Radio Times: Review by:; David Butcher

“Why does the tree need the fish?” wonders Chris Packham, sounding like a Zen monk addressing a novice. He wants us to think about the way ecosystems are made up of unlikely connections. But trees and fish? The link lies in grizzly bears and the way that, in the forests of North America, they feast on spawning salmon in autumn, then leave the leftovers to rot down on roots.

Snowshoe hares and lynx are involved too, including a phenomenally sweet lynx cub. There’s also some great stuff on the vast network of underground fungi that exchange nutrients between plants, a kind of forest welfare system or, as it has been christened, the “wood wide web”.

About this programme

3/4. Chris Packham investigates the ecosystem of North America's temperate forests, examining how it rebuilds itself in spring after harsh winters. He also reveals how the prey of the Canada lynx is dependent on a caterpillar that lives high up in the canopy, and discovers why the large trees of the north-west of the continent are reliant on bears and salmon.