Vancouver Island bull Roosevelt Elk. Most of its critical old growth winter habitat already logged. Photo by Tyrone Danlock
Conservation Biology
The science of preserving biodiversity
Biodiversity is more than the totality of the different varieties of plants and animals now living on Earth. It also encompasses the web of life and the ecosystems that interconnect them. Earth's biodiversity is the product of millions of years of adaptations and natural selection - species evolving to fit into, and take advantage of, unique niches in different environments. This is why ancient forests sustain so much biodiversity, and why many of their species cannot survive in tree plantations clearcut every eighty years or so.
Now, due to human activities, this complex web is rapidly unravelling. Habitats are being extensively altered, niches eliminated and the species which depend upon them driven to extinction. The slow process of evolution cannot keep up with the losses. It took millions of years to evolve the same number of species lost in the catastrophic era of dinosaur extinction.
Only a few species thrive when their habitats are radically altered. Most decline...and those that go extinct, like the dinosaurs, don't come back! The current loss of species globally is accelerating and now is estimated to be between 1,000 and 150,000 each year, a biodiversity crisis that has scientists world-wide scared. The wide range in the estimates testifies to the lack of scientific knowledge about what is really happening. Scientists can only guess how many species die with an ecosystem that disappears.
Will 12 percent left in a natural state be enough to protect Vancouver Island's biological heritage
The Harcourt NDP government has adopted 12 percent of the land base as the goal to shoot for in its expansion of the parks and protected area system on Vancouver Island. Where did this specific goal come from? More importantly, is 12 percent adequate?
The 12 percent goal has no scientific validity. It was recommended without substantiation in the Brundltland Commission on sustainable development. E.O. Wilson, one of the founding fathers of ecology, predicted that if only 10 percent of the natural would was most strategically preserved, while the other 90 percent was transformed by human activity, 50 percent of the species now living on Earth would go extinct.
Jefferey McNeely, Chief Biodiversity Officer for the IUCN, the World Conservation Union, stated in a recent letter to WCWC that this 12 percent figure was nothing more than a political guess" in which he had "no particular confidence."
Herb Hammond, well known B.C. environmental forester, said in a recent interview reported in EarthKeepers magazine that "about 25 to 30 percent of the [forest] land base" was needed to protect biodiversity.
Vancouver Island has a great variety of ecosystems, unique landscape features, and large mammals, including carnivores, which require large ranges. Given what we know about genetics and habitat requirements, limiting the amount of protected land to 12 percent, while allowing status quo industrial development on the rest, will result in a total failure to protect the natural ecosystems and biodiversity of Vancouver Island.
There is not even an agreed-upon estimate of the total number of species on Earth. Guesses rage from 5-50 million. Less than 1.5 million of the world's species have even been described by scientists, and only a tiny number have been thoroughly examined. With such scant knowledge, caution should prevail. Let's remember, "the first rule of intelligent tinkering is to save all the parts."
Much of the accelerating rate of species extinction is linked to tropical deforestation. However, recent research indicates that the temperate rainforests in B.C. are much more biodiverse than previously thought. At WCWC's canopy research station in the Upper Carmanah Valley on Vancouver Island, 60 new species of invertebrates, mostly insects, have been recently identified, yet less the 3 percent of the 750,000 of those collected there have been analyzed by scientists.
Some ecosystem types, especially ancient forests, are indeed more "species- rich" than others. Prior to industrial logging, which began a little more than a century ago, old growth forests in the Pacific Northwest supported the greatest diversity of forest wildlife on the continent. The quality of habitat for most wildlife, and thus the number and diversity of species, generally decline with increasing elevation.
Currently 90 percent of high alpine and mountain tops on Vancouver Island are protected in parks. Fifty-eight percent of the Island's protected area system is alpine, tundra, bog forest and mountain hemlock forest. Only 5.6 percent of the Island's temperate rainforests are protected and more than 20 percent of this is second growth, not ancient forests.
Clearcutting and Roads - The Greatest Threats
Clearcuts and roads are among the greatest threats to biodiversity. Clearcuts radically alter the ecosystem eliminating many niches and whole habitats. Research indicates that many small animals rarely, if ever, cross roads. Roads fragment populations, provide access to disturbances like landslides, and offer dispersal routes for invasions of exotic or "weed" species.
Principles of Conservation Biology
Conservation biology reveals that the amount of biodiversity maintained in an area is related to land size. An island one-tenth size of another similar island, for example, will have about half the number of species. Reserves surrounded by clearcuts essentially function as islands. Over the long term they cannot maintain large animals that once lived in the larger region.
Experience has also shown that a patchwork of small reserves doesn't work. It is now apparent that very few of the reserves in the United States, despite 36 million hectares of protected wilderness, are large enough to maintain their existing diversity. They are too small to enable natural processes to succeed. Inbreeding has occurred amongst the wild animals and normal extremes of climate variation has locally wiped out some species. Forty-two species of mammals have disappeared form North American parks over the last several decades. Over 600 species in the USA are now federally listed as endangered or threatened.
Biologists warn that the evolution of large mammals in North America will be coming to an end unless very large reserves are established. They estimate that small reserves of 10,000 to 100,000 ha might be able to maintain viable populations of smaller mammals including small ungulates, but large predators and ungulates require much larger reserves, generally over 200,000 hectares.(The entire Clayoquot Sound land area is only 162,000 hectares.)
Protecting biodiversity therefore requires two things:
The Conservation Vision was developed by applying the principles of conservation biology.
