○○○
The food web has far-reaching implications, many indirect. There is a relationship between species diversity and the topology of predator-prey linkages. The concept of trophic cascade encapsulates the dynamic of predators preventing overgrazing, and thus increasing plant growth by chewing away at herbivore populations.
Yellowstone Wolves
As humans settled the US west, predators of all sorts were wantonly slaughtered to protect livestock.
An 1872 law established Yellowstone National Park. Despite Federal statute protecting wildlife, wolves were eliminated there in the 1920s. By the mid-20th century, wolves were almost wiped out of the continental 48 states.
Through remorse, wolves were reintroduced into Yellowstone in 1996. Their predation reduced browsing pressure by herbivores. Instead of eating greenery to the nub, elk and deer only take a bite or 2 before for checking for threats and moving on.
The increased vegetation improved the park’s degraded streams. Beavers, despite being on the wolf’s menu, benefited. The extra lumber provides food and shelter. Beavers in turn create dams that help keep rivers clean and lessen the effects of drought.
In altering water flow in the lakes where they live, beavers provide accommodations for other lives. Insects, fish, amphibians, birds, and small mammals all gain from beaver efforts. The improved vivacity in the ecosystem helps feed the wolves.
