5.1 Definitions

Rare vegetation communities include:

  • areas that contain a provincially rare vegetation community
  • areas that contain a vegetation community that is rare within the planning area

Specialised habitats include:

  • areas that support wildlife species that have highly specific habitat requirements
  • areas with exceptionally high species diversity or community diversity
  • areas that provide habitat that greatly enhances a species' survival

5.2 Ecological function/effects of loss

5.2.1 Rare vegetation communities

Rare vegetation communities often contain rare species, particularly plants and small invertebrates, which depend on such habitats for their survival, and cannot readily move to, or find alternative habitats. Some communities such as tall-grass prairies and savannahs were never widespread in the province. Now these habitats and many of the species they support are rare or threatened because of changes to the landscape. Often these habitats are very sensitive to changes in moisture or amount of vegetative cover.

The ecological function of these rare communities is to ensure that species that depend upon them will maintain viable populations and biodiversity of communities on the landscape. Loss or degradation of rare habitats will lead to an increase in the numbers of species that are rare, vulnerable, threatened, and endangered and, over time, to a decrease in biodiversity within the planning area and province. Protection of rare vegetation communities now, will protect their associated species and reduce costs of future species recovery programs.

5.2.2 Specialised habitats for wildlife

Certain wildlife species have highly specific requirements for their survival. For example, the larvae of some butterfly species require specific plants, many of which are confined to just a few small areas. Many species of birds and mammals require tree cavities in which to nest or find shelter. Salamanders require moist, sheltered, and temperate habitats for survival. Large fallen logs that are moss-covered and in an advanced state of decomposition provide such specialised habitat for them. Sometimes the presence of a specialised habitat may not mean life or death to the animal in the short-term, but it may affect the long-term survival of them or their offspring. For example, black bears depend heavily on acorn crops to build fat reserves required for hibernation. If this food source is not available, their survival through winter may be jeopardised or females may lose their cubs.

Figure 5.1. Bogbean buckmoth, specific to eastern Ontario fen habitat, are known in only in two locations in Ontario.
Figure 5.1. Bogbean buckmoth, specific to eastern Ontario fen habitat, are known in only in two locations in Ontario.

Often the use of a specialised habitat is seasonal. For example, moose use at least two specialised habitats in early summer. Mineral licks provide specialised habitat that allows these animals to replenish sodium levels that have been seriously depleted during the winter months. Aquatic habitat that contains abundant sodium-rich plants in early summer is also critical to moose.

The ecological function of specialised habitats is to enhance and, in some cases, ensure the survival of the associated wildlife species that depend on them. Protection and maintenance of these areas will contribute to higher biodiversity within the planning area. Loss or degradation of these areas and features could seriously stress and even eliminate the wildlife populations that intrinsically depend upon them.

5.3 Identification of potentially rare vegetation communities or specialised habitat for wildlife

Since many rare vegetation communities and specialised habitats for wildlife exist within the other six natural heritage components, emphasis should be on finding habitats outside these areas. The following information sources can help the planning authority identify potentially rare vegetation communities and specialised habitats.

  • Use the information outlined in Table 3-1 and discussed in Section 3.2 to identify these potentially significant habitats.
  • The OMNR ANSI Site District and inventory reports can be particularly useful for identifying rare vegetation communities. For example, they identify provincially, regionally, and locally significant wetlands communities such as bogs and fens, and rare vegetation associations for the Site Districts they cover.
  • Refer to Table I-3 in Appendix I for a list of information sources for identifying rare vegetation communities or specialised habitats for wildlife. The habitat matrices in Appendix G describe the habitat requirements of species associated with specialised habitats.

5.3.1 Potentially rare vegetation communities

A list of rare vegetation communities for southern Ontario (Site Regions 6 and 7) has been prepared and described in a document entitled “Natural Heritage Resources of Ontario: S-ranks for Communities in Site Regions 6 and 7” (Bakowsky, 1996). This document is found in Appendix J. All of the vegetation communities are listed for southern Ontario, including marshes, swamps, bogs, fens, beaches, sand dunes, barrens, alvars, prairies, savannahs, and forests. Dominant species and a site description based largely on soil moisture and texture are used to discern communities. The rarity of each community and its presence or absence in Site Regions 6E and 7E of southern Ontario are provided.

The Natural Heritage Information Centre also has a web site (see Appendix F), that can be checked to see if there are any updates.

The Ecological Land Classification for Southern Ontario (Lee et al. 1998), provided more specific details for vegetation communities in southern Ontario, including: descriptions of how each community is broadly defined; its status and distribution; the principle ecological factors that have helped to determine communities; topography and soils of the communities; the dominant and associated species; and sometimes the distribution of vegetation within the community.

Some vegetation communities described in these publications are difficult to identify because considerable field experience is required. However, they provide an excellent starting point for the identification of rare vegetation communities. Appendix L describes a practical approach for identifying rare vegetation communities using the Ecological Land Classification (ELC) system.

A summary of the approach to the identification of potentially rare vegetation communities is outlined below.

