how do food chain gets shortened or howled the shortening of the food chain affect the biosphere?

Food chains are generally short comprising of only 3-4 steps. This occurs because only 10% of total energy is absorbed in going from one trophic level to the other. Also only 10% of energy is stored in an organism. As we go up in the food chain energy available to top heterotrophs will be less. This is the reason why food chains are short. Also there occurs extinction of animals which will adversely affect the organisms feeding on these animals. This will therefore affect the functionality and stability of biosphere.