Campus News

Published by Communications and Public Affairs (519) 824-4120, Ext. 56982 or 53338

News Release

March 27, 2002

Rock climbing hurting cliff ecosystems, study finds

A groundbreaking study by University of Guelph researchers reveals that recreational rock climbing definitely harms cliff ecosystems. The report will appear in the April edition of Conservation Biology.

The study is the first to isolate rock climbing from other environmental factors and examine the sport's effect on all types of vegetation, including trees, bryophytes (rootless plants such as moss) and lichens. "We looked at the impact on the plant community as a whole we didn't just isolate one species," said researcher Michele McMillan, who conducted the study with botany professor Doug Larson. Added Larson: "No other study has ever looked at the effect on all different kinds of plants at the same time. It was very comprehensive."

The results show that "rock climbing is having a negative effect on everything," McMillan said. "It's not just the trees, it's the entire community of organisms. Not only is the sport decreasing the abundance of plants, but it is also reducing the number of species present."

McMillan and Larson, both members of the University's Cliff Ecology Research Group, studied the ecological effects of rock climbing on the cliffs of the Niagara Escarpment in the Halton Region Conservation Authority. The escarpment is home to various habitats, including forests of ancient, slow-growing trees - some more than 1,000 years old. "Many of these are areas that have gone untouched for centuries, but the growing popularity of rock climbing over the past 20 years has changed all that," Larson said.

"When some people think of rock climbing, they're thinking it's part of nature, but in fact what we've shown is that they're destroying the very thing they're climbing to see."

The researchers compared vegetation on three parts of the cliffs -- the plateau, cliff face (middle) and base -- and looked at both climbed and unclimbed cliffs. They found that cliffs used by rock climbers had only 46 per cent as many vascular plant species as unclimbed cliffs had. The diversity of bryophytes and lichens was 60 to 70 per cent less than the diversity in undisturbed areas. Rock climbing also decreased the cover of vegetation on cliffs by about 40 per cent.

In addition, the proportion of non-native species is three times higher in areas that are subjected to rock climbing -- 81 per cent compared with 27 per cent. "Rock climbing reduces plant density, so the weedy species can take over after the delicate natives are excluded," McMillan said. Added Larson: "The invading species come in from anywhere they can: on the wind, dogs, other wildlife. But people are a major entry point as well, carrying in other species on their shoes and clothing."

To help reduce future environmental damage, the researchers suggest banning new climbing routes in protected areas. "We are not against rock climbing," Larson said. "We are simply saying that it's better to keep climbing restricted to areas that have already been damaged than to take a pristine area and develop it for climbing."

McMillan added that while the study was limited to a section of the Niagara Escarpment, it is applicable to other regions in North America as well. "The communities that grow on these cliffs are pretty similar."

Michele McMillan
(519) 829-3731
(519) 824-4120, Ext. 8523

Doug Larson
Department of Botany
(519) 824-4120, Ext. 2679 or 6008

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Communications and Public Affairs,
519-824-4120, Ext. 3338.

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