International Year of Biodiversity
- January 8, 2010 3:40 PM |
- By Quirks
By Bob McDonald, host of the CBC science radio program Quirks & Quarks
Following on the International Year of Astronomy, the United Nations is continuing its scientific theme this year with a salute to the hugely important, but often misunderstood, concept of biodiversity.
This term, also known as natural diversity, species richness, or natural heritage, is generally defined as the "totality of genes, species, and ecosystems of a region."
It’s a holistic concept that goes beyond the usual poster children for the environmental movement: polar bears, penguins, snowy owls or eagles. While protecting them is important, they only represent a small part of the food chain. What’s really important are all the other creatures needed to support them: the sea urchins, bacteria, tree fungus, rodents, bugs, the forms of life that don’t look so great blown up to poster size. It’s that entire web of life, the foundation, which is seriously crumbling because of the human tendency to prefer monoculture.
Biodiversity is nature’s backup program. By providing a diverse variety of life in any one environment, the system will be strong enough to withstand stress. If a species is wiped out, whether by hurricane, disease or even climate change, another form of life will fill in the gap. If there is only one form of life, such as a field of corn, the whole thing can be wiped out at once by a single parasite. So, for biodiversity to work, there has to be a huge stock of diverse species to begin with.
Humans, on the other hand, like to focus on one or a few varieties of life and cultivate them. We like yellow corn and golden wheat stretching uniformly all the way to the horizon. We like our apples red and bananas yellow. We cut down the rich diversity of the forest and replace it with green grass, pastures or pavement. We like our food to be consistent wherever we go, lawns free of weeds; in fact, even areas that have been protected from development and designated as parks are often stripped down to the bare minimum of mature trees and grass, so we can spread out our picnic blankets and barbecues.
At the same time, these monoculture landscapes are costing us billions every year in pesticides and herbicides because they’re so vulnerable to attack.
Scientists refer to the current time period as the Holocene Extinction because humans are causing species to disappear worldwide at a rate that hasn’t been seen since a big asteroid hit the planet, 65 million years ago.
Scientist E.O. Wilson calls it HIPPO: Habitat Destruction, Invasive species, Pollution, over-Population, Over-harvesting.
This week on Quirks, Dr. Nancy Shackell describes the impact overfishing has had on the food web in the Atlantic, but also points to more environmentally sensitive fishing practices that would ease the stress on the system.
Preserving biodiversity involves more than saving rainforests from clear cutting. It means including ourselves as one of the species in the mix. Yes, we are the source of the problem, but we also have the unique ability to be a big part of the solution. Farmers have learned the lesson of inter-cropping, animal corridors allow migration, gene banks are attempting to preserve species before they disappear. Many new communities incorporate wetlands to filter runoff water. Solutions come in many forms.
By the most pessimistic estimates, if the current rate of extinction continues, we could wipe the planet clean in the next hundred years. And since we depend on other life for food and medicine, I guess that scenario involves wiping ourselves out as well. But even if that happens, (I think we’re smarter than that) it doesn’t mean we’ve destroyed the planet. The Earth has been sterilized by extinction events many times in the past. Life always renews itself. But what returns is different than what went before, as nature continues to endlessly experiment - with diversity. There’s an irony to that.
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