Huge development projects such as roads and railways that are planned or under construction in Africa threaten swathes of its ecosystems.

Credit: Richard Stupart/CC-by-2.0

William Laurance and his team at James Cook University in Cairns, Australia, mapped 33 'development corridors' that are being upgraded or planned, plus their human populations and surrounding lands. They found that these corridors would stretch 53,000 kilometres and cut through 408 protected areas, 29 of which would be cut by two or more corridors.

Corridors are often justified on the basis of their benefits to agricultural production, but the team found just five that would have both low environmental impact and large agricultural benefit. Six would degrade areas with high conservation value and bring low agricultural benefits, and the rest would bring only “marginal” returns. Many of the developments would cause serious and irreversible damage.

Curr. Biol. (2015)