  • Some provincially and regionally significant vegetation communities such as alvars and prairie remnants have already been described and mapped by the OMNR. Table 1 in Appendix M describes the locations of some of these rare vegetation communities. Ask the OMNR ecologist for locations of rare vegetation communities found within the planning area.
  • Map (preferably at 1:10,000 scale) all these known rare vegetation communities.
  • Use the Ecological Land Classification for Southern Ontario and the list of rare communities found in southern Ontario (Appendix J) as reference, and then use aerial photographs to locate and map the distribution of potential rare communities.
  • Ask the OMNR ecologist, local botanists, and CAC members to help to verify the presence of suspected rare communities.
  • Determine the potential rarity of a vegetation community by its degree of representation within the planning area.

5.3.2 Specialised habitats for wildlife

Below is an approach to identification of specialised habitats for wildlife.

  • find out what is already known about these habitats. The OMNR ecologist will know locations of previously identified specialised habitats in the municipality. In some areas, few will have been documented, but there may be some information about the following habitats:
    • old-growth forest
    • areas known to support an unusually high diversity of species or vegetation communities
    • raptor nesting habitat
    • areas with concentrations of cavity trees
    • moose or bear foraging areas
  • map all these known specialised wildlife habitats, preferably at 1:10,000 scale.
  • refer to the wildlife habitat matrices (Appendix G). These tables provide lists of species that use specialised habitats.
  • Encourage the assistance of knowledgeable people to help find specialised habitats. A CAC could work on or coordinate such a task. Local naturalists are one of the best sources of information about such habitats because they spend much time exploring natural areas and know the local flora and fauna. Landowners with potentially significant wildlife habitats on their property might be able to provide additional information.
  • Sub-section 5.4.2 provides a detailed description of how to find specific specialised habitat.
Figure 5-2. Monarch caterpillars feed strictly on milkweed.
Figure 5-2. Monarch caterpillars feed strictly on milkweed.

5.4 How to find some rare vegetation communities or specialised habitats for wildlife

The following sections provide detailed descriptions of rare vegetation communities and specialised habitat for wildlife. They are provided to familiarise the reader with these vegetation communities and habitats, so they will be able to recognise them. Most of these habitats, especially the specialised habitats for wildlife, have not been identified and mapped, and finding them can be difficult. Some of these habitats may not exist in the planning area, while some habitats may exist, but the species that normally use it may not occur. For example, there may be springs and seeps that are not used by wintering wild turkeys.

Each rare vegetation community and specialised habitat description is accompanied by some specific suggestions on how to find them. The following is a list of information sources that can be used to find these habitats:

  • Table 3-1, general information sources required to find significant wildlife habitat.
  • Appendix F, list of agencies and their areas of expertise (these include web sites for updated information).
  • Appendix I, information sources for the identification of specific significant habitat.
  • Appendix G, wildlife habitat matrices, with lists of species that use specialised habitats.
  • Appendix J provides a list of all the rare vegetation communities in Site Regions 6 and 7.
  • Appendix M describes the locations of all known rare vegetation communities.
  • Appendix L provides a suggested approach for using the Ecological Land Classification system to identify rare vegetation communities.
  • Seek advice from the local OMNR ecologist for locations of rare or specialised habitats.
  • Involve the CAC and local naturalists in searches for rare and specialised habitats.

5.4.1 Rare vegetation communities

Refer to Table M -1 in Appendix M for a list of known locations of provincially and regionally rare vegetation communities of southern Ontario.

5.4.1.1 Alvars

Alvars are naturally open areas of thin soil over essentially flat limestone, dolostone or marble rock. They support a sparse vegetation cover of shrubs and herbs, and trees are often absent or scattered. In spring, alvars may have standing water; in summer, soils can become very hot and dry. Vegetation is adapted to these extreme variations in temperature and soil moisture. Some of the characteristic plants that can indicate the presence of alvar communities include spring forget-me-not, long-plumed purple avens, false pennyroyal, small skullcap, and narrow-leaved vervain. Table N–1 in Appendix N is a list of alvar plant indicator species.

Approximately 85% of alvar sites and more than 90% of alvar landscape area in the Great Lakes region are in southern Ontario (Catling & Brownell, 1995). Concentrations of alvars are found in the following areas: Manitoulin Island, Bruce Peninsula, Lake Erie Islands, Carden Plain, Napanee Plain, and the Smiths Fall Plain. Many alvars have been identified in southern Ontario. Refer to Appendix L for locations of known alvars.

How to find

  • Use soil reports and maps and aerial photographs to locate open areas of flat topography, with shallow soils over limestone bedrock.
  • Check “Barren and Scattered” areas on FRI maps with corresponding aerial photographs.
  • Refer to the list of plant species that are considered indicators of an alvar (Table N–1 in Appendix N).
  • Published alvar reports (e.g. Catling and Brownell 1995, etc.)
Figure 5-3. Alvar, Misery Bay, Manitoulin Island.
Figure 5-3. Alvar, Misery Bay, Manitoulin Island.

5.4.1.2 Tall-grass prairies

Tall-grass prairies in Ontario are usually small remnants (< 1 ha) located mainly in the southwestern part of the province. High quality prairies have few trees, non-native plant species, and a large proportion of provincially significant species. A history of burning eliminates or controls invasion by woody shrubs and maintains this rare community. Prairie habitats are very susceptible to natural succession and must be frequently disturbed by such natural processes such as fire in order to be maintained. Many of the prairie remnants that remain have invasive plant species.

