The Natural Heritage of Gatineau Park

Overview

Gatineau Park is very popular because of its tranquility and natural beauty. However, even regular visitors may be unaware of its unusual diversity of habitats, plants and animals. This amazing biodiversity is largely because Gatineau Park lies in the transition zone between the boreal forest of the Canadian Shield to the north and the eastern temperate forest of the St. Law rence Lowlands to the south. Species typical of both zones live in the park, resulting in an interesting blend of species not commonly found elsewhere in Canada. Gatineau Park provides habitat for 27% of all of the plant and verte brate species found in Canada, and more than 40% of those found in Quebec and Ontario. Probably no other park in Canada of comparable size is so rich with flora and fauna.

Flora

The distribution of plant species within Gatineau Park is determined by several factors, including microclimate, topography and geology. The carbonate-rich soils common in the park support a rich diversity of plants.

Nearly 90% of the park is forested, presenting some of the most ecologically diverse woodlands in central Canada. An afternoon's walk can take the hiker through deciduous-dominated forests of sugar maple, American beech, yel low birch and eastern hemlock, then through coniferous-dominated black spruce and balsam fir forests typically asso ciated with the boreal forest. Red and white oaks dominate along the steep slopes of the Eardley Escarpment.

Remnant stands of the park's original mature white pine forests are very rare, as most of these magnificent trees were harvested for the square timber trade in the 1800s. Similarly, small virgin stands of white spruce and balsam fir are found only in a few remote locations. Virgin stands of eastern hemlock are also rare, but can be found on some cool, north-facing slopes. Maintaining the health of these species is very important, as they contain the genetic diversity of the once-vast forests of the St. Lawrence Lowlands.

More than 1100 species of vascular plants have been documented in Gatineau Park. Notable are the more than 40 species of orchids, including showy lady's slipper, green adder's mouth, grass pink and rose pogonia. Many orchids thrive in the wet, rich environ ment of marshes, fens and bogs.

Aquatic Environments

MusselAs important as its forests are, it is water that underpins Gatineau Park's ecology. The park is dotted with some 50 lakes, the largest being La Pêche, Philippe, Mousseau (Harrington) and Meech. The latter three form a chain of lakes through the centre of the park and drain through Meech Creek Valley to the Gatin eau River. The park also has many streams, ponds and wetlands.

Pink Lake is a fine example of a rare meromictic lake; the lake's bowl-like shape and its sheltered location prevent its waters from intermixing. At its greatest depth, the lake is almost oxygen-free, and supports an an aerobic bacterium whose photosyn thetic process uses sulphur instead of oxygen. The lake, once part of the Champlain Sea, is also home to a unique freshwater population of the saltwater threespine stickleback fish.

The numerous marshes and bogs provide critical feeding and breed ing habitat for many insects, inver tebrates, fish, amphibians, reptiles, birds and mammals. Wetlands are among the world's most productive ecosystems, producing as much biomass per hectare as a tropical rainforest. Wetlands store rainfall then slowly release it to meet downstream needs, such as those of plants and animals during dry spells. They also serve as a natural "water treatment system," improving water quality by filtering, diluting and degrading various sediments and pollutants.

Over 50 species of fish have been inventoried in park waters. Several salmonid species such as lake trout, speckled trout and lake whitefish are native. At least 12 species were introduced by people; these include popular sport fish such as smallmouth bass, rainbow trout, and brown trout. Sport fishing is regulated through provincial legislation.

Mammals

WolfGatineau Park provides habitat to many mammals typical of Canada's wilderness, such as river otter, snowshoe hare, red fox, moose, coyote, wolf, beaver, raccoon, white-tailed deer and black bear. Wolverine and Eastern Cougar occur here, but are rarely seen.

Perhaps the most influential mammal in Gatineau Park is the beaver, which plays a major ecological role by flooding habitats, changing the flow of streams, and modifying plant communities. Evidence of such beaver activity is com mon throughout the park. Once plentiful, by 1930 beaver populations in eastern Canada had declined to low levels due to excessive harvesting for the animal's fur. To restore the local population, breeding pairs were reintroduced into Gatin eau Park. Since the 1950s, beavers have once again become widespread and abundant in the park.

