Ecosystem Important Questions for CBSE Class 12 Biology Energy Flow and Ecological Succession 1.Energy Flow (i)Sun is the only source of energy for all the ecosystems on earth, except for deep sea hydrothermal ecosystem. (ii)Of the total incident solar radiation, less than 50% is Photosynthetically Active Radiation (PAR). (iii)Plants capture only 2-10% of the PAR and this … [Read more...]