Indicator species are usually the dominant grasses including big bluestem, Indian grass, switch grass, and tall cord grass. Soil depth is variable; soils are usually fine-textured, ranging from dry-mesic sands to wet-mesic sandy loams, over limestone bedrock. Table N-2 of Appendix N is a list of Tall-grass prairies and Savannah indicator species.

Many prairie remnants have been identified. In Site Region 7E prairie remnants have been identified on the following landforms: Horseshoe Moraines, Caradoc Sand Plains, Bothwell Sand Plains, St. Clair Clay Plains, Norfold Sand Plain. In Site Region 6E prairie remnants are found on the Peterborough Drumlin Field. See Appendix M for locations of known provincially or regionally significant sites.

How to find
  • Use aerial photographs in conjunction with County Soil Survey reports and maps, and FRI maps to find open, treeless areas of non-cultivated land.
  • Early writings or maps documenting the location of aboriginal communities may help to find remnant prairies. The frequent burning in these areas helped to maintain these habitats.
  • Maps of vegetation communities have been prepared from the original surveyors’ notes, and these may identify where prairies originally occurred. These are available for southern Ontario from the Ministry of Citizenship, Culture, and Recreation.
  • Refer to Table N–2 in Appendix N for a list of tall-grass prairie plant indicator species.

5.4.1.3 Savannahs

Savannahs are characterised by widely-spaced, open-grown trees producing a cover of 60% or less growing in association with an assortment of grasses and forbs that are characteristic of prairie communities. Soil depth is variable and is usually underlain by limestone bedrock. Soils are often silt loams and Farmington loams. In the spring, they are frequently saturated and internal drainage is restricted due to the underlying bedrock. Conversely, in mid to late summer, soils dry out, often creating drought-like conditions. Fire maintains these communities by controlling the invasion of woody shrubs and non- native species of grasses.

The trees are usually oaks and hickories, mainly black oak, bur oak, and shagbark hickory. Black oak is the dominant species in southern Ontario savannahs. On dry sites, other dominant species include white oak and red cedar. Some dominant or indicator plant species of oak savannahs include big bluestem, hair grass, rough-leaved dogwood, wild bergamot, gray-headed coneflower, nodding wild onion, fragrant sumac, and common juniper. Poorly-stocked, and barren and scattered stands as depicted on FRI maps, should not be considered savannahs unless they have the appropriate canopy and understorey characteristics. Refer to Table N–2 of Appendix N for a list of savannah indicator species.

Many savannahs have been identified. These communities are found mainly in southwestern Ontario. In Site Region 7E they are found on the following landforms: St. Clair Clay Plains, Horseshoe Moraines, Norfolk Sand Plain, and Erie Spits. In Site Region 6E they are found on the Oak Ridges Moraine. See Appendix M for locations of some provincially or regionally significant savannahs.

How to find
  • Use aerial photographs and soil survey reports to find open areas of flat topography, with shallow soils over limestone bedrock, and scattered trees.
  • Check “barren and scattered” areas on FRI maps with aerial photographs.
  • Check the distribution maps of some savannah indicator species, such as black oak.
  • Refer to Table N-2 in Appendix N for a list of savannah indicator species.

5.4.1.4 Rare forest types

Forests are treed communities with greater than 60% canopy closure. A deciduous forest is a forest in which deciduous tree species are more than 75% of the total tree cover. In Site Districts 6E and 7E, there are several rare deciduous forest types consisting mainly of regionally or locally uncommon tree associations or supporting some provincially or regionally rare trees. A mixed forest has greater than 60% canopy closure, and both coniferous and deciduous tree composition, with each component forming greater than 25% canopy cover. A coniferous forest has greater than 75% conifer composition. Potentially rare forest community types are listed in Appendix J.

Reports produced by the Ontario Soil Survey can further help in finding rare forest habitats. Soil formation, soil depths and textures, drainage, relief, and indigenous forest associations of the counties of southern Ontario are summarised. This information can be used to narrow the search for certain forest types. These soil surveys and maps are available from the Ontario Ministry of Agriculture, Food and Rural Affairs in Toronto. More information about landforms, their formation and distribution, can be found in the Physiography of Southern Ontario (Chapman and Putnam 1984). Finally, Trees in Canada (Farrar 1995) is a good reference textbook for information about the habitats and distribution of trees in the province.

The forest communities listed in Appendix J are those that may be significant at the provincial level. Planning authorities may wish to identify additional forest community types that may be significant within their jurisdiction. Certain community types that are common within the province or site district may be rare within a municipality. This may occur if the municipality is at the periphery of a vegetation community’s distribution range, or if land-use practices have resulted in the loss of a high proportion of the community.

How to find
  • Use FRI maps to locate potentially rare tree associations and to determine relative rarity of existing associations within the planning area. FRI maps note tree composition of forest stands.
  • Use Ontario Soil Survey reports and maps to determine the range of specific soils types, textures, and depths in the planning area. This information, used in conjunction with Appendix J and the ELC for southern Ontario, FRI maps, and Trees in Canada can help to indicate areas with good potential to support rare communities.
  • Check the OMNR site district report(s) that apply to the municipality for descriptions of potentially rare forest types. Site district and inventory reports often include detailed site descriptions that can narrow the search and they identify landforms that may support some of these forest types.
  • Contact the director of the Ontario Tree Atlas Program at the Arboretum, University of Guelph, for information about the location of locally and regionally uncommon or rare trees in southern Ontario. Volunteers have collected data on tree species distribution in southern Ontario, within 10 x 10 km blocks.
  • Conduct field investigations of the most likely areas.

