Bringing Back the Wolves: How a Predator Restored an Ecosystem
yellowstone National Park Yellowstone National Park is almost 9000 km2 3500 min nearly three times the size of the state of Rhode Island
AN UNINTENTIONAL EXPERIMENT A city park a beach a forest a desert What do they And if the people who tend the park were gone have in common What would happen to the ecosystem then They are full of living things that interact with one If any one part of the web disappears the entire another and their environment Take for instance a ecosystem can change city park It may be full of soil trees grasses shrubs So what if you could do a simple experiment What if flowers insects gray squirrels birds and people And you really could take away one important member and each has a relationship with the other They are part of watch what happens an ecosystem a web of connections between the living It was an unintentional experiment but that's just and non living what occurred in Yellowstone National Park Every member of this park affects all the others For First declared a national park in 1872 Yellowstone example if there was no soil there would be no trees is a complex ecosystem There are tiny things and big Without trees where would the squirrels find nuts to things furry things and scaly things stationary things eat Where would they den And where would the birds and mobile things All insects plants and animals are build their nests part of the community of the living They are neighbors Now take away the insects What would pollinate the that affect one another directly and indirectly flowers What would the birds eat What would help One of those neighbors however went missing for decompose dead things seventy years wolves
ber TAMING THE WILD In the late 1800s the American government offered money a bounty to encourage people to hunt top predators cougars grizzly bears and wolves The goal was to tame the West the heart of cattle ranching and rid the landscape of all threats to livestock The result hunters killed so many wolves that by 1926 no wolf packs were left in Yellowstone National Park Wolves are a keystone species And the absence of a keystone species affects the ecosystem both directly and indirectly In Yellowstone wolves directly affected elk by eating them But they indirectly affected many other living things too aspen trees coyotes songbirds and beetles to name just a few And they also affected non living things such as the soil and the stream bank A Missing Link Wolves are top or apex predators When such an important member of an ecosystem goes missing many other living things are indirectly affected causing a chain reaction of events This is called a trophic cascade A trophic cascade works in the opposite direction too Reinstating the missing link can also cause a chain reaction
Direct and Indirect Effects of the Wolf Bears Wolves Coyotes Bison Scavengers Small mammals Pronghorn Berries Streams Woody plants and grasses Direct effec Indirect effect Beavers Birds Invertebrates
