Humans have invaded the Earth. Many people are often afraid of predators, especially big cats and other big carnivores. To feel protected they have removed some species without understanding their unique role in the maintenance of healthy ecosystem. But for those, who understand their importance, the question arising in this process is: Would not a word without predators be something to fear even more?
This essay will first discuss the effects of removal of top predators in some ecosystems and explain the importance of all the elements in tropic cascade, then showing some evidences of the positive effects of their reintroduction in landscapes where they were found historically, and finally, talk about their importance for the human existence on this planet. Ecosystems are diverse and very complex networks of organisms and their non-living environment, with many levels and intricate relationships in-between. From human view eliminating predators from a territory sometimes is seen as a positive influence on environment as getting rid of the animal that kills the livestock or other animals is thought to be necessary. On the other hand, some look at it with a romantic eye only thinking about the awful possibility never to see again a beautiful creature. Reality is much worse, because removing any level, especially top predators, from an ecosystem, ruin a balance that may have evolved over millions of years. But the reality of the loss of predators is far worse, say ecologists reporting in Science, and “may be humankind’s most pervasive influence on nature,” they write. Predators kill, of course. But everything in the nature has it’s meaning. Predators keep lower predators and herbivores in check. They do not overbreed and decimate plant life. And reverse – predator population is limited by the availability of prey. Without predators to limit the population growth, herbivores reproduce uncontrollably. More herbivores eat more plants, and without any control they can quickly degrade the habitat. This puts pressure on the plants as they are the food source for them. This is known as a trophic cascade, and in extreme cases, can lead to the complete destruction of the ecosystem. For example, when wolves were eliminated from the American West, there were enormous visible changes in the elk population and the vegetation the elk ate. But also, invisible changes like …. (rivers and etc. from video)