The view from above: canopy walks around the world

摘要

In 1917, United States naturalist William Beebe elegantly described the treetops as "another continent of life remaining] to be discovered". Forest canopies are thought to contain as many as 40 percent of plant species, to intercept up to about 25 percent of precipitation and to provide pollination valued at around US12 dollar billion per year (Global Canopy Programme, 2002). They have also become a new frontier for tourism. Forest walkways, originally constructed for research, are increasingly visited by people seeking a novel experience and a spectacular view. While evidence of scientific interest in the forest canopy can be traced back hundreds of years, the first recorded expedition into the treetops was made in 1929, by an Oxford University expedition in Guyana (then British Guiana) (Mitchell, 2002). Early canopy researchers applied mountain-climbing techniques to scale large old-growth trees in temperate and tropical forests. In the ensuing 80 years, methods for conducting aerial forest research evolved to include pulley systems, hot-air balloons, airships, towers and large industrial cranes. Today, forest walkways provide a safe way for scientists to ascend to the crowns and set up long-term study sites, while also limiting damage to treesand the organisms that inhabit them. These walkways range in construction from rope and wood