At present, the greatest pressure on Central Ontario's greenlands is being exerted in three areas:
- within the existing boundaries of the Zone's most rapidly urbanizing municipalities;
- along the shorelines of the many lakes and rivers within the Zone;
- within areas targeted for new agricultural use, recreational development (for example, golf courses), and mineral resource (limestone and aggregate) extraction.
The first pressure-point is a fairly obvious one and is based on the premise that urban development will occur first on land already designated in Official Plans and that any greenlands within these areas that are not currently protected by the upper-tier Official Plan will not persist. The issue of continued urban sprawl and a discussion of those municipalities which are experiencing the greatest pressure to grow are well documented in the Toronto-Related Complex Urban Futures Study by the IBI Group, published in 2002. Two examples illustrating the extent of greenlands under threat within (a) a rapidly urbanizing Central Ontario municipality and (b) a largely rural municipality are provided in Figures 2 and 3, respectively.
Figure 2 Greenlands affected by new urban growth in Brampton, a rapidly growing municipality
Figure 3 Greenlands affected by new urban growth in Wasaga Beach, a rural municipality
Another immediate threat is to coastal, lakeshore and riverside greenland systems and arises from an ever-growing demand for recreational-residential development within several hours' drive of the major urban centres. This type of development is favoured by the more affluent "baby boomers" seeking a summer or weekend retreat, or "empty nesters" looking to downsize their home, move out of the city, and take up residence in an adult lifestyle community. Typically, these developments include amenities such as golf courses and marinas to support the residential component. Furthermore, the areas targeted for large-scale developments of this kind are often not located within a predominantly urban municipality or, in the case of many rural municipalities, even within a designated settlement area. Although large stretches of the shorelines of the Zone's lakes have already been developed with cottages and marinas, many of the areas that are still in a natural or semi-natural state support coastal marshes, sand dunes, beaches, glacial shorecliffs, fish spawning beds, and important woodlands. Some examples of shoreline areas that are presently experiencing development pressure of this kind include: Frenchman's Bay (Pickering), Lynde Shores (Whitby), Oshawa Second Marsh, the Towns of Collingwood and Wasaga Beach, Oro Lea Beach (Oro-Medonte), Alcona (Innisfil), and Balsam Lake (Kawartha Lakes).
Agricultural practices are considered by some to be among the primary agents responsible for the loss and impairment of healthy, functional greenlands in the Central Ontario Zone. Wetlands are still being drained and woodlots cut down to create more agricultural land. Farmers are generally exempt from any requirement to preserve greenlands when creating new arable land. There are numerous examples throughout the Zone of areas where groundwater and surface water quality and associated fish habitat have been severely degraded by unregulated water takings, uncontrolled livestock access to watercourses, and contaminated runoff from barns. Although some farmers voluntarily adopt environmentally responsible agricultural practices, it is often the one or two poorly run operations that are responsible for the bulk of the problem at a local level. Generally speaking, however, when it comes to identifying major threats on our greenlands the agricultural community avoids scrutiny and enjoys a certain degree of immunity from criticism.
The ever-growing demand for golf courses has been partially responsible for an increase in the amount of agricultural and forested land converted to this use. Although many golf courses adopt best management practices in water conservation, turf care and pest management, a number of ancillary environmental impacts are associated with the operation of a golf course. In terms of where new golf courses are being built in this part of Ontario, there doesn't appear to be any strong geographic pattern emerging, although proximity to a large population base is undoubtedly a major business advantage. A golf course is often a permitted use within land designated as Open Space in an Official Plan and, unless associated with a residential development, is unlikely to rely on the availability of municipal services (such as sewer and water). As a rule, 18-hole golf courses occupy a minimum of 80 hectares (200 acres). For reasons of aesthetics and challenge of play, land with some topographic relief, surface water features and forest cover is favoured over flat, open areas, thereby placing more pressure on greenlands.
Other outdoor recreation facilities such as snowmobile trails, cross-country ski resorts, and mountain biking centres are gaining in popularity. These facilities require the creation of extensive trail networks that result in the human disturbance to wildlife, loss of tree cover, the introduction of invasive plants, soil compaction, increased erosion, and, most significantly, fragmentation of large forest blocks. Snowmobile trails and cross-country ski resorts tend to be located in more northerly areas subject to greater snowfall and longer winters, while both cross-country ski and mountain bike facilities need variable terrain and extensive tree cover.
New aggregate extraction operations (pits and quarries) are generally driven by two principal factors: 1) the presence of an economically viable resource and 2) proximity to a major demand area. That aggregate extraction and greenlands are conflicting land uses, at least in the short term, has long been recognized and is borne out by the way the PPS deals with each. This policy conflict is further exacerbated by the fact that the same provincial body that has jurisdiction over the licensing and operation of pits and quarries - the Ministry of Natural Resources - is also the lead agency in the area of Natural Heritage protection. Approval of a new pit or the expansion of an existing operation is often granted at the expense of a greenlands feature. The one advantage that aggregate operations have over other large-scale, intrusive land uses is that there is a requirement to rehabilitate these sites after extraction is complete, providing an opportunity to create or restore lost habitat in the long term.
New roads, particularly the multi-lane, 400-series highways, and other linear infrastructure facilities such as pipelines and hydroelectric transmission corridors can also have a profound impact on greenlands. Because these linear facilities link one area to another, the most economical method of construction is in a straight line over the shortest possible distance. This approach virtually guarantees that the preferred alignment will pass through a greenland feature at some point. Valleys are often selected for linear facilities such as sewer mains, because the disruption of agricultural or already urbanized land can be avoided. Although the routing of public utilities such as roads is subject to an Environmental Assessment under the Environmental Assessment Act, features such as Provincially Significant Wetlands (protected under the PPS) are not exempt from intrusion or encroachment. The approved alignment of the northeasterly extension of Highway 404 through the Town of Georgina (northern York Region) crosses several such wetlands, as it was not possible to find a socially and economically acceptable route that avoided all greenlands features.
By their very nature, the creation of roads, pipelines and hydro corridors causes habitat fragmentation, introduces a physical barrier to wildlife movement, bisects major valley systems, and results in the partial enclosure of watercourses in culverts. There are related impacts of roads on the natural environment, such as salt runoff, noise, animal roadkills, and exhaust emissions, although these are not necessarily well understood.
The types of greenlands that are most under threat in the Central Ontario Zone are:
- tableland woodlots that have no policy status (i.e., they are not ANSIs, ESAs, or Significant Woodlands);
- unevaluated wetlands;
- intermittent headwater streams.
In rural areas, small isolated woodland patches are found scattered throughout a mosaic of agricultural fields. Because these woodlots lack protection, even in many GTA municipalities, they are viewed as future development land. On the other hand, these features may be the only greenlands remaining on the rural landscape and, as such, are seen as strong candidates for protection by the local populace.
Contrary to popular belief, there are a great many wetlands throughout Central Ontario that have not been formally evaluated in accordance with the Provincial Wetland Evaluation System. This is particularly true on the Canadian Shield, where wetlands are so prevalent that typically only the largest, most prominent, and most easily accessible ones have been evaluated. These features also lack any protective status under the PPS. By definition, however, any wetland greater than 2 hectares meets the minimum size criterion for evaluation. Once it has been evaluated, a wetland can score no lower than Locally Significant.
As discussed earlier, the ecological and hydrological significance of intermittent headwater streams have traditionally been overlooked, particularly in rural areas where these features have been substantially altered by agricultural practices. Because these features drain relatively small areas and thus are not subject to fill and flood line regulations, they are often allowed to be modified or eliminated altogether through development.