If several species of carnivores and removed from an ecosystem, the most likely effect on the ecosystem will be

A decrease in stability among populations

Explanation: if several species of carnivores are taken away from an ecosystem, there will be an instability among populations. Some of the factors that might cause the decrease in stability are that there would be an over population of the prey animal that would not be eaten by the carnivores and that the plant life would be in danger because of the over population of hervibores.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.    

materials water oxygen those are the things i can think of in this moment.