How are plants and algae important to energy transfer and organism diversity in creeks?

The most prominent role played by plants and algae is that in energy transfer; they are producers and they introduce energy into the ecosystem and different food chains. The earth's only source of energy is the sun, and plants and algae transform this light energy into chemical energy, which is obtained by organisms that consume these plants and algae. 
Moreover, plant and algae species are diverse and adapted to carry out their function and survive in different environments, which means they also increase the biodiversity of a region.