The Ancient Forest Trail

Antique Forest Stands in B.C.'s Inland Rainforest.

As Pacific storm systems sweep over the interior mountain ranges of British Columbia they create a zone of elevated precipitation. In the watershed of the upper Fraser River this has given rise to a unique inland wet-temperate rainforest; a forest ecosystem that combines attributes of both the coastal wet-temperate rainforests of British Columbia and adjacent boreal forests of Alberta and the far north.

Although the wet biogeoclimatic zones associated with the inland rainforest cover more than 110,000 ha in the upper Fraser River valley, stands that contain ancient Western Redcedars (Thuja plicata) and associated biodiversity are quite limited in their distribution within the upper Fraser River valley. These hallmark images of the inland rainforest derive largely from what scientists now call Antique Rain Forest stands; sites where the last major disturbance event in the stand, such as fire, happened well before the current generation of trees established (Goward and Arsenault 2000).

Antique Forest stands are typically located in wet toe-slope or bench topographic positions, often in close proximity to the valley sides. The mesic nature and topographic position of these localized microsites has over time protected them from stand destroying fires that occasionally sweep across surrounding hill slope positions. As a consequence Western Redcedars in toe-slope Antique Forest stands can show exceptional longevity; with many individual trees estimated to be over one thousand years in age. Recent studies have shown that Antique Forest stands are important repositories of canopy biodiversity, containing an internationally significant assemblage of canopy lichen species (Goward and Spribille 2005) . Further, the structural features associated with large trees in these stands support many important wildlife habitat attributes.

Unfortunately, the same conditions that favored the development of Antique Forest stands at the base of mountain slopes, i.e. gently sloping alluvial fans or benches, were also prime considerations in the location of transportation corridors in the region. Highway 16 east of Prince George, particularly in the area between Hungary and Slim Creeks, was placed in the middle of what we now recognize were some of the most exceptional Antique Forest stands in B.C. Given the easy access afforded by the highway and the exceptional stature of trees in these stands, most of the toe-slope Antique Forest stands along the highway corridor in this area have been logged over the last half century. Consequently opportunities to view this exceptional feature of B.C.'s inland rainforest are now limited (see High Biodiversity Cedar Stands at Risk?).

Where is the Ancient Rain Forest Trail?

The recent construction of the Ancient Forest Trail on the south side of Highway 16 near Slim Creek now provides an opportunity to view an Antique Forest stand within BC's inland rainforest. The trailhead, located 113 km east of Prince George (6.6 km west of the Slim Creek rest area), is marked by signage "Ancient Forest 1 km ahead". Pull into the trailhead parking lot (an abandoned gravel quarry) and spend an hour walking through one of BC's best kept secrets.

What can I see on the Ancient Rain Forest Trail?

The overwhelming question posed by first-time visitors to the Ancient Forest Trail is "How can such large trees, reminiscent of rainforests on BC's west coast, grow within sight of the Rocky Mountains?" Visitors are right to ask this question. By all rights, the summers are too hot and dry, and the winters too long and cold. However, it is the long, cold, and snowy winters which hold the answer to this question.

Numerous small streams indicate the presence of abundant sub-surface water in antique forest stands

One of the most important elements supporting the growth of ancient Western Redcedars in toe-slope stands of the inland rain forest is the abundance of sub-surface water. The large cedar trees in these stands are literally watered by sub-surface irrigation throughout the dry summer period. The evidence of a shallow water table in these toe-slope stands can be seen in the many small seepage areas and streams alongside the Ancient Forest trail. Crucial to the continued flow of these seepage areas is ground water recharge from melting of the winter snow pack, both within the stands themselves, and from melt on adjacent higher elevation slopes.

This link with higher elevation catchments of the watershed is dramatically evident in the vigorous flow at Treebeard Falls, on the southern spur of the Antique Forest Trail. Water cascades over the rock escarpment at the edge of the Antique Forest Stand, sustaining ground water supply and supporting lush plant growth. The spray zones of waterfalls within the inland rainforest often serve as refugia for rare canopy lichens. In many cases the nearest population of these same species is found in wet-temperate rainforests on BC's west coast and/or in other Pacific rim west-temperate rainforests (e.g. in Chile or New Zealand). The lush moss mats adjacent to Treebeard Falls contain several interesting species of saxifrages and ferns. These moss mats, however, are quite fragile. They can easily be dislodged by people climbing near the falls.

Buttress roots (shown here on the "Radies" tree) can extend outwards for many meters at the base of large cedars. Their presumed roles include providing mechanical support for the trunk and creating a greater surface area for respiration by the roots, important in sites with waterlogged soils.

Many of the plants growing within the Antique Forest stands demonstrate adaptations to growth under wet conditions. Large Western Redcedars on the Ancient Forest Trail often show picturesque buttress roots at their base. Buttress roots are more well known in tropical rain forest trees, where it is hypothesized that they provide both mechanical support for the tree, as well as enhancing oxygen exchange for below-ground roots in waterlogged soils. Hikers should take care not to climb on buttress roots along the Ancient Forest trail. Their bark can be easily damaged by even light trampling.

