Canopy Bridges Allow Arboreal Animals to Traverse Pipeline Corridors

Mark Thurber
Walsh Ecuador, La Floresta, Quito, Ecuador

The Eden-Yuturi field, developed by Occidental Petroleum, is located in an ecologically sensitive region of the Ecuadorian Amazon which is also inhabited by indigenous communities.

Occidental and WALSH Ecuador, an environmental consulting firm, identified the new 135-kilometer-long pipeline corridor as the most significant social-environmental and construction challenge of the project.

Protection of biodiversity was a key management goal in the 42-kilometer-long corridor within the tropical primary forest. A strategic decision was made to bury the pipeline and to construct no permanent access roads.

One of the greatest concerns was the barrier effect of breaking the forest canopy by cutting a 15-meter wide corridor, effectively cutting off migration routes of arboreal mammals that rarely walk on the ground.

The project team of WALSH and Occidental devised an innovative solution: the use of "canopy bridges" to provide migration pathways for arboreal mammals. A canopy bridge is basically a short section where the working corridor has been narrowed to seven meters.

Canopy bridges were selected based on the presence of big trees, quality of habitat and even spacing. Only smaller trees and brush were removed during the clearing of the working corridor.

During construction, a sandwich of synthetic fabrics, riprap and soil was installed to protect the thin topsoil and roots from damage while moving heavy equipment through the canopy bridges. After construction, five out of the 15 meters of the pipeline corridor were reforested with the cooperation of the native communities that own the land.

Movement of arboreal mammals, mainly monkeys, has been observed at all of the canopy bridges, during and after construction. This experimental technique has proved effective in conserving biodiversity in tropical rainforest and can be used in other linear projects in tropical environments.

AAPG Search and Discovery Article #90039©2005 AAPG Calgary, Alberta, June 16-19, 2005