They built dams which enabled them to control the flow of water and conserve water for future cases where a drought comes. So far it has been useful even though dams can be controversial because of natural habitats of animals that usually get affected.
The name for all organisms that get their nutrients and energy from other organism are called parasites.
All of these components are reservoirs of carbon. The cycle is usually discussed as four main reservoirs of carbon interconnected by pathways of exchange. The reservoirs are the atmosphere, terrestrial biosphere (usually includes freshwater systems), oceans, and sediments (includes fossil fuels).
