The idea that a balanced and diverse investment portfolio is important to preserve capital investments, promote growth and protect against financial ruin in a volatile economy has long been promoted as the best strategy towards financial health.
A study published this week in the international science journal Nature brings scientific validation to the long-held belief of ecologists and conservationists that nature works in this same way.
Ecosystems are better able to recover from disturbances when biological diversity is high. Nature doesn’t put all of its eggs in one basket, either.
The 10-year study, conducted by researchers at the University of Guelph and the University of B.C. under the leadership of Andrew MacDougall, tested the theory that even apparently healthy and productive natural areas around the world are vulnerable to sudden and catastrophic collapse if they lack the very thing that enables stability when adapting to rapid change: diversity.
As a conservationist and a scientist, I am gratified to see hard scientific evidence that supports the basic mission of nature conservation efforts around the world: to protect, restore and enhance biodiversity.
MacDougall conducted his study on the Cowichan Garry Oak Preserve on Vancouver Island, lands owned by the Nature Conservancy of Canada. The preserve is a rare remnant of Garry oak savannah that was once much more common in the Pacific Northwest.
Today, only about five per cent of this habitat remains. The rest has been converted to agricultural, residential and urban land uses. Many of the plants and animals that rely on the Garry oak ecosystems are at risk of extinction. Some have already disappeared.
The partnership between NCC and MacDougall provides him with a real-life testing ground for his research while also fulfilling NCC’s management goals for the preserve.
I have witnessed first-hand the way the land has responded to fire, one of the key methods MacDougall used to shock the ecosystem to test its resilience. In the areas of the preserve where we have restored the Garry oak meadows, fire was like the equivalent of a tall drink of water. The wildflowers and other native species rebounded spectacularly.
But in the unrestored areas of the preserve, which are dominated by a small number of agricultural grasses, MacDougall’s fire was devastating. Within one growing season, invasive trees and shrubs had completely taken over. These grassy areas shifted even further away from functioning as a native ecosystem and were no longer any good for agriculture, either.
Many people want to protect biodiversity for reasons of beauty, spirit or moral conviction. These reasons are valid and hold meaning, but are subjective. Having scientific rationale for the importance of maintaining diversity in our ecosystems — both natural and human-altered — suggests that the best investment we can make in this world is one that protects, enhances and restores nature’s biological diversity.
Tim Ennis is West Coast program manager for the Nature Conservancy of Canada.