5.4.1.5 Talus slopes

These habitats are characterised by blocks of limestone/dolostone, sandstone, or granite of variable size, found at the base of cliffs of steep slopes. Often substantial amounts of rock rubble accumulate through the formation and weathering of cliffs. These sites have coarse rocky material occupying greater than 50% of the ground surface. Soils are shallow, have little mineral material, and are primarily made up of organic debris. In general, vegetation is sparse and patchy.

Talus slopes provide specialised habitat (hibernacula) for some snakes. The accumulated broken rocks at the base of the cliffs frequently provide subterranean entry points for snakes that must hibernate below the frost line. Often these slopes support diverse vegetation communities, particularly if they have a southern exposure, basic soils, and presence of some water.

How to find
  • Use topographical maps to locate areas of sharp relief that could be searched. Sometimes abandoned quarries will provide talus habitat.
  • Check geological maps for areas of limestone outcrops.

5.4.1.6 Rock barrens

Rock barrens are open to moderately-treed sites (up to 60% crown coverage) characterised by exposed bedrock and very shallow soils (less than 15 cm). Precambrian barrens, including the more common metamorphic types, and the less common granitic and marble types are normally found on ridges and other elevated, glacially scoured sites. Paleozoic barrens, including limestone/dolostone and sandstone types are generally flat.

In southern Ontario they are largely restricted to Site Region 6E, where they are found on limestone plains adjacent to the Precambrian Shield. Good examples of metamorphic/granitic rock barrens are found on the northern part of the Frontenac Axis in eastern Ontario. Extensive limestone rock barrens (also referred to as dolostone pavement) are found on Manitoulin Island, the Bruce Peninsula and the Napanee Limestone Plain. Sandstone barrens are much rarer. Small examples occur on the Nepean Sandstone Formation in eastern Ontario.

Several provincially rare species are associated with granitic rock barrens including pitch pine found only in Leeds County, winged sumac, small prickly pear cactus, bear oak, Case’s ladies’ tresses, sharp-leaved goldenrod, and several grasses and sedges. Precambrian rock barrens often attract mammals such as red fox, coyote, and black bear that come to forage on berries and insects found under rocks. Flat rocks on many barrens also provide important foraging and cover habitat for many snakes and five-lined skinks. They may also function as animal movement corridors, especially in areas with numerous wetlands and ponds.

How to find
  • Use aerial photographs to locate open areas and large rock outcrops with little or no vegetation.
  • Check distribution maps for some of the species listed above.

5.4.1.7 Sand barrens

Sand barrens are open (tree cover < 25%) herbaceous communities occurring inland on dry, deep sand deposits. These rare vegetation communities are dominated by species such as bracken fern, hay sedge, deep-green sedge, and New Jersey tea. Mosses and reindeer lichen form a substantial component of the vegetation cover. Vegetation is usually low to the ground, sparse and patchy, and there is much exposed mineral soil. These rare habitats are known to occur in Site Region 6E on the Iroquois Plain. See Appendix M for a description of some of their locations.

How to find
  • Use County Soil Survey reports and maps to locate areas with deep sandy soils.
  • Use aerial photographs to locate open areas with little noticeable vegetation cover in parts of municipality with deep sandy soils.

5.4.1.8 Great Lakes dunes

Great Lakes dunes are open vegetation communities occurring on sand dunes along the shores of the Great Lakes. Soils are severely-drained calcareous sands. Further back from more active shoreline areas, the more stabilised sand has greater cover of trees and shrubs. Dominant tree species include eastern cottonwood, red cedar, white pine, red pine, black oak, red oak, and white oak. Characteristic grasses include beachgrass, Canada wild rye, switch grass, and little bluestem; characteristic plants include tall wormwood, rock sandwort, and starry false Solomon’s-seal. The beach communities consist mainly of sea rocket, seaside spurge, Russian thistle, and horsetail, among other species.

Several important dune areas have been identified and include: along Lake Huron shorelines at Manitoulin Island, Sauble Beach, McGregor Point, Inverhuron, Grand Bend, Pinery, Ipperwash; along Lake Erie shorelines at Point Abino, lesser remnants at Fish Point, Port Burwell; and along Lake Ontario at Burlington Beach, Weller Bay, Prince Edward Peninsula. Other dunes are found in Georgian Bay and include the Mississagi River mouth, Wasaga Beach, and the Penetang Peninsula. See Appendix M a description of the locations of some provincially and regionally significant Great Lakes dunes.

How to find
  • Use County Soil Survey reports and maps in conjunction with aerial photographs to locate areas of sand along the Great Lakes.

5.4.2 How to find specialised habitats for wildlife

Most specialised habitats have not been formally identified and mapped by any agency. The planning authority can identify many of them by working with knowledgeable people who know the natural heritage features and areas of the municipality (local naturalists, CAC, OMNR, landowners). OMNR site district and inventory reports and wetland evaluations, as well as consultant and naturalist reports, are good sources of written information.

