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Ecosystems

The Clayoquot Sound UNESCO Biosphere Region is situated in the coastal temperate rainforest on the west coast of Canada. Dominated by large old trees, principally western hemlock (Tsuga heterophylla), and western cedar (Thuja plicata), these unique and special forest stands represent some of the last remaining examples of old-growth coastal perhumid temperate rainforest to be found in British Columbia undisturbed by logging (in several watersheds) or other significant industrial development.

As expected in a rainforest, the region receives heavy rainfalls and accumulates high volumes of fresh water in short periods of time. Mountainous topography with deep valley bottoms have numerous watercourses, including major rivers and ephemeral streams which eventually bring nutrients to the coastal and offshore waters. A diverse range of ecosystems exist within the region’s boundaries; all of which are associated with the coastal geography and high volume of rainfall. These ecosystems include ancient temperate rainforest, large and small lakes, rivers and streams, alpine peaks, open ocean, rocky coastal shores, long sand beaches, estuaries and mudflats.

With the continued development in temperate rainforests worldwide, these areas are of increased global ecological significance. Some watersheds in the region have been extensively logged in the past fifty years and others have been subject to human activity. While the core protected areas of the biosphere region include National and Provincial parks, which prohibit industrial logging, there are significant areas of old-growth forest located within BC Timber Forest License agreements.

The marine and terrestrial components of the Biosphere Region provide habitat for many species, a significant number of which are endangered or rare. Clayoquot Sound provides vital feeding, breeding and staging habitat for resident, migrating and transient populations of birds, marine mammals, fish, terrestrial mammals, amphibians, and other species. However, development activities in Clayoquot Sound sometimes result in the fragmentation of forest and alpine ecosystems and the loss of biological diversity in coastal rainforests. Read more about the intertwined ecosystem components of the biosphere region below.

Temperate rainforest

95% of the Clayoquot Sound Biosphere is temperate rainforest and more than half of this is considered highly productive old growth (older than 250 years and produces high biodiversity). Old growth temperate rainforest ecosystems are highly complex, consisting of multiple layers of understory, high canopies, large woody debris, creating numerous habitats supporting for higher biodiversity than second-growth forests. Some old growth forest stands on the west coast of Vancouver Island are over 6,000 years old, meaning they have not been disturbed by fire or stand-replacing windthrow events for that duration. Researchers have found individual trees to be older than 1,400 years and with a diameter of 15 metres.

Old-growth forests in Clayoquot Sound can represent true all-aged stands. For instance, in one stand containing amabilis fir, western red cedar, yellow-cedar, and western hemlock, ages were distributed continuously from young saplings to trees almost 1,000 years old. These forests are structurally complex and provide microhabitats for a great variety of plants, animals, fungi, and micro-organisms.

Large and small lakes

While the ocean and rainforest are a primary focus for visitors, residents, and researchers alike, the region is also home to numerous lakes. These range from marshy pond-like wetlands to large open freshwater bodies, including Kennedy Lake, which at 65 km² is Vancouver Island’s largest lake and is easily mistaken for an ocean inlet as visitors enter the region on Highway 4. Less in the public eye, smaller lakes and ponds make up crucial habitat for the region’s diverse and sensitive wetland ecosystems. For example, Swan Lake just outside of the southern boundary of Pacific Rim National Park Reserve is one of the most productive breeding sites in all of Canada for northern red-legged frogs, a species listed as “special concern” under Canada’s Species at Risk Act.

Rivers and streams

The region’s many valleys collect the region's tremendous 3098mm average annual rainfall, channelling the water through the terrestrial ecosystems and eventually out to sea. These rivers nourish the forests they flow through, and the flat, fertile valley bottoms where rivers flow are home to some of the regions largest, oldest trees. Due to their proximity to the ocean, the rivers act as a unique bridge between marine and terrestrial ecosystems.

