Black Cottonwood

Black cottonwoods along Yellowstone's rivers tell the cascade story most dramatically. Before wolves, elk congregated along rivers—predator-free zones where water provided escape routes. They browsed cottonwood saplings constantly, preventing any trees from reaching maturity. After wolves made riverbanks dangerous, elk moved away. Cottonwoods that had been suppressed as shrubs suddenly grew into trees.

The cottonwood recovery triggered secondary cascades. Tree roots stabilized riverbanks, changing stream dynamics. Shade cooled water, benefiting fish. Leaves provided food for aquatic insects. Beaver returned to harvest cottonwood. A single behavioral change by elk—avoiding riverbanks—cascaded through the entire riparian ecosystem.

The business parallel is how changes at one level trigger reorganization at many levels. Cottonwoods are like infrastructure that becomes possible when dominant players retreat from a space. When a monopolist exits a market segment, the entire value chain reorganizes: new suppliers, new customers, new business models become viable. Elk retreat didn't just benefit cottonwoods—it reorganized the entire riverbank ecosystem. Similarly, dominant player retreat can reorganize entire market sectors.