The 54 ha (133.6 A) Old Growth Conservancy is a District of West Vancouver protected forest area located on Hollyburn Mountain, west of the Cypress Bowl Road and south of the Cypress Provincial Park boundary. The Conservancy is a remnant of the ancient temperate rain forests that once covered West Vancouver’s mountainside. British Columbia’s temperate rain forests are dominated by conifers which, unlike deciduous trees, are able to photosynthesize and grow throughout the year, resulting in big trees. These rain forests are “one of the most biologically productive environments in the world.” [Footnote: R. & S. Cannings, British Columbia: A Natural History, p. 129]
BC’s temperate rain forests are divided into four main biogeoclimatic zones: Coastal Western Hemlock, Coastal Douglas-Fir, Mountain Hemlock and Interior Cedar-Hemlock. At 760 metres (2,500 feet) elevation, the Conservancy is near the upper limit of the Coastal Western Hemlock zone and the lower limit of the Mountain Hemlock zone. Due to its “transition zone” location, the Conservancy contains plant species from both zones, increasing its biodiversity. While its dominant tree species are western hemlock and western redcedar, the Conservancy also contains mountain hemlock, yellow-cedar, and amabilis fir, all typical Mountain Hemlock zone species. This forested area provides food and shelter for numerous wildlife species, including some that are considered old-growth dependent.
The Conservancy is a mosaic of different aged forest stands, reflecting a complex history of logging and fire disturbance. The impressive 30 ha (74 A) old-growth stand in the Conservancy’s northern corner regenerated after a major fire that took place in the early 1600s and is approximately 375 years old. Some western redcedars in this stand managed to survive that fire and range from 665 to over 900 years old. Most of the Conservancy’s older trees are western redcedar, many with a diameter at breast height (DBH) of over two metres.
During the 1970s, long before the Conservancy became a protected area, ski trails were cut through some parts of the forest, but were abandoned within a few years. In the late 1980s a few mountain biking trails were built in the southeast corner of what is now the Conservancy Crossing trail. At present, this is the only public access trail within the Conservancy and OGC Society members are in the process of installing two educational signs along this stretch of trail.