Perhaps most notably, five species of Pacific Salmon (Chinook/Spring, Coho, Pink, Chum, and Sockeye) travel up these rivers in late summer to spawn in the upstream gravel beds. These salmon are a source of nourishment for the terrestrial ecosystems they swim through, feeding many animals who in turn spread nutrients throughout the riparian (river-side) forests and beyond. Significant (25-70%) proportions of nitrogen found in the coastal forest of our region have been found to have oceanic (salmon) origin! However, given that valley bottoms house the biggest trees, they were historically the first places to be logged, causing landslides, sedimentation, and reduced shade cover, all things that compromise rivers as viable salmon spawning grounds. Clayoquot Sound Salmon populations are currently at historic lows. Community groups such as Central Westcoast Forest Society, in partnership with Tla-o-qui-aht Tribal Parks Guardians, Ahousaht Stewardship Guardians, and Hesquiaht Fisheries are working to rebuild these compromised ecosystems.

Estuaries

The Biosphere Region contains 450 hectares of mapped estuaries: unique habitats where rivers meet the ocean. These partially enclosed waterbodies contain brackish (part salt, part fresh) water from the mixing of the river and the ocean. This mixing provides high levels of nutrients in both the water column and the sediment, creating a highly productive habitat where a diverse range of marine and terrestrial animals come together to grow and feed. Historically, nuučaan̓uł (Nuu-chah-nulth) family groups have resided in seasonal villages and camps at many estuaries in the area, with the river mouths bridging both terrestrial and marine environments and providing an abundance of food and resources. Today estuaries continue to provide key ecosystem functions and remain important nuučaan̓uł places for cultural purposes and food harvest.

Alpine

The mountains that form the high northeast boundary Clayoquot Sound watershed rise abruptly from the tidewater, especially along the steep-sided fjords thrusting inland away from the open Pacific. In some cases, high alpine tundra extends above the tree-line barely 10km from the tidewaters at the heads of these inlets. The rapid changes in altitude result in a succession of mico-climates at various elevations, generating more diverse habitat conditions, and in turn, more biodiversity.

The region’s immense average annual rainfall is received largely as snow in the alpine areas during the winter months, accumulating in a deep snowpack between November and April. In some locations, such as the Mt Mariner glacier visible above Lemmens Inlet from Tofino, the snow remains year-round. During the warmer and drier summer months, cold meltwater from the alpine snowpack plays an important role in regulating temperature and water levels in the river valleys, which is particularly import for the annual salmon run.

Marine

The marine ecosystem varies in its nature from open ocean to iconic deep fjords. Known to be some of the most productive and diverse communities in the world, the marine ecosystem boasts a high species diversity with a total of 31 marine mammals and over 120 marine bird species documented thus far off the Pacific coast of British Columbia. Many of these species rely on the waters of Clayoquot Sound for breeding, foraging, resting, and as a migratory route and these species include SARA listed species at risk such as: Killer Whales (all populations), Grey Whales, Humpback Whales, Fin Whales, Sea Otters, Steller Sea Lions, Albatross, and more. And while BC’s salmon begin and end their legendary life cycle in freshwater, they spend most of their years in the ocean and inlets, inextricably linking the marine ecosystem with the temperate rainforests.

Mudflats

Mudflats are a unique and highly important habitat making up more than 20 square kilometers of Clayoquot Sound’s intertidal zones. More sheltered and richer in nutrients than most intertidal environments, mudflats are also far rarer along the coast of Vancouver Island and are a critical habitat as a “stop-over point” for shorebirds who migrate from Alaska to as far south as Central America each year. During high-tide, these muddy flats are covered in shallow water, while at low tide, they are exposed the air, allowing birds and terrestrial creatures access to a rich and nutritious slurry of mud and eelgrass containing invertebrates, small fish, and worms.

The Tofino Mudflats Wildlife Management Area is one of the most important wetland complexes on the west coast of Vancouver Island and a significant habitat for wintering waterfowl and migrating shorebirds. In 2013, the area was designated a Western Hemisphere Shorebird Reserve - the Tofino Wah-nah-jus Hilth-hoo-is Mudflats,

Rocky coastal shore

The rocky coastal shores of Clayoquot Sound provide another important intertidal habitat, both on the surf-pounded outer coast and the gentler inside waterways. The rocks provide nooks, crannies, and tide-pools for organisms that bind to rock to protect themselves from fast moving water, including multiple species of barnacles, anemones, limpets, sea stars, and more. Many more mobile shellfish and molluscs also reside in the rocky intertidal zone as well as a variety of seaweed. At high tide, fish will frequent these zones to feed, while at low tide, terrestrial creatures including bears, wolves, and deer find nutrition here.