Some 200 black bears live in Gatineau Park. These omnivores require sig nificant space to maintain a viable population. Forested natural landscapes and networks of protected areas are critical to the continued survival of this important native species. Bears play an important role in dispersing seeds.

The population of white-tailed deer in the park and surrounding rural areas has increased markedly in the past several decades. The species is over-abundant relative to the park's ability to sustain the population. An estimated 1200 deer were resident in the park in the spring of 2005, 50% above the park's "carrying capacity." The high number of deer is manifested in the heavy browsing of vegetation along the Eardley Escarpment, severely impacting the natural regeneration of its red and white oak forest. The main predator of deer in the park is the wolf; unfortunately Gatineau Park is not large enough, is too fragmented, and has too many disturbances to sustain a wolf population large enough to control the burgeoning deer population.

Gatineau Park was made a provincial game reserve in 1973 and is shown as the Parc de la Gatineau Game Sanctuary in the Conservation and Develop ment of Wildlife Act (October 2007). This is very significant since all hunt ing is prohibited therein.

Birds

About 230 species of birds have been observed in Gatineau Park. The forests are alive with ruffed grouse, pileated woodpeckers, white-throated spar rows and nuthatches. The lakes and ponds provide habitat for great blue herons, wood ducks, buffleheads and hooded mergansers, while other species, such as the Virginia rail, live in the extensive cattail and sedge marshes. Many migratory song birds, including warblers, sparrows and thrushes, also nest in the park.

Eagles, hawks and owls are signifi cant top avian predators in the park. Turkey vultures, red-tailed hawks and broad-winged hawks soar over the Eardley Escarpment, looking for prey or carrion. Vultures clean up deer carcasses left by wolves and other predators. Great horned owls and barred owls hunt along swamps and forest edges.

Species of Conservation Concern

Gatineau Park is home to 125 species of plants and animals that are of con servation concern in Quebec. Twenty-three of these species are also listed as endangered in Canada by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). This Government of Canada committee of experts assesses and designates which species are in danger of disappearing from Canada.

Of the 125 species of conservation concern in Gatineau Park, 90 are plants—a number higher than for any protected area in the province. These include wild ginger, wild leek, blunt-lobed woodsia fern, and ram's-head lady's slipper orchid. Seven of the 90 plant species are trees: white oak, swamp white oak, eastern red cedar, black maple, common hackberry (or sugarberry), butternut and rock elm. These tree species are of particular interest because they are all near the northern limit of their natural range. Ram's-head lady's slipper and butternut are also listed by COSEWIC as endangered species. More than 40 plant species of conservation concern are concentrated on the dry, south-fac ing slopes of the Eardley Escarpment. For example, along the escarpment live more than 80% of all eastern red cedar trees found in Quebec.

Three Gatineau Park fish species —margined madtom, bridle shiner and brassy minnow—are of conservation concern. The park is also home to a significant number of nationally important reptiles that are considered to be of conservation concern, including the milk snake, ringneck snake, common map turtle and blandings turtle. The blandings turtle is listed by COSEWIC as endangered.

Thirteen species of birds observed in the park are of conservation concern; these include the golden eagle, red-headed woodpecker, least bittern and loggerhead shrike. The southern flying squirrel, wolverine, eastern cougar and eastern wolf are four of the ten park mammal species of conservation concern. The loggerhead shrike, wolverine and cougar are also listed by COSEWIC as endangered in Canada.

Geology

The Gatineau Hills are remnants of Quebec's ancient Grenville (or Laurentian) Mountains, one of the oldest mountain ranges in the world. These mountains, part of the vast Canadian Shield, may have once towered as high as today's Rockies! Their hard Precambrian rock, mainly granite and gneiss, has been worn down by a billion years of erosion. The impressive Eardley Escarpment, which forms the southwestern border of Gatineau Park, is part of a major geological fault along the southern margin of the Canadian Shield. The Lusk Caves on the Eardley Plateau were formed in deposits of metamor phosed limestone (marble) lying upon the older Precambrian rock.

*from Gatineau Park: A Threatened Treasure