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TODAY Thursday 7 August 1997 Each weekday. Conn Nugent on what's new in the world, on the site.

 

TODAY IN THE WORLD: A Little More Room

In the upcoming issue of Conservation Biology (available 15 August from the Society for Conservation Biology), there's an interesting article about some margins for error in the natural world, or at least the natural world of the mixed forests of eastern North America. Two researchers at the University of Ottawa -- Scott Findlay and Jeff Houlahan -- have discovered that the conventional wisdom underestimates the size of the buffer zone you need around a wetland in order to protect the species that inhabit the wetland.

It's well known that swamps and bogs and ponds are especially fecund habitats, and that the loss of wetlands poses one of the greatest threats to biodiversity. In southern Ontario, 75% of the wetlands found in the early 19th Century have been drained or covered. Aware of the problem at last, provincial authorities started protecting wetlands from development. Heeding advice from scientists, they also established buffer zones, wooded strips around the wetlands where no roads or buildings could go. Typically these buffer zones were a kilometer or less in width.

The problem, according to Findlay and Houlahan, is that that's too narrow. They examined 30 wetlands in the area and found that you need a strip at least two kilometers wide if you want to preserve the whole range of wetland species: birds, mammals, reptiles, amphibians, and plants. Most birds and many plants can tolerate less ample buffers, but for the broad spectrum you need the big width. You also need to keep it wooded, for the forests and the wetlands are closely interdependent.

Road building is the biggest culprit. It reduces the size of contiguous natural habitats while it provides a medium for the introduction of non-native species. Findlay and Hulahan document a direct relationship between increases in paved roads near a given wetland and decreases in the diversity of its species, with the exception of its mammals (we milksuckers just can't stay off the streets). The phenomenon is particularly harmful to snakes and lizards and amphibians ("Herons and Frogs"). Says Professor Findlay: "Our results suggest that our current picture of reptile and amphibian wetland diversity -- gloomy though it is -- is nonetheless rosier than it ought to be."

Oy.

 

TODAY ON THE SITE:

Deb Callahan, tough, feisty, funny, political to the tips of her digits, pays us the big favor of answering Five Questions on the current state of environment and elections. Check her out.

 

Recent "Today" columns:

8/06: Big Victory, I Guess
8/05: Necessary Vulgarization
8/04: More Crime, Please
8/01: Wise Use, Smart Use
7/31: DC Blues
7/30: Atlanta and Salina
7/29: Herons and Frogs
7/28: Golf
7/25: Climate Chess: Arkansan Opening
7/24: Top and Bottom

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