Many of the specialised habitats described below can be identified using the information discussed in Section 3.2 and listed in Table 3-1, plus some knowledge of the natural history of their associated species and the unique physical structure of each habitat. Many specialised habitats are likely to exist in most municipalities. The following is a description of several potentially specialised habitats, their value to wildlife, and how to find them.

5.4.2.1 Habitat for area-sensitive species

Some wildlife species require large areas of suitable habitat for their long-term survival. This seems to be particularly true for larger mammalian carnivores such as gray wolf, lynx, and fisher. On a smaller scale, many birds require substantial areas of suitable habitat for successful breeding and their populations decline when habitat becomes fragmented and reduced in size. Over time, competitive species, predators, and nest parasites (primarily the brown-headed cowbird) reduce productivity of these birds. See the habitat matrices in Appendices C and G for a list of area-sensitive bird species of forested and open areas such as grasslands.

The larger and least fragmented forest stands within a planning area will support the most significant populations of forest-area sensitive birds. Forests should cover about 30% of the regional landscape to provide minimal conditions for these species and there should be several large woodlands (30 to 100+ ha) present to provide enough suitable forest-interior bird nesting habitat. Forests comprised of a mainly closed canopy of large trees and a variety of vegetation layers tend to support a greater diversity of species because of the broader range of habitats they provide.

The minimum forest habitat for area-sensitive species is at least 100 metres from any edge habitat. Edges can have adverse effects on forest-interior habitat. For example, some forest birds may nest near or in forest edge habitat and then suffer reduced reproductive success because of nest predation and parasitism.

For area-sensitive grassland bird species, large grassland areas are required as they are more likely to be buffered from disturbance, more likely to increase the distance of nesting habitat to woody edges (thereby reducing nest predation and parasitism), and provide more opportunities for nesting. An endangered species in Ontario, the Henslow’s sparrow, appears to prefer tall-grass fields of at least 30 ha. Sufficient habitat is required for several breeding pairs before the habitat will be used, although one pair of birds may only use an area of 1 to 2 ha in size. Even more common grassland species such as bobolinks, savannah sparrows, and grasshopper sparrows are more abundant as breeding birds in grasslands of at least 10 ha. Grasslands with a variety of vegetation structure, density, and composition tend to support a greater diversity of grassland nesting birds because different species require different nesting habitat.

Protecting significant woodlands as suggested in the Natural Heritage Section of the Provincial Policy Statement, will also maintain some critical habitat for area-sensitive forest species. The significant woodland component is closely linked to this important significant wildlife habitat. The largest, least-disturbed grasslands might also be identified for their value to area-sensitive grassland species and provision of further landscape diversity. Each planning area should protect representative examples of these habitats.

How to find

  • Use FRI maps together with aerial photographs of the municipality to identify potentially significant forest-interior habitats.
  • Use aerial photographs to determine the amount of contiguous forest cover and potential grasslands, the spatial arrangement of forest and grassland fragments, and the extent and nature of edge habitat within the planning area.
  • Planning authorities with their resource data in a GIS system can make queries of forest stands based on size.
  • Ask local birders for local woodlands and grasslands that support abundant and species rich populations of area-sensitive species. These people may know many of the most important areas. Appendix C provides a list of area-sensitive birds and important references.
  • Contact the Canadian Wildlife Service (CWS) for the location of forest bird monitoring sites and names of volunteers who might assist the planning authority in locating important areas.
  • Bird Studies Canada may be of assistance. They conducted a 3-year study of 287 woodlots to determine the effects of forest fragmentation on forest birds and to determine what forests were of greatest value to interior species.
  • Conduct field investigations of the most likely looking areas in spring and early summer when birds are singing and defending their territories.

5.4.2.2 Forests providing a high diversity of habitats

Forests with a variety of vegetation communities and dominant tree cover are most likely to have the highest diversity of plant and wildlife species. Complexes of upland and wetland habitats also may have high diversity.

Many species of wildlife such as squirrels, and cavity-nesting birds like pileated woodpeckers, barred owls, and wood ducks use large trees with hollow cavities to bear and raise young. These trees can also provide resting or loafing habitat for mammals like raccoon and porcupine. Refer to the habitat matrices in Appendix G for the habitat preferences of species that depend on tree cavities. Older forest stands usually have more cavity trees and support a higher diversity of species than young stands. Best sites contain a mix of large and small tree cavities. Cavities in living trees are generally better than those in dead trees because they last longer. Some tree species make better cavity trees than others do. For example, species such as red pine or white birch break down very quickly and are of limited use for cavities.

Very tall trees, such as white pine, that grow above the main canopy (supercanopy trees), provide important habitat for birds of prey, that may use these trees for nests, roosts, and hunting perches.

Forests with numerous vertical layers of vegetation also contribute greatly to site diversity because of the many microhabitats they provide for wildlife. In addition, an abundance of ground structure such as large fallen logs and leaf litter further enhances a site’s ability to support wildlife. Fallen logs are essential habitat for some salamanders, members of the weasel family, certain woodpeckers, and many invertebrate species.

How to find
  • Examine FRI maps for older forest stands (average tree age greater than 100 years old or the oldest stands in the planning area), forests with several stand types, and stands with composition consisting primarily of trembling aspen, largetooth aspen, beech, basswood, white cedar, and white pine. These tree species readily form cavities that are important to wildlife.
  • Use aerial photographs to locate the largest, contiguous forests in the planning area. In addition, forest stands that are closely associated with other forest stands usually provide greater diversity than isolated stands.

