The amazing ways plants defend themselves – Valentin Hammoudi

Plants are constantly under attack. They face threats ranging from microscopic fungi to small herbivores like caterpillars, up to large herbivores like elephants. But plants are ready, with a whole series of internal and external defenses that make them a less appealing meal — or even a deadly one. Valentin Hammoudi explains some of the fascinating ways that plants defend themselves.

Will the ocean ever run out of fish? – Ayana Elizabeth Johnson and Jennifer Jacquet

When most people think of fishing, we imagine relaxing in a boat and patiently reeling in the day’s catch. But modern industrial fishing — the kind that stocks our grocery shelves — looks more like warfare. Ayana Elizabeth Johnson and Jennifer Jacquet explain overfishing and its effects on ecosystems, food security, jobs, economies, and coastal cultures.

How Wolves Change Rivers

When wolves were reintroduced to Yellowstone National Park in the United States after being absent nearly 70 years, the most remarkable “trophic cascade” occurred. What is a trophic cascade and how exactly do wolves change rivers? George Monbiot explains in this movie remix.