; and
  • cultural services that provide recreational, aesthetic and spiritual benefits.281

There is considerable global interest in applying ecosystem service concepts as a rationale for conservation and as a method to support the design of effective resource management policies.313 Ecosystem services can be understood in biophysical terms, for example, the amount of forest required to sequester a specific amount of carbon.  They can also be expressed in economic terms, for example, the estimated economic benefit of carbon sequestration of a given amount of forest.

The Mixedwood Plains Ecozone+ has undergone significant alteration in habitat since settlement.  This has resulted in impacts on the flow of ecosystem services that can be supplied by the area’s remaining natural features. The specific impacts have not been comprehensively or quantitatively measured, but trends in ecosystem services are driven by trends in ecosystem structure, function, and composition.281,314 The transformation of the ecozone+’s forests, wetlands, and plains vegetation into agricultural and urban areas has impaired natural supporting ecosystem services such as soil formation, nutrient cycling, and pollination, as well as regulating services, such as water regulation and water supply.

A pilot study in eastern Ontario that was part of the National Agri-Environmental Standards Initiative found that a significant portion of the study area did not contain sufficient natural cover at the landscape level to provide full or partial pollination services to farm fields.315 Although there has been evidence of improvement,106,107 the loss of natural cover, urbanization, and the expansion of agriculture have affected the ecosystem services of water regulation, quality, and supply. This is due to fragmentation and channelization of rivers and streams, dams and altered flow regimes, and elevated levels of sediments and nutrients.104,105,115,122

Even though the Mixedwood Plains Ecozone+ is highly disturbed, there are significant ecosystem service benefits provided within the area. Agriculture is the dominant provisioning service within the ecozone+. Although it occupies only 9% of Canada’s land area, the Mixedwood Plains yields 38% of Canada’s agricultural production.206,207 Forests are important in both conventional economic terms and for their ecosystem services.316 The network of forests and other natural areas in the ecozone+ are also important in combating climate change: they contribute to sequestration of carbon and allow for movement of plants and animals to new areas in response to a changing environment. Hunting and fishing are important components of the resource-based recreation economy; for example, recreational fishing alone in the Ontario portion of the Mixedwood Plains Ecozone+ accounted for $570 million of spending on goods and services in Ontario in 2005.317 There are also important ecosystem service benefits associated with the ecozone+’s protected areas including cultural, social, and spiritual benefits, as well as the direct economic benefits accruing from recreational use of parks.318 A number of recent studies have utilized the valuation of ecosystem services to assess the indirect economic value of the remaining natural areas in southern Ontario.  These studies have found that these areas “represent a significant, yet often uncounted, portion of the total economic value” of the landscape.319 For example, a 2004 study estimated the annual indirect (uncounted) economic benefits from the ecosystem services of the Grand River watershed to be about the same value as the direct economic benefits that are counted from agricultural land within the watershed.320 Two studies completed in 2008 estimated the annual value of the measurable, but uncounted, ecosystem services of Ontario’s Greenbelt and the Lake Simcoe Basin to be $2.6 billion annually and $975 million annually, respectively.321,322 

A recent study assessed the ecosystem services for the entire Ontario portion of the Mixedwood Plains Ecozone+ using spatially-explicit economic valuation. The study conservatively estimates that the area’s ecosystem services provide at least $84 billion a year in economic benefits that are otherwise not counted.319 Urban and suburban wetlands provide the ecosystem services of water filtration, water supply and flood attenuation, which provide at least $40 billion annually.319 Urban and suburban river systems provide ecosystem services estimated at $236,000 per hectare per year, some of the greatest economic benefits for their size primarily because they benefit large human populations.319

The study of ecosystem services and their valuation are still relatively new areas of research and there are a number of priorities for further investigation. These include:

  • determining whether sufficient natural areas exist to provide the ecosystem services required by the ecozone’s growing population;
  • more rigorously identifying how the loss or rehabilitation of natural areas affects the supply of ecosystem services; and
  • filling gaps in the ecosystem services valuation literature and reviewing how contextual factors such as scarcity and landscape configuration affect values.313,319

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Footnote i one

An analysis by the Province of Ontario found that 1.8% of the ecozone was protected as of May 2009. Reasons for the discrepancy between this analysis and the ESTR analysis are not entirely known but likely reflect differing interpretations of the boundary of the Mixedwood Plains Ecozone+ by the federal and provincial governments. Regardless, both numbers show that the amount of protected areas in the Mixedwood Plains Ecozone+ is low relative to other ecozones+ in Canada and the Convention on Biological Diversity’s target to protect 10% for each of the world’s ecological regions.

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Footnote ii two

Carillon, Charleston Lake, Awenda, and McRae Point Provincial Parks were created under ARDA.

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Footnote iii three

Black Creek, Fish Point, Komoka, Bass Lake, Cabot Head, Stoco Fen, James N. Allan and many other provincial parks were created  (OMNR 1983)

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Footnote iv four

IUCN follows Gray et al., 2009 and CARTs v.2009.05. Note within IUCN categories level of protection varies from fully to partially protect depending on the policies in place.

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Footnote v five

Denotes protected area classification present in the CARTS v.2009.05 database.

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Footnote vi six

Total summary provided by MNR’s State of Ontario’s Protected Areas Report.  Data presented includes cultural heritage, natural environment, nature reserve, waterway and recreational provincial parks with some protected areas overlapping ecozone boundaries.

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Footnote vii seven

P. Kor, pers. comm. July 22, 2010 and SOPAR 2011.

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Footnote viii eight

For this summary Ecozone means Ontario portion only.

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Footnote ix nine

Critical load is a quantitative estimate of the exposure to one or more pollutants, below which significant harmful effects on specified elements of the environment are not known to occur.

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