5.4.2.3 Old-growth or mature forest stands

Although definitions of old-growth forest vary depending on tree species, generally these sites are characterised by having a large proportion of trees in older age classes, many of them over 120 to 140 years old. Other features include: a broad spectrum of tree sizes with some very tall trees, an uneven canopy with scattered gaps due to fallen trees and large limbs, and abundant fallen logs in various stages of decomposition. These older, relatively undisturbed forests usually support a high diversity of wildlife species.

Old-growth forest stands are rare throughout the province, particularly in southern Ontario, largely due to past logging practices. Most candidate sites will likely be small stands that have experienced little or no forestry management.

How to find
  • Ask OMNR foresters for locations of old growth candidate sites in the planning area.
  • Examine FRI maps to locate the oldest stands and use aerial photographs to verify FRI information.

5.4.2.4 Foraging areas with abundant mast

Over 75 species of birds and mammals consume fruit and nuts within the Great Lakes-St. Lawrence forest region and abundant supplies can enhance their survival and productivity. In summer and fall, black bears search for areas of abundant food. The most important areas are forests containing numerous large beech and red oak trees that supply the energy-rich beechnuts and acorns that bears prefer. These sites are especially important in the fall because the animals are building fat reserves for hibernation. Other animals such as white-tailed deer that remain active throughout winter may also rely on supplies of nuts to build fat reserves. In summer, in more open areas, large patches of berry-producing shrubs (blueberries, raspberries, huckleberries) provide important feeding habitat for a variety of animals and birds. Black cherry, mountain ash, and apple trees also may attract wildlife. If these food sources are unavailable or drastically reduced, bears may wander into human communities in search of food.

How to find
  • Ask OMNR staff for locations of known feeding areas as well as sites with a high composition of mast-producing trees. Landowners and local hunters may also know of important sites, particularly more visible “bear nests” or claw marks in beech and oak trees.
  • Use FRI maps to locate forest stands with high proportion of beech and red oak trees.
  • Use aerial photographs to locate large bedrock outcrops where shrubs producing berries are often found. Forest openings, old fields, and utility corridors are often excellent sites.

5.4.2.5 Amphibian woodland breeding ponds

These ponds are used for breeding by several species of frogs and salamanders. Such water bodies may be small and ephemeral but nevertheless, important to local amphibian populations, especially if they provide the only suitable habitat in the area.

The best breeding ponds are unpolluted, and contain a variety of vegetation structure, both in and around the edge of the pond, for egg-laying and calling by frogs. The best adjacent habitats are closed-canopy woodlands with rather dense undergrowth that maintains a damp environment. Moist fallen logs are another important habitat component required by salamanders. Sites with several ponds and/or ponds close to creeks are especially valuable.

How to find
  • Ask the OMNR ecologist and biologist and local naturalists for locations of important woodland ponds. Local landowners may also provide assistance as they may hear springtime choruses of frogs on their property.
  • Soil reports and maps may indicate presence of ponds by describing drainage patterns and locations of shallow soils over rock and relatively impervious soils (clay soils), physical characteristics that often lead to pond formation.
  • Examine topographical maps to locate low-lying, poorly drained areas of the municipality.
  • Ask CWS (Burlington) if amphibian-monitoring programs (amphibian call counts and backyard surveys) are being conducted in the planning area. If so, they can provide names of volunteers and areas surveyed.
  • Contact Bird Studies Canada for information on their marsh-monitoring program.
  • Conduct field investigations in spring; warm spring evenings in April are good times to listen for calling frogs to determine their relative abundance. For later-calling species such as green frog and bullfrog, late May and early June is more optimum timing.
  • Refer to the Ontario Herpetofaunal Summary for historical records.

5.4.2.6 Turtle nesting habitat

In spring and early summer, turtles lay their eggs in areas that may be used year after year. Preferred nesting habitats are usually on relatively soft substrates such as sand or fine gravel that allow turtles to easily dig their nests, and are located in open, sunny areas (enhancing development). In general, the best nesting habitats are close to water and away from roads (less mortality of adults and hatchlings) and sites less prone to loss of eggs by predation from skunks, raccoons, and other animals.

Areas with numerous turtle nests are hard to find and it is unlikely that many such sites will be found. However, the following suggestions will help to narrow the search for prime areas.

How to find
  • Use Ontario Soil Survey reports and maps to help to find suitable substrate for nesting turtles (well-drained sand and fine gravel).
  • Check the Ontario Herpetofaunal Summary records for uncommon turtles; location information may help to find potential nesting habitat for them.
  • Use aerial photographs and maps to narrow the search for prime nesting areas including shoreline beaches located near good turtle habitat (weedy areas of wetlands, lake and river shorelines), road embankments near turtle habitat, and stream crossings/culverts on water bodies.
  • Conduct field investigations during prime nesting season near wetlands deemed to provide the best turtle habitat.

