Keystone Species and Tropical Cascades
The earth is home to many habitats, from the wet tropical forest to the dry desert, from the top of mountain to the seashore, the earth is full of unique habitats. Every habitat contains community of plants and animals and every community is populated by different species and each community has different keystone species.
The story of keystone species started on rocky Pacific shore in 1963, Young zoology professor at University of Washington named Robert Paine start his experiment by pull off starfish from the rocks and throw it out into the bay. Paine was studying about the role of predators. He began by identifying all the organism and mapping out who eats who, such as gastropods feeding on barnacles or sea urchin feeding on algae. Starfish is a predator too, they kill and eat slowly. They eat mussels, so what happen when Paine removes the predator starfish from the rocky shore? Within a year and a half. The ecosystem started to change rapidly.
By removed the top predator, the number of species decreased from 15 to 8. After 3 years, it went down to seven, then by seven years it simplified itself, and become monoculture, the mussels monopolizing almost all of the available space and pushing all other species out. After that, Paine had discovered that one predator could regulate the composition of an entire community and its called keystone. it’s like a wedge-shaped stone to support the top of an arch in a bridge or other construction. Just as other stones in the construction depend on the keystone for support, other species in a biological community depend on the presence of a keystone species to maintain the community’s structure.
So. What is keystone species? Keystone species is a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically. By removing keystone species in an ecosystem will result tropical cascade. Tropical cascade are powerful indirect interaction that can control entire ecosystem. By removing star fish, the ecosystem will have more thais or known by the common name as rock shells or mussels, and then the ecosystem will have fewer other species such as Limpets, Bivalves, or Acorn Barnacle.
By discovered Keystone Species and tropic cascades in many places. Just like starfish, the removal of predators, such as wolves, sharks, and lions has had profound impacts on the number of species, variety of other species and on ecosystem as a whole. This study given ecologist or conservationist a set of tools and it gives us a clue that we really need to study more and deeper. Also as approval for human to keep the earth balance.