Another feature commonly associated with the presence of large buttress roots in Western Redcedar is the formation of hollow cavities at the base of the tree truck. These cavities, which can lead into the hollow trunk of old trees, provide important wildlife habitat for species such as bears. They are thought to form after the original nurse logs, on which many of these trees germinated, rot out over time.

The moist soils along the Ancient Forest Trail support an abundance of ferns and fern allies. Some of these, such as the Beech Fern (Thelypteris phegopteris), are known indicators of sites that have rich soils and moist substrates. Others ferns, such as the Ostrich Fern (Matteucia struthiopteris) or Fiddlehead Fern , are harvested yearly for their edible fronds as they emerge in the spring. Another well known edible (and medicinal) plant of the Ancient Forest trail is the Wild Ginger (Asarum caudatum). The roots of Wild Ginger have a pleasant, though sharp ginger taste, while the leaves smell strongly of lemon-ginger when crushed. Perhaps the most utilized plant species in the inland rain forest was the Western Redcedar itself; which historically was used in many facets of day-to-day life by First Nations communities in B.C.'s inland rainforest. The Ancient Forest trail falls within the traditional territories of the Lheidli T'enneh First Nation.

Tree trunks along the ancient forest trail glitter in the afternoon sun, reflecting the deep golden hue of gold-dust lichens (Chrysothrix candelaris), an abundant bark epiphyte in these moist antique forest stands.

The exceptional longevity of Antique Forest stands, when taken together with the diversity of canopy substrates, and humid canopy microclimate in these stands, creates ideal conditions for the growth of canopy lichens. One of the more visible lichens within the canopy of Antique Forest stands is that of gold-dust lichen (Chrysothrix candelaris). The sweeping vertical trunks of ancient cedars are often painted bright yellow by the growth of this crustaceous lichen. Although gold-dust lichen reaches its greatest abundance in Antique Forest stands, it is common on old snags, especially those of sub-alpine fir (Abies lasiocarpa), in many of the wet montane forests in B.C.

Another major group of lichens along the Ancient Forest Trail is that of foliose (leaf-like) cyanolichens (lichens which contain blue-green algae) such as the Lungwort (Lobaria pulmonaria) and Powdered-paw Lichen (Nephroma parile). These cyanolichens, much like a crop of alfalfa or legumes, are capable of nitrogen fixation, and thus play an important role in supporting ecosystem nutrient cycling. A significant number of foliose cyanolichens along the Ancient Forest trail are highly restricted in their distribution. Their survival is closely linked to that of the Antique Forest stands themselves. One of these, the Cryptic Paw Lichen (Nephroma occultum), has been listed as a species of special concern with the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). Other indicators of canopy biodiversity along the Ancient Forest trail include the pendulous moss mats that can be found draped over branches within the lower canopy. These mosses are more typically associated with very wet coastal temperate rainforests in B.C.

Many of the large Western Redcedars found alongside the Ancient Forest Trail lean prominently to one side, reflecting the growth history of individual trees. The upper and lower bark exposures on these trees support quite different lichen and moss communities. Caliciod lichens, also known as Pin lichens, prefer the sheltered underside of these large cedar trunks, where they obtain their moisture solely from atmospheric humidity. Pin lichens have increasingly been used as indicator species for the exceptional site continuity of the very old Antique Forest Stands.

The presence of decay agents, such as conks of Echinodontium tinctorium , is an integral part of the dynamics of Antique Forest Stands in the inland rainforest. Although many of the Western Redcedars and Western Hemlocks (Tsuga heterophylla) in these stands show signs of heart rot, the trees remain biologically fit, and are important contributors to the biodiversity of these stands. Interestingly, recent scientific studies have suggested that fungal endophytes (fungi that grow intimately between the cells of the host plant, for instance, in leaf tissue) may actually confer protection from other pathogens and herbivores. These interactions provide fascinating possibilities for future studies in B.C.'s wet-temperate rainforests.

Given the longevity of cedar trees in the Antique Forest Stands, the regeneration of these stands by processes of gap dynamics (where young trees grow in the gaps created by newly fallen old trees) is a slow and barely perceptible process. Parallel studies on BC's west coast suggest that cedar seedlings can persist for long time periods in shaded understory forest floor environments, awaiting the opportunity for growth afforded by occasional tree-fall events. When large individual cedars ultimately do fall to the forest floor they create a unique set of microenvironments. These provide both important wildlife habitat features and support the growth of many different lichens and mosses. These large structural elements are an important component of inland rainforest stands.

Please note that trail conditions may change by season and that ongoing trail upgrades may require closures or detours on some sections. All hikers should be aware that conditions on mountain trails can change quickly and that wildlife may be encountered.

More information available at: http://ancientcedar.ca

You Tube and Blogs!

Ancient Cedar Forest - A walk through the northern wetbelt

Ancient Forest in British Columbia

The Ancient Forest by Rebecca Bollwitt

http://www.miss604.com/2010/02/the-ancient-forest.html

Top Of Page