5.4.2.7 Specialised raptor nesting habitat

Several raptors, including ospreys, those nesting and hunting in forests, and several other woodland and grassland raptors require somewhat specialised nesting habitat for their long-term survival. For example, red-shouldered hawks prefer mature forests with closed canopies, near water. If the site remains undisturbed, they may continue to use the same nest or site in consecutive years. Osprey nest along lake shorelines as well as in wetlands close to productive fishing waters. Short-eared owls nest on wet ground in open areas, including marshes and wet fields with sufficient ground cover.

Shorelines of productive water bodies with numerous large conifers and/or deciduous trees and with extensive areas of shallow water (< 1 m) for fishing are prime nesting habitat for ospreys. Trees used for perching and nesting are large and sturdy and provide birds with clear flight paths and good visibility.

Most woodland raptors require mature trees that are large enough to support the nest, full canopy closure, and a minimum of trees and shrubs in the understorey. Since these birds of prey hunt within the forest, an unimpeded flight zone under the canopy is required.

The presence of displaying or vocalising adults or active nests, is the most expedient approach to take when attempting to identify specialised habitat for these species. Also, the presence of inactive nests can indicate important raptor nesting habitat because some species may have several inactive nests within their nesting territory. see habitat matrices in Appendix G for descriptions of nesting habitats of raptor species and Appendix O for how to find and identify their nests.

How to find
  • Use FRI maps and aerial photographs to identify the largest tracts of contiguous forest in the planning area. FRI maps indicate species composition and age of forest stands (two important factors in nesting habitat selection for several species of raptors, including red-shouldered hawk). To find potential osprey nesting habitat, focus on old shoreline forest stands first. FRI maps and aerial photographs may also be used to identify large (>75 ha) fields and meadows that may be suitable for short-eared owl nest sites.
  • Use maps and aerial photographs to identify forests with few roads that tend to have less human disturbance. Use aerial photographs to identify areas of water within forested areas that may provide red-shouldered hawk nesting habitat.
  • Ask the OMNR ecologist or biologist. They may be aware of locations of nesting raptors. Often osprey nests are reported to OMNR. In addition, these staff may know local naturalists that may be aware of the locations of raptor nests.
  • Conduct field investigations from mid April to the end of May. The use of tape- recorded hawk calls can help to find raptor nests by eliciting calling responses from courting or nesting hawks.
  • Short-eared owls may hunt with other raptors in winter seasonal concentration areas (open fields with abundant small mammals). If suitable nesting habitat is present, some birds may remain to breed.
  • Check data from the red-shouldered hawk survey administered by Bird Studies Canada.
  • Conduct aerial flights, concentrating on shorelines of lakes, large rivers, and marshes.
  • Check the Atlas of Ontario Breeding Birds or Rare Breeding Birds in Ontario for species documented in your planning area.

5.4.2.8 Moose calving areas

Shortly before giving birth in mid-May, solitary cow moose move to areas providing isolation, cover, and escape paths from predators. Calving sites are usually slightly elevated areas. Islands and peninsulas seem to be preferred, but shorelines and upland areas are also used if they are relatively close to open water (100 to 500 metres). These sites are hard to find by field investigation because at this time of year moose are solitary and intentionally looking for secluded areas.

The OMNR has the greatest expertise in looking for and finding moose calving areas, as well as moose aquatic feeding areas and mineral licks briefly discussed below. OMNR biologists are aware of these specific habitat requirements. Very few calving sites will be known.

How to find
  • Topographical maps used with aerial photographs will help locate potential habitats such as islands and peninsulas.
  • Consult the OMNR biologist for known calving sites.

5.4.2.9 Moose aquatic feeding areas

From June through July, moose move as far as 30 km to consume large quantities of aquatic plants, especially subagent species, to replenish their bodies with sufficient sodium. They feed several times a day at preferred aquatic feeding sites. Ideal sites provide abundant food, particularly pondweeds, water milfoil, and yellow water lily, and have adjacent stands of lowland conifers to provide shade and hiding cover. Several moose may use prime sites.

How to find
  • Use aerial photographs to identify bays, shorelines, and river and creek systems with aquatic vegetation.
  • Contact the OMNR biologist for the locations of potential sites.
  • Use FRI maps and aerial photographs to locate coniferous tree cover adjacent to potentially suitable areas.
  • Conduct aerial flights in June and July to locate concentrations of moose or evidence of use (an OMNR protocol is available).

5.4.2.10 Mineral licks

In spring, moose seek mineral licks to consume sodium that is found in upwelling groundwater and the soil of these seepage areas. Mineral licks surrounded by forest cover and free of human disturbance may be used by large concentrations of moose for many years. These sites are rare, occurring most frequently in areas of sedimentary and volcanic bedrock. They rarely occur on granitic bedrock, except where the site is overlain by calcareous glacial till.

How to find
  • Contact the OMNR biologist for the location of any known or potential areas. Local residents may also know the location of licks.
  • Consider using a small aircraft to verify reported sites because mineral licks are uncommon; however, these areas stand out because they are so trampled.

5.4.2.11 Mink, otter, marten, and fisher denning sites

These species are members of the weasel family. They are predators with large home ranges and must cover a large area in search of food (a male fisher may have a home range of 17.5 to 39 sq. km). Like most larger carnivores, they are rarely found in high densities, and have specific habitat components critical to their survival.

Mink prefer shorelines dominated by coniferous or mixed forests for feeding and denning. Dens are usually located underground, especially where shrubs and deadfalls provide more cover for dens and habitat for prey. They also den in abandoned muskrat lodges.

