Plants depend on them for carbon dioxide.Carbon dioxide is  used by plants for respiration and photosynthesis.The  decomposers decompose dead plants and animals .By this  process the soil get back its fertility which is good for  plants.Some insects and birds are also carriers of pollen  grains which are good for development of plants.The animals are the agents of dispersal of seeds which helps the plants  to grow.Humans take care of plants which help the plants to  grow.   

Posted By: Arpita