Closed loop systems
-All outputs are recycled within a perfect closed loop system they are used as inputs into other processes in the system
-There are NO outputs from a perfect closed loop system (NO WASTE) and there are no inputs
-However most systems arent perfect closed loops they have inputs and outpts too
-Ecosystems are a type of closed loop system due to most of the waste (output) produced by organisms isnt lost- its recycled as food or reactants for other organisms eg humans breath out CO2 as waste which is recycled by trees.
-Oxygen is a waste product produced by plants during photosynthesis and is recycled by organisms in repiration
Stable Ecosystems have balanced inputs and outputs