Conservation Assessment: Summary

The full 35 page report, written by Dr. Katherine Dunster and others, can be viewed here (5mb adobe pdf file.) See full report for credits and sources. This summary was composed by Matt Tobey.

On January 30, 2008, a group of biological, ecological, and historical experts met in Creekside Rainforest to conduct a “biodiversity blitz.” Their goal was to make a professional assessment of the land the community seeks to save from logging and development. Although winter is not a good time of year to study migratory birds, seasonal plants, and animals which hibernate, there was still a great deal to be discovered.

Unlike most areas on the relatively dry Gulf Islands, the Creekside Rainforest contains life that is representative of the old growth hemlock and cedar rainforests on the West Coast of Vancouver Island. The deep ravine and continuous tree cover keep the land and creek at lower temperatures with higher levels of moisture compared to the rest of Salt Spring Island. As a result, at-risk species such as the coastal Cutthroat trout, red-legged frog, and Pacific sideband snail can survive here, but are dependent on the forest remaining unlogged and undeveloped.

The experts discovered that for hundreds of years, the wet conditions and deep creek ravine have protected the Hemlock, Cedar, and Maple trees from the worst ravages of forest fires. The only significant logging on this land was done before the invention of the chainsaw, and was limited to hand-sawing only a few of the largest Douglas Firs. Therefore, what remains is a richly diverse and highly sensitive riparian ecosystem, very similar to what existed before modern human influence.

During his brief visit to the Creekside Rainforest, Dr. Terry McIntosh identified over 50 species of mosses, liverworts, lungworts and lichens, still only a partial sample of what this fragile ecosystem supports. His findings are biological evidence that Creekside is an old growth rainforest.

Meanwhile, gastropod expert Laura Matthis was able to identify 13 percent of the 68 known species of land-dwelling snails and slugs. Small mammals and gastropods are an important link in the rainforest ecosystem, spreading fungi spores which support plant growth and nitrogen fixation in the soil. Slugs and snails generally live close to the ground and are highly sensitive to changes in their environment. Thus any clearing of the tree cover could have a detrimental effect on the long-term survival of rare species-at-risk that share this ecosystem.

Both Coho salmon and Cutthroat trout spawn in gravel beds along the 350 metres of Cusheon Creek that bisect the Creekside Rainforest, where juvenile fish live throughout the summer in deep pools. Alteration to the forest could detrimentally affect water flow and the temperatures essential for spawning and the survival of juvenile fish. (Note: The legally protected, 10-metre strips of land that border the creek do not protect its ecosystem, because most of the trees that shade the creek are outside the protected area.)

The “biodiversity blitz” also revealed a number of trees showing evidence of cultural modification by aboriginal people. Archaeologist Kim Kornbacher identified at least seven cedars with classic signs of traditional bark stripping. She found the close proximity of the rainforest to large shell middens at the Cusheon Creek estuary, combined with apparent tool marks on one of the trees, as unequivocal, historic evidence of aboriginal use of this land. Culturally modified trees can verify oral histories and early records of how the first inhabitants of the Gulf Islands lived within their environment. The fact that such trees are now rare in the Gulf Islands only accentuates the need for protection and conservation of Salt Spring’s Creekside Rainforest.

The “blitz” also partially-quantified this forest’s contribution to mitigating global warming. Temperate rainforests pull greenhouse gases from the air and store them as wood and soil. The experts calculated that alone, the above-ground parts of Creekside’s nearly 20 acres of trees capture 27 tons of carbon dioxide per year. By preserving the complete forest, at least two to three average Canadian carbon footprints will be offset each year in perpetuity.

In general, riparian forests play a central role in regulating the characteristics of aquatic ecosystems and have high levels of biodiversity and productivity. On Salt Spring Island, Creekside Rainforest is so interconnected with Cusheon Creek that long-term protection of their ecological integrity can only happen if the entire site is left undisturbed and managed solely for conservation values.