Canary Islands Trees
The Canary Islands are an archipelago only 70 kilometers west of the Sahara Desert. The islands receive virtually no rainfall.
But the Canary Islands long had rich forests. Moisture-rich fog drifted in from the Atlantic Ocean and anointed the trees with plentiful water. These trees were key to a viable biome.
When humans populated the islands, they chopped down enough trees to deforest entire islands. When the number of trees went past the point of self-organized criticality, there was not enough water to sustain any population. Drying out the land destroyed the ecosystem.
Restoration has not been possible. The islands’ water supplies are inadequate to keep newly planted trees from drying out.