UBC Reports | Vol. 49 | No. 12 | Dec. 4, 2003

How Many Species can We Afford to Lose?

Researchers use new approach

By Michelle Cook

Will we really be worse off when the last giant panda disappears from the earth? Does our own survival depend on the fate of the mountain gorilla? The whooping crane? The common house sparrow?

The popular answer to all these questions would be ‘yes.’ The fact is we just don’t know, says UBC zoology professor Anthony Sinclair, who has launched a project to study what really happens when a species gets “knocked out” of one of the planet’s ecosystems.

“One of the dogmas that our society has is that biodiversity plays an important role in the stability of our systems, but we haven’t actually got the evidence yet to support this,” says Sinclair. “It sounds nice. It sounds logical, but my own experience of seeing so many species is that they can’t all have equally important roles. There must be a huge number which don’t matter.

“We need to ask, ‘does it matter?’ and it’s important to recognize that we don’t know the answer.”

With a worldwide environmental movement fighting to protect thousands of plants, animals, insects and birds on endangered species lists, Sinclair knows it’s a loaded question but one he will keep asking with the Biodiversity Knockout Experiment (BIOKO).

Launched two years ago with a pilot project in the Yukon, the BIOKO’s goal is to find out how the loss of a certain species from an ecosystem affects the system’s ability to cope.

“We want to find out whether losing a species prevents the system from coping with the abuses humans subject the system to -- abuses such as introducing fertilizers, burning, trampling, and polluting it,” Sinclair explains.

“It’s a fundamental problem of human society. It’s inevitable that, as we develop, we’re taking up more resources in the world which will cause more species to go extinct. The question is how many species can we afford to lose before we impair the habitat that we live in and depend upon?”

After spending almost 40 years studying large mammals, mostly on the Serengeti Plain in his native Tanzania, Sinclair has seen the effect one species can have on an entire ecosystem. Fifty years ago, disease had reduced the population of wildebeests on the plain to 100,000. Today, they number 1.5 million. With their comeback, Sinclair and others have been able to track the effect on thousands of other species of plants, insects and animals and also on the climate in the wildebeest’s habitat. But nobody has ever tried a controlled knock-out before.

For the BIOKO experiment, researchers will first remove a key species group from a controlled study plot. They will then subject the plot to a man-made disturbance. In the Yukon pilot being undertaken by UBC botany professor Roy Turkington and student Jennie McLaren, groups of native plants, legumes and fungi have been removed from the study area and fertilizer has been applied. The effects of the species loss on the plot will be monitored over three years.

It’s an approach that’s never been tried before. In the past, researchers have studied biodiversity by putting a few species together in a controlled environment, and extrapolating the results to determine the effects on larger habitats. The knock-out experiment starts at the opposite end of the scale with thousands of species and systematically removes key groups. If the Yukon pilot is successful, plans are underway to conduct the same experiment in many different geographical environments such as grasslands, savannah and tundra. Sinclair says that Canada, with its extreme environments ranging from the Far North with no species to the Prairies with a diversity of species, is particularly suited to the BIOKO experiment.

The massive, worldwide initiative will be run from UBC’s Integrated Biodiversity Laboratory, a new facility for multidisciplinary research that will be built with $33 million in funding from the Canada Foundation for Innovation and the B.C. Knowledge Development Fund, in addition to funding from UBC.

Once the lab is completed, in about five years, Sinclair expects BIOKO to swing into high gear, with a new generation of ecosystem specialists from around the world involved in knock-out research.

“This is a big idea, and a big experiment; it will take a lot of people, and we can’t do it all at once,” Sinclair explains. “So this is going to be done bit by bit and when we get different people trying different things, we’ll learn from that to build a more comprehensive experiment.”

And if animal lovers were getting nervous, rest assured there are no plans to knock out any of the big predators or beloved furry poster animals -- elephants, otters, orangutans -- that we’ve come to associate with habitat loss or extinction.

Researchers will be focusing instead on insects, plants, fungi and species like the nematode -- a hard working little organism that lives in the soil decomposing dead plant material and recycling nutrients from it -- because that’s where they suspect most of the real biodiversity action is.

“If you knock out mammals, at a certain scale, it doesn’t matter,” Sinclair says. “In terms of the way the world functions, it probably doesn’t matter whether we’ve got pandas or not. They’re nice and furry, appeal to us emotionally and esthetically, and could act as flagships to promote conservation, but in terms of how the system works, it’s probably not a big deal.

“Whereas, if you knock out certain bacteria from the soil, it’s a big deal. We don’t know that -- yet, but there’s an old adage that the answer lies in the soil and it probably does.”

For this reason, the project may not capture the public’s imagination and attention the way the studies of specific species done by scientists like Diane Fossey and Jane Goodall did 40 years ago, but Sinclair says the issues that BIOKO will be addressing are very much on the 21st century agenda.