Since otters avoid humans, undisturbed shorelines with abundant shrubby vegetation and downed woody debris provide prime denning habitat. They often use old beaver lodges for dens and log jams and crevices in rock piles. Since this mammal eats primarily fish, it requires shoreline habitats that support large, productive fish populations.

Marten and fisher share the same general distribution and habitats. Both require large unbroken tracts of coniferous or mixed forest with abundant large trees for maternal denning sites. Fisher dens are usually in cavities in dead or living trees or fallen logs and these animals appear to prefer trees larger than 40 cm diameter at breast height. Marten often use cavities originally made by woodpeckers.

Exhaustive searches are not recommended, since feeding and denning sites for all these mammals are usually very hard to find. Long-term survival of these species and other carnivores with large ranges is best assured by taking a broad, landscape approach to Natural Heritage System planning by identifying and protecting large natural areas that include the best quality habitat for these species. Protection of sufficient habitat for these area-sensitive species will also help provide suitable habitat for many other species.

How to find
  • Although specific sites are hard to find, OMNR biologists and foresters, local naturalists, and residents may know the location of some potential feeding and denning habitats. OMNR staff can also provide contact with trappers who may know the location of prime habitats.
  • Use aerial photographs, topographical maps, and FRI maps to locate relatively undisturbed shorelines, wetlands, and closed-canopy forests with larger, older trees that might provide suitable structure.
  • Habitat supply models are available through OMNR.

5.4.3 Highly diverse areas

These are areas of high species or vegetation community diversity. If protected within a Natural Heritage System, such sites will contribute greatly to maintenance of overall biodiversity. Although these areas may be found throughout the province, they have certain characteristics that can help to narrow the search for them. Often highly diverse areas contain a wide range of habitats or ecosystems and the large variety of plants and animals associated with them. These areas frequently have species with both northern and southern affinities, and rare species are often found on such sites.

The deciduous forest region of Ontario (the Carolinian zone) has long been recognised as a part of the province with many highly diverse areas. More vulnerable, threatened and endangered species are found here than in any other Canadian life zone. Other parts of southern Ontario with many highly diverse areas include the Frontenac Axis of southeastern Ontario; Grey and Bruce counties; and parts of Frontenac, Lennox- Addington, Lanark, Renfrew, Hastings, and Haliburton counties.

On the Canadian Shield, areas underlain by carbonate bedrock frequently support rich communities because these substrates are less erosion resistant than the acidic granite and gneiss bedrock types, and encourage development of more nutrient-rich, basic soils. In southern Ontario, sites within the contact zone between Paleozoic limestone and the precambrian bedrock of the Canadian shield often support highly diverse communities.

How to find

  • Use local expertise, aerial photographs, and maps to look for areas with the following characteristics that frequently result in highly diverse communities:
    • good diversity of vegetation and vertical structure, usually in the form of different vegetation layers
    • good diversity of ecosystems such as wetlands, forests, and old fields
    • biophysical features such as the presence of cliffs; springs or seeps; pockets of deeper, more fertile soils; abundant organic debris on the ground (e.g., large decaying logs)
    • relatively little human disturbance
  • Conduct field investigations where necessary to check potentially diverse sites.
  • Site district and inventory reports and environmentally significant areas studies often provide descriptions of many sites. This information may provide a start for further investigations.

5.4.4 Cliffs

Cliffs are dominated by bedrock with sharp or variably broken edges and a vertical relief greater than three meters. Average soil depth is usually less than 15 cm and restricted to places where organic debris and mineral material can accumulate such as in cracks, hollows, and along the upper rim.

Many cliffs may be locally significant because of their value as specialised habitat for wildlife such as nesting peregrine falcons or rare plants such as purple-stemmed cliff brake. During summer, large numbers of turkey vultures may roost on secluded cliff faces. Many cliffs have areas where groundwater seepage creates a thin film of water running over the rock surfaces. Often unique floral and insect species are associated with these specialised habitats. Some surfaces contain a diverse assemblage of algae and fungi that live within the crystalline structure of the rock.

Cliffs composed of limestone, dolostone and/or sandstone are most prevalent along the Niagara Escarpment, from Manitoulin Island to near Niagara-on-the-Lake. Granite cliffs are more widespread in the province, but metamorphic/granitic cliffs are only found on the Frontenac axis in Site Region 6E.

How to find

  • Use topographical maps to locate areas of sharp relief.

5.4.5 Seeps and springs

Seepage areas, springs, and small intermittent streams provide habitat for numerous uncommon species such as northern two-lined salamander and ginseng. In winter, wild turkey and white-tailed deer also forage in these areas because of the lack of snow on the ground. Often these areas support a high diversity of plant species. Many of the most important seeps are in forested areas where the canopy maintains cool, shaded conditions.

These landscape features are hard to find but, because of their importance to many species, considerable effort should be made to find them, especially sites with several seeps and springs.

How to find

  • Use topographical maps and aerial photographs to locate small streams and headwater areas that could indicate the presence of seeps. Headwater areas for coldwater streams are often excellent areas to find seeps and springs. These areas often have rolling topography.
  • Use of thermography, location of brook trout redds and reference to local to